Memory effects of vegetation after extreme weather events under various geological conditions in a typical karst watershed in southwestern China

Extreme weather events have destructive impacts on ecosystems and are expected to increase. Understanding how forest ecosystems respond to climate extremes has attracted much attention in recent decades. However, the mechanisms of climate extreme under various geological conditions are still unclear and difficult to quantify. Here, we selected four extreme weather events, namely, compound dry–hot extremes, compound wet–hot extremes, compound dry–cold extremes, and extreme precipitation, to explore the memory effects of vegetation after these extremes occurred. We combined satellite observations and climate data to quantify the resistance, tolerance and resilience of vegetation using lag response time, memory strength and memory length, respectively. Our results showed that among these events, compound dry–hot extremes were the most crucial climate stressors in the Red River Basin due to longer memory length and higher memory strength. There is a trade-off between resistance (lag response time), tolerance (memory strength) and resilience (memory length). Compared with grassland, arbor and shrub forests exhibit a higher resistance and tolerance to drought and a relatively lower resilience. The tolerance to extreme precipitation of grassland surpasses that of forest, while the resistance is inferior. The vegetation in the carbonate distribution area has higher tolerance and resilience and a weaker resistance than that in the non-carbonate area. Compound hot events may accentuate the severity of the influence exerted by both extreme drought and extraordinary precipitation on vegetation. These results highlight the unique extreme weather responses of karst vegetation and supplement the theory of vegetation extreme weather response strategies.