Natural Hazards Research (Jun 2022)
ENSO modulates interaction between forest insect and fire disturbances in China
Abstract
Growing evidence shows that global warming has greatly changed the forest disturbance mechanism. The interactions of disturbance factors are also an indispensable part of forest disturbance mechanism. However, the interactions of disturbance factors and their sensitivity to climate change remain largely unknown. In this study, we not only analyzed the sensitivity of forest insect and fire disturbances to climate, but also analyzed the relationship between forest insect and fire disturbances, and the sensitivity of interaction between forest insect and fire disturbances to climate change. In addition, we explored the relationship between forest insect-fire disturbance interactions and El Niño-Southern Oscillation (ENSO). The results suggested that the temperature-related variables (eg. temperature and diurnal temperature range (DTR)) were the most prominent climate driving factors of forest insect and fire disturbances, and both forest insect and fire disturbances have significant relationship with ENSO in spring. The interaction between forest insects and fires is strongly tied to insect history, fire history, plant responses, and climate change. The damage after the fires affects the physiology of trees, reduces the resistance of trees, and makes trees vulnerable to insect invasion. At least 7 years after the fires, vegetation restoration increased the landscape heterogeneity and diversity, thus avoiding the occurrence of forest insects. After the outbreak of insects, the forest fine fuel load decreased and even led to forest death and gap expansion, reducing the occurrence of forest fires. Moreover, the interaction between forest insect-fire disturbances and ENSO in spring was significantly related. Therefore, it is beneficial to prevent forest insect outbreaks and fire by means of fuel removal and planned fire, and the prediction of ENSO events can prevent forest insect and fire disturbances and promote the sustainable development of forest ecosystem.
