Carbon Storage Abstracts - MASTER

Transcrição

Carbon Storage and Exchange
79
Carbon dioxide measurements over pasture and Amazonian forest during the wet
season Atmospheric Measuring Campaign LBA
Niek J. Bink 1
Jan Elbers 2
Friso Holwerda 3
Pavel Kabat 4
Bart Kruijt 5
Rosivaldo Lelis da Silva 6
Beatriz Machado Gomes 7
Antonio Ocimar Manzi 8
Paulo Jorge Oliveira 9
Celso von Randow 10
Maarten Waterloo 11
12
Fabrício B. Zanchi
During the season of 1999 carbon dioxide measurements were carried out over two pasture
sites and one forest site in Rondonia. The pasture sites were at the Fazenda Nossa Senhora
and near the University of Rolim de Moura, the forest site was Reserva Jaru. Turbulence
measurements of carbon dioxide were carried out. The measuring method, data processing
procedure and the results of daily variations in concentration and fluxes will be presented.
1
VU, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands, Tel: +31204447362, Fax: +31206462457,
2
3
Email:
[email protected];
ALTERRA,
Email:
[email protected];
VU,
Email:
4
5
[email protected]; ALTERRA, Email: [email protected]; ALTERRA, Email:
[email protected]; 6 UNIR, Email: [email protected]; 7 UNIR, Email: [email protected];
8
9
CPTEC/INPE,
Email:
[email protected];
CPTEC/INPE,
Email:
[email protected];
10
11
CPTEC/INPE, Email: [email protected];
ALTERRA, Email: [email protected];
12
UNIR, Email: [email protected].
80
The Spatial Distribution of Forest Biomass in Amazonia
R. A. Houghton 1
The amount of carbon released to the atmosphere as a result of deforestation is determined,
in part, by the amount of carbon held in the biomass of the forests converted to other uses.
Uncertainty in forest biomass is responsible for much of the uncertainty in current estimates
of the flux of carbon from land-use change. Here we compare several estimates of biomass
for Brazilian Amazonia, based on spatial extrapolations of direct measurements, climatic
variables, and remote sensing data, and ask three questions.
First, do the methods yield similar estimates? Second, do they yield similar spatial
distributions of biomass? And, third, what factors need most attention if we are to predict
more accurately the distribution of biomass over large areas?
The answer to the first two questions is that estimates of biomass (including dead and
belowground biomass) vary widely, from a low of 39 PgC to a high of 93 PgC for Brazilian
Amazonia. Furthermore, the estimates disagree as to the regions of high and low biomass.
The lack of agreement among estimates, despite extensive calibrations and validations for
each, confirms the need for reliable methods for determining aboveground biomass over
large areas. Candidates include direct measurement of aboveground biomass from satellite
(for example, using LIDAR) or dynamic modeling of observed stand-replacing
disturbances.
1
WHRC, P.O. Box 296, Woods Hole, MA 02543 USA, Phone:508-540-9900, Fax: 508-540-9700, Email:
[email protected].
81
Impact of climate variability and human activity on terrestrial carbon dynamics in
Amazonian ecosystems
Hanqin Tian 1
Jerry M. Melillo 2
David W. Kicklighter 3
Berrien Moore III 4
Charles V. Vörösmarty 5
Previous analyses suggest that undisturbed Amazonian ecosystems, on average, acted as a
sink of atmospheric CO2 as a result of climate variability and increasing CO2 (Tian et al.
1998; Prentice and Lloyd 1998). Other analyses show that Amazonian ecosystems release a
large quantity of carbon to the atmosphere as a result of deforestation (Houghton et al.
2000). In this study, we have investigated how the combination of climate variability,
increasing CO2 , deforestation and associated changes in cropland and pasture have affected
terrestrial carbon dynamics in the Amazon Basin by using the Terrestrial Ecosystem Model
(TEM). To address effects of land-use change on carbon storage, we have incorporated
algorithms from MBL TCM (Houghton et al.1983; Melillo et al. 1988) into TEM. We ran
TEM in transient mode using historical input data including: 1) historical mean
atmospheric CO2 concentration; 2) gridded historical monthly data for air temperature and
precipitation; and 3) gridded historical yearly data for cropland and pasture area based on
remote sensing analyses and land use model. Our preliminary analyses have indicated that
the carbon storage of Amazonian ecosystems during 1980-1995 remain unchanged as a
result of the combined effects of CO2 , climate, deforestation and abandonment of
agricultural lands. Our simulated results also suggest that the carbon sink induced by
climate variability and increasing CO2 offsets the carbon source from land-use change in
the Basin. The modeled net carbon storage in Amazonian ecosystems, however, varies
more than 100% from year to year due to interannual variability in climate and deforested
rates.
1
The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA02543, USA, Tel: (508) 2897498, Fax: (508) 457-1548, E-mail: [email protected] ,; 2 The Ecosystems Center, MBL Woods Hole,E-mail:
[email protected] ; 3 The Ecosystems Center, MBL Woods Hole, E-mail: [email protected]; 4 Institute for the
Study of Earth, Oceans and Space, UNH, E-mail: [email protected]; 5 Institute for the Study of Earth,
Oceans and Space, UNH, E-mail: [email protected].
82
Spatial and Historical Trends in the Amazon Carbon Sink
Oliver Phillips 1
Yadvinder Malhi 2
Samuel da Almeida 3
Niro Higuchi 4
William Laurance 5
Percy Nuñez V. 6
Agustín Rudas 7
Natalino da Silva 8
Rodolfo Vásquez M. 9
By providing regularly recensused samples of all trees with significant biomass, permanent
sample tree plots can yield accurate local measures of growth and death across time and
space. In Amazonia, tree plots have recently been used to quantify changes in forest
biomass, revealing that most old-growth Amazonian tree plots were accumulating biomass
at the end of the twentieth century (Phillips et al.: Science 282:439-442, 1998).
However the existing tree plot network is patchy both in space and time.Yet, if replicated
and located across the environmental conditions of Amazonia, tree plots have the potential
to reveal both the ecological processes involved in the carbon sink and the environmental
factors controlling them. As part of the EU-funded CARBONSINK-LBA project, we are
therefore collaborating to draw together local studies into a more systematic panAmazonian network of permanent tree plots. The project will concentrate on remeasuring
existing plots, some of which may have been abandoned due to lack of funding or research
interest. It will focus on the East-West LBA transect in Brazil and the natural extension of
this transect to the aseasonal forests in western Amazonia (Colombia, Ecuador, Peru).
Along the transect, we will work at sites where there is a critical mass of sample plots,
providing local replicates across varying edaphic conditions. This will provide insight into
the process and persistence of carbon sequestration, and a unique spatial and temporal data
set with which to test and calibrate basin-wide carbon balance models.
1
University of Leeds, School of Geography, Tel: 44-1132-2336832; Fax: 44-1132-333308, E-mail:
[email protected]; 2 University of Edinburgh, E-mail: [email protected]; 3 Museu Goeldi,
5
E-mail: [email protected]; 4 INPA, E-mail:
[email protected];
INPA, E-mail:
6
7
[email protected] ;
UNSAAC, E-mail: [email protected]; Instituto de Ciencias
Naturales, E-mail: [email protected] ; 8 EMBRAPA, E-mail: [email protected];
9
Proyecto Flora del Peru, Missouri Botanical Garden, E-mail: [email protected].
83
Heterogeneity of soils and vegetation in the Tapajós National Forest:
Implications for scaling up
Mathew Williams 1
Y. E. Shimabokuro 2
D. A. Herbert 3
S Pardi Lacruz 4
C. D Renno 5
E. B. Rastetter 6
A critical goal of the LBA project is to understand the Amazon basin as a regional entity.
This requires that detailed, site-specific investigations of ecosystem function are extended
across the entire region. The extension process must take account of the regional variability
in the key controls on ecosystem dynamics. For example, regional gross primary
production will be constrained by spatial and temporal variation in both vegetation and soil
characteristics. To determine the heterogeneity of these constraints, we undertook detailed
surveys of several ecosystem parameters within the Tapajós National Forest on thirteen
0.25 ha plots, during November 1999. Our results showed that leaf area index was more
variable within sites (0.0-8.9) than among sites (means varied from 5.2-7.0). In the two
sites with the lowest gravimetric soil water content and very sandy soils (>80%), averaged
–1 MPa. Apart from this link, there were no other clear correlations between soil
parameters and vegetation characteristics. The variation in soil texture among sites was
notable; at four sites clay content >80%, while at five sites the sand content > 75%. In
summary, our surveys of vegetation structure suggest considerable heterogeneity at fine
spatial scales (50 m or less). While soil characteristics were consistent within sites, the
extreme variability in texture among sites has important implications for drought stress,
local hydrology, soil biogeochemistry, and response to disturbance.
1
7 MBL, Tel: +1 508 289 7489; Fax: +1 508 457 1548, E-mail: [email protected]; 2 INPE, E-mail:
[email protected] ; 3 MBL, E-mail: [email protected] ; 4 INPE, E-mail: [email protected]; 5 INPE, Email: [email protected]; 6 MBL, E-mail: [email protected] .
84
Estoque e Fluxos de Carbono e Nutrientes nas Raízes de Pastagens Abandonadas e
Sistemas Agroflorestais na Amazônia Central
Jorge Luis Enrique Gallardo-Ordinola 1
Flávio Luizão 2
Erick C. M. Fernandes 3
O trabalho será desenvolvido na Estação Experimental do CPAA/EMBRAPA, 60 km ao
norte de Manaus. Pretende-se, comparar a produção de biomassa e a distribuição das raízes
em sistemas agroflorestais com as da capoeira natural nas diferentes camadas do solo até
1,5 m de profundidade para avaliar seu papel no seqüestro de carbono, na estocagem e
fluxo de nutrientes, e na conseqüente recuperação de pastagens degradadas. Os tratamentos
incluem um sistema agroflorestal com cupuaçu e pupunha e um Sistema Agrossilvopastoril:
com “altos insumos”, com ingá , mogno e paricá, e um controle de capoeira (CAP),
correspondente à vegetação secundária que cresceu espontaneamente sobre o solo da
pastagem após a queima e abandono. Para a amostragem de raízes, serão combinadas duas
técnicas de amostragem: a técnica do trado para raízes finas e das trincheiras para raízes
grossas. As raízes nos é 150 cm. As raízes maiores serão separadas em raízes de 2-5 mm e
de 5 mm, por espécie de plantas. Nas raízes separadas do solo e secas a 65-70 ºC, serão
analisados os teores de carbono e de macronutrientes, que serão também usados para
calcular as relações C:N, C:P e N:P; serão também analisados os conteúdos de polifenóis e
de lignina das raízes. Taxa de renovação de raizes será avaliado por minirhizotron e trado.
1
Instituto Nacional de Pesquisas da Amazônia, Rua Nelson Batista Sales 114, Cj Petro - Aleixo, Manaus,
AM, Tel: 92 643 1911, Fax: 92 642 1838, E-mail: [email protected]; 2 INPA, E-mail: fluizã[email protected] ;
3
Cornell University, E-mail: [email protected].
85
Biomass combustion experiments conducted in Fazenda Caiabi, town of Alta Floresta,
MT, Brazil
João Andrade de Carvalho Jr. 1
Fernando de Souza Costa 2
Ralf Gielow 3
David V. Sandberg 4
Ernesto Alvarado 5
Carlos Alberto Gurgel Veras 6
Aguinaldo Martins Serra Jr. 7
José Carlos dos Santos 8
Uncertainties in the estimates of emission rates from land use are very high, mainly due to
a) measurement uncertainties in deforestation rates and clearing areas by fire, (b) ifficulties
in determining biomass stock and (c) destination of deforested land. A large uncertainty to
assess the impact of biomass burning in the atmosphere chemistry and in the global climate
is the amount of biomass burning from each eco-system. These difficulties and
uncertainties are more significant in Brazil, the country with the arger carbon stock in the
vegetation in the world (five times larger than Zaire’s stock, with the second larger stock in
the world). CO2 emissions from deforestation and biomass combustion are of great concern
not only in Brazil, but also globally. This paper describes the work to estimate the
completeness of biomass burning and the amount of carbon released to the atmosphere due
the process of forest clearing in five test areas. The experiments were carried out at Fazenda
Caiabi, in the town of Alta Floresta, state of Mato Grosso, Brazil, which is located in the
Amazonian deforestation arc. The tests were performed in areas of 1 ha each, denominated
A, B, C, D, and E. The following are the main characteristics of each area:
A. located in the frontier with a pasture, with three sides directly on the forest, cut and
burned in 1997;
