Setting the priorities straight - Species distribution models assist to prioritize conservation targets for the mangroves.

Abstract

Mangrove forests provide a wide range of ecosystem services, yet they are declining rapidly due to climate change and human activities. Identification of conservation priority targets across spatial and temporal scales may assist in planning and decision making, especially in areas having rich mangrove diversity but with limited response capacity. In this study, we aimed to identify the species and areas which should be prioritized for conservation in the Indo-West Pacific (IWP) region, one of the two global hotspots of mangroves. We used an ensemble species distribution modelling framework to map the potential distribution of ten species, including true mangroves and mangrove associates, in current, past, and future environmental conditions. The priority targets were then identified through a weighted-scoring approach with the current distribution and the modelled outputs. Our study revealed that precipitation and surface elevation could influence the distribution of the true mangroves, while temperature was the important variable for the mangrove associates. Although suitable habitat for the true mangroves is predicted to increase in future, primarily due to the northward range expansion of six species, areas with high species richness would decrease. We found 7.09% and 4.16% areas of the IWP should be prioritized for conservation of the true mangroves and mangrove associates, respectively. The characteristics of these priority sites indicated that the inclusion of the anthropogenic component in the conservation framework and species-targeted management plans in the protected areas are required for the effective implementation of conservation actions. Five of the studied species, namely Acanthus ilicifolius, Dolichandrone spathacea, Heritiera littoralis, Pemphis acidula and Xylocarpus granatum, were found to have the highest priority score for conservation. The glacial refugia of the species, mostly distributed in Philippines, New Guinea, southern India and Madagascar, should be explored further for species-specific conservation actions.