Version 2.43 of Co$ting Nature was applied at 1km spatial resolution to examine the baseline ecosystem services and conservation priority for the northern half of Madagascar and especially the Ankeniheny-Zahamena Corridor (CAZ) area and then to examine the impacts of a scenario for continued deforestation on the provision of services and conservation priority.
Baseline services and conservation priority are as follows (all indexed 0-1 globally):
Realised Carbon storage and sequestration services index (Relative carbon sequestration and relative carbon stock (from living plant biomass and soil) services (all potential is realised)) indicates much higher values (upto 42% of the global maximum) to the east.
Realised Water provisioning services index (Relative volume of clean (not human impacted) water available to downstream people and dams) indicates important areas around Antanarivo, propagating significantly downstream into the dry zones of the country. The values remain low on a global scale because of relatively low downstream population densities and concentrations of dams and other uses of produced water.
Realised Hazard mitigation services index (Relative hazard mitigation services for flood/drought, landslide/erosion, inundation/tsunami/cyclone according to relative risk protected against) indicates some significant services consumed in populated coastal areas but also in the dry interior, near populated places and along roads.
Realised Nature based tourism services index (Realised nature-based tourism services measured as relative density of Panoramio photos in non-urban areas) indicates significant service use to the west of Antanarivo and around some of the regions protected areas
Total realised bundled services index (Total realised services including water, carbon, nature based tourism and hazard mitigation services) indicates a dominance of the carbon service (all of the potential of which is realised by the global community of beneficiaries). This service is particularly high in the in the Ankeniheny-Zahamena Corridor (CAZ) area.
Current Pressure index (Current pressure according to population, wildfire frequency, grazing intensity, agricultural intensity, dam density, infrastructure (dams,mines,oil and gas, urban) density) is highest in the centre and west of the country and dominated by the agricultural footprint and grazing. Areas under pressure in the east are usually because of observed deforestation.
Future Threat index (Future threat according to accessibility, proximity to recent deforestation (MODIS), projected change in population and GDP, projected climate change, current distribution of nighttime lights) shows particularly high values in the westdue to the presence of oil and gas concessions (no mining concessions map is available for Madagascar) with some populated areas showing recent forest loss having particularly high values.
Relative biodiversity index of red-list species (mammals, amphibians, reptiles, birds) (Relative richness and endemism for redlisted mammals, reptiles, amphibians, birds) indicates a central core of lower richness in these groups surrounded by a ring of high richness, especially in the CAZ where there are also significant pockets of endemism (though these data will be subject to effects of sampling effort)
The contribution of protected areas, REDD project areas and TG (Transfer de Gestion) areas
Here we examine the distribution of CN indices within the various conservation zones. In each case the index scales 0-1 locally within the tile (Northern Madagascar)
Carbon index (0-1 locally) in TG areas, in REDD areas and in protected areas (the linear features reflect above ground and soil carbon stocks)
Bundled realised ecosystem services index (0-1 locally) in TG areas, in REDD areas and in protected areas (highest where there are many human beneficiaries eg close to lowlands and near road networks)
Current pressure (0-1 locally) in TG areas, in REDD areas and in protected areas (highest near road networks, populated areas, mining sites)
Future threat (0-1 locally) in TG areas, in REDD areas and in protected areas (highest where accessibility is high and near the agricultural and populated nroth-west)
Relative aggregate nature conservation priority index (realised services) (0-1 locally) in TG areas, in REDD areas and in protected areas (refelcting threatened and pressure realised ecosystem service provision)
A higher resolution (1-hectare) analysis for the central CAZ gives more detailed results as follows:
Carbon index (0-1 locally) in REDD areas (higher in the eastern lowlands, linear features reflecting stocks)
Bundled realised ecosystem services index (0-1 locally) in REDD areas (highest near roads, populated areas and in catchments that drain to the populaous and agricultural west)
Current pressure (0-1 locally) in REDD areas (largely concentrated along roads, mining sites and dammed rivers e.g. in south)
Future threat (0-1 locally) in REDD areas (highest closest to the most populous and agricultural areas in the west)
Relative aggregate nature conservation priority index (realised services) (0-1 locally) in REDD areas (most threatened ecosystem service provision in the south west)
The ratio of locally to globally realised services in REDD areas is high (>0.5) where local benefits (water, hazard mitigation, nature based tourism) are greater than global benefits (carbon and biodiversity). For example in the north-west and south-west where water provision are important, along roads and in the isolated forest patches to the east.
Projected tree cover change (deforestation and forest degradation) in the next 50 years without protected area support are shown here
Projected tree cover change (deforestation and forest degradation) in the next 50 years with protected area support for REDD areas are shown here
If we choose the top 12% of areas on the basis of biodiversity, carbon, realised water provision, hazard mitigation, nature based tourism, pressure and threat we get very different distributions of priority areas for protection, though with some overlap. These are, in turn, very different to the top 12% conservation priority of the major conservation NGOs and so some form of trade-off analysis needs to occur
Relative aggregate nature conservation priority index (realised services) (Pressured and threatened conservation priority areas with high realised service provision) with urban areas masked thus indicate the eastern and northern forests (both because of high threat, high carbon and high conservation priority) as very important with the top 10% of conservation priority areas shown here
Relative aggregate development priority index (realised services) (Pressured with low conservation priority and realised service provision) are largely in the dry centre of the country where few of these ES are provided and biodiversity is also relatively low (note that plants are not yet included) and pressure is already high. The top 10% of these areas for development are shown here
The land use change scenario applied assumes recent rates of deforestation and new roads but no deforestation in protected areas is as follows:
...and results in a change in tree cover as shown here indicating much deforestation in the eastern forests but with relatively little loss in the Ankeniheny-Zahamena Corridor (CAZ) because of high levels of protection in that area.
The impacts of the scenario are as follows:
Change in bundled ecosystem services index shows relatively little loss in the Ankeniheny-Zahamena Corridor (CAZ) because of high levels of protection in that area but significant loss elsewhere in the region, largely because of decreases in the carbon storage and sequestration service.
Change in pressure index largely due to the change in population, land use and grazing associated with deforestation
Change in biodiversity index tends to decrase in the deforested areas of the east, especially at higher elevations
Change in Relative total ES and nature conservation priority index (realised services) shows the expected reduction in conservation priority of the deforested areas and a re-location of the top 10% of priority areas