B. located approximately 400 m inside the forest, with four sides directly on the forest, cut
and burned in 1997;
C. located inside a deforested 9-hectare area, all cut and burned in 1998;
D. located inside a deforested 4-hectare area, all cut in 1998 and burned in 1999; and
E. located inside a deforested 4-hectare area, all cut and burned in 1999.
1
Av. Ariberto Pereira da Cunha, 333, Guaratinguetá, São Paulo, Tel: 12-5252800/r.149; Fax: 12-5252466
3
E-mail: [email protected] ; 2 INPE, E-mail: [email protected];
INPE, E-mail:
4
5
[email protected]; USDA, E-mail: [email protected]; University of Washington, E-mail:
[email protected]; 6 UnB, E-mail: [email protected]; 7 INPE, E-mail:
[email protected]; 8 INPE, E-mail: [email protected] .
86
One year of water and carbon fluxes from central Amazonia (ZF2), 1995-1996
Pegoraro Emiliano 1
Yadvinder Malhi 2
Antonio D. Nobre 3
A. Marques Filho 4
Maria G.P. Perreira 5
We report data on water and energy fluxes collected over one year at a dense terra firme
forest in central Amazonia in 1995-1996. CO2 fluxes have been reported in a previous
publication. In the dry season the mean net radiation peaks at 550 Wm-2, as opposed to
450Wm-2 in the wet season. Changes in long-wave radiation balance are more important
than changes in forest albedo. The direct measurements of latent and sensible heat fluxes
seemed too small to close the surface energy budget. This is not likely to be due to nonmeasurement of within-canopy heat storage. We corrected the data using the assumption of
energy budget closure. The canopy conductance ranged between 10 mol m-2 s-1 in the wet
season to 6 mol m-2 s-1 in the dry season. The dry season reduction was strongly correlated
to reductions in soil water content. Although the Bowen ratio of the forest canopy increases
significantly in the dry season, overall transpiration rates remained approximately constant
because of the increased solar radiation. A comparison of the results with basin water
balance studies suggested that the errors were likely to be purely in measurements of water
fluxes, rather than in sensible heat fluxes.
1
Darwin Building, King's Buildings, Maifield Road, EH9 3JU, Edinburgh (Scotland, UK), Tel: +44-01316595744, Fax: +44-0131-6620478, E-mail: [email protected] ; 2 Edinburgh University, E-mail:
[email protected]; 3 INPA, E-mail: [email protected]; 4 INPA; 5 INPA.
87
Estimating the Exchange of CO2 and its Stable Isotopes Between Amazonian
Ecosystems and the Atmosphere at Multiple Spatial Scales
Scott Denning 1
Lara Prihodko 2
Neil Suits 3
Marek Uliasz 4
Melville Nicholls 5
Elicia Inazawa 6
Niall Hanan 7
Pier-Luigi Vidale 8
We have developed a series of methods for estimating temporal and spatial variations in the
exchange of CO2 and its stable isotopes. A numerical model of biophysical, hydrological,
and biogeochemical processes (SiB2) has been adapted for Amazonian forests and
grasslands. The model predicts exchanges of water, energy, carbon, and momentum on time
scales of several minutes from environmental conditions, and also predicts the fractionation
and changes in storage of 13 C and 18O in CO2 . The model was evaluated by comparison
with flux data collected during ABRACOS, and has been coupled to a mesoscale model
(CSU RAMS). Spatial and temporal variations in vegetation parameters are estimated using
AVHRR imagery and soils are parameterized from a spatial database (IGBP-DIS). The
model is reasonably successful in capturing the major features of the limited data available
to date. The coupled model is used to estimate variations in CO2 and its stable isotopic
composition in the atmosphere over several scales. These include diurnal cycles in the
canopy air; regional patterns simulated in RAMS; and basin-wide variations simulated by
coupling to a global general circulation model. Using a Bayesian synthesis inversion
technique, we test a method for direct estimation of regional fluxes from hypothetical
aircraft data. Results suggest that atmospheric properties can form a significant integral
constraint to regional carbon fluxes. A campaign of aircraft sampling to implement this
method is planned for 2001.
1
Department of Atmospheric Science, Tel: +1-970-491-6936; Fax: +1-970-491-8449, E-mail:
[email protected] ; 2 Colorado State University, E-mail: [email protected] ; 3 Colorado
4
State University, E-mail:
[email protected];
Colorado State University, E-mail:
5
[email protected] ;
Colorado State University, E-mail: [email protected] ; 6
Colorado State University, E-mail: [email protected]; 7 Colorado State University, E-mail:
[email protected]; 8 Colorado State University,E-mail: [email protected] .
88
Radon-222 Determination of Forest Canopy-Atmosphere Gas Exchange Rates: New
Methods and Initial Results
Christopher S. Martens 1
Howard Mendlovitz 2
Osvaldo L.L. Moraes 3
Patrick M. Crill 4
The primary goal of our LBA project is to quantify air exchange rates and gas fluxes
between old growth and selectively logged forests and the overlying atmosphere. We use
continuous, in situ radon-222 measurements and compare calculated vertical gas fluxes
with values derived from independent eddy correlation and flux chamber measurements.
Arrays of specially designed flow-through radon detectors are being deployed as of late
April 2000 at both the primary forest (km 67) and selective logging (km 83) sites in the
Flona Tapajos, following exhaustive laboratory and field calibrations and experiments in an
experimental forest in North Carolina,. Our field tests in North Carolina have provided an
initial data set that illustrates the capabilities of the new detectors to accurately resolve 0.01
pCi/l/m radon activity gradients within the forest canopy using15 minute counting
intervals. A continuous six month data set from the North Carolina reveals both diel and
seasonal changes in canopy inventories. Soil radon fluxes are measured using an adaption
of flow-through detector designs to produce a fluxometer capable of repeated flux
determinations taking approximately one hour each using existing flux chamber collars
located around the tower sites.
1
CB-3300, Department of Marine Sciences, Chapel Hill, NC 27599-3300 USA, Tel: 919 962 0152; Fax: 919
962 1254, E-mail: [email protected] ; 2 UNC, E-mail: [email protected]; 3 UFMS, E-mail:
[email protected]; 4 UNH, E-mail: [email protected] .
89
Variabilidade espacial do carbono do solo em área com pastagem
na Amazônia Ocidental (RONDÔNIA)
Carlos Eduardo Pellegrino Cerri 1
Carlos Clemente Cerri 2
Reynaldo L. Victoria 3
Martial Bernoux 4
Vincent Chaplot 5
Boris Volkoff 6
Maria Victoria Ballester 7
Marisa C. Piccolo 8
Brigitte J. Feigl 9
Jerry M. Melillo 10
Christopher Neill 11
Paul A. Steudler 12
Diana Garcia 13
O objetivo da pesquisa é avaliar a variabilidade espacial dos estoques de carbono do solo
em uma área de 63 ha com pastagem na Amazônia Ocidental, Rondônia (Fazenda Nova
Vida, 10o 10'05"S e 64o 49'27"W) e correlacionar os estoques de C do solo, com os fluxos de
CO2 e carbono imobilizado na biomassa microbiana. Efetuou-se uma amostragem
sistemática coletando-se amostras de solo de acordo com uma malha regular de 25 x 25
metros. Em cada um dos 985 pontos referenciados geograficamente coletou-se amostras nas
camadas 0-10, 10-20 e 20-30 cm de profundidade, totalizando 2955 amostras. Foram
realizadas tradagens espaçadas a cada 100m, nas profundidades 50-60, 70-80 e 90-100cm,
totalizando 198 amostras. No decorrer da amostragem sistemática verificou-se que o
terreno apresenta heterogeneidade entre as distâncias de 25 m, justificando uma
amostragem mais adensada. Adotou-se então um sistema de coleta idêntico ao utilizado na
amostragem sistemática, entretanto, utilizando grades regulares de 5 x 5 m e de 1 x 1 m.
Foram amostradas as camadas 0-10, 10-20 e 20-30cm em quatro sub-áreas com 68 pontos
cada, totalizando 816 amostras. Durante a amostragem verificou-se que existem cerca de
cinco variações de solos na área de estudo. Com o intuito de conhecer e caracterizar tais
solos, foram abertas 7 trincheiras com 2m de profundidade. Em cada uma das trincheiras
foram descritos morfologicamente os horizontes diagnósticos e coletadas amostras para
serem análisadas em laboratório.Esse levantamento servirá como base para a instalação de
um experimento de intensificação de manejo de pastagens de baixa fertilidade. Atualmente
as amostras estão sendo processadas. Assim que os resultados foram sendo disponibilizados
serão incorporados ao banco de dados do LBA.
1
Avenida Centenário, 303 - Cx. Postal 96 Piracicaba, São Paulo, Tel: (19) 429-4708; Fax: (19) 429-4610,
E-mail: [email protected] ; 2 CENA/USP, E-mail: [email protected]; 3 CENA/USP, E-mail:
[email protected]; 4 IRD/CENA; 5 IRD/CENA; 6 IRD/CENA; 7 CENA/USP; 8 CENA/USP; 9 CENA/USP;
10
Marine Biological Laboratory (MBL) - The Ecossystem Center; 11 MBL - The Ecossystem Center; 12
MBL - The Ecossystem Center; 13 MBL - The Ecossystem Center.
90
Daily Course of Carbon Release from Stems and Branches
J. Viviana Horna 1
Reiner Zimmermann 2
John Tenhunen 3
Inundated forests of Central Amazon are believed to have a high carbon release since net
wood productivity is low in spite of favorable nutrient supply and climate. Diurnal courses
of carbon release were measured in the main stem and branches of deciduous trees (Albizia
multiflora, Tabebuia barbata, Pseudobombax munguba, Crataeva benthami, Vitex cymosa)
and evergreen tree species (Nectandra amazonum, Laetia corymbulosa, Pouteria
glomerata). Measurements were taken between March 1999 and March 2000. Stem and
branch cuvettes were used in an open system with an integrated infrared gas analyzer
running in differential mode. From March until September the area adjacent to the Amazon
River is flooded by several meters. Rates for woody tissue respiration where higher during
the beginning of the flooding season (March-April) and varied from 2 to 14 mmol CO2 m-2
s-1 among species. Carbon release was highest in the main stem of the evergreen Nectandra
amazonum. During the dry season, from October to February, the values of respiration
varied from 1 to 8 mmol CO2 m-2 s-1 among species. During this time carbon release was
higher in the stem of the deciduous Albizia multiflora.
Carbon release measurements for the complete annual cycle still need to be separated into
maintenance and growth respiration that follows closely the phenology of the species. The
final step of this study will be to develop a model to estimate carbon loss by respiration of
the species studied.
1
University of Bayreuth, Plant Ecology. D-95440 Bayreuth, Germany, Tel: 0049-921-552573; Fax: 0049921-552564, E-mail: [email protected]; 2 Forest Ecology and Remote Sensing Group,
University of Bayreuth, E-mail: [email protected]; 3 Plant Ecology, University of
Bayreuth, E-mail: [email protected] .
91
The Ecosystem Demography Model (ED)
Paul Moorcroft 1
George C. Hurtt 2
Steve Pacala 3
Elena Shevliakova 4
Berrien Moore 5
Natural disturbances and human land-use activities have a large impact on the structure,
dynamics and fluxes of ecosystems at a variety of scales.
As a result, ecosystems are more heterogeneous in important ways than is explained by
climatic and edaphic factors alone. A critical impediment to incorporating relevant finescale detail in large-scale models is the problem of scaling-up. We developed a new
individual-based terrestrial ecosystem model, the Ecosystem Demography Model (ED), that
addresses these issues.
ED predicts both ecosystem structure (e.g. above and below-ground biomass, vegetation
height and basal area, and soil carbon stocks) and corresponding ecosystem fluxes (e.g.
NPP, NEP and evapotranspiration) from climate, soil and land-use inputs. The model
consists of integrated sub-models governing processes such as leaf-level physiology, plant
allocation, allometry, phenology, dispersal, the effects of fire disturbances, and belowground sub-models for soil carbon dynamics and hydrology. Using a new method for
scaling-up it is possible to predict ED's large-scale behavior without simulating the fate of
every plant individually. ED is being used to examine how climate and edaphic factors,
natural disturbances, and human land-use practices affect vegetation structure and fluxes
within the Amazon Basin. Coupled versions are in development to consider potential
feedbacks to the atmosphere.
1
Princeton University, Dept. Ecology and Evolutionary Biology, Princeton, NJ 08544-1003 USA
Tel: 609-258-6886; Fax: 609-258-1334, E-mail: [email protected]; 2 University of New Hampshire,
E-mail: [email protected]; 3 Princeton University, E-mail: [email protected]; 4 Princeton
University, E-mail: [email protected] ; 5 University of New Hampshire, E-mail: [email protected] .
92
Non-CO2 volatile carbon emissions and net ecosystem exchange in Amazônia
Jim Greenberg 1
Alex Guenther 2
Oscar Veja 3
Peter Harley 4
Luciana Vanni-Gatti 5
At present, the global CO2 budget requires the addition of a large, unidentified terrestrial
