荒漠草原不同围封措施下羊草枯落物分解及养分释放特征  

Characteristics of Decomposition and Nutrient Release of Leymus chinensis Litter under Different Enclosure Measures in Desert Steppe

作　　者：邬瑞鑫 蒙仲举 万芳 WU Ruixin;MENG Zhongju;WAN Fang(College of Desert Control Science and Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China;Otog Front Banner Forestry Grassland Ecological Protection Center,Ordos 016299,Inner Mongolia,China)

机构地区：[1]内蒙古农业大学沙漠治理学院,呼和浩特010018 [2]鄂托克前旗林业草原生态保护中心,内蒙古鄂尔多斯016299

出　　处：《林草资源研究》2024年第3期51-59,共9页FOREST AND GRASSLAND RESOURCES RESEARCH

基　　金：内蒙古自治区直属高校基本科研业务费“荒漠生态系统保护与修复创新团队”(BR22-13-03)。

摘　　要：围封是退化草原生态修复行之有效的管理手段,封育后植被群落发生改变,影响了地上生物量及枯落物的产生,研究枯落物分解及养分释放特征可为后续荒漠化草原恢复治理提供科学理论支撑。通过选取季节封育和完全围封荒漠草原,设计羊草枯落物网袋自然分解实验,对两种围封措施下羊草枯落物的分解及养分释放进行研究。结果表明:1)季节封育分解常数(k=0.02587)>完全封育常数(k=0.01832),季节封育措施下的羊草枯落物分解较快,分解速率呈现由慢到快的趋势,分解转折点为180 d;2)羊草枯落物分解过程可以较好地拟合为Olson指数回归模型(R^(2)>0.97),通过模拟得到季节封育和完全封育措施下羊草分解50%分别需要2.23 a和3.15 a,分解95%分别需要9.65 a和13.62 a,季节封育有明显优势;3)季节封育和完全封育两种封育措施的元素释放量表现为有机碳(OC)值最低,分别为44.24%和52.13%,全氮(TN)累积指数分别为71.67%和61.35%,全磷(TP)含量分别为77.41%和57.08%,碳氮比(C/N)变化表现为季节封育<完全封育,氮磷比(N/P)变化则相反。研究表明:在荒漠草原下,季节封育有利于羊草枯落物分解,C、N、P元素的富集与枯落物释放分解密切相关,季节封育的效果明显优于完全封育。Enclosure is an effective management method for ecological restoration of degraded grassland.After enclosure,the vegetation community changes,which affects the above-ground biomass and litter production.Studying the characteristics of litter decomposition and nutrient release can provide scientific theoretical support for the subsequent restoration and management of desertification grassland.The decomposition and nutrient release of Leymus chinensis litter under two enclosure measures were studied by selecting seasonal enclosure and complete enclosure of desert steppe and setting up a natural decomposition experiment of L.chinensis litter bag.The results showed that:1)The decomposition constant of seasonal enclosure(k=0.02587),was greater than that of complete enclosure(k=0.01832).The decomposition of L.chinensis litter under seasonal enclosure measures was faster,and the decomposition rate showed a trend from slow to fast.The turning point of decomposition was the 180 th day.2)The decomposition process of L.chinensis litter can be well fitted to the Olson index regression model(R^(2)>0.97).Through simulation,under seasonal enclosure and complete enclosure measures,50%decomposition of L.chinensis takes 2.23 years and 3.15 years respectively,and 95%decomposition takes 9.65 years and 13.62 years respectively.Seasonal enclosure has obvious advantages.3)The element release of seasonal enclosure and complete enclosure showed the lowest organic carbon(OC)value,which was 44.24%and 52.13%,respectively.The total nitrogen(TN)accumulation index was 71.67%and 61.35%,respectively.The total phosphorus(TP)content was 77.41%and 57.08%,respectively.The change of carbon-nitrogen ratio was less than that of complete enclosure,and the change of nitrogen-phosphorus ratio was the opposite.The results showed that seasonal enclosure was beneficial to the decomposition of L.chinensis litter in desert steppe.The enrichment of C,N and P elements is closely related to the release and decomposition of litter.The effect of seasonal enclosure

关 键 词：封育措施 枯落物 荒漠草原 养分释放 化学计量特征 

分 类 号：S171.1[农业科学—农业基础科学]