降水量对4种荒漠草原植物凋落物碳氮磷释放的影响  

Effects of precipitation on the release of carbon,nitrogen,and phosphorus from decomposing litter of four plant species in a desert steppe

作　　者：韩翠 康扬眉 余海龙[5] 李春环 黄菊莹[2,3,4] HAN Cui;KANG Yang-mei;YU Hai-long;LI Chun-huan;HUANG Ju-ying(School of Agriculture,Ningxia University,Yinchuan 750021,China;School of Ecology and Environment,Ningxia University,Yinchuan 750021,China;Breeding Base far State Key Laboratory of Land Degradation and Ecological Restoration in Northwestern China,Yinchuan 750021,China;Key Laboratory far Restoration and Reconstruction of Degraded Ecosystems in Northwestern China of Ministry of Education,Yinchuan 750021,China;School of Geography and Planning,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学农学院,银川750021 [2]宁夏大学生态环境学院,银川750021 [3]西北土地退化与生态恢复国家重点实验室培育基地,银川750021 [4]西北退化生态系统恢复与重建教育部重点实验室,银川750021 [5]宁夏大学地理科学与规划学院,银川750021

出　　处：《生态学杂志》2022年第6期1090-1100,共11页Chinese Journal of Ecology

基　　金：国家自然科学基金(31760144、32160277、41961001);宁夏大学研究生创新项目(GIP2021-17)资助。

摘　　要：探索降水量对荒漠草原植物凋落物分解特征的影响,有助于深入了解全球变化下草原植被-土壤系统生物地球化学循环规律。基于2014年设立于宁夏荒漠草原的降水量变化野外控制试验,通过480 d的分解试验,研究了4种植物凋落物分解特征(C、N、P释放及生态化学计量特征)及其与土壤元素含量的关系。结果表明:480 d的分解过程中,4种植物凋落物C释放缓慢。除猪毛蒿(Artemisia scoparia)外,多数情况下分解360 d后C释放率仍低于50%。4种植物凋落物N和P释放均前期快于后期,大多情况下分解180 d后N和P释放率即可超过50%;与自然降水量相比,减少50%降水量显著降低了猪毛蒿3种元素累积释放量和白草(Pennisetum centrasiaticum)P累积释放量(P<0.05)。增加降水量表现出相反的效应,但增加50%降水量显著降低了猪毛蒿C和N累积释放量(P<0.05);与减少30%降水量相比,减少50%和增加降水量改变了4种植物凋落物C∶N∶P生态化学计量特征,但其影响程度随物种不同而异,且缺乏明显的规律性;猪毛蒿和草木樨状黄芪(Astragalus melilotoides)凋落物P累积释放量均与土壤全P呈显著正相关(P<0.05),意味着二者凋落物P释放有助于促进土壤P库积累。Exploring the impacts of precipitation on litter decomposition of plant species will help to deeply understand the biogeochemical cycle of grassland ecosystems under global changes.We carried out a 480-day decomposition experiment based on a field experiment of precipitation change in a desert steppe of Ningxia conducted in 2014.The element release and ecological stoichiometry of four plant species litters were examined,and their relationships with soil element supply level were analyzed.The results showed that the C release from the litters of the four species was slow.Except Artemisia scoparia,the C release rates even did not reach 50%after 360 days of decomposition in most cases.The release of N and P from litters of the four species was faster in the early stage than that in the late stage.The release rates of N and P exceeded 50%after 180 days of decomposition in most cases.The 50%reduction in precipitation significantly decreased the cumulative release of the three elements in the litters of A.scoparia and the cumulative release of P in the litters of Pennisetum centrasiaticum(P<0.05).The increasing precipitation showed opposite effects,but the 50%increase in precipitation significantly reduced the cumulative release of C and N in the litters of A.scoparia(P<0.05).Compared with the 30%reduction in precipitation,the 50%reduction,30%increase,and 50%increase in precipitation changed litter C∶N∶P ecological stoichiometry of the four species.However,their impacts were species-specific and without clear trends.The cumulative release of P in the litters of A.scoparia and Astragalus melilotoides were significantly positively correlated with soil total P concentration(P<0.05),indicating that the P release from the litters of A.melilotoides and A.scoparia is helpful for soil P accumulation.

关 键 词：降水格局改变 荒漠草原 凋落物分解 凋落物元素释放 土壤元素归还 

分 类 号：S812[农业科学—草业科学]