sink in order to balance. After peatlands, forests contain the largest terrestrial reservoirs of
carbon. Landuse changes in forested areas, therefore, represent a significant potential
impact on the global carbon cycle. The net exchange of CO2 between ecosystems and the
atmosphere is a measure of the net ecosystem exchange of carbon (NEE). The net flux of
CO2 should be into young, rapidly growing forests; out of areas of recently cleared forest
areas (as the organic matter decomposes); but near zero for mature or primary forests.
The estimation of the net carbon exchange is complicated by the potential for missing a
significant exchange of non-CO2 carbon. Living and dead organic matter emit a variety of
volatile organic compounds (VOCs), including carbon monoxide, methane, isoprene,
monoterpenes, methanol, acetone, acetaldehyde, formaldehyde, many VOCs related to
damage of plant tissue, etc.
We have measured several of these non-CO2 VOC emissions at the landscape level in
various states in Amazônia, including Amazônas (near Balbina, primary and secondary
forest), Rondônia (recently cleared forest and pasture as well as primary forest) and Pará
(near Santarém, primary and secondary forest). The atmospheric concentration profiles of
these VOC emissions were used to estimate hourly and daily emissions; a biogenic
emission model was used to extrapolate these emissions to na annual flux. This annual
emission estimate was then used to gauge the importance of non-CO2 VOC emissions to
NEE in Amazônia.
1
P.O.Box 3000, Boulder, Colorado, USA 80307- 3000, Tel: 303-497-1454; Fax: 303-497-1477,
E-mail: [email protected] ; 2 NCAR; 3 IPEN; 4 NCAR; 5 IPEN.
93
Decrease in CO2 emissions related to increase in the iron level of Brazilian soils
Newton La Scala Júnior 1
José Marques Júnior 2
Caio Vinícius dos Santos 3
Gener Tadeu Pereira 4
Brazilian soils may be characterised by color. A great part of Brazilian soils have a dark red
color, due to the iron level. The range if iron content is from 4% to as high as 33%, and the
coloration is related directly to the iron content. In this work we have studied the CO2
emissions of a bare soil having a great contrast in the iron level. In our experimental field
we have installed a transect, where CO2 emission was measured using an IRGA-based soil
chamber, at points separated 10 meters from each other, ranging from a yellow to a red dark
soil. We have also collected a 20 cm depth soil layer in all the measurement points and
analyzed pH, organic carbon, Fed level among other soil properties. Our results are
presented in terms of linear correlation and spatial variability analyzes of CO2 emissions
and the soil properties studied. In particular, we have observed a significant negative linear
correlation between soil respiration and iron level of the soil (r = -0.31, P < 0.05).
Finally, the similarity of the spatial variability models of the CO2 emission, when compared
to the iron level also supports the relationship between these two properties.
1
Rod. Paulo Donato Castellane s/n, 14870-000, Jaboticabal-SP, Tel: 16 + 323-2500 ext. 112; Fax: 16 + 3224275, E-mail: [email protected] , 2 FCAV/UNESP; 3 FCAV/UNESP; 4 FCAV/UNESP.
94
Photosynthetic response of canopy species in a forest area
in eastern Brazilian Amazonia
Moacyr B. Dias-Filho 1
José Benito Guerrero M. 2
Daniel C. Nepstad 3
The functional changes to experimental rainfall exclusion of a one-hectare area of primary
forest in Santarém, State of Pará, Brazil, will be studied during a three-year period. The
objective of the present study was to gather baseline data on the photosynthetic response of
canopy (> 10m) species in the area, prior to implementation of the rainfall exclusion
treatment. Measurements on individual species were made during the rainy and dry seasons
of 1999, between 8:30h and 15:30h, local time, with an open portable photosynthesis
system (Li-Cor LI-6400) under standard conditions. Wood towers provided access to the
high forest canopy.
Mean PPFD during gas exchange measurements were 212.1 ± 323.2 (mean ± standard
deviation) and 298.1 ± 455.7 µmol m-2 s-1 for the rainy and dry seasons.
Mean photosynthetic rates for the rainy and dry seasons were 5.37 ± 2.73 and 7.62 ± 3.96
µmol m-2 s-1, and maximum photosynthetic rates were 21.1 and 22.7 µmol m-2 s-1.
1 Lab. Ecofisiologia Vegtal, C. Postal 48, Belém PA, 66017-970, E-mail: [email protected];
2
IPAM; 3 The Woods Hole Research Center.
95
Characterization of the Esecaflor/Caxiuanã Experimental Sites, PA
Maria de Lourdes Pinheiro Ruivo 1
Antônio Fernado S. Marques 2
Everton da S. Cunha 3
Beatriz Quanz 4
Among several researches developed by the LBA project at Estação Científica Ferreira
Penna (Caxiuanã, PA), the ESECAFLOR project is investigating the influence of the water
exclusion from the soil on the forest cycle. This experiment is in its initial phase of
collecting basic data related to soil, vegetation and climate. We will present the preliminary
results on soil characteristics in tree plots (sites 1, 2 and 3). Samples were taken from 5m
soil pits. The soils, classified as yellow Latosol, present A, B and C horizonts, are moderate
to well drained, have pH values ranging from overly acid (3,5) to moderately acid (5,5),
colors are dark yellow brown (10YR, 3/6) to yellowish red (7,5 YR, 6/6). Texture varies
from sandy to clay, organic carbon (OC) varies from high (109 g/kg) to low (1.9 g/kg) and
there is a high proportion of fulvic acid in relation to humic acids. Site 3 shows higher
accumulation of OC and humic substances in relation to the others. This fact may be related
to variation in drainage, topography or vegetation cover of the sites since the material of
origin is the clay-sand sedimentary rocks of the Alter do Chão Formation.
1
Museu Paraense Emílio Goeldi , Av. Magalhães Barata, 376; Belém, Pará, Brasil, Tel: 091.249-0793; Fax:
091. 249-0466, E-mail: [email protected]; 2 Museu Paraense Emílio Goeldi; 3 Faculdade de Ciências
Agrárias do Pará; 4 Museu Paraense Emílio Goeldi .
96
Carbon Budget in different components of a woody savanna in Brazilian Cerrado
Roberto Engel Aduan
Carlos Augusto Klink
Eric A. Davidson
1
2
3
The Cerrado savanna covers 2,000,000 km2 in Central Brazil. The human occupation has
been accelerating over the past few decades, and currently around 45% of its natural area
have already been converted into agro-ecosystems, mainly planted pastures and cash crops.
Despite the magnitude of human occupation, the effects of land use change on carbon
balance of the converted areas, are still poorly understood. The aim of this work is to
evaluate the carbon budget of a "Cerrado denso" (savanna dominated by trees and shrubs)
area in the Reserva Ecologica do Roncador (RECOR/IBGE), near Brasília, by monitoring
key processes related to carbon dynamics in the ecosystem: soil respiration (using the
dynamic chamber IRGA technique), litterfall (using litter bags) and plant growth
(dendrometry). The spatial and temporal variation of this processes will be correlated to the
variation of key environmental factors (precipitation, humidity, soil water content and
temperature), and which may be expected to vary with changes in land use and climate.
Preliminary results of soil respiration show that CO2 fluxes from soil surface, in the rain
season, are similar to other tropical savannas (0,11-0,22gC m-2 h-1) and to eastern Amazon
primary forests in the dry season.
1
Campus Universitário - ICC - Ala Sul Departamento de Ecologia, Tel: 61 2721132,
E-mail: [email protected] ; 2 Universidade de Brasília; 3 Woods Hole Research Center.
97
Carbon stocks and dynamics in a neotropical rain forest
Deborah A. Clark 1
Steven F. Oberbauer 2
David B. Clark 3
At the La Selva Biological Station (Costa Rica), we are carrying out a long-term,
landscape-scale assessment of carbon stocks and the climatic controls of carbon fluxes in a
lowland neotropical rain forest (the "CARBONO" project). Since January 1998, we have
continuously measured forest-level CO2 exchange with the atmosphere from a 42 m tower
with eddy covariance techniques. For complementary ground-based studies, we stratified
18 0.5 ha plots over 600 ha of old-growth forest (six plots each on: steep ultisol slopes;
ultisol plateau; and old alluvial terraces). Measurements began in the 18 plots in September
1997 for: SOC stocks (to 4 m) and coarse woody debris (CWD) stocks (at project
initiation); fine roots (every 6-8 weeks); fine litterfall (biweekly); fine woody litterfall
(monthly); CWD inputs (annual); tree growth and survival and aboveground biomass
increment (annua ix 4-m deep soil pits. Soil respiration is measured at the surface biweekly
in 6 plots, and bole and soil respiration are measured continuously with automated
chambers at the tower site. Short-term (day-month) climatic responses of 10 canopy tree
species are being quantified with xylem sapflow and dendrometer studies. Additional pilot
studies and currently proposed work focus on forest- and species-level isoprene emissions,
dry deposition of carbon, precipitation throughfall, litter chemistry, CWD decomposition,
and microbial activity. The results from these studies to date reveal substantial temporal
and spatial variation in the carbon dynamics of this forest.
1
Interlink-341, P.O. Box 02-5635, Miami FL 33102, USA, Tel: 506-766-6565x146; Fax: 506-766-6535,
E-mail: [email protected] ; 2 Florida International University, E-mail: [email protected] ;
3
University of Missouri-St. Louis, E-mail: [email protected] .
98
Torres metálicas para instalação de sistemas de medição de fluxos sobre florestas
George Sanches Suli 1
Nicolau Priante Filho 2
A tomada de dados por aparelhos de precisão instalados nas torres metálicas em regiões de
estudo requer a adaptação da estrutura dessas torres de modo a proporcionar funcionalidade
e segurança na instalação de aparelhos, algumas vezes tão caros quanto a própria estrutura.
O fato do serviço de manutenção e coleta de dados ser executado por pessoas não
qualificadas para o manejo de peças e deslocamento em grandes alturas, como bolsistas e
professores, torna desejável que as torres apresentem certa ergonomia, como escadas
inclinadas e patamares de descanso, e ofereçam sensação de segurança a quem deva
executar qualquer operação em qualquer nível. Além disso, deve apresentar solução
estrutural para possibilitar sua construção em regiões de difícil acesso, sem a derrubada de
árvores e seja resistente às forças da natureza, como esforços devidos ao vento, corrosão e
eventual que exigências mínimas quanto a peso e volume de fundações, baixo impacto
ambiental, apresentando boa resistência à queda de grandes árvores, a idealização de um
modelo otimizado precisa ser efetuada. Serão apresentados projetos de torres otimizados
quanto à adaptabilidade de suportes à estrutura da torre e materiais empregados, como aço
(A-36) galvanizado ou pintado e alumínio (6061-T6) para torres de até 120 m, visando a
maior relação custo/benefício, com a adoção de um modelo geométrico único o que se
verifica interessante no caso de previsão de verbas para uma estrutura de forma final
definida e coleta de orçamentos sobre um projeto estabelecido.
1
Universidade Federal de Mato Grosso, Rua França n. 12, Q. 1, J. Europa, 78065-440 Cuiabá, Mato Grosso,
Tel: (0xx65)6342050, E-mail: [email protected]; 2 UFMT, E-mail: [email protected].
99
The net CO2 exchange of a transitional tropical forest (cerradão) during portions of
the wet and dry season
George L. Vourlitis 1
Nicolau Priante Filho 2
Mauro M. S. Hayashi 3
José de S.Nogueira 4
José Holanda Campelo Jr 5
Eddy covariance and measurements of the vertical CO2 gradient within the canopy were
used to quantify the net CO2 exchange of a 30m tall transitional tropical forest (cerradão)
over portions of the wet and dry season. The study was conducted near the city of Sinop in
NW Mato Grosso, Brazil (11°24.75'S: 55°19.50'W), which is located near the ecotone of
two major regional ecosystem types of South America (wet evergreen rain forest and
cerrado). The eddy covariance system consisted of a 3-dimensional sonic anemometerthermometer for measuring the mean and fluctuating quantities of wind speed and
temperature and an open-path infrared gas analyzer for measuring the mean and fluctuating
quantities of CO2 and H2 O vapor. The eddy covariance sensors were mounted at a height of
42 m above ground level, which corresponds to a height of ca. 12m above the canopy. The
vertical CO2 concentration was measured using a closed-path CO2 analyzer. Canopy CO2
storage was quantified by determining the rate of change of CO2 in the air column between
the ground surface and the eddy covariance sensors. This term was important because of
the tall and dense forest canopy and the relatively low nocturnal wind speed typical of the
Sinop area. Preliminary data suggest that the cerradão stand was approximately in balance
