- Scenarios of biodiversity in sub-saharan Africa Research needs and available tools:

Transcription

1 - Scenarios of biodiversity in sub-saharan Africa Research needs and available tools: a case study of surface-water impacts on biodiversity in the context of climate change Simon Chamaillé-Jammes Centre National de la Recherche Scientifique

2 Drivers of biodiversity change Climate drivers Direct anthropic drivers biodiversity (genes to biomes) + spatial organization Species interactions tim e Time

3 An example: expectations for biodiversity under various scenarios of surface-water availability Savanna and Sahelian systems are semi-arid to arid systems Critical importance of surface-water (distribution and dynamics) for animal biodiversity and ecosystem functioning

4 An example: expectations for biodiversity under various scenarios of surface-water availability Savanna and Sahelian systems are semi-arid to arid systems Critical importance of surface-water (distribution and dynamics) for animal biodiversity and ecosystem functioning Africa Southern Africa Strong reliance on non-river sources (ponds...) De Wit & Stankiewicz Science 2006

5 Impact of climatic fluctuations Chamaillé-Jammes et al Austral Ecol data from Hwange National Park (Zimbabwe)

6 A key driver of biodiversity and of human development Permanent water sources are a critical need for human populations (human, livestock and agricultural needs) Potential for conflicts in at wildlife/human interface outside PAs

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8 wilderness Natural ponds, variability Unmanaged protected area, isolated places Hands-on managed protected areas Natural ponds, boreholes & dam, less variable Communal or private; livestock, agriculture few natural ponds, boreholes & dam, little variability An gr thr ad op ien iza tio t n Town

9 wilderness Natural ponds, variability Unmanaged protected area, isolated places St re ng Hands-on th managed protected areas of Natural St ponds, an re & dam, thr boreholes ng op th less variable ic of dr cli ivecommunal or private; ma rlivestock, s te agriculture dr ive ponds, few natural rs boreholes & dam, little variability An gr thr ad op ien iza tio t n Town

10 What information and tools are required? Systematic review of surface-water effect on biodiversity we know well: water needs for some biota, impact on distribution of herbivores affecting habitats and ecosystem functioning Down-scaled climate scenarios Local socio-economic scenarios Identification of the role of biodiversity in driving local- to regional- land use and land management (PAs vs. other land use)

11 What information and tools are required? Systematic review of surface-water effect on biodiversity we know well: water needs for some biota, impact on distribution of herbivores affecting habitats and ecosystem functioning Down-scaled climate scenarios Local socio-economic scenarios Identification of the role of biodiversity in driving local- to regional- land use and land management (PAs vs. other land use) Models of surface-water driven biodiversity changes under contrasted scenarios

12 What information and tools are required? Systematic review of surface-water effect on biodiversity we know well: water needs for some biota, impact on distribution of herbivores affecting habitats and ecosystem functioning Down-scaled climate scenarios Local socio-economic scenarios Identification of the role of biodiversity in driving local- to regional- land use and land management (PAs vs. other land use) le Models of surface-water driven biodiversity changes a sc l under contrasted scenarios a rk o w n U le b a a e e n d s ca e ie d stu b o l tg t s r i sf

13 A current study in Hwange National Park (Zimbabwe), prospective, and challenges ahead

14 seasonal river artificial waterholes

15 Effectif estimé Creation of the park Surface-water definitively contributes to a 30-fold increase in elephant density

16 Homogeneity log(species) We are currently developing an understanding of the biodiversity effects of water provision practice Broken trees (%) Distance to water (m)

17 Emphasis on extreme events even in places with little change in mean climate, droughts may become more frequent / severe Chamaillé-Jammes et al J. Arid Environ. data from Hwange National Park (Zimbabwe) particularly acute problem for drinking water, as animals (and livestock/people) can't go long without water

18 Where is this system going? How to know it, and deal with it? Hotter and drier climate sustainability of the current practice, ability to mitigate changes?

19 Where is this system going? How to know it, and deal with it? Hotter and drier climate sustainability of the current practice, ability to mitigate changes? Hydrological models of water dynamics are easily implemented Tools to design spatially-explicit optimal biodiversity-oriented management strategies may exist

20 Where is this system going? How to know it, and deal with it? Hotter and drier climate sustainability of the current practice, ability to mitigate changes? Hydrological models of water dynamics are easily implemented Tools to design spatially-explicit optimal biodiversity-oriented management strategies may exist But need to include direct constraints tourism, logistics, rising fuel costs... And possibly indirect constraints, particularly those originated from regional dynamics perception, acceptability of the PA by neighboring communities under certain scenarios

21 Where is this system going? How to know it, and deal with it? Hotter and drier climate sustainability of the current practice, ability to mitigate changes? Hydrological models of water dynamics are easily implemented Tools to design spatially-explicit optimal biodiversity-oriented management strategies may exist But need to include direct constraints tourism, logistics, rising fuel costs... And possibly indirect constraints, particularly those originated from regional dynamics perception, acceptability of the PA by neighboring communities under certain scenarios Most of these constraints originates (on the short-term) from local to regional (not global) processes A model-aided co-construction of scenarios is required

22 Way forward Scenarios for global processes (particularly climate) are available Tools to build ecological and social local scenarios are available, and we are able to make people interact within the scenario-building process Need for interdisciplinary studies We need to bring experts together at common sites, systematically review the available knowledge, fully integrate stakeholders in the scenario-building process Build definitive studies that would (1) be credible (i.e. integrated) scenarios, (2) acknowledge uncertainty, (3) provide exemplary case studies

23 Thank you / Merci