recent change in mature amazonian forests, 1980- 2005. · 1 recent change in mature amazonian...

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Recent Change in Mature Amazonian Forests, 1980-

2005.

Amazon Conference, Oxford, 21st March 2007

Oliver Phillips, University of Leeds

Mount Kinabalu4100 m

2

Fredy Ramirez, Iquitos, Peru

Thanks to these RAINFOR investigators & collaboratorsT. Baker, J. Lloyd, Y. Malhi, J. Peacock, G. Lopez Gonzalez, C. Czimczik2 , L. Arroyo3,4, N.

Higuchi5, T. Killeen3,6, W. F. Laurance7,8, S. L. Lewis1,9, A. Monteagudo10,11, F. Ramirez, D. Neill4, P. Núñez Vargas10, N. Silva12,13, J. Terborgh14, R. Vásquez

Martínez11, M. Alexiades15, S. Almeida16, S. Brown17, J. Chave18, J. A. Comiskey19, A. Di Fiore20, T. Erwin19, E. Jimenez, C. Kuebler6, S. G. Laurance7,8, H. E. M.

Nascimento7,8, J. Olivier18, W. Palacios21, S. Patiño2, 22, N. Pitman15, A. Prieto, C. A. Quesada23,2, M. Saldias3, A. Torres Lezama24, B. Vinceti25, E. Alvarez26, A. Rudas-

Ll27

1. University of Leeds, UK. 2. Max-Planck-Institut für Biogeochemie, Jena, Germany. 3. Museo Noel Kempff Mercado, Santa Cruz, Bolivia. 4. Missouri Botanical Garden, St. Louis MO, USA. 5. Instituto National de Pesquisas Amazônicas, Manaus, Brazil. 6. Center for Applied Biodiversity Science, Conservation International, Washington DC, USA. 7. Smithsonian Tropical Research Institute, Panama. 8. Biological Dynamics of Forest Fragments Program, Manaus, Brazil. 9. School of Geosciences, University of Edinburgh, UK. 10. Herbario Vargas, Universidad Nacional San Antonio Abad del Cusco, Peru. 11. Proyecto Flora del Perú, Jardin Botanico de Missouri, Oxapampa, Perú. 12. CIFOR, Tapajos, Brazil. 13. EMBRAPA Amazonia Oriental, Belém, Brazil. 14. Center for Tropical Conservation, Duke University, Durham NC, USA. 15. New York Botanical Garden, Bronx NY, USA. 16. Museu Paraense Emilio Goeldi, Belem, Brazil. 17. Winrock International, Arlington VA, USA. 18. Laboratoire Evolution et Diversité Biologique, CNRS/UPS Toulouse, France. 19. Smithsonian Institution, Washington DC, USA. 20. Department of Anthropology, New York University NY, USA. 21. Fundacion Jatun Sacha, Quito, Ecuador. 22. Alexander von Humboldt Biological Research Institute, Bogotá, Colombia. 23. Departamento de Ecología, Universidade de Brasilia, Brazil. 24. INDEFOR, Universidad de Los Andes, Mérida, Venezuela. 25. International Plant Genetic Resources Instit te Rome Ital 26 Eq ipo de Gestión Ambiental Intercone ión Eléctrica S A ISA

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Outline


1.RAINFOR objectives and plot methodology

2.On-the-ground evidence for recent changes in Amazon forests

3.Some future prospects

Main objectives of RAINFOR

1. Understand how and why they vary in space

2. Understand how and why they change through time

Use permanent plots to research the biomass, tree dynamics, production, biodiversity of Amazonian forests

to…

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NOEL KEMPFF 2001,6,7TAMBOPATA 2002,3,6