over the 97 d measurement period (average ±1SD daily net CO2 flux = 0.6 ± 1.3 gC m-2 d1; positive values denote net CO2 loss from the ecosystem). Net CO2 accumulation
increased during the beginning of the wet-season measurement period (average ±1SD daily
net CO2 flux = -1.7 ± 0.4 gC m-2 d-1), suggesting that seasonal variations in rainfall have
important implications on the seasonal pattern of net CO2 exchange.
1
Biological Sciences Program, California State University, Tel: 760-750-4119, Fax: 760-750-4111, E-mail:
2
3
[email protected];
UFMT, E-mail: [email protected] ;
UFMT, E-mail:
4
5
[email protected];
UFMT, E-mail:j [email protected] ;
UFMT,
E-mail:
[email protected].
100
Biomass of moist tropical forests decreases with increasing rainfall
Jon Lloyd 1
A global analysis has been undertaken of the relationship between above-ground biomass
and rainfall for tropical forests and woodlands. Once effects of disturbance and soil type
are taken into account, a clear non-linear relationship emerges. Tropical forest biomass
increases linearly up to about 2000 mm rainfall but declines significantly thereafter.
Possible causes for this decline in biomass at high rainfall will be discussed.
1
Max-PLanck-Institut für Biogeochemie; POstfach 100164, 07743 Jena Germany, Tel: 49-3641-643711,
Fax: 49-3641-643710, E-mail: [email protected].
101
Soil organic carbon pool, soil CO2 efflux and CO2 profile concentration under old
growth neotropical rainforest
Luitgard Schwendenmann 1
Edzo Veldkamp 2
Tania Brenes 3
Jens Mackensen 4
Deborah A. Clark 5
David B. Clark 6
Steven F. Oberbauer 7
Estimates of carbon pools and fluxes in tropical forests are important in the current
discussion of the world's carbon balance of forests. The main objectives of this study are (i)
to present results on the soil carbon stocks, (ii) CO2 efflux and (iii) soil CO2 profile
concentration under undisturbed tropical rainforest in the Atlantic zone of Costa Rica.
In three Inceptisol plots (old alluvial terraces) and three Ultisol plots (highly weathered
residual soils) 4 m deep shafts were installed. Soil samples were taken by depth for bulk
density, soil organic cabon (SOC) and for 13 C and 14 C analysis. Since March 1998 we
measure CO2 efflux bi-weekly from 8 permanent soil chambers per plot using an infrared
CO2 analyzer. At the same time we measure soil CO2 concentrations at 5, 20, 40, 75, 150,
250 and 350 cm depth using a GC. In addition controlling environmental factors like soil
temperature and soil moisture are determined. Soil organic carbon stock to 3 m depth for
inceptisol ranged from 242 to 306 Mg C/ha. A significantly higher amount of carbon (315
to 394 Mg C/ha) is stored in the Ultisol sites. At the Inceptisol sites, soil CO2 efflux rates
ranged from 10.4 to 11.7 Mg CO2 -C ha/yr. Significantly higher flux rates occurred in the
less fertile Ultisols where efflux rates ranged between 12.4 to 15.8 Mg CO2 -C ha/yr. Higher
soil CO2 concentrations in the upper soil profile under moist conditions (up to 2 % in
Inceptisols) supports the idea that higher soil moisture contents partially inhibit CO2
diffusion to the soil surface.
1
Institute of Soil Science and Forest Nutrition, University of Goettingen, Germany
La Selva Biological Station, Costa Rica, INTERLINK-341, P.O. Box 02-5635, Miami FL 33102, USA
Tel: ++506-766-6565, Fax: ++506-766-6535, E-mail: [email protected] ; 2 University of
Goettingen, E-mail: [email protected] ; 3 La Selva Biological Station, Costa Rica; 4 University of
Goettingen; 5 University of Missouri-St.Louis; 6 University of Missouri-St.Louis; 7 Florida International
University.
102
Biomass in the Tapajos National Forest, Brazil: Examination of Uncertainties arising
from Sampling and Allometric Relationships
Michael Keller 1
Michael Palace 2
George Hurtt 3
Changes in the biomass of Amazon region forests represent an important component of the
global carbon cycle but the biomass of these forests remains poorly quantified. We
examined forest survey data for trees with a diameter at breast height (DBH) greater than
35 cm from 392 ha in the Tapajos National Forest near Santarem, Para, Brazil. Based on
tree diameter data, allometric relations, and published relations for biomass in other
compartments besides trees, we estimated a total biomass density of 372 ± 59 Mg ha-1
(mean ± standard error). This estimate includes all live and dead plant material above and
below ground with the exception of finely divided soil organic matter. We propagated
errors in sampling and those associated with allometric relations and other ratios used to
estimate biomass of roots, lianas and epiphytes, and necromass. The major sources of error
in our estimate were found in the allometric relations for trees with DBH greater than 35
cm, in the estimates of numbers of trees with DBH less than 35 cm, and in root biomass.
Simulated sampling based on our full survey, suggests that we could have estimated mean
tree biomass (DBH > = 35 cm) to within 20% with 95% confidence by sampling 23
randomly selected 0.25 ha plots in our study area.
1
International Institute of Tropical Forestry, USDA; Forest Service, Rio Piedras, PR 00928-5000 USA and
Complex Systems Research Center, Morse Hall, University of New Hampshire, Durham, NH 03824 USA
E-mail: [email protected]; 2 UNH, Complex System Research Center, E-mail: [email protected];
3
UNH, Complex Systems Research Center, E-mail: [email protected] .
103
How sensitive are calculations of CO2 and water?
Yadvinder Malhi 1
Robert Clement 2
Antonio Nobre 3
Flux data are being collected at a number of sites within LBA.
There are a number of possible methods for processing and analysing such data, including
different procedures for detrending time series, rotating data, averaging periods and high
and low frequency corrections.
A number of sites report some problems with the resulting flux measurements, such as nonclosure of energy balance or low night-time CO2 fluxes. Here we examine raw data for
heat, water and CO2 fluxes collected from ZF2 (near Manaus) in 1995, to examine the
nature and spectral structure of turbulent flux transport, and to estimate the sensitivity of
the resulting calculated fluxes to changes in analysis procedure. We conclude that a
significant proportion of flux transport in tropical regions is at very low frequencies.
1
IERM, University of Edinburgh; Mayfield Road, Edinburgh EH9 3JU, Tel: +44 131 650 5744; Fax: +44
131 662 0478, E-mail: [email protected]; 2 IERM, E-mail: [email protected]; 3 INPA, E-mail:
[email protected].
104
CO2 , water and energy fluxes at Caxiuana National Forest, Para:
the first year of results
Fiona Carswell 1
Marcia Palheta 2
Antonio Lola da Costa 3
Yadvinder Malhi 4
Jose Maria da Costa 5
Maria das Gracas Pires Pereira 6
John Grace 7
Eddy covariance measurements have been carried out at a 56 m tower at Caxiuana National
Forest, Para, since April 1999, as part of the LBA-EUSTACH and ECOBIOMA projects.
We report here on the first year of data from this site. We examine the results and compare
them with previous studies in Rondonia and Manaus The uptake of CO2 in the day was up
to 20 or 30 µmol m-2 s-1, consistent with what has been observed in Rondonia and
Manaus. This similarity suggests that bulk photosynthesis and respiration rates are very
similar across the terra firme forests of Amazonia, irrespective of species composition.
Overall, the data imply an annual uptake of about approximately 7 t C ha-1 year-1.
1
Gerald St., PO Box 69, Lincoln 8152, New Zealand, E-mail: [email protected] ; 2 UFPA, E-mail:
[email protected]; 3 MPEG, E-mail: [email protected] ; 4 University of Edinburgh, E-mail: [email protected]; 5
6
Universidade de Vicosa,
E-mail:[email protected];
Universidade de Vicosa, E-mail:
7
[email protected]; University of Edinburgh, E-mail:[email protected].
105
Measurements of soil moisture, CO2 efflux and leaf area index
in Rondonia during 1999
Humberto R. da Rocha 1
Maria A.F. Silva Dias 2
Helber C. Freitas 3
Amaury Caruzzo 4
Jorge M. Lopes 5
Maarten Waterloo 6
Osvaldo M.R. Cabral 7
Regina Alvala 8
Ralf Gielow 9
Antonio Manzi 10
Celso von Randow 11
Beatriz Gomes 12
During the AMC-LBA (Jan-May,1999) and 1999 in Rondônia, we collected specific
cophysiological data and installed automatic instrumentation to provide further
interpretation of aerological, surface fluxes and numerical modelling data. To this end, soil
moisture, soil CO2 efflux and leaf area index measurements were made at a pasture
(Fazenda N. S. Aparecida) and a forest (Reserva Biológica do Jarú) site near Ji-Paraná,
Rondônia. The variation in the 95% continuous soil moisture data series reflects the
seasonal and intra-seasonal variability of rainfall, in addition to single rainfall events
within the dry season. The soil respiration data showed the correlation of respiration with
soil temperature and moisture status is in principle evident. Other issues from the analysis
are a low correlation of single measurements against temperature and, more important, a
suggested difference in the mechanisms controlling CO2 efflux in the dry and wet seasons.
In addition, evidence of periodic events (compatible with intra-seasonal temperature
variations) have shown to result in a negative trend from the early dry season (June) to the
middle wet season (January). Preliminary results of the leaf area index profile in the forest
suggest a pattern consistent with the exctintion radiation profile obtained simultaneously. In
January, the average LAI values for forest and pasture were 4.9 and 2.7 m2 m-2,
respectively.
1
Universidade de Sao Paulo; Rua do Matao, 1226, Tel: (011)8184713, Fax: (011)8184714, E-mail:
[email protected] ; 2 USP, 3 USP, 4 USP, 5 USP, 6 Alterra G.W. Research; 7 Embrapa
8
INPE; 9 INPE; 10 INPE; 11 INPE; 12 UNIR.
106
Preliminary assessment of VOC fluxes from a primary rain forest performed in the
LBA site at Manaus
Paolo Stefani 1
Riccardo Valentini 2
Paolo Ciccioli 3
Enzo Brancaleoni 4
Massimiliano Frattoni 5
Antonio D. Nobre 6
Alessandro C. De Araujo 7
To precisely assess the turnover of carbon from vegetation covered areas, it is essential to
quantify the amount of assimilated carbon that is released in the atmosphere in the form of
isoprenoid compounds. A suitable way to do it is to measure fluxes of biogenic volatile
organic compounds (BVOC) by relaxed eddy accumulation. To gain information on the
carbon balance of primary rain forests of the Amazon basin, a measuring site for VOC and
CO2 was built in the test site managed by the INPA of Manaus. Eddy correlation (EC)
measurements were combined with relaxed eddy accumulation (REA) determinations in a
40 m tower located inside a primary rain forest located 80 km from the city of Manaus
(North direction). Preliminary data on BVOC fluxes collected from August 1999 to January
2000 indicate that the most abundant compound released by this forest ecosystem was
isoprene with average normalized fluxes ranging from 1000 to 1500 ng m-2 s-1. Main
monoterpene compounds released were pinenes and sabinene. Their fluxes ranged between
200 and 250 ng m-2 s-1. In terms of carbon, a net emission of reduced carbon ranging from
90 to 120 nmol m-2 s-1 was measured under standard conditions of PAR and temperature.
Based on these preliminary data, fraction of emitted vs. assimilated varying from 0.46 and
0.6% were measured for the type of rain forest existing in Manaus. More extensive
investigations are planned to confirm our preliminary observations and to follow the
seasonality of BVOC emissions. They will be performed within the frame of the LBACarbosink project sponsored by the European Union.
1
Department of Forest Science (DISAFRI), Università della Tuscia, Viterbo, ITALYvia C. De Lollis, 01100,
Tel: ++390761357394 Fax:
++390761357389, E-mail: [email protected]; 2 DISAFRI, E-mail:
3
[email protected] ; Istituto sull’Inquinamento Atmosferico del CNR, E-mail: [email protected];
4
Istituto sull’Inquinamento Atmosferico del CNR; 5 Instituto sull’Inquinamento Atmosferico del CNR; 6
INPA, E-mail: [email protected] ; 7 INPA, E-mail: [email protected].
107
Annual carbon dioxide fluxes across the Amazon basin: Preliminary comparison of
1999 results for some LBA-flux tower sites
Pavel Kabat 1
Antonio Nobre 2
John Grace 3
Antonio O. Manzi 4
Bart Kruijt 5
Celso von Randow 6
Jan A. Elbers 7
Yadvinder Malhi 8
Alistair Culf 9
Carlos Nobre 10
Maarten J. Waterloo 12
Alessandro C. de Araujo 13
Helber C. Freitas 15
During 1999, continuous measurements of carbon dioxide fluxes were carried out at several
LBA sites, set up jointly by the Europe – Brazil flux tower consortium: Rondonia (1 forest
and 1 pasture site); Manaus (2 forest sites) and Caixuana (forest site). In addition to these
continuous CO2 measurements, towers in both forest and pasture were set up to collect
micrometeorological and soil data during the Wet AMC campaign in Rondonia. The
