Variation of forest ecosystems with elevation: insights from a 3500 m elevation gradient in

the Andes

The Andes Biodiversity and Ecosystems Research Group (ABERG)

Y. Malhi, M. Silman, P. Meir, K. Feeley, N. Salinas, S. Saatchi, M. BirdL. Aragao, C. Girardin, J. Fisher, T. Marthews, D. Metcalfe, J. Espejo, W. Farfan, K. Garcia, A. Nottingham, J. Whittaker, M. Zimmerman, K. Feeley, J. Rapp. J.

Lloyd, R. Guerreri, O. Atkin and many more

University of Oxford UK,Wake Forest University USA, University of Edinburgh UK,Univesidad San Antonio Abad ,Cuzco, Peru Pontoficia Universidad de Lima, PeruJet Propulsion Laboratory, NASA

Yadvinder.malhi@ouce.ox.ac.ukwww.yadvindermalhi.org

Talk structure

Study regionPlant diversity and distributionsEcosystem productivityHeterotrophic processesPlant distribution changeTree line studies

Kosñipata Valley and adjoining Amazon lowlandsAndes Biodiversity and Ecosystem Research Group:

www.aberg.org

3450m 3250m3000m

2750m

2500m

2000m 2250m1750m

1500m

1250m

1000m

200m

8.5oC 9.2oC10.5oC

11.9oC

13.3oC

15.3oC 14.8oC16.7oC

19oC

21oC

22.1oC

26.4oC

Malhi, Y. et al (2010) Elevation gradients in the tropics: laboratories for ecosystem ecology and global change research, Global Change Biology, 16, 12, 3171-3175

Malhi, Y. et al (2010) Elevation gradients in the tropics: laboratories for ecosystem ecology and global change research, Global Change Biology, 16, 12, 3171-3175

Talk structure

Study regionPlant diversity and distributionsEcosystem productivityHeterotrophic processesPlant distribution changeTree line studies

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Elevation (m)

Pre

cipit

atio

n (m

m y

r-1)

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Mea

n A

nnual

Tem

per

ature

(deg

C)

Precipitation (mm yr-1)

Mean Annual Temperature(deg C)

>60 ha

1 ha plotsTrees 10cm dbh

Temperature and rainfall gradients

Tree Species Diversity

Lowland levels of diversity maintained to ~1700 m **

Most species have narrow elevation ranges

Tree species ranking

Elev

ation

(m)

Talk structure

Study regionPlant diversity and distributionsEcosystem productivityHeterotrophic processesPlant distribution changeTree line studies

Measuring Tropical Forest Carbon Allocation and Cycling: A RAINFOR-GEM Field Manual for Intensive Census Plots (v2.2). Manual, Global Ecosystems Monitoring network,

gem.tropicalforests.ox.ac.uk

GPP= 36.15±3.97 The carbon cycle of a forest at Tambopata. Peru

R leaf =8.86±2.78

R stem = 5.85±2.50

NPPTotal = 15.14±0.83

NPPAG = 9.96±0.41

NPPBG = 5.18±0.72

D fine litterfall

5.61±0.32

D CWD 3.59±0.26

R rhizosphere

5.07±0.86

R soil =12.98±0.82

D root

5.18±0.72

R soilhet = 7.14±0.49

NPP coarse roots = 0.51±0.05

NPP fine roots = 4.67±0.72

NPP ACW= 2.64±0.24

NPP litterfall = 5.61±0.32

NPP branch turnover = 0.95±0.10

NPP herbivory = 0.76±0.05

R cwd

R coarseroot

1.23±0.62

Malhi et al, Plant Ecology and Diversity, 2014

GPP and NPP decline with elevationbut the transition is abrupt at around 16-1700 m asl

(dry season cloud base)

Canopy photosynthetic capacity and leaf area index donot show a strong decline or abrupt transition with

elevationMax photosynthesis

under high light Leaf Area Index

Once cloud immersion is factored out, autotrophic processes may have little dependenceon mean temperature

