How To Predict Biodiversity In Malagascar

Transcription

1 BioSceneMada Scénarios de la biodiversité sous l'effet conjoint du changement climatique et de la déforestation à Madagascar

2 BioSceneMada Biodiversity scenarios under the effect of climate change and future deforestation in Madagascar Ghislain Vieilledent 1 Tom Allnutt 2 Clovis Grinand 3 Miguel Pedrono 4 Jean-Roger Rakotoarijaona 5 Dimby Razafimpahanana 2 [1] Cirad BSEF, [2] WCS, [3] ETC Terra, [4] Cirad AGIR, [5] ONE

3 1 Introduction Madagascar biodiversity Objectives 2 Deforestation Maps of past deforestation Deforestation modelling 3 Biodiversity Biodiversity data-set Local endemism 4 Climate-change 5 Pespectives

4 1 Introduction Madagascar biodiversity Objectives 2 Deforestation Maps of past deforestation Deforestation modelling 3 Biodiversity Biodiversity data-set Local endemism 4 Climate-change 5 Pespectives

5 An unparralleled biodiversity Madagascar: top 3 of the countries with mega-diversity Vascular plants: species, endemism=85% Trees: endemism=96% Invertebrates: 5800 species, endemism=86%

6 Introduction Deforestation Concentrated in forests Tropical forests >50% of the terrestrial species Biodiversity Climate-change Pespectives

7 Deforestation and demography 10 to 15% of original forest Deforestation rate: 1% yr : 10% of species committed to extinction Demographic rate: >3% yr 1 Doubling-time: 25 years

8 Predicted climate change Mean temperature increase: +1.1 to +2.7 C Wetter summer (up to +200 mm.yr 1 ) Drier winter in the SE (down to -100 mm.yr 1 ) and wetter winter elsewhere (up to +100 mm.yr 1 )

9 Introduction Deforestation Biodiversity Climate-change Predicted climate change Andriamasimanana 2013, Vieilledent 2013, Raxworthy 2008 Pespectives

10 Objectives Scientific objective Future refuge areas for biodiversity Areas under high risks of deforestation Conservation planning Anticipating climate change and deforestation Adapting the protected area network Biodiversity safeguards for REDD+ projects

11 1 Introduction Madagascar biodiversity Objectives 2 Deforestation Maps of past deforestation Deforestation modelling 3 Biodiversity Biodiversity data-set Local endemism 4 Climate-change 5 Pespectives

12 Maps of past deforestation 1 1. Harper et al. 2007, Environmental Conservation Forest map c with clouds 2 2. Hansen et al. 2013, Science Tree cover map in 2000 without clouds Deforestation map

13 Maps of past deforestation Clouds were remove from 1990 and 2000 Harper s forest map Assuming a tree cover >75% in moist forest for 2000 Hansen s map Deforestation using Hansen s data on the period

14 Maps of past deforestation Results: deforestation maps Without clouds At 30m resolution ForestMaps

15 Maps of past deforestation

16 Deforestation Model: two processes Intensity Mean annual deforestation area (in ha.yr 1 ) for each km grid cell on the period National average: 73,000 ha.yr 1

17 Deforestation Model: two processes Location At the pixel level (30 m resolution). δ: spatial probability of deforestation on δ = f (spatial environmental factors) Environmental factors: landscape (dist. to forest edge, dist. to past deforestation), accessibility (altitude, dist. to road, town, river), land-policy (protected area network). Algorithm used to fit the model: randomforest.

18 Deforestation Forecasts Date Forest area (Mha) Scenario: The most likely outcome given some hypothesis

19 Deforestation Demography Actual population growth rate is 3%.yr 1 Doubling time: 25 years No demographic transition before 2050 More than 50 M people in 2050 compared to 20 M in 2010

20 1 Introduction Madagascar biodiversity Objectives 2 Deforestation Maps of past deforestation Deforestation modelling 3 Biodiversity Biodiversity data-set Local endemism 4 Climate-change 5 Pespectives

21 Biodiversity data-set Group Species Genus Obs. Plants Trees Palms Ferns Legumes Grasses Other Vertebrates Mammals Lemurs Birds Reptiles Amphibians Invertebrates Snails Ants Butterflies Other TOTAL=

22 Comparison with other studies Comparison Allnutt et al. 2008: 2843 Kremen et al. 2008: 2315 (Ants, Butterflies, Frogs, Geckos, Lemurs and Plants) BioSceneMada: 4969

23 Local endemism Contrasting hypothesis explaining local endemism in Madagascar Climate gradient Retreat-dispersion watersheds

24 Local endemism GDM: percentage of deviance explained. Group Clim WS C+WS Full Plants Trees All Animals Lemurs Birds Reptiles and Amphibians Invertebrates All The effect of climate in determining community composition varies depending on the taxonomic group.

25 1 Introduction Madagascar biodiversity Objectives 2 Deforestation Maps of past deforestation Deforestation modelling 3 Biodiversity Biodiversity data-set Local endemism 4 Climate-change 5 Pespectives

26 Climate-change IPCC AR5 climate data for Madagascar: SDM: α diversity Species level: atlas of the biodiversity GDM: β diversity Community level Modelling species turnover Loss of habitat

27 1 Introduction Madagascar biodiversity Objectives 2 Deforestation Maps of past deforestation Deforestation modelling 3 Biodiversity Biodiversity data-set Local endemism 4 Climate-change 5 Pespectives

28 Pespectives Combining projections for deforestation and climate change Hotspots of biodiversity under high threats of deforestation Optimizing the actual protected area network More info and results:

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