coverage of the seasonal cycle by direct measurements was satisfactory; we have collected
data on 70 - 90 % of the days, depending on respective site and starting date of the
measurements. After preliminary analysis, data for all 5 forest sites indicate a high CO2
uptake during 1999, ranging between 3 to 7 ton C ha-1 y-1 . We will demonstrate several
ways of analysis applied to the 1999 data, including the role of flux corrections and the
sensitivity of the results to the treatment of night time CO2 fluxes and canopy storage.
Through systematic inter-comparison between the sites and comparison with results
obtained in previous studies, we attempt to further narrow down possible uncertainties in
these potentially very high carbon uptake values.
1 Alterra Green World Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands, Tel: +31 317
474314; Fax: +31 317 424812, E-mail: [email protected]; 2 INPA, E-mail: [email protected] ; 3
University of Edinburgh, E-mail: [email protected]; 4 CPTEC-INPE, E-mail: [email protected];
(5) Alterra Green World Research, E-mail: [email protected] ;
6 CPTEC-INPE, E-mail:
[email protected] ; 7 Alterra Green World Research, E-mail: [email protected]; 8 University
of Edinburgh, E-mail: [email protected];
9 NERC-Institute of Hydrology, E-mail:
[email protected]; 10 CPTEC-INPE, E-mail: [email protected]; 11 Universidade de
São Paulo, E-mail:
[email protected];
12 Alterra Green World Research, E-mail:
[email protected] ; 13 INPA, E-mail: [email protected] ; 14 CPTEC-INPE, E-mail:
[email protected]; 15 Universidade de São Paulo, E-mail: [email protected]
108
The sensitivity of NEP to radiation, CO2, temperature, air and soil humidity in three
Amazon rain forests
Bart Kruijt 1
Celso Von Randow 2
Antonio Donato Nobre 3
Fiona Carswell 4
Lourdes Ruivo 5
Yadvinder Malhi 6
Antonio Manzi 7
Pavel Kabat 8
John Grace 9
Alistair Culf 10
Jan Elbers 11
Maarten Waterloo 12
Allessandro Carioca 13
Paulo George 14
Paulo Stefani 15
Patrick Meir 16
Humberto Da Rocha 17
Since early 1999, net ecosystem exchange of CO2 as well as fluxes of water and heat and
meteorological variables have been measured almost continuously in three Amazon forest
sites: in the Cuieiras basin near Manaus, in Reserva Jaru, Rondonia and in the Reserva
Caxiuana, Para. Of the first two of these sites, earlier data sets exist as well. In this study,
we give an overview of these data sets and explore the relationships between measured
variables. In particular, we will look at the ecosystem physiology, as represented by the
response curves of NEP to incident radiation, air and soil humidity and nocturnal NEP
(ecosystem respiration) to temperature. We will also calculate surface conductance using
the evaporative and momentum flux measurements, and explore the sensitivity of this
variable to the environment, comparing with earlier parameterisations for this variable at
leaf empirical model of NEP, and use this to explain seasonal variations observed as well as
inter-site differences.
1
Alterra, P.O. Box 47 , 6700 AA Wageningen, The Netherlands, Tel:
+31 317 474331, Fax: +31 317
419000, E-mail: [email protected] ; 2 CPTEC-INPE, E-mail: [email protected] ; 3 INPA, Email: [email protected] ; 4 University of Edinburgh, E-mail: [email protected] ; 5 Alterra Green
6
World Research,
MPEG, E-mail: [email protected];
University of Edinburgh, E-mail:
7
8
[email protected] ; CPTEC-INPE, E-mail: [email protected] ; Alterra Green World Research, E-mail:
[email protected] ; 9 University of Edinburgh, E-mail: [email protected] ; 10 NERC-Institute
of Hydrology, E-mail: [email protected] ; 11 Alterra Green World Research, E-mail:
[email protected] ; 12 Alterra Green World Research, E-mail: [email protected] ; 13
INPA, E-mail: [email protected] ; 14 CPTEC-INPE, E-mail: [email protected] ; 15 University of
16
Tuscia, E-mail: [email protected] ;
University of Edinburgh, E-mail: [email protected]
17
Universidade de São Paulo, E-mail: [email protected].
109
Seqüestro de carbono uma experiência concreta: Resultados iniciais do projeto de
seqüestro de carbono da Ilha do Bananal e seu entorno
Divaldo Rezende 1
O principal objetivo do Projeto de Seqüestro de Carbono da Ilha do Bananal e seu Entorno
(PSCIB) é desenvolver e implementar um sistema inovador, eqüitativo e sustentável para
equilibrar as emissões dos gases causadores do efeito estufa através do Seqüestro de
Carbono, compatível com as realidades sociais e ambientais da região da Ilha do Bananal.
Um das características do PSCIB é que o projeto está inserido em uma zona ecotonal, ou
seja onde ocorre uma interação entre dois ou mais ecossistemas, desta forma foram obtidos
resultados específicos para 4 tipos de vegetação abrangendo 3 diferentes ecossistemas;
Floresta de terra seca, floresta inundada, cerrado e várzeas.
Os cálculos de estoque de Carbono da área do projeto foram calculados considerando duas
variáveis. Primeiramente o geoprocessamento de imagens temporais nos anos de 1986,
1991,1995 e 1998 para definição da dinâmica de desmatamento e análise do uso da terra. E
a Segunda variável, considerada neste estudo, são os teores de biomassa dos diversos
ecossistemas da Ilha do Bananal e seu entorno.
As perdas que ocorrem na área sem o projeto é de algo aproximado em torno de 993.888
toneladas de carbono, considerando somente a área tampão (as áreas entre os parques do
Araguaia e do Cantão) estes valores são reduzidos a 615.531 toneladas de carbono que
deixam de ser absorvidas a cada ano, mesmo assim são valores significativos que se
extrapolados para os 25 anos de vida do projeto somarão algo em torno de 15.388.275
toneladas de carbono. Neste trabalho não foram consideradas as possíveis perdas em função
das queimadas, mas esta variável deverá ser monitorada ao longo do projeto.
1
ECOLOGICA ASSESSORIA; ACSV-SE 22 LT 20 sls. 103/104 Palmas -TO Cep 77125-220
Tel: 063-215-1279, Fax: 063-225-3101, E-mail: [email protected].
110
Avaliação de modelos biofísicos nas trocas de energia, água e carbono:
PROJETO LBA-TRMM/1999
Julio Tota 1
Humberto R. Rocha 2
Carlos Nobre 3
Antonio Ocimar Manzi 4
Lianhong Gu 5
D. Fuentes 6
Gilberto Fisch 7
Fotossíntese e respiração da vegecao e solos têm um papel importante no ciclo do carbono
em florestas úmidas da região da Amazônica. Um grande esforco tem sido feito para medir
e modelar esses processos, os quais formam uma importante componente das interacoes
entre a biosfera-atmosfera dentro do ecossistema amazonico. Como parte do projeto
TRMM-LBA, foi realizada uma campanha de campo com medidas meteorológicas de
superfície (temperatura, pressão, umidade e CO2 , etc.) em uma área de pastagem no Estado
de Rondônia durante a estação chuvosa de 1999. Esta constou de medidas de superfície em
uma torre micrometeorológica. As medidas de resposta rápida dos fluxos de CO2 foram
feitas a 6 metros de altura por um sistema de "Eddy Covariance". Tambem foram feitas
medidas das concentrações de CO2 em 4 níveis (0,5; 1,5; 4,0 e 9,5 metros) através de um
perfilador de gás (Gas Profile). Neste trabalho sao realizadas simulacoes com modelos
biofisicos (SiB2c e "Gu model") e a performance dos modelos para os principais fluxos de
superficie sao avaliadas junto aos dados observados durante a campanha de campo do
projeto LBA-TRMM/1999. O comportamento do ciclo diurno desses fluxos (em particular
o CO2 ) associados as diferentes condicoes de estabilidade sao tambem analisados. Uma
comparacao entre os fluxos de CO2 obtidos em dois pontos numa area de pastagem e em
uma area de floresta sao analisados e comparados a simulacoes dos modelos biofisicos.
1
CPTEC, Rodovia Presidente Dutra, Km 40, Cachoeira Paulista, São Paulo, Tel: 5608400, E-mail:
[email protected]; 2 USP, E-mail: [email protected]; 3 CPTEC, E-mail: [email protected]; 4
CPTEC, E-mail: [email protected] ; 5 University of Virginia, E-mail: [email protected] ; 6 University of
Virginia, E-mail: [email protected]; 7 IAE-CTA-ACA, E-mail: [email protected] .
111
Influence of fire and soil water content on the aboveground phytomass in the “campo
sujo” ecosystem
Alexandre José Barbosa Santos 1
Gabriela Tunes da Silva 2
Carlos Alberto Quesada 3
Lacê Medeiros Breyer 4
Heloísa Sinátora Miranda 5
Antonio Carlos Miranda 6
The biomass production in the cerrados region presents strong seasonal changes which are
related mainly with rain distribution along the year, in addition these ecosystems are often
subject to fire that has influence in the productivity. This study was carried out in two
adjacent areas of “campo sujo”, a type of grassland with sparse shrubs. The aboveground
phytomass (AGP) productivity was compared for a recently burned area and for an area that
had been kept unburned for one year. Along with the assessment of the phytomass
production, the soil water content was measured at depths from 5 to 360 cm with a neutron
probe. In the burned area, the estimated AGP production was 36 g m-2 two months after the
fire, during the same period the unburned area presented a AGP increase of 56 g m-2. With
the progression of the rainy season, the burned area presented more productivity as soil
water content increased. From November to February the AGP accumulation was 202 g m2 in the burned area while in the unburned area it was only 40 g m-2. Both areas presented
similar behavior relative to soil water storage, the water availability for the soil was
calculated as 120 mm m-1 and the estimated evaporation rate 27 days after the fire was 0.4
mm day-1.
1
Universidade de Brasília, SQN 406 bloco F apto 208, E-mail:
UnB; 5 UnB; 6 UnB; 7 UnB.
[email protected] ;
2
UnB;
3
UnB;
4
112
Measuring carbon balances in the Amazon Basin: II. A new instrument for obtaining
long-term eddy-covariance fluxes and high-accuracy [CO2 ] in the tropics
Bruce C. Daube 1
Scott R. Saleska 2
J. William Munger 3
Steven C. Wofsy 4
V.W.J.H. Kirchhoff 5
In part II of a two-part presentation (see also Saleska et.al.), we describe a new instrument
for measuring eddy-covariance fluxes of CO2 , water vapor, momentum and sensible heat,
and for making continuous >high-accuracy measurements of [CO2 ] in terrestrial and
marine boundary >layer air. Fluxes will be measured in an old-growth Amazonian
rainforest >(Tapajos National Forest, km 67, Santarem, PA), and high- accuracy [CO2 ] will
be measured continuously both at the forest site and in Atlantic marine boundary layer air
as it advects into the Amazon basin from the South American coastline (at Maxaranguape
observatory, just north of Natal, RN - see Kirchoff et al.). The instruments consist of
modular tower-mounted units (approximately 1m x 0.6m x 0.2m) which contain all key
measurement and datalogging instrumentation, thus minimizing sample tube length (~2m
in our case) between air intake and the closed-path pressure-controlled infra-red gas
analyzer (Licor 6262). This eddy-covariance instrument maintains advantages of closedpath designs (e.g. precise instrument calibration) while also adding some advantages (e.g.
minimal disturbance of the air sample before measurement) attributed to open-path
designs. This system is particularly suitable for very tall vegetation ecosystems where
sample tube-wall adsorption problems would be exacerbated by the long travel distance
from the top of the tower to a ground-based measurement device. The high-accuracy
[CO2] measurements (<0.5 ppm) will be compatible with the global CMDL sampling
network, and can provide valuable near-surface boundary conditions for airborne
campaigns designed to estimate regional or basin-wide CO2 fluxes.
1
Harvard University, 20 Oxford Street, Tel: 617-496-2766,
Fax:
617-495-2768, E-mail:
[email protected] ; 2 Harvard University, E-mail:
[email protected] ; 5 INPE, E-mail:
[email protected] .
113
Measuring carbon balances in the Amazon Basin: I. Woody vegetation dynamics in an
old-growth tropical rainforest
Scott R. Saleska 1
Lucy Hutyra 2
Elizabeth Hammond-Pyle 3
Edna G.T. Guimarães 4
Steven C. Wofsy 5
A major scientific question is the present status of Amazonia as a source or a sink for
atmospheric carbon dioxide. We are using ground-based measurements of woody tree
increment (dendromtery), combined with whole-system CO2 fluxes (eddy covariance), to
elucidate ecological and climatic controls on the interannual carbon balance at na oldgrowth tropical forest (Tapajos National Forest, km 67, Santarem).
Here, in part I of a two-part presentation (see also Daube, et al.), we characterize woody
vegetation structure, and present results of the first few months of wood growth
measurements. We inventoried a total of 945 large (DBH * 35 cm) trees on four 5-ha plots
(number density: 47 large trees/ha), and sub-sampled 1643 small trees (10cm < DBH
<35cm) on these same plots (number density: 413 small trees/ha). Most trees were
provisionally identified to species: 217 species were distributed over 47 families. A
stratified weighted random subsample of 1000 trees were selected for intensive study via
