Conservation priorities and trade-offs for western Zambia

Co$ting Nature 2.43 was used to examine the overall and top 12% priority areas on the basis of biodiversity, ecosystem services, threat and delphic conservation priority for western Zambia

Baseline ecosystem services
Realised ecosystem services (on a global scale 0-1 globally) in western Zambia including nature based tourism, carbon sequestration and storage , water provision (Relative volume of clean (not human impacted) water available to downstream people and dams) and hazard mitigation (Relative hazard mitigation services for flood/drought, landslide/erosion, inundation/tsunami/cyclone according to relative risk protected against) are highly spatially variable as is the distribution of threatened biodiversity (Relative richness and endemism for redlisted mammals, reptiles, amphibians, birds).  

Current pressure (Current pressure according to population, wildfire frequency, grazing intensity, agricultural intensity, dam density, infrastructure (dams,mines,oil and gas, urban) density) on ecosystems is also highly spatially variable as is future threat (Future threat according to accessibility, proximity to recent deforestation (MODIS), projected change in population and GDP, projected climate change, current distribution of nighttime lights).  

Current conservation prioritisation schemes (Conservation priority by overlap of EBAs (Birdlife), Global200 Ecoregions (WWF), Hotspots (CI), Last of the Wild (WCS,CIESIN), Important Bird Areas (Birdlife) and Key Biodiversity areas (IUCN, BI, PI,CI)show a complex pattern of priorities but the Co$ting Nature Relative aggregate nature conservation priority index (realised services) (Pressured and threatened conservation priority areas with high realised service provisionshows priorities also in other locations.

Deforestation over the last 10 years has occurred over upto 1% of the study area and affected some 660 of the 28660 units (2.3%) of  Relative total realised bundled services index (ie realised services) and some 3200 out of 143200 (2.2%) of potential ecosystem services. 


Trade-offs
The top 12% of areas for the bundle of realised ecosystem services (Total realised services including water, carbon, nature based tourism and hazard mitigation services) is different to the top 12% for biodiversity (Relative richness and endemism for redlisted mammals, reptiles, amphibians, birds), delphic conservation priority (Conservation priority by overlap of EBAs (Birdlife), Global200 Ecoregions (WWF), Hotspots (CI), Last of the Wild (WCS,CIESIN), Important Bird Areas (Birdlife) and Key Biodiversity areas (IUCN, BI, PI,CI)) and on the basis of threat (Future threat according to accessibility, proximity to recent deforestation (MODIS), projected change in population and GDP, projected climate change, current distribution of nighttime lights).

Trade-offs therefore need to be made to protect the most important areas on multiple metrics

Projecting land use change into the future

Recent deforestation rates were projected for a further 100 years (with little attention to forest degradation) and assigned according to proximity to existing deforestation, accessibility and likely future road developments.  Protected areas were considered to be robust and thus no deforestation in wxisting protected areas was permitted.  This results in relatively little deforestation over the period.

The resulting changes in forest cover were used to better understand impacts on biodiversity and  ecosystem services  Bundled ecosystem services decrease in the deforested areas and also affect areas downstream and could lead to losses of 25 million tonnes of carbon storage and 5.8 million tonnes of carbon sequestration per year.  The populations of on average 30 and upto 60  redlisted amphibians, reptiles, mammals and birds  would be affected.

A further scenario was run in which land use change was permitted also inside protected areas.  The resulting level of deforestation is a little higher and occurs also inside certain protected areas and leads to greater changes in the bundle of ecosystem services and in biodiversity, especially in the east