Bogi 2002,7

IQUITOS 2001,5,6MANAUS

2002,5CAXIUANA

2002,4,5,6

BRAGANCA2002

TAPAJOS 2003Jatun Sacha 2002,7

RAINFOR Field Activities 2001-2007, permanent plots

ACRE2003 SINOP 2002

SAN CARLOS2004,6

JARI 2003

MOCAMBO2003

EL DORADO2004

Andes Transect 2003,6

RIO GRANDE2004

AMACAYACU2004,5,6,7

Alta Floresta 2002

Cusco Amazonico2003,6

ZAFIRE2005,6

Mabura Hills2006

Jenaro Herrera 2005,6,7

Dois Irmaos2003,6

Tiputini 2002,7

Sacta 2006BEEM 2006

Porongaba2003,6

Combine the “botanical approach”… (floristic data), with…

Allpahuayo, Peru

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… the “forestry approach”… (biomass and growth), with…

Caxiuana, Brasil

Sucusari, Peru

… the “ecophysiological approach”… standardized dataset of soils and leaves nutrient status

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DRY SEASON

+

-

+

-SOIL FERTILITY

RAINFOR Sampling Strategy

Some Results

Recent changes in the structure and dynamics

of tropical forests

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Rate of change in biomass for 59 plots Mg DW ha-1 a-1

Baker et al. (2004), Phil. Trans Roy. Soc, 359, 353-365.

C source C sinkChanges in the biomass of old growth Amazonian forest plots

1 Pg = 1 billion metric tonnes

0.61 ± 0.21 Mg C ha-1 a-1

Scaled up to basin-level (6 m km2) the biomass sink (0.3-0.6 Pg C a-1),

is equivalent to emissions from Amazonian deforestation (0.2–0.4 Pg C a-1)

So…

• ON AVERAGE, stocks of biomass and stems have increased

• What is the proximal mechanism?

i.e., is it increasing growth or decreasing mortality?

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1

1.5

2

2.5

3

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000

Year

Ann

ual r

ate

of s

tem

mor

talit

y or

recr

uitm

ent,

%Recruitment meanRecruitment mean-CIRecruitment mean+CIMortality meanMortality mean-CIMortality mean+CI

Phillips et al, 2004. Phil. Trans. Roy. Society

Tree recruitment and mortality, South American plots

Changes within 50 Amazon plots with 3 censuses

Stand BA growth

Stand BA mortality

Stem recruitment

Stem mortality

Annu

al ra

te, %

0.0

0.5

1.0

1.5

2.0

2.5 Interval 1 Interval 2

Relative increase ~2 to 4 % a-1

P<0.001 P<0.05 P<0.001 P<0.01

Lewis et al. 2004 Phil Trans Roy. Soc. London

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Stand BA growth

Stand BA mortality

Stem recruitmentStem mortality

Ann

ual r

ate,

%

0.0

0.5

1.0

1.5

2.0

2.5

3.0Interval 1 Interval 2

Stand BA growth

Stand BA mortalityStem recruitment

Stem mortality

Ann

ual r

ate,

%

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Eastern & Central Amazonian Forests (SLOW FORESTS)

Western Amazonian Forests (FAST FORESTS)

Lewis et al. 2004 Phil. Trans. Roy. Soc.

Western Amazonia Central & Eastern Amazonia

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Increase in biomass ca. 1980-2003, apparently at a rate related to soil fertility

00.20.40.60.8

11.21.41.61.8

2

Old ox

isols

Spodo

sol/p

sammen

t

Ultisols

Young

er ox

isols

Crystal

line s

hield

Holoce

ne al

luvium

Older a

lluviu

m

incep

tisols

/andis

ols

Bio

mas

s ca

rbon

incr

emen

t (t

C/h

a/yr

)n = 95

Increasing fertility

unpublished RAINFOR data

Annual relative BA change, %-2 -1 0 1 2 3A

nnua

l rel

ativ

e st

em tu

rnov

er c

hang

e, %

-10

-5

0

5

10

15

20

25

30

30

1

8

11

Concerted changes in forest structure and dynamics

unpublished RAINFOR data

bigger

faster

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Tasa de reemplazo, arboles pantropicales

paleotropicos (azul); neotropicos (rojo). prom edio y intervales de confianza

0.5

1

1.5

2

2.5

3

1950 1960 1970 1980 1990 2000Year

Ann

ual t

ree

turn

over

, %

unpublished data, updated from Phillips and Gentry 1994

So, the dominant mechanism(s) must …

1. Boost growth first, rather than mortality

2. Be very large scale (possibly global, certainly continental)

3. Have greatest absolute impact on fluxes in nutrient-rich, productive forests

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The simplest explanation is that an externaldriver is accelerating forest growth, which in turn is

accelerating tree death.BUT, the difference between the two is rather small

Net C sink

Accelerated treegrowth and recruitment

Acceleratedtree death (lagging growth)

