增温对川西亚高山冷杉林凋落叶分解过程中有机碳含量的短期影响

打开文本图片集

Abstract：Globalwarming profoundlyimpacts thedecompositionof surfaceliterin terrstrial ecosystems.Understanding theresponseofliterdecompositionand itsorganiccarboncomponents inalpine forests to warming isof great significance forcomprehending forestcarbon turnover under climate change.To explore the short-term impactof warming-induced hydrothermal changes onorganic carboncomponentsduring liter decomposition，aone-year in-situ decomposition experiment was cariedoutin a subalpine firforest in western Sichuan.The dynamic changes of leaf liter mass and its organiccarbon components were monitored through continuous sampling using simulated warming in an open-top chamber （OTC）.The results were as follows：（1） Compared with the control，simulated warming significantly increased soil temperature （ +0.55° ），while significantly decreased litter water content by 7.46% ，however，it had no significant effcton soil water content.（2）Simulated warming did not significantlychange the massremaining and the content of majororganiccarbon components （suchas total organic carbon，hot water-soluble organic carbon，and non-structural carbon）of leaf liter.However，the content of dissolved organic carbon（DOC），dissolved sugar，and starch was significantlyaffcted bythe interactionbetwee warming and thesampling period，indicatingthat liter massremaining and the content of most organic carbon components are notsensitive to short-term warming.（3）The partial least squares structural equation model （PLS-SEM）analysis showed that although simulated warming didnot alter the association pathways among soil temperature and watercontent，litter mass，and organic carboncomponents，it significantly strengthened thenegative corelation between litter watercontentand organic carbon components.This suggests that futuretemperature increases in subalpine areas of western Sichuanmayafect the inputoflitter organic carbon into soil as asource of nutrients by altering the moisture status of surface litter.This study emphasizes that future research should focus more onthe impactof warming on liter moisture dynamics andits role incarbon turnover.These findings provide an important basisforadeperunderstanding ofthecarbon cycle in alpineecosystemsandforoptimizing forestresponse prediction models under future global climate change scenarios.

Key words：warming，liter，organic matter decomposition，organic carbon，subalpine forest

凋落物分解是森林生态系统物质循环和能量流动的核心环节。（剩余20061字）