The role of functional diversity in driving global forest functioning

Forest ecosystems are increasingly affected by anthropogenic climate change and human-driven biodiversity loss, with major implications for their functioning and stability. Functional diversity, as a key component of biodiversity, provides a valuable framework for understanding how variation in plant traits influences ecosystem functions and resilience.

To explore these relationships at large scales, Dynamic Global Vegetation Models (DGVMs) can be employed. DGVMs are process-based models that simulate vegetation dynamics and associated carbon and water fluxes in response to changing environmental conditions. Here, we use the model LPJmL-FIT, a DGVM that represents functional diversity through individual trees with varying trait combinations, allowing us to analyses how trait variation influences ecosystem functions under changing climates [1,2,3].

We present a new set of global simulation experiments in which we systematically vary functional diversity to analyse how the relationships between functional diversity and key ecosystem functions (B-EF relationships) develop across landscapes, ecoregions, and biomes. Beyond examining current spatial patterns, we assess how these B-EF relationships may shift under different climate futures. This allows us to identify regions where functional diversity contributes most strongly to carbon and water-related ecosystem functions today, and where these contributions may strengthen or decline as climate changes.

This work highlights the broad scale benefits of forest biodiversity under climate change. It provides new insights into the role of forest functional diversity in maintaining ecosystem functioning and regulating the Earth’s carbon and water cycles.

[1] Sakschewski, B., Von Bloh, W., Boit, A., Poorter, L., Peña-Claros, M., Heinke, J., ... & Thonicke, K. (2016). Resilience of Amazon forests emerges from plant trait diversity. Nature climate change, 6(11), 1032-1036.

[2] Billing, M., Thonicke, K., Sakschewski, B., von Bloh, W., & Walz, A. (2022). Future tree survival in European forests depends on understorey tree diversity. Scientific Reports, 12(1), 20750.

[3] Billing, M., Sakschewski, B., von Bloh, W., Vogel, J., & Thonicke, K. (2024). ‘How to adapt forests?’—Exploring the role of leaf trait diversity for long-term forest biomass under new climate normals. Global Change Biology, 30, e17258. https://doi.org/10.1111/gcb.17258