Adapting Protected Area Networks to the Impacts of Climate Change: Potential Options for the Sub-Saharan Africa Important Bird Area (IBA) Network

Abstract

Predicted climate change represents a major challenge to conservation over the 21st Century and beyond. Currently, conservation is largely reliant upon static Protected Areas (PAs) to conserve uncommon species. However, evidence from past climate change events suggests that species distributions are dynamic and alter in relation to species’ bioclimate envelopes. Adapting PA networks to cope with projected changes in species distributions is a vital role of conservation biology.

The sub-Saharan Africa Important Bird Area (IBA) network is designed to protect sites containing significant proportions of the populations of congregatory species, species which have restricted ranges or species of global conservation concern found on the continent. Here I explore ways in which the IBA network can be adapted to the impacts of climate change. Data of present species ranges and simulations of future range shifts for 1608 bird species for the time periods 2011-2040, 2041-2070, 2071-2100 were used. Initially, using a reserve selection algorithm (RSA), I created optimal PA networks of one- and quarter-degree cells for present and future time periods. I then created near-optimal reserve networks using IBAs alone, or permitting the selection of additional land-areas. Finally, I incorporated economic opportunity costs of land into the RSAs to assess how to adapt the network to climate change in the most economical way.

The results showed that while some areas of Africa will undergo a large reduction in their importance to a complementarity-based PA network (such as West Africa), other areas will increase in importance (East and Southern Africa). Selected PAs often coincided with areas of currently recognised importance to conservation in both present and future projected scenarios. However, the selection of sites in these areas generally increased over the century. The number of additional sites needed to complement the IBA network and reach conservation targets also increased over time. The areas of increased importance were, on the whole, areas of increased economic opportunity costs to conservation and therefore the acquisition costs of PAs selected in the future may be greater than those selected for the present.