Integrating habitat availability into restoration efforts for biodiversity conservation: Evaluating effectiveness and setting priorities

Numerous restoration programs have been launched worldwide in recent years, but the effectiveness of such programs for biodiversity conservation remains unclear. Additionally, priority areas of restoration need to be identified in a region where resources are limited. Habitat availability combines habitat amounts with interpatch connectivity, governing whether a landscape can shelter biological populations in the long term. Consequently, restoration efforts should focus on enhancing habitat availability to promote biological flows. In this study, we proposed a multi-scale approach to evaluate the effectiveness of restoration program and to set priority areas for forest restoration. The evaluations of effectiveness highlighted the contributions of forest cover change to habitat availability. The restoration priorities of landscapes were ranked by three indicators which are also tightly associated with habitat availability: relative urgency of intervention, efficiency of restoration, and connectivity importance for broader-scale biotic flows. We applied the approach in the Eastern Himalaya region of China, a global biodiversity conservation hotspot. Forest cover has been increasing by 3.4% in this region since 2000 due to the implementation of the Grain-for-Green Program, but not all the new forest areas were available as species habitat and/or stepping stones. By the method we developed, 14% of the areas are ranked as the high restoration priorities aiming to enhance available habitat for multiple species with different dispersal abilities. Our approach can significantly improve the outcome of a restoration program. It is flexible and can aid policy makers in optimizing restoration efforts given the biodiversity conservation goals and available resources.