dendrometry. Preliminary results indicate both high growth rates and high damage and
mortality (~3% per year) among subclasses of trees.
1
Harvard University, 20 Oxford Street, Cambridge, MA 02138, USA, Tel: 617-495-9624, Fax: 617-4952768, E-mail: [email protected], ; 2 Harvard University, E-mail: [email protected] ; 3 Harvard
University, E-mail: [email protected] ; 4 Fundação Floresta Tropical; 5 Harvard University, E-mail:
[email protected] .
114
Comparison of the specific leaf area of 32 woody species in three Cerrado savanna
plant communities in Brasilia
Carlos A. Klink 1
Dulce A. da Silva 2
In order to predict the behavior of species, communities and whole ecosystems to changes
in land use and climate, ecologists are seeking simple ways to describe key plant traits.
Specific leaf area (SLA, leaf area per unit dry mass) is easy to measure and is an indicator
of the capacity of plants to exploit resources in the environment. Our objective in this study
was to compare the SLA of 32 woody species in three Cerrado savanna plant communities
in the Reserva Ecologica do IBGE, Brasilia, Federal District, that differ from each other in
woody plant density: a grassland with scattered shrub and trees; a Cerrado savanna; and a
savanna woodland. Leaf area was measured with an electronic leaf area meter in the field
and leaves were oven dried and weighed in the laboratory. SLA ranged from a maximum of
375.8 for the shrub Vellozia flavicans to a minimum of 1.8 for the tree Pali (P<0.001). No
significant difference was found between the Cerrado savanna and the grassland but the
average SLA of the savanna woodland was significantly higher (P<0.001).
1
Dept. of Ecology, University of Brasilia (UnB), C.P. 04631, UnB, Brasilia DF 70919-970, Tel:
61-3072182, Fax:
61-273-4571, E-mail:
[email protected]; 2 Dept. of Ecology, UnB, E-mail:
[email protected] .
115
CO2 flux between soil and atmosphere in forests and pastures of Western Amazonia
Cleber Ibraim Salimon 1
Antonio Willian Flores de Mello 2
Eric A. Davidson 3
Irving Foster Brown 4
Reynaldo Luis Victoria 5
Conversion of forest to cattle pastures and subsequent abandonment of those pastures are
occurring throughout the Amazon Basin, including regions with eutrophic (nutrient rich)
and dystrophic (nutrient poor) soils. The objectives of this project are to determine the
effects of land-use change and native soil fertility on soil respiration in pastures, secondary
forests, and primary forests near Rio Branco, Acre.
We are also investigating the relationship between CO2 flux and soil carbon stocks and
whether CO2 flux can be used as an indicator of the degree of ecosystem degradation. CO2
flux measurements are made in the field with an infrared gas analyzer on a monthly basis in
sixteen sites.
Preliminary data analyses from June/99 to Aug/99 shows that the greatest CO2 fluxes are
observed in pastures (193 mgC m-2h-1) and not in primary forests (127 mgC m-2h-1).
Regarding to soil nutritional status, the preliminary results do not yet show a consistent
pattern. For example pastures on eutrophic soils had higher flux in Jul/99 and lower flux in
Aug/99 compared to pastures on dystrophic soils. Complementary analysis of microbial
biomass, aboveground plant biomass, and root biomass and soil carbon stocks in the three
types of land cover and two types of soils are planned.
1
Centro de Energia Nuclear na Agricultura/USP, Av. Centenário, 303 Cx.Postal 96, Piracicaba,SP,
13400-970 Brasil, Tel: (0--19)429-770, Fax: (0--19)4294610, E-mail: [email protected];
2
Universidade Federal do Acre, E-amil: [email protected] ; 3 Woods Hole Research Center, E-mail:
[email protected] ; 4 Woods hole Research Center, E-mail: [email protected] ; 5 CENA/USP, E-mail:
[email protected] .
116
Enhancing The Simplified Biosphere Model (SSiB) And A Test With Amazonian Field
Measurements
Xiwu Zhan 1
Yongkang Xue 2
George J. Collatz 3
Terrestrial ecosystems is recognized as one of the most important parts of the global
carbon cycle and the climate system, and accurate assessments of the CO2 fluxes between
the terrestrial ecosystems and the atmospphere are pressingly needed. The current version
of the Simplified biosphere model (SSIB) does not consider the photosynthetic activities of
CO2 assimilation of plants and thus is unable to model the CO2 fluxes. The work to be
presented here is to enhance the SSiB model with the capability of modeling CO2 fluxes.
The equations and parameters of the photosynthesis-stomatal conductance coupled models
by Collatz et al. for C3 or C4 plants are adopted for simulating the uptake or release of
CO2 by land surface ecosystems. These models have sound physiological basis and fine
description to the interactive effects of environmental factors of plant photosynthesis and
stomatal movement. In the current literature, however, the equations of these models were
solved numerically with iterations, which consumes a great amount of computational time.
In some cases, the iteration process may not be convergent and an appropriate solution
may be difficult to obtain. In this study, a new procedure is developed to quasi-analytically
solve the equations of these models. When na appropriate solution of these models does
not exist under some night time environmental conditions, the procedure applies simpler
empirical equations from literature to simulate the processes because the land surface
fluxes in these cases are not significant. Off-line testing of the enhanced SSIB model for
modeling the land surface fluxes of CO2 , water vapor and sensible heat is conducted
against the field measurements from an Amazonian Eddy Covariance Study in 1995 and
1996. The results of the test will be presented.
1
University of Maryland, 2181 LeFrak Hall, Department of Geography, College Park, MD 20742, Tel: 301405-7168, Fax: 603-806-8375, E-mail: [email protected] ; 2 University of California Los Angeles, E3
mail: [email protected] ;
Laboratory for Terrestrial Physics, NASA/GSFC, E-mail:
[email protected].
117
Carbon Stocks in Agroforestry Systems
Karen A McCaffery 1
Erick C M Fernandes 2
In the past three decades an estimated 25-40 Mha of forest have been cleared in the
Amazon basin (Serrao et al., 1995) and approximately 70% of this land has been converted
to pasture. Under current land-management practices, some 60% of new pastures degrade
to woody secondary forest within fifteen years of establishment and the remaining 40% to
unproductive grassland (Fearnside 1995). There are na estimated 20-35 million hectares of
abandoned pastures in the Amazon, with low rates of regeneration and carbon sequestration
and low biodiversity. While many studies have investigated the effects of deforestation and
land conversion on carbon and nutrients (Fernandes et al. 1997; Cerri et al. 1991; Kang and
Juo 1986), few studies have measured carbon sequestration in recovering agroecosystems
(De Camargo et al. 1999). In 1992 a series of four prototype agroforestry systems we
underway to quantify carbon and nutrient stocks in these agroforestry systems compared to
unmanaged naturally regenerating secondary forest. Biomass is being estimated through a
destructive harvest and the development of species-specific allometric equations. This
study is generating information on the contribution of managed agroecosystems to carbon
sequestration, nutrient levels and distribution. Agroforestry systems merit attention because
they represent (1) an ecosystem management approach that can increase carbon and
nutrient sequestration and; (2) an economically viable farming approach that can enhance
the productive potential of cleared, degraded land and may reduce the need to clear
additional forest.
1
Cornell University/Embrapa, CD Bougainville, Bloco Sandalo, Apto. 505, Rua Rei Arthur, PQ Dez,
Manaus, AM, Brasil, Tel: 92-55-236-0042 (Manaus), E-mail: [email protected]; 2 Cornell University, Email: [email protected] .
118
Modelling Rainforest Carbon and Water Dynamics in the Colombian Amazon
Lina María Mercado Montoya 1
Sharon A.Cowling 2
Conrado Tobón Marín 3
Germán Poveda 4
Tropical rainforests play a crucial role in regulating global climate processes, with tropical
deforestation potentially having severe adverse effects on both regional and global climate
conditions and on the global carbon budget . The Colombian Amazon is one of the tropical
regions that remains poorly studied in terms of deforestation and its effects on the carbon
and hydrological cycles. The objective of this study was to develop a simplified model that
can simulate basic processes of carbon and water cycling in an undisturbed mature
Colombian rainforest, to compare relative trends in carbon and water dynamics under
different land-use change scenarios. Modeling data show conclusive evidence that
deforestation followed by intensive agriculture (with subsequent pasture development) has
long-term effects on net CO2 emissions to the atmosphere. Alternatively, deforestation
followed by less-intensive agricultural practices such as shifting cultivation (with
subsequent secondary vegetation regrowth) has much shorter and less severe consequences
for net CO2 release to the atmosphere, because of carbon conservation induced by
secondary forest regrowth. Modeling trends, such as presented in this study, can be of
significant use for policy-makers and forest managers in Colombia, because not only does it
help to illustrate some of the general impacts of tropical deforestation and land-use systems
on global CO2 budgets, but it plays an even greater role in highlighting the need for more
detailed and site-specific research addressing carbon and hydrological cycling in the
Colombian Amazon rainforest.
1
Max-Planck Institute fuer Biogeochemie, Postfach 10 01 64, 07701 jena, Tel: 49 3641 643711, E-mail:
[email protected]; 2 Lund University, Department of Plant Ecology, E-mail:
[email protected] ; 3 University of Amsterdam, E-mail: [email protected]; 4
Universidad
Nacional
de
Colombia,
Posgrado
de
Recursos
Hidráulicos,
E-mail:
[email protected] .
119
Forest dynamics and biomass estimation in bamboo-dominated forest in Acre State,
southwestern Amazonia
Marcos Silveira 1
Carlos Augusto Klink 2
Irving Foster Brown 3
José Marcelo Domingues Torezan 4
Arborescent bamboo species (Guadua spp.) dominate much of the canopy of forests in the
state of Acre. These bamboo-dominated forests cover an area of 122.000 km2 of
southwestern Amazonia, including parts of Peru and Bolivia. Our objective in this study is
to understand the dynamics of bamboo-dominated forests and the contribution of bamboo
species to the total forest biomass. We study forest dynamics at three ecological scales:
landscape (edge geometry from Landsat TM images); vegetation structure and tree
diversity (field surveys in Acre), and population dynamics (growth, natality and mortality
of tagget seedlings and culms). The bamboo-dominated forest dynamics are characterized
by flowering, die-back and colonization events. The patches show distinctive features that
permit using time sequence Landsat imagery to follow their evolution, as B. Nelson of
INPA has shown. Surprisingly, tree diversity is among the highest of forests studied in
Amazonia. G. weberbaueri biomass was estimated through regression analyses on the dry
above-ground biomass; this species is among the 7 tree species with the highest biomass.
From a carbon-stock perspective, bamboo contributes only a small proportion of the total
biomass, but in terms of resource partitioning, it is important due to the understory
dominance. The culms of G. weberbaeuri grows rapidly in rainy season, reaching 15 m in
height in few months. Their fast growth, coupled with arborescent habit appears to alter the
development of certain tree species.
1
Universidade de Brasília, Universidade Federal do Acre, Campus Universitário, 70910-900, E-mail:
2
3
[email protected];
Universidade de Brasília, E-mail: [email protected] ;
Woods Hole Research
Center/Universidade Federal do Acre/Universidade Federal Fluminense, E-mail: [email protected]; 4
Universidade Estadual de Londrina, E-mail: [email protected].
120
Spatial and temporal variation in carbon cycling dynamics in central Amazon forests
Jeffrey Q. Chambers 1
Roseana Pereira da Silva 2
Luis Claudio de Oliveira 3
Joaquim dos Santos 4
Niro Higuchi 5
Central Amazon forests that lie off the floodplains of major rivers are often designated as terrafirme. Many of these forests, however, are characterized by small-scale (< 1 km) changes in
elevation, soil type, water balance, and floristic composition that can alter carbon cycling
dynamics. Soil texture, for example, shifts from ~80% clay on plateaus (Oxisols) to ~5% clay in
valleys associated with ubiquitous small streams ("baxio"). The baxio represents about 1/3 of the
forests spatial exent, and the slopes about another 1/3, however, most studies have focused on
plateaus. We are measuring tree growth, soil respiration, and stem wood respiration in two 20 x
