Analyzing uncertainty and constraining projections for future vegetation in mid-to-high-latitude Asia

Mid-to-high-latitude Asia (MHA) is one of the regions most impacted by global warming and is highly vulnerable to the effects of climate change on its ecosystems. The future vegetation changes in this region are still uncertain, warranting a comprehensive investigation. In this study, the authors conducted a comparative analysis of leaf area index (LAI) projections by models in phases 5 and 6 of the Coupled Model Intercomparison Project (CMIP5 and CMIP6, respectively) under high emission scenarios (RCP8.5 and SSP5–8.5, respectively). It was found that the CMIP6 models offer greater consistency with historical observations and demonstrate reduced prediction uncertainty compared to the CMIP5 models. There are strong linear relationships between the historical and future vegetation characteristics among the CMIP6 models, which enables a constrained projection of future vegetation based on historical vegetation observations. The model projections suggest a prospective overall increase in the mean, interannual variability, and seasonal amplitude of LAI in the MHA region in the future period (2061–2100) in comparison to the historical period (1985–2014). These results underscore the imperative need to enhance the understanding of ecosystem responses to climate extremes in this region.

摘要

亚洲中高纬地区是受全球变暖影响最严重的地区之一, 其生态系统高度受到气候变化的影响. 然而, 该地区未来植被变化仍不确定, 需要进行全面调查. 在这项研究中, 作者比较分析了耦合模式比较计划第五和第六阶段 (CMIP5和CMIP6) 中高排放情景 (分别为RCP8.5和SSP5–8.5) 下的叶面积指数 (LAI) 预测. 分析发现, CMIP6模式的LAI结果与历史观测数据更为一致, 并且相比CMIP5模式表现出更小的预测不确定性. CMIP6模式的历史和未来植被特征之间具有强线性关系, 这使得基于历史植被观测进行未来植被预测成为可能. 预测表明, 未来 (2061–2100年) 与历史时期 (1985–2014年) 相比, 亚洲中高纬度地区LAI的平均值, 年际变率和季节振幅将整体增加. 研究结果强调了提高对该地区生态系统应对气候极端事件的理解的重要性.