Asynchrony within trophic levels maintains community stability over millennial-scale climate changes in a high-altitude lake

This study provides new insights into how climate change affects long-term ecosystem stability in high-altitude lakes, which are particularly vulnerable due to their simplified food webs and heightened environmental sensitivity. Despite their ecological importance, the long-term mechanisms through which multitrophic interactions govern ecosystem stability in these fragile systems remain poorly understood. In this study, we reconstruct over 1200 years of community succession in Lake Ngoring on the Qinghai–Tibet Plateau using sedimentary eDNA to elucidate these dynamics. Multivariate analyses revealed temperature as the dominant driver of community turnover (Mantel r = 0.58, P < 0.001), with warm periods fostering enhanced mutualistic networks between algae and decomposers. Network topology metrics demonstrated that while warming reduced overall cross-trophic interaction strength, it maintained robust cooperative linkages within trophic levels. Structural equation modeling further showed that climate-mediated species interactions significantly influenced ecosystem stability (path coefficient = 0.35), with intratrophic asynchrony emerging as a critical stabilizing mechanism (path coefficient = 0.20) that buffers climate impacts. Our findings provide novel insights into the resilience of high-altitude lake ecosystems, emphasizing the fundamental role of within-trophic-level dynamics in maintaining long-term ecological stability under climate change.