Seminar: Chenwei Xiao

Terrestrial ecosystems are vital for human livelihoods and play a crucial role in climate regulation as a significant carbon sink. However, increasing climate extremes, such as droughts, pose a threat to these ecosystems. The resilience and resistance of ecosystems to such climate extremes can be altered by expanding land use and land cover change (LULCC). During my PhD, I investigated the impacts of LULCC on ecosystem resistance to drought and explored LULCC effects on future atmospheric and agricultural drought conditions, using satellite observations, vegetation models, and earth system models.

I found that regions with higher forest fractions demonstrate stronger resistance to extreme droughts compared to croplands, and converting forests to grasslands or croplands results in reduced resistance to droughts. However, vegetation models underperform in simulating the effects of the forest-crop transition. My analysis also indicated that strong deforestation exacerbates future atmospheric and agricultural droughts in the Amazon and Central Africa. The increased vapor pressure deficit is unlikely to be attributed to internal variability, whereas the decreases in soil moisture may be due to internal variability.

The findings underscore the critical role of LULCC, particularly deforestation, in shaping ecosystem resistance to drought and future drought conditions. This research emphasizes the need for an integrated assessment that considers the interactions between ecosystem resilience, LULCC, and climate change in managing terrestrial ecosystems.