Biome diversity in South Asia - How can we improve vegetation models to understand global change impact at regional level?

The distribution of biomes in South Asia is expected to be affected severely by climate change. Understanding plant-climate interactions and the impact of climate change, rising CO2, land use change, deforestation and fire on vegetation has become a major challenge for ecologists. Therefore, developing the capacity to project vegetation change is of critical importance if we are to mitigate and efficiently adapt to climate change impacts. The lack of an accurate representation of different vegetation types and ecosystem processes at regional scale is a main source of uncertainty in Dynamic Global Vegetation Models (DGVMs). This manifests in a lack of key growth forms such as bamboo, lianas and mangroves and biome types such as savanna which are essential components of ecosystems in South Asia. Plant communities like mangroves and bamboos, despite covering just small areas, account for high carbon sequestration whereas lianas can decrease carbon sequestration capacity of host trees. Here, we review the current state of vegetation modeling for South Asia and we propose a research agenda for an improved representation of biome diversity in DGVMs. We account for both the traditional plant functional type (PFT) approach and for the functional trait (FT) approach that considers growing knowledge on plant-trait variability and eco-evolutionary principles of different plant communities. We argue that an adequate representation of different vegetation types and growth forms characteristic of South Asian biomes is necessary in DGVMs for robust assessments of climate change impacts on their distribution, diversity and carbon budget. (C) 2019 Elsevier B.V. All rights reserved.