2,500 m permanent transect plots (toposequences) ~60 km north of Manaus Brazil that
representatively sample the landscape. We find that the cycling of carbon changes significantly
along this toposequence, and that, in some respects, forests associated with baxio behave more like
floodplain than terra-firme forests. Monthly changes in tree diameter using highly accurate (±0.01
mm) tree dendrometers bands (~400), for example, show a significant seasonal change in carbon
allocation to wood production associated with precipitation variability and topography. In August,
the driest month, forest-wide wood production averaged 5.0 g kg-1 day-1, whereas, in December,
one of the wettest months, average wood production increased to 60.5 g kg-1 day-1. Growth rates
were log-normally distributed, however, a number of trees, at any given time, were not producing
stem wood. In the historically driest month, August, only 54% of trees grew in diameter, whereas
by December (one of the wettest months), 72% of trees were producing wood. This seasonal shift
in carbon allocation varied with topography. Forests in the baxio produced most wood in the late
dry season, when the water table had fallen, and on plateaus the peak in wood production occurred
in the early wet season. When these signals are combined, December (considered both late-dry and
early-wet), is the most productive month because the entire forest experienced a peak in wood
production. This peak dropped by about 50% in January, from 60.5 g kg-1 day-1 to 34.5 g kg-1
day-1, as baxio wood production diminished. These results agree with previous eddy covariance
measurements at a site near our plots that demonstrated a significant decline in forest productivity
as the wet season progressed. With respect to other carbon cycling measures, soil respiration also
demonstrated strong spatial variability in the mid wet season, with the baxio showing extremely
low respiration rates associated with soil moisture saturation. Surprisingly, there was only a weak
correlation between wood production and wood respiration rates, and variability in this carbon
cycling component is still being explored. Overall, we are finding that spatial and temporal
heterogeneity associated with topography influences large-scale carbon cycling patterns in central
Amazon forests, and that these forests are better characterized as islands of terra-firme surrounded
by a dendritic network of seasonally inundated forests.
1
Univeristy of California and Instituto Nacional de Pesquisas da Amazônia INPA/CPST CP 478, Manaus,
Amazonas, Brasil, 69070-110, Tel: 92-642-3990, Fax: 92-642-4078, E-mail: [email protected]; 2 INPA, Email: [email protected]; 3 INPA, E-mail: [email protected]; 4 INPA, E-mail: [email protected]; 5 INPA,
E-mail: [email protected] .
121
Prediction of delta 13 C for Yellow Latosolos of Amazon under primary forest
Everaldo de Carvalho Conceição Telles 1
Plinio Barbosa de Camargo 2
Susan E. Trumbore 3
Luiz Antonio Martinelli 4
Reynaldo Luis Victória 5
Marcelo M. Zacharias 6
This work analyzes the del-13C and the carbon and nitrogen content of soils using multiple
linear regression and non-linear regression. The samples were collected in triplicate in pits
at depths of 0-5, 5-10, 10-20, 20-30, 30-40 and 40-50 cm in two yellow Latosol plateaus
under primary forest near to Manaus (ZF-2). In the first plateau the spacing between pits
was 30 meters, and in the second, three pits were chosen according to morphologic
variation. The elemental and isotopic analyses were accomplished using a massspectrometer (Delta plus-Finnigan Mat), coupled to an elemental analyzer (Carlo Erba
EA1110). The generated models explain the variation of the del-13C accurately to within
about 0,2‰, similar in magnitude to the analytical error. The best model to predict del-13C
based on the two plateaus of Manaus, with the variables C and depth was tested in others
Yellow Latosols with similar vegetation in the Amazon region at Santarem, Altamira, and
Paragominas in Para; Manaus and Humaita in Amazonas; and Pimenta Bueno in Rondonia.
The model predicted soil properties with an error below 1‰. The correlation of the
obtained results and the available data in the literature through modeling are important
because it increases the possibilities of extrapolation of the data obtained in Manaus and
Santarém in relation to the del-13C in the soil associated with mechanisms of physical and
chemical protection of the carbon and the time of cycling in the soil.
1
Av. Centenário 303, 13416-000, SP, Brazil, Tel: 55-19-4294600, Fax: 55-19-4294610, E-mail:
[email protected]; 2 CENA-USP, E-mail: [email protected] ; 3 UC- Irvine, E-mail:
[email protected]; 4 CENA-USP, E-mail: [email protected]; 5 CENA-USP, E-mail: [email protected]; 6
CENA-USP, E-mail:
[email protected]; 7 INPA.
122
Soil CO2 Efflux in Tropical Forest in Central Amazon
Eleneide Doff Sotta 1
Antônio D. Nobre 2
Patrick Meir 3
Yadvinder Malhi 4
This study investigated the spatial and temporal variation of the soil CO2 efflux in a forest
near Manaus, Amazonas, Brazil, as well as its relationship with soil temperature and
rainfall. After normalization of the soil CO2 efflux data for the mean soil temperature (25º
C), we found CO2 the lowest value was 2.18 micromol CO2 m-2s-1 and the highest 10.22
micromol CO2 m-2s-1; the average value was 5.74 micromol CO2 m-2s-1. The diurnal
cycle in efflux was most strongly correlated with soil temperature, which peaked between
13 and 14 hours. The temperature was responsible for nearly 80% of the daily soil CO2
efflux variation when soil water content was not a limiting factor.
Soil CO2 efflux decreased by nearly 1.4 micromol CO2 m-2s-1 during rainfall. Soil CO2
concentration gradient measurements showed that there was a build up in the concentration
of CO2 within the soil after the rainfall, when the soil pores were filled with water, creating
a barrier for the gas exchange between soil and atmosphere. Soil CO2 efflux rate also
decreased when the soil was dry. The soil water proved to be an important controlling
factor to the efflux during rain events and dry season.
1
Rod. do Coqueiro, Conj. Pau D'arco, casa 9, Tel: (091) 235 0068, Fax: (091) 235 0122, E-mail:
[email protected]; 2 INPA; 3 University of Edinburgh; 4 University of Edinburgh.
123
Estimating above ground biomass and carbon in young secondary vegetation in
Eastern Amazonia
J. C. Randolph 1
Eduardo S. Brondizio 2
Emilio F. Moran 3
Using field data collected across 38 secondary succession sites, this poster presents
allometric equations to estimate biomass in areas of young secondary vegetation in eastern
Amazonia. Data derived from destructive measurements of biomass are used in
conjunction to vegetation inventory estimates for the same sites. Laboratory analysis
provides data on wood density and total carbon for sampled individuals. Research sites are
located around the towns of Igarape-Acu and Tome-Acu, Para State. Above ground
biomass direct estimations are compared to allometric equations derived from literature
data. The poster discusses issues of extrapolation and accuracy in above ground biomass
and carbon estimation in Eastern Amazonia.
1
SPEA 441, Bloomington, IN, USA, 47405, Tel: 812-8556181,
Fax: 812-8553000, E-mail:
[email protected]; 2 Indiana University, E-mail: [email protected]; 3 Indiana University, E-mail:
[email protected].
124
Above-ground biomass and leaf area index of pastures in Rondônia, Brazil
Maarten J. Waterloo 1
Pavel Kabat 2
Helber C. Freitas 4
Amaury Carruzo 5
Niek Jan Bink 6
Friso Holwerda 7
Rosivaldo Lelis da Silva 8
Fabrício B. Zanchi 9
Beatriz Machado Gomes 10
The leaf area index of man-made pastures is an important parameter for modelling the
effects of deforestation in the Amazon region on climate change. Yet, little is known about
its spatial and temporal variation. To partly fill this gap in our knowledge on these pasture
ecosystems, aboveground biomass, litter mass, specific leaf area and leaf area index were
measured at two pasture sites in Rondônia, Brazil. At the Rolim de Moura mixed grass
pasture (71% Brachiaria sp., 13% Panicum maximum, 16% other species) measurements
were made during the wet season of 1999. These indicated an above-ground biomass, litter
mass, specific leaf area and leaf area index of 0.317 kg m-2, 0.047 kg m-2, 18 m2 kg-1, and
1.5, respectively. At Fazenda Nossa Senhora Aparecida, near Ouro Pretu, monthly
measurements were made over a year in a rather homogenous (99%), grazed Brachiaria
pasture. Biomass and litter mass averaged 0.317 kg m-2 and 0.272 kg m-2 respectively.
Both biomass and litter mass showed distinct seasonal patterns with biomass being higher
during the wet season and litter mass being higher during the dry season. Monthly values of
the specific leaf area ranged between 14 and 19 m2 kg-1, with somewhat higher values
measured during the dry season. The leaf area index showed a distinct seasonal variation,
ranging from about 1 in the dry season to about 2 in the wet season. Wet season LAI
results, obtained from destructive sampling at Fazenda Nossa Senhora, showed fair
agreement (2.1 versus 2.7) with those obtained using optical techniques.
1
P.O. Box 47, 6700-AA, Wageningen, The Netherlands, Tel: +31 317 474778, Fax: +31 317 424812,
E-mail: [email protected]; 2 Alterra Green World Research, Wageningen, The Netherlands, Email: p.kabat@alterra,wag-ur.nl; 3 USP, E-mail: [email protected]; 4 USP, E-mail:
[email protected]; 5 USP, E-mail: [email protected]; 6 Vrije Universiteit Amsterdam, Email: [email protected]; 7 Vrije Universiteit Amsterdam, E-mail: [email protected]; 8 UNIR,
E-mail: [email protected]; 9 UNIR, E-mail: [email protected], 10 UNIR, E-mail:
[email protected]; 11 CPTEC - INPE, E-mail: [email protected].
125
Increasing Carbon Sequestration on Deforested Land Through the Use of Legume
Trees and Fertilizer Inputs
Karen A McCaffery 1
Erick C M Fernandes 2
The predominant soil constraints in the Amazon are P deficiency, Al toxicity, and low
nutrient reserves (Sanchez 1987). This has significant implications for carbon sequestration
in recovering ecosystems. Oxisols occupy an estimated 220 m ha or 46% of the land base in
the Amazon (Cochrane and Sanchez 1982), and have poor chemical characteristics,
including low levels of base-forming cations and limited nutrient reserves (Cochrane and
Sanchez 1982). On upland soils, Ca and P may be the primary limiting nutrients to plant
productivity (Fernandes et al. 1997). A study is underway to evaluate the potential of P, Ca
and gypsum combined with legume trees for increasing carbon sequestration on deforested,
degraded land. Soil fertility management that encourages deep rooting may lead to C
deposition at deeper horizons where it may be less likely to be lost via oxidation (Lugo and
Brown 1993). Gypsum can promote movement of cations into the subsoil making nutrients
available to developing roots at depth. The study was established on an upland clayey
Oxisol near Manaus, Brazil in March 2000 in a RCBD with six fertilizer treatments (+P;
+Ca; +P and Ca; +Ca and gypsum; +P, Ca and gypsum; and an untreated control) x four
tree species (Gliricidia sepium ‘14/84’; G. sepium ‘vertical’; Inga edulis and Senna
reticulata). This study will assess whether additions of P, Ca combined with gypsum
improve the exploitable rooting volume, NPP, and BNF, and thereby increase contributions
to ecosystem carbon and nutrients.
1
Cornell University/Embrapa, CD Bougainville, Bloco Sândalo, Apto. 505, Rua Rei Arthur, PQ Dez, Manaus,
AM, Brasil, Tel: +31 317 474778, Fax: +31 317 424812, Email: [email protected]; 2 Cornell University,
Email: [email protected]
126
Biomass dynamics in anthropogenic landscapes of the Central Amazon
William F. Laurance 1
Rita C. G. Mesquita 2
We summarize results from a large-scale study of biomass dynamics in fragmented, intact,
and secondary forests in the central Amazon. Repeated censuses of over 64,000 trees (>=10
cm diameter) in permanent forest-mensuration plots reveal a substantial loss of aboveground biomass in fragmented forests, the result of sharply elevated tree mortality near
fragment margins. This loss of tree biomass is not offset by increased growth of lianas and
small trees in fragments. In contrast, intact forests in this region and elsewhere in the
Amazon may be functioning as a globally significant carbon sink, possibly because of
faster plant growth resulting from increasing CO2 fertilization. Secondary forests in this
region rapidly accumulate above-ground biomass, accruing up to 30% (90-110 tons/ha) of
that in primary forests (360+/-50 tons/ha) in the first ten years of growth. However, landuse history and especially repeated burning have dramatic effects on soil seedbanks,
regenerating forests, and rates of carbon sequestration. Some implications of these findings
for Amazon biomass dynamics and conservation will be highlighted.
1
