Scientists find tree diversity enhances forest resilience in face of storm

European forests with a greater diversity of tree species have been found to be more resilient to storms, according to a recent study published in the British Ecological Society journal, Functional Ecology. The research, conducted by scientists at the French National Research Institute for Agriculture, Food and Environment (INRAE), sheds light on the importance of tree diversity in protecting forests and the ecosystem services they provide.

The study used simulations to model how forests with different characteristics resist and recover from storm damage. The researchers discovered that forests with a higher diversity of tree species, particularly those dominated by slow-growing species with high wood density like oaks, demonstrated greater resilience to storms. This positive effect was especially pronounced in extreme climatic conditions, such as the hot-dry Mediterranean region and the cold-wet northern Scandinavia.

Europe has experienced a rise in the frequency and severity of windstorms in recent decades, posing a significant threat to forests and their vital ecosystem services, including habitat preservation, carbon storage, and timber production. The findings of this study can aid in predicting the impact of escalating storm frequency and intensity on forests and provide insights into how forest management practices can be adjusted to enhance their resilience.

Dr. Julien Barrere, the lead author of the study and a researcher at INRAE, emphasised the importance of promoting diversity and slow-growing tree species like oak in forest management. He explained, “An important takeaway from our study is that monocultures of fast-growing species such as pine, although economically valuable, are more susceptible to storm damage. In a context of increasing storm losses across the continent, our study therefore argues for forest management practices that promote diversity and slow-growing tree species such as oak.”

The researchers calibrated their models using data from 91,528 real-life forest plots across Europe, encompassing a wide range of climate conditions and forest compositions. By simulating the dynamics of hundreds of forests after a storm, they were able to quantify the relationship between forest composition and resilience to storm disturbance, while also considering the European climatic gradient.

While the study provides valuable insights, the researchers caution that further field work is needed to support the findings. Dr. Barrere emphasized the importance of combining modeling studies with on-the-ground research, stating, “Although modeling studies like ours are essential for drawing conclusions about forest dynamics due to the long timescales in nature, the results must be interpreted with a clear understanding of the model hypotheses and complemented by field studies.”

This research highlights the critical role that tree diversity plays in protecting European forests from storm damage. As climate change continues to impact weather patterns and increase the frequency and intensity of storms, preserving and promoting diverse tree species becomes increasingly crucial in ensuring the resilience of our forests and the ecosystem services they provide.