Talk structure

Study regionPlant diversity and distributionsEcosystem productivityHeterotrophic processesPlant distribution changeTree line studies

8.5oC 9.2oC10.5oC

11.9oC

13.3oC

15.3oC 14.8oC16.7oC

Exploring heterotrophic processes

19oC

21oC

22.1oC

26.4oC

Translocation of root-free soilZimmermann et al. (2010)

Large-scale leaf and wood translocation experiment

Salinas et al. (2011) New Phytologist

10 12 14 16 18 20 22 24 260

0.5

1

1.5

2

2.5

Annual mean soil temp. (°C)

k (x

10-

3 d-

1)

Leaf litter4725 litter bagsQ10 = 3.06±0.28(r2 = 0.97, p = 0.002)

Salinas et al.,New Phytologist, 2011

Fine wood litter1575 litter bagsQ10 = 4.0±0.56(r2 = 0.95, p = 0.004)

Salinas et al.In review.

Translocation experiments along the elevation gradient

The sensitivity of heterotrophic decomposition is so high becausesoil microbial and macrofaunal communities completely change atwarmer temperatures

Microbial biomass increases with elevation

Increased dominance of fungi relative to bacteria at high elevation

Termites are only abundant in the lowlands

Whittaker et al. (2014) Journal of Ecology

Palin et al. (2011) Biotropica

Palin et al. (2001) Biotropica

Implications under warming

Autotrophic processes may be very insensitive to temperature (within the range observed) because of acclimation and community turnover

Heterotrophic processes may be very sensitive to temperature because of community turnover

Hence warming would be expected to increase loss of carbon from soil more than it increases gain of carbon in tree biomass

Talk structure

Study regionPlant diversity and distributionsEcosystem productivityHeterotrophic processesPlant distribution changeTree line studies

Niches from collection data

The mean plant community in most plots has been increasing over last 10 years by 2.0m yr-1 (+0.5 – +3.5m yr-1).

PLOT

MIG

RA

TIO

N R

AT

E (

m y

r-1)

Feeley et al. 2011 JBioGeo

-2

0

2

4

6

8

10

+2.0m yr-1 (+0.5 – +3.5m yr-1). +2.0m yr-1 (+0.6 – +3.6m yr-1)

Feeley, et al. 2013, Global Change Biology

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MIG

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m y

r-1)

Perú: Costa Rica:

Required migration rate for climate equilibrium

Talk structure

Study regionPlant diversity and distributionsEcosystem productivityHeterotrophic processesPlant distribution changeTree line studies

So tree species are shifting upslope.Is the forest biome also shifting?

1963

2005

1963

2005

1963

2005

1963 US Air Force Recon aerial photography

IKONOSsatellite imagery

Results: Andean timberline migration

• Across study area, ~80% of timberline did not change

• Upslope migration more likely in protected areas

• Upslope migration rates decreased with increasing elevation

• Overall migration rates far slower than required to maintain equilibrium with climate change

StatusAnnualized migration rate (m y-1)

Years to 2100 climate equilibrium (+5⁰C)

Timberline Timberline

Protected 0.24 3,750Unprotected 0.05 18,000

The Grass Ceiling?

Ecotone migration rates are 12 to 110 times slower than the observed species migration rates in our valley

Protected areas help, but management may be needed interventions are needed to assist migration

Large changes in composition with elevation

0 200 400 600 800 1000 1200 1400 1600 1800 20000

100

200

300

400

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600

188.37962188.99268168.76875

225.52113

167.84694

453.13455

92.96796

0

209.59856183.77533

551.02478

413.05328

188.90228188.59557

191.03906194.22687184.69325

192.62175209.4856207.71837

189.28239

DCA Axis 1

DCA

Axi

s 2

Composition and Elevation(1 ha plots)

DCA

Axi

s 1

Elevation (m)

0 500 1000 1500 2000 2500 3000 3500 4000-800

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