Mortality mean in 2000 = 1.6% a-1

Growth mean in 2000 = 1.9% a-1

Outline


1.RAINFOR objectives and plot methodology

2.On-the-ground evidence for recent changes in Amazon forests

3.Some future prospects

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How vulnerable is the mature forest biomass sink?

1. Drought will affect growth or mortality, possibly both

2. Increases in turnover rates (growth or mortality) will probably impact species composition

Currently, forests appear not to be at equilibrium, and are probably already responding to

atmospheric changes

1. Drought impacts?

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Recensus 60 plots

• Bolivia, Brasil, Colombia, Guyana, Peru, Venezuela• Census interval captures 2005 drought and

immediate post-drought period• Evaluate impacts by comparison with long-term

trends… … analysis just begun

How vulnerable is the mature forest biomass sink? 2005 Amazonian drought

Plots recensused across Amazonia post-2005

drought


Aragao et al. 2007

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1. Plots gained biomass before 2005 (P<0.01)2. During drought period biomass change not different from zero (P=0.85)

Net

chan

ge, m

2 ba

sal a

rea

per

hect

are

per

year

drought period clusternon-drought period cluster

0.2

0.1

0.0

-0.1

-0.2

0

Interval Plot of non-drought period cluster, drought period cluster95% CI for the Mean

Preliminary ResultsHow vulnerable is the mature

forest biomass sink?

2. Increases in turnover could affect species composition

and biomass?

• Faster turnover = more rapid gap formation, conditions favoured for fast-growing, light-wooded species

• Potential for positive feedback on turnover rates• Currently Amazonia is extremely varied: there

are many different ways of being a forest, different functional composition, different biomass….


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Lots of functional diversity is available

in Amazonia!

Baker et al. (2004), Global Change Biology, 10, 545-562.

0

5

10

15

20

25

30

0.15 0.25 0.35 0.45 0.55 0.65 0.75 0.85 0.95 1.05

Midpoint of specific gravity class / g cm-3

% s

tem

s

NW Amazonia

C & E Amazonia

SW Amazonia


2. Increases in turnover could affect species composition…

Stand-level mean wood density as a function of annual stem turnover; 127 lowland plots

across South America

y = 0.7075x-0.1605

R2 = 0.334

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0 1 2 3 4 5 6

Mean of mortality and recruitment, % a-1, census-interval corrected

Stan

d-le

vel w

ood

dens

ity, g

cm

-3


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2. Increases in turnover could affect species composition and therefore biomass

Biomass as a function of annual stem turnover rate; 127 lowland

plots across South America

y = 349.43x-0.1955

R2 = 0.198

100

200

300

400

500

0 1 2 3 4 5 6


Bio

mas

s, M

g ha

-1


Biomass as a function of stem turnover; 229 lowland forest plots

across South America, Africa, Australia

y = 392.58x-0.3231

R2 = 0.356

100

200

300

400

500

600

700

800

0 1 2 3 4 5 6


Bio

mas

s, M

g ha

-1

2. Increases in turnover could affect species composition and therefore biomass across the tropics

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Compositional change already: Large liana density is increasing across Western Amazonia

2

6

10

14

18

1981 1986 1991 1996 2001

Lian

a st

ems

per h

aN.Peru S.Peru Bolivia Ecuadormean+CI mean-CI mean

Phillips et al. 2002

• Amazonia old-growth has provided a biomass C sink of 0.3-0.6 Pg C a-1, for at least two decades

Conclusions. Permanent Plots indicate:

• Wood production and mortality have increased – there appears already to be a signal of atmospheric change

• Anticipated changes in composition put this at risk, even before considering climate change and land-use change

recent change in mature amazonian forests, 1980- 2005. · 1 recent change in mature amazonian...

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