According to a new study published in the journal Nature Ecology and Evolution the increase in gymnosperm sensitivity to drought suggests that their increasing intrinsic water use efficiency may not have alleviated the impacts of drought stress. Picture by Shutterstock

The frequency and intensity of droughts have grown over the decades, leading to increased forest decline. The response of forest to drought can be evaluated by its sensitivity to drought (resistance) and the post-drought recovery rate (resilience). However, it remains uncertain how drought resistance and resilience of forests have changed across the space and over time under climate change.

In a new study published in the journal Nature Ecology and Evolution authors assessed the spatio-temporal dynamics of forest resistance and resilience to drought over the past century (1901-2015) with global tree ring data records from 2935 sites and associated plant trait data. Authors point out that this study based on an analysis of long-term tree-ring data is the first one to report a trade-off in their recent trends between gymnosperm resistance and resilience to drought. According to the authors such decrease in drought resistance but increase in their drought resilience may potentially indicate a recent life-history strategy shift of gymnosperms in coping with changing climate and drought stress regimes.

“Surprisingly, we found that the trade-off between resistance and resilience for gymnosperms, previously reported only spatially, also occurred at the temporal scale. In particular, drought resilience significantly increased but resistance decreased for gymnosperms between 1950-1969 and 1990-2009, indicating that previous models simulations may have underestimated the impacts of drought on gymnosperm-dominated forests under future climate change”, said the PhD student  Xiangyi Li from the Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, China.

“We suggest that the altered ecosystem carbon cycle processes should be considered in the next generation of forest simulators to improve their predictive capacity of future ecosystem functioning and terrestrial carbon balance. The priority for further studies is to establish a network for long-term and synchronized observations of plant growth conditions and traits” said Prof. Josep Penuelas from CREAF-CSIC Barcelona.

Reference: Li, X., Piao, S., Wang, K., Wang, X., Wang, T., Ciais, P., Chen, A., Lian, X., Peng, S., Peñuelas, J. 2020. Temporal trade-off between gymnosperm resistance and resilience increases forest sensitivity to extreme drought. Nature Ecology and Evolution.