基于MaxEnt模型的青藏高原草原毛虫虫害发生趋势预测

Predicting the risk of grassland caterpillar infestation based on MaxEnt model in Qinghai-Tibet Plateau

摘要:

【目的】草原毛虫是青藏高原主要害虫之一，受到气候变化的强烈影响。预测未来气候变化影响下的草原毛虫虫害发生情况，有利于制定合理的草原管理政策。【方法】基于从公开文献获取的 24 个草原毛虫虫害发生位点 ，利用 MaxEnt 模型和 GIS 软件模拟了两种社会共享经济路径（Shared Socio-economic Pathways，SSPs）下当前（2021-2040 年）和未来（2081-2100 年）草原毛虫虫害的潜在发生区。【结果】1）在两种 SSPs 下主导当前和未来草原毛虫虫害发生的环境因子均为年降水量和坡度；2）在两种 SSPs 下，未来草原毛虫虫害发生的最适宜年降水量较当前有所升高，最适宜坡度较当前降低；3）在两种 SSPs 下，未来草原毛虫虫害发生中高风险区面积较当前有所降低；4）未来草原毛虫虫害发生中高风险区海拔范围在 SSP126 下下移，其海拔分布上限和下限在 SSP585 下分别下移和上移。 【结论】气候变化将不利于草原毛虫虫害的发生。未来制约草原毛虫虫害发生的主要环境因子是年降水量。现有的基于野外控制试验的草原毛虫研究不足以模拟气候变化情境下的情况，未来草原毛虫相关研究需着重关注降水的变化。

Abstract:

【Objective】 Grassland caterpillars are significant pests on Qingha‐Tibet Plateau，impacting the functioning of alpine grassland ecosystems. Recent control experiments suggest that warming and nitrogen deposition may facilitate caterpillar growth and population expansion，potentially intensify grassland caterpillar infestation due to climate change. However，conflicting findings exist regarding the effects of nitrogen deposition on caterpillar feeding behavior. Consequently，understanding how grassland caterpillars respond to climate change remains incomplete. 【Method】 To predict future grassland caterpillar infestation under climate change，we utilized 24 occurrence sites obtained from the public literature. Employing MaxEnt model and GIS software，we analyzed current （2021-2040） and future （2081-2100） potential occurrence zones under two Shared Socioeconomic Pathways （SSPs）. 【Result】1） Annual precipitation and slope emerged as dominant environmental factors influencing current and future caterpillar occurrence under both SSPs；2） Optimal future precipitation level for caterpillar occurrence were higher than the current level，with lower optimal slopeconditions；3） The future mediumhigh risk area for caterpillar occurrence in grasslands decreased under both SSPs；4） Altitude ranges of future mediumhigh risk areas shifted downward under SSP126 and showed mixed upward and downward shift under SSP585.【Conclusion】 Climate change is projected to reduce grassland caterpillar infestations，with annual precipitation being a key factor. However，existing field controlled experiments may not fully capture caterpillars responses to climate change，emphasizing the need for future research focusing on precipitation dynamics.