Long-term forest damage due to an extreme weather event: An ice storm mediated by elevation causes tree breakage in sub-tropical China

Abstract

Extreme weather events pose an ever-greater threat to people, infrastructure, and nature. Forest ecosystems are highly sensitive to extreme cold events that can disrupt ecosystem functions, especially in montane regions. Ice storms can be particularly destructive, with rapid ice accretion causing tree branches to break, even snapping or uprooting entire trees. In March 2022, the Shennongjia forest in central China experienced severe ice storm conditions that severely damaged over 230,300 ​ha. We utilized this opportunity to assess the vulnerability of different tree types (coniferous, deciduous, and evergreen broad-leaved) and stand compositions to damage resulting from ice glaze along an elevation gradient from 1,200 to 2,400 ​m a.s.l. Among the 7,144 trees surveyed, 10.1% suffered some extent of damage, which was most prolific in the middle elevation zone. While 96.8% of all damage occurred to deciduous broadleaved trees that dominated the forest community, the most severe damage (uprooting and lower trunk breakage) occurred to coniferous trees. The extent and severity of tree damage were moderated by forest composition, with secondary effects of forest structure and slope. Abiotic factors predominantly affected coniferous trees. We emphasize that more research and monitoring are needed to better understand the full impact of extreme weather events on forests, especially as the frequency and intensity of these events increases due to climate change.