增温对川西北高寒草甸草场植物凋落物分解的影响

doi:10.11686/cyxb2020191

摘要/Abstract

摘要： 凋落物分解是陆地生态系统碳循环的重要环节,温度是凋落物分解的关键影响因子。为探究增温对川西北高寒草甸草场植物凋落物分解的影响,使用开顶式生长箱(OTCs)研究模拟增温对分解袋法处理的凋落物样品的影响,以阐明增温对川西北高寒草甸生态系统中优势物种凋落物:禾本科的披碱草、发草,杂草类的野茴香、鹅绒委陵菜、蒙古蒿、星状雪兔子、长毛凤毛菊等群落混合地上凋落物和群落地下根系凋落物分解的影响。结果表明:1)模拟增温并未显著改变混合地上凋落物的分解周期,但是显著提高了根系凋落物的分解效率,地上、地下凋落物的分解周期对温度变化的响应存在差异。2)尽管不同种类植物凋落物的养分含量与化学计量特征存在显著差异(P<0.05),但与自然分解条件相比,模拟增温条件下单种植物地上凋落物的分解效率并未发生明显改变,模拟增温对单种植物地上凋落物的分解释放过程影响不显著。综上所述,川西北高寒草甸生态系统地上凋落物的分解过程对模拟增温响应不显著,而模拟增温显著影响地下凋落物分解过程。

关键词: 增温, 凋落物, 高寒草甸, 青藏高原

Abstract: Litter decomposition is an important part of the carbon cycle in terrestrial ecosystems, and temperature is a key determining factor of litter decomposition rate. This research explored the effects of warming on the decomposition of plant litter from alpine meadow grasslands in Northwestern Sichuan, using open-top chambers (OTCs) and the decomposition-bag method, to study the effects of warming on the litter decomposition rate of dominant species: Elymus nutans, Deschampsia caespitosa, Foeniculum vulgare, Potentilla anserine, Artemisia mongolica, Saussurea stella, and Saussurea nigrescens. The decomposition bags in this experiment contained mixed aboveground litter and community root litter from the dominant plant species. It was found that: 1) Warming did not significantly change the decomposition cycle of mixed aboveground litter, but significantly improved the decomposition efficiency of root litter. The decomposition-cycle responses of aboveground and underground litter to temperature changesdiffered. 2) Although there were significant differences in nutrient content and stoichiometric characteristics of litter from different plant species (P<0.05), compared with natural decomposition conditions, warming had no significant effect on the decomposition efficiency and the decomposition and release process of litter from individual plant species. In summary, the decomposition process of aboveground litter in the alpine meadow ecosystem in Northwestern Sichuan did not respond significantly to simulated warming, but simulated warming significantly affected the decomposition process of underground litter.

Key words: warming, litter, alpine meadow, Tibetan Plateau

杨阳, 田莉华, 田浩琦, 孙怀恩, 赵景学, 周青平. 增温对川西北高寒草甸草场植物凋落物分解的影响[J]. 草业学报, 2020, 29(10): 35-46.

YANG Yang, TIAN Li-hua, TIAN Hao-qi, SUN Huai-en, ZHAO Jing-xue, ZHOU Qing-ping. Effect of climate warming on decomposition of plant litter in alpine meadow pastures in Northwestern Sichuan[J]. Acta Prataculturae Sinica, 2020, 29(10): 35-46.

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