Smithsonian Institution and INPA, C.P. 478, Manaus, AM, 69011-970, Brazil, Email: [email protected],
Tel.: 92 642 1148, Fax: 92 642 2050; 2 Smithsonian Institution and INPA, Email: [email protected]
127
Carbon Dioxide Measurements in the Bolivian Amazonia
René Gutiérrez 1
The environmental CO2 mixing ratio was measured in Cobija, Bolivia (11º3´S, 68º31´W)
during one year. The location is a small town surrounded by humid tropical forest ans is
typical of the Bolivian Amazonia. The air samples were taken near one meter below the
canopy height, and this is reflected in the large variations inside the daily cycle values: a
difference which usually is gretar than 100 ppmv between maxima and minima. The mean
value for the steady period in the afternoon hours is 406 ppm. The fires incremented this
value in 28 ppm during the 1999 "burning season". Also, some special events are reported,
whith short-duration peaks of extremely high values. Most of these events had been
identified with large forest firesand strong winds.
1
Laboratorio de Física de la Atmósfera, Instituto de Investigaciones Físicas, Universidad Mayor de San
Andrés, La Paz, BOLIVIA. Postal Address: P.O. Box 3164, La Paz, Bolivia, Tel - fax: (591 - 2) – 799155,
E-mail: [email protected].
128
Mudanças globais e taxa de crescimento das espécies arbóreas da Amazônia
Simone Aparecida Vieira 1
Plínio B. de Camargo 2
Susan Trumbore 3
Irving F. Brown 4
Elsa R. H. Mendoza 5
Diogo Selhorst 6
Jeffrey Chambers 7
Para compreender o papel da região Amazônica no balanço global de carbono e em
particular o potencial das florestas primárias de atuarem como provedor (“source”) ou
sorvedor (“sink”) de carbono devido à mudanças climáticas, é essencial que se conheça a
dinâmica de importantes reservatórios de carbono que operam em escalas de tempo maiores
que as anuais, em especial os processos de crescimento e mortalidade das árvores.
A determinação da idade das árvores da floresta tropical úmida pode fornecer informações
cruciais para o entendimento da dinâmica das populações arbóreas e das taxas de ciclagem
de carbono assim como estimar o tempo médio de permanência do carbono na vegetação.
Os objetivos deste trabalho são: (1) determinar as taxas médias anuais de crescimento das
árvores, (2) o crescimento diamétrico médio dos últimos 30 anos, (3) a distribuição etária
(4) o estoque e o tempo de permanência do carbono na vegetação e como estes parâmetros
variam em decorrência do gradiente climático existente na Amazônia utilizando-se análise
do 14C da celulose do tronco das árvores.
Serão feitos estudos dendrométricos, dendrocronológicos e isotópicos. Os resultados da
atividade isotópica obtida nos anéis de crescimento das árvores serão utilizados no ajuste de
uma curva de calibração de atividade do 14 C.
As amostras serão coletadas em plots implantados próximos a Manaus, Santarém e Rio
Branco.
1
CENA/USP, Av. Centenário 303, 13416-000, Piracicaba, SP, Telefone: 19-4294788. Fax: 19-4294610, Email: [email protected]; 2 CENA/USP, E-mail: [email protected]; 3 UCI-Dept Earth System Science,
E-mail: [email protected]; 4 UFAC, E-mail: [email protected]; 5 UFAC:
E-mail:
[email protected]; 6 Harvard:
[email protected], [email protected]; 7 INPA, E-mail:
[email protected]; 8 INPE, E-mail: [email protected].
129
Photosynthetic gas exchange among ecosystem compartments
in forest and pasture ecosystems
Tomas Domingues 1
Jean Ometto 2
Luiz Martinelli 3
Larry Flanagan 4
Jim Ehleringer 5
The biosphere exerts a strong influence on the atmosphere via gas exchange processes, such
as photosynthesis. The objective of this study is to collect photosynthetic response curves
of dominant life forms in both forest and pasture ecosystems at Santarém and Manaus. Data
collected with a LiCor 6400 are providing an integrated picture of photosynthetic gas
exchange and will be of considerable use in interpreting ecosystem gas exchange
measurements and isotopic data collected by other projects. Measurements are being made
at regular intervals so that phenological dynamics in the structural and physiological
properties of the canopy can be assessed. In particular, measurements are being made
during both the rainy and the dry season to better understand and represent in models the
effects of moisture stress on canopy processes. Over a 2-year period, the photosynthetic gas
exchange measurements that will characterize plant responses during wet and dry seasons
are, photosynthetic dependence on light (30 °C, 70 % r.h., 360 ppm CO2 ), internal CO2 (30
°C, 70 % r.h., 1800 µmol m -2 s-1 PFD), and humidity (30 °C, 360 ppm CO2 , 1800 µmol m -2
s-1 PFD). Response curves are being measured from trees (up, mid, and lower canopy) and
lianas (upper canopy) within reach of towers in the forest ecosystems and from grasses and
shrubs at pasture ecosystems. Measurements taken from different heights will relate
photosynthetic response curves to CO2 , humidity, and light with foliar nitrogen and water
potential for both wet and dry seasons.
1
University of Utah, E-mail: [email protected];
University of Utah.
2
CENA/USP;
3
Lethbridge University;
4
130
Stable Isotope Analyses of Air, Water, and Organic Materials
in Forest and Pasture Sites
Jean Ometto 1
Larry Flanagan 2
Luiz Martinelli 3
Tomas Domingues 4
Jim Ehleringer 5
The concentrations and isotopes ratio of CO2 atmospheric in plant canopies have been
measured to characterize isotope fluxes in forest and pasture sites in Manaus (ZF2 Tower
and Fz. Esteio), Santarem (Flona Tapajos wooden tower and Km 77 pasture flux tower) and
Rondonia (Rebio Jaru flux tower and Fz. Nossa Senhora) during the past year. In addition,
we have measured (a) the oxygen isotope ratios of leaf water, stem water, and water vapor
to help interpret the oxygen isotopes of carbon dioxide, and (b) carbon and nitrogen isotope
ratios in leaves and soils within these ecosystems to help interpret the carbon isotopes of
carbon dioxide. The results encompass four field campaign on March, May and October,
1999 and February 2000, for Manaus and Santarem, and from May 1999 and February
2000 for Rondonia. The carbon isotope ratios of atmospheric CO2 at the forest sites ranged
from -16.73 to -7.47 ‰, with most of the differences accounted for by canopy height.
Oxygen isotope ratios of carbon dioxide exhibited a similar variance, but the highest values
were observed at the top of the canopy. At pastures the carbon isotope ratios of
atmospheric CO2 were more enriched than at forest sites. Data are presented for oxygen
isotope ratios of various water sources as a mechanism for interpreting variation in the
oxygen isotopes of carbon dioxide. Carbon and nitrogen isotope ratios have been analyzed
on the dominant plants in forest and pasture systems in all 3 regions. In Manaus, the
average carbon isotope values were - 32.41 ‰, -12.60 ‰, and -30.34 ‰ for forest trees,
pasture grasses and pasture shrubs, respectively. In Santarem the average carbon isotope
values were -33.58 ‰, -12.80 ‰, and -30.35 ‰ for forest trees, pasture grasses and pasture
shrubs, respectively.
1
CENA-USP; 2 University of Utah, Lethbridge University;
Utah; 5 University of Utah.
3
CENA-USP;
4
CENA-USP, University of
131
Light and water capture by vegetation communities on abandoned degraded pastures
in the Manaus region
Steven A. Welch 1
Susan J. Riha 2
John M. Duxbury 3
Marco A. Rondon 4
Erick C.M. Fernandes 5
Abandoned, degraded pastures, when compared to mature forest or healthy pastures, are
believed to have less photosynthetic canopy and roots. Reduced ability to capture light and
water resources decreases plant productivity, thereby impeding forest recovery or
development of other desirable plant communities. Also, fewer leaves and roots could
affect critical interactions between the biosphere and atmosphere, such as
evapotransporation, light absorption and albedo. If occurring on a large scale, the sensible
and latent heat balance could be affected. Monitoring the capture of light and water
resources offers a means to evaluate the recuperation of abandoned, degraded pastureland
while generating information essential to evaluate impacts of land use change in Amazonia.
This research proposes to use repeated measurements of leaf area indices (LAI) and soil
water stocks as indices of resource capture in areas of different land use. Resource capture
dynamics are being monitored in primary forest, pastures, and secondary forests of various
ages (4, 8 and 12 years). Agroforestry management areas are also being monitored. Soil
water stocks are being monitored weekly at 0-3 m depth using a neutron probe and at 0-2 m
using a TDR probe. LAI is being measured using hemispheric images on a bimonthly
basis. Results from this work are expected to offer insight about development of resource
capture systems by recovering vegetation, and how human intervention might accelerate
that development.
1
2
Cornell/Embrapa-CPAA, Manaus, E-mail: [email protected];
Cornell University, E-mail:
3
[email protected];
Cornell University, E-mail: [email protected]; 4 EMBRAPA-CPAA, E-mail:
[email protected]; 5 Cornell University, E-mail: [email protected].
132
Modeling Seasonal and Interannual Variability in Terrestrial Ecosystem Hydrologic
Fluxes for the Brazilian Amazon Region
Christopher Potter 1
Alicia Torregrosa 2
Steven Klooster 3
Joseph Coughlan 4
Vanessa Brooks Genovese 5
Jennifer Dungan 6
Matthew Bobo 7
Previous field site measurements have implied that regional hydrology and productivity in
the Amazon basin has varied significantly during the past decades of El Nino events in both
managed agricultural and natural forest areas. We investigated this hypothesis using a
regional ecosystem model for coupled water and biogeochemical cycling. Seasonal and
interannual controls on evapotranspiration and net ecosystem production (NEP) were
studied with integration of multi-year satellite data to characterize Amazon land surface
properties over time. Background analysis of temporal and spatial relationships between
regional rainfall patterns and satellite observations for vegetation land cover reveals several
notable patterns in the model driver data. Autocorrelation analysis for monthly vegetation
"greenness" index (NDVI) from the Advanced Very High Resolution Radiometer
(AVHRR) and monthly rainfall (both at 8-km resolution) indicates a significant lag time
correlation of up to 12 months. At lag times of 24 and 36 months, autocorrelation values
did not exceed the 95 percent confidence interval at locations west of about 47 deg. W,
which is near the transition zone of seasonal tropical forest and other (non-forest)
vegetation types. At lag times of 12 months or less, the location near Manaus (ca. 60 deg.
W) represents the farthest western point in the Amazon region were seasonality of rainfall
accounts significantly for monthly variations in forest phenology, as observed using NDVI.
Ecosystem model results using this newly generated combination of regional forcing data
from satellites suggest that (1) evapotranspiration fluxes from deeply rooted Amazon
forests are driven primarily by seasonal and interannual variability in surface radiation
fluxes, and (2) Amazon primary forests can be relatively strong net sinks for atmospheric
carbon dioxide, particularly during wet (non El Nino) years. However, drought effects
during El Nino years can reduce net primary production in forests of the eastern Amazon
by 10-20 percent, compared to long-term average estimates of regional productivity.
1
NASA Ames Research Center, Ecosystem Science and Technology Branch, Moffett Field, CA 94035; 2
Earth System Science and Policy, California State University, Monterey Bay, Seaside, CA 93955; 3 CA SU;
4
NASA Ames; 5 Johnson Controls World Services, NASA; 6 CA SU; 7 Johnson Controls World Services,
NASA.
133
Fluxes of CO2 , water and energy over several savannas
John Grace 1
Savanna-type vegetation is the most abundant land surface, constituting almost 17 % of the
terrestrial cover. We report new data on the biophysical characteristics of savanna
vegetation in Venezuela and Brazil, from the project SAVAFLUX. Data from eddy
covariance sensors, investigating intact and disturbed ecosystems, reveal seasonal and
geographical variation. We show the effect of burning campo sujo. Comparison will be
made with other forms of tropical vegetation including tropical forests and pastures.
1
University of Edinburgh, United Kingdom, E-mail: [email protected]

Carbon Storage Abstracts - MASTER

Transcrição

Documentos relacionados

Results - soil compaction Con

occurrence of eej irregularities under disturbed - DGE

The potential importance of road deaths as a cause of mortality for

The Brazilian Forest Service and Brazilian Forests

Case study: Energy efficiency combined with

Manaus Rainforest in the LBA: Physical, Ecological and Land Use

CelCulture

FINE ROOT ISOTROPY IN EUCALYPTUS GRANDIS

75ms - CloudConf

Storyboarding INGLES ON LINE:Layout 1.qxd