Conservation planning in the Nepal Himalayas: Effectively (re)designing reserves for heterogeneous landscapes

Landscapes consisting of heterogeneous environmental conditions (e.g. elevational gradients) are richer in species diversity than more homogeneous landscapes. Furthermore, the importance of heterogeneous landscapes has been widely acknowledged in biodiversity conservation due to expected elevational shifts in ranges as a result of climate change. This is especially important in mountainous landscapes. There is as yet no protocol that conservation planners can use to integrate landscape heterogeneity in the design of protected area (PAs) systems. In this study, we tested whether Nepal, as a whole, consists of highly heterogeneous landscapes in term of elevation, and whether heterogeneity of PAs is correlated with their size and species diversity. We developed a conservation index of elevational zones within Nepal to evaluate their representativeness in the protected area system. The results showed that, in Nepal's PAs, indices of elevational heterogeneity were strongly associated with species richness. However, heterogeneity indices were not strongly associated with sizes of PAs despite the fact that Nepal is a highly heterogeneous country. The same is true for national parks and conservation areas based on IUCN-The World Conservation Union's categories of PAs. The conservation index of elevation zones suggested a bias in reserve selection towards higher elevations. There is an urgent need to rectify past biases in reserve design so as to ensure protection of elevational heterogeneity during conservation planning, especially in these times of human-induced climate change. [Display omitted] •The heterogeneity index was determined using a Shannon's diversity index of the elevation zones.•Heterogeneity indices and species diversity of reserves were related.•Heterogeneity indices of reserves were not associated with the size of reserves.•Reserves were preferentially established at high elevations (>2700 m).•Future planning of reserves should focus on encompassing large elevational gradients.