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Effects of landscape connectivity on ecosystem adaptation to climate

change in Central America

Bruno Locatelli, CIRAD-CIFOR, Indonesia

Pablo Imbach, CATIE, Costa Rica

EuropeAid/ENV/2004-81719

Seminar series on climate change and forest management, BC Ministry of Forests and Range Future Forest Ecosystem Initiative.November 6, 2008. Teleconference between Canada and Costa Rica

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Climate change and ecosystem migration

• CC modifies location of suitable environments for plants (Hannah et al., 2002)

• Future distribution of ecosystems depends on the ability of plants to migrate (Pitelka et al., 1997; Kirilenko et al., 2000)

– High migration rates (>1000 m/yr) required to adapt to CC (Malcolm et al., 2002)

• Many studies on CC and ecosystems consider unlimited dispersal or no dispersal (Pearson, 2006)

• Uncertainties on migration rates of trees:– During post-glacial warming

• 100’s to 1000’s m/yr(Pearson 2006, Malcolm et al., 2002),

• less than 100 m/yr (McLachlan et al., 2005)

– Models of current migration• Around 100 m/yr (Dyer, 1995)

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Biological corridors and protected areas

• Landscape alteration may reducemigration capacity (Pitelka, 1997)

– Altering dispersal rate– Reducing suitable habitat for successful colonization

• Corridors can enhance landscape connectivity between valuable vegetation areas (e.g. protected areas)

• Their role in migration under CC depends on spatial patterns

• Latitudinal and altitudinal gradients– Is it so simple?

ProtectedArea

Corridor

Direction of species movement due to CC

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Can corridors facilitate ecosystem migration between protected areas in a context of CC?

Case of the Mesoamerican Biological Corridorin Costa Rica

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Costa RicaPanama

NicaraguaHonduras

El SalvadorGuatemala

BelizeMexico

Study site

• Costa Rica– Biological richness & conservation policies– “Increasing isolation of protected areas may

prevent them from functioning as an effective network” (Sánchez-Azofeifa et al., 2003)

(CCAD-UNDP/GEF, 2002)

Protected Areas

Biological Corridors

• The Mesoamerican Biological Corridor (MBC)

– Regional initiative – Conceptualized and agreedupon in 1997– Under progressive implementation

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Protected Areas

Mesoamerican corridor

Pacific Ocean

Caribbean Sea

Nicaragua

Panama

Costa Rica

N

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Approach and model assumptions (1/2)

• Simple representation of vegetation– Model ≠ evolution of vegetation

– Model = landscape connectivity

– Vegetation types =Holdridge life zones

– Each vegetation type is composed of 5 groups of species with different migration rates

• From slow (100 m/yr) to fast-moving (2000 m/yr)

Holdridge

• Cellular Automata

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Model assumptions (2/2)

• Migration is possible through contiguous pixels with vegetation

• 4 scenarios– No migration– Migration

• With vegetation only in protected areas

• With vegetation in protected areas and corridors

• With vegetation everywhere (“Eden”)

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Algorithm

Controller Pixel px Species spft,lz

Estimate 1990 Life Zone (lz1990)

Create baseline presence:presence(px,spft,lz1990)=1

Initialize

RunEstimate Current

Life Zone (lzcurrent ) sp adapted to lzcurrent? No: presence:=presence/2

Yes: sp already present in px?Yes: presence:=presence*2

(with upper bounddue to carrying capacity)

No: sp in neighbourhood? (radius=migration(ft))

Yes: presence:=0.25No: presence:=0

Updateindicators

Next decade

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Data• Scales

– Spatial = 2.5 arc min (around 4.6 km x 4.6 km)

– Temporal = Decades, from 1990 to 2050

Nicaragua

Costa Rica

PanamaPacific Ocean

Caribbean Sea

Nicaragua

Costa Rica

Panama

Pacific Ocean

Caribbean Sea

Protected AreasBiological Corridors

• Climate and altitude– WorldClim dataset (Hijmans et al., 2005):

• Altitude, Monthly Precipitation and Temperature

– Current and future • IPCC scenario A2• HadCM3 climate model

• Protected Areas and Biological Corridors– CCAD map, 2001

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Results and discussion

Life zonemovement

86°W 81.5°W

12°N

8°N

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High impacts

Low impacts

Pacific Ocean

Caribbean Sea

Nicaragua

Panama

N

Protected areas most sensitive to CC(no migration scenario)

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Protected areas under different migration scenarios

1990 2000 2010 2020 2030 2040 20500.5

0.6

0.7

0.8

0.9

1

Years

Ve

ge

tatio

n In

de

x (R

ela

tive

to E

de

n S

cen

ario

) Evolution of Vegetation in Protected Areas

Protected areas and corridorsProtected areas onlyNo migration

Effect of corridors

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Which protected areas benefit morefrom corridors?

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Which corridors contribute moreto the adaptation of protected areas?

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How to explain these results?

Direction of Life Zone Movement

Corridors and Areas not evaluated

Important corridors

(connecting isolated and vulnerable areas, in a

good direction)

Missing corridors?

Already connected protected areas

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Conclusion• Sensitivity of protected areas to CC

– Especially isolated areas and in mountain and dry zones

• Role of corridors for reducing vulnerability

• Useful tool for:– Identifying vulnerable protected areas– Prioritizing corridors in a context of CC

• Further steps:– Consider actual vegetation outside protected

areas and corridors– Use different climate scenarios– Use different representations of ecosystem

dynamics and migration– Perform sensitivity analysis

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Thank you!