毛乌素沙地黑沙蒿与赖草凋落物混合分解对增温的短期响应  

Short⁃term response of the decomposition of mixed leaf litter of Leymus secalinus and Artemisia ordosica to warming in the Mu Us Desert

作　　者：罗凯 高圣杰[1,2] 郝少荣 梁琨 查天山 贾昕[1,2] LUO Kai;GAO Shengjie;HAO Shaorong;LIANG Kun;ZHA Tianshan;JIA Xin(Yanchi Researcher Station,College of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;National Key Laboratory for Efficient Production of Forest Resources,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,宁夏盐池毛乌素沙地生态系统国家定位观测研究站,北京100083 [2]北京林业大学林木资源高效生产全国重点实验室,北京100083

出　　处：《生态学报》2024年第16期7301-7312,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金(32071843,32071842);中央高校基本科研业务费专项资金(PTYX202324,PTYX202325)。

摘　　要：植物凋落物分解过程受环境和生物因素共同调控,而气候变暖如何改变凋落物分解的物种混合效应仍存较大不确定性。采用开顶式增温箱和分解袋相结合的方法,研究增温对毛乌素沙地黑沙蒿、赖草以及两者的混合凋落物分解前150d质量损失和养分释放的影响。结果表明:增温导致赖草凋落物质量、C、N、P、纤维素和木质素残留率分别下降7%,7.6%、12%、8.8%、20%和10%,黑沙蒿凋落物质量、P和木质素残留率分别上升2.2%、2.2%和0.8%,C、N和纤维素残留率分别下降1.1%、2%和2.5%。与单独分解相比,混合凋落物质量、C、P、纤维素和木质素残留率分别上升7.7%、8.2%、4.1%、3.9%和5.9%,N元素残留率下降4.1%,增温导致混合凋落物质量、C、N、P、纤维素和木质素残留率分别上升16.9%、18.8%、11.4%、18.5%、21.5%和21.1%。黑沙蒿和赖草凋落物混合在前期分解过程中产生了拮抗效应,即相比于单种凋落物分解具有更低的质量损失;此外,增温处理下拮抗效应更强。本研究表明,在气候变化和植被恢复背景下,预测毛乌素沙地灌丛生态系统的生物地球化学循环时,应该考虑气候变暖和物种混合的交互因子对凋落物分解的影响。The decomposition of plant litter is jointly regulated by environmental and biological factors.However,considerable uncertainty remains on how climate change may modify the effects of species mixing on litter decomposition.Using open⁃top chambers to create conditions of higher temperatures and litter bags to investigate decomposition processes,we examined the effects of warming on mass loss and nutrient dynamics of the leaf litter of Artemisia ordosica,Leymus secalinus,and their 1:1 mixtures(on a mass basis)in first 150 days of decomposition in the Mu Us Desert.Warming resulted in 7%,7.6%,12%,8.8%,20%and 10%decreases in the residual rate of litter mass,C,N,P,cellulose and lignin,respectively,for L.secalinus.In contrast,warming led to 2.2%,2.2%and 0.8%increase in the residual rate of litter mass,P and lignin,respectively,and 1.1%,2%and 2.5%decreases in the residual rate of C,N and cellulose,respectively,for A.ordosica.Compared to separate decomposition,the residual rate of mixed litter mass,C,P,cellulose and lignin increased by 7.7%,8.2%,4.1%,3.9%and 5.9%,respectively;while the residual rate of N by 4.1%.Warming resulted in 16.9%,18.8%,11.4%,18.5%,21.5%and 21.1%increases in the residual rate of mixed litter mass,C,N,P,cellulose and lignin,respectively.Therefore,antagonistic litter⁃mixing effects occurred during the early stage of decomposition,resulting in lower mass loss than that under separate decomposition.Furthermore,antagonistic litter⁃mixing effects were enhanced under warming conditions.Our findings suggest that the interactive effects of warming and species mixing on litter decomposition should be considered in predicting the biogeochemical cycling in shrubland⁃steppe ecosystems of the Mu Us Desert under the background of ongoing climate change and vegetation restoration.

关 键 词：凋落物分解 混合 拮抗 增温 养分释放 

分 类 号：Q948[生物学—植物学]