碳、氮、钾添加对荒漠草原凋落物分解特征的影响  

The effects of carbon,nitrogen,and potassium addition on the decomposition characteristics of litter in desert grasslands

作　　者：骆欣怡 邱开阳[1,2,3,4] 金涛 鲍平安 黄业芸 何毅 谢应忠 LUO Xin-yi;QIU Kai-yang;JIN Tao;BAO Ping-an;HUANG Ye-yun;HE Yi;XIE Ying-zhong(College of Forestry and Grassland,Ningxia University,Yinchuan 750021,China;Ningxia Grassland and Animal Husbandry Engineering Technology Research Center,Yinchuan 750021,China;Key Laboratory of Innovation in Efficient Grass Production Models of the Ministry of Agriculture and Rural Affairs,Yinchuan 750021,China;Ningxia Field Scientific Observation and Research Station on Desert Grassland in the North of Yanchi,Yinchuan 750021,China;Ningxia Helan Mountains National Nature Reserve Administration,Yinchuan 750021,China)

机构地区：[1]宁夏大学林业与草业学院,宁夏银川750021 [2]宁夏草牧业工程技术研究中心,宁夏银川750021 [3]农业农村部饲草高效生产模式创新重点实验室,宁夏银川750021 [4]盐池北部荒漠草原宁夏野外科学观测研究站,宁夏银川750021 [5]宁夏贺兰山国家级自然保护区管理局,宁夏银川750021

出　　处：《草业学报》2025年第2期41-53,共13页Acta Prataculturae Sinica

基　　金：中国科学院“西部之光”人才培养计划项目;中国人力资源和社会保障部高层次留学人才回国资助项目(人社厅函[2019]160号)资助。

摘　　要：凋落物分解是草地生态系统能量流动和物质循环的重要过程,而荒漠草原凋落物分解如何响应碳(C)、氮(N)、钾(K)添加尚不清楚,揭示这一关系对深入理解荒漠草原养分循环过程具有重要意义。本研究选用网袋分解法,进行随机区组设计,在试验样地分别设置C_(1)(0 g·m^(-2)·a^(-1))、C_(2)(52.54 g·m^(-2)·a^(-1))、C_(3)(705.09 g·m^(-2)·a^(-1));N_(1)(0 g·m^(-2)·a^(-1))、N_(2)(5 g·m^(-2)·a^(-1))、N_(3)(20 g·m^(-2)·a^(-1));K_(1)(0 g·m^(-2)·a^(-1))、K_(2)(9.0 g·m^(-2)·a^(-1))、K_(3)(18.0 g·m^(-2)·a^(-1))3个C、N、K浓度梯度,研究外源C、N、K添加对宁夏荒漠草原优势种短花针茅和赖草凋落物分解特征的影响。结果表明:(1)C、N、K添加对荒漠草原两个物种凋落物分解的影响具有显著差异(P<0.05),短花针茅和赖草凋落物分解速率进程不同,分别在分解至120和240 d时,分解速率开始减缓;(2)不同物种对C、N、K养分添加的响应不同。K_(3)、K_(3)+N_(3)+C_(2)处理下赖草凋落物分解速率较快,但CK、K_(2)+N_(2)处理下短花针茅凋落物分解速率较快。依据指数衰减模型预测分解速率结果为:赖草>短花针茅;(3)短花针茅和赖草凋落物均在秋季分解较快。综上,同一生境不同物种凋落物分解速率存在差异,高添加量的K、N和低添加量的C相较于其他养分添加梯度,对凋落物分解速率的促进作用更明显。Decomposition of litter is an important component process of energy flow and material cycling in grassland ecosystems.However it is not clear how litter decomposition in desert grasslands responds to the addition of carbon(C),nitrogen(N),and potassium(K).Clarification of this relationship is needed to improve our understanding of the nutrient cycling process in desert grasslands.In this study,the mesh bag decomposition method was used in a randomized block design,to study the effects of exogenous C,N,and K addition on the litter decomposition characteristics of the dominant species Stipa breviflora and Leymus secalinus in Ningxia desert grassland.Litter decomposition was tested in soils fertilized with one of three rates of C(vermicompost,30%C),N(urea,46%N)or K(KCl,60%K)as follows:C_(1)(0 g·m^(-2)·yr^(-1)),C_(2)(52.54 g·m^(-2)·yr^(-1))and C_(3)(705.09 g·m^(-2)·yr^(-1))set at the experimental site;along with nutrient addition treatments.N_(1)(0 g·m^(-2)·yr^(-1)),N_(2)(5 g·m^(-2)·yr^(-1))and N_(3)(20 g·m^(-2)·yr^(-1)),three C,N,and K concentration gradients,K_(1)(0 g·m^(-2)·yr^(-1)),K_(2)(9.0 g·m^(-2)·yr^(-1))and K_(3)(18.0 g·m^(-2)·yr^(-1)).It was found that significant differences in the effects of C,N,and K addition on litter decomposition and different decomposition rates of litter from S.breviflora and L.secalinus(P<0.05).Half-lives for L.secalinus decay ranged from 4.93 to 17.54 months and for S.breviflora from 10.76 to 20.51 months.The decomposition rates of litter from S.breviflora and L.secalinus began to slow down at 120 and 240 days,respectively.Leaves of the two grass species displayed different responses to the addition of C,N,and K nutrients.Under the K_(3) and K_(3)+N_(3)+C_(2) treatments,the decomposition rate of L.secalinus litter was faster,while under the CK and K_(2)+N_(2) treatments,the decomposition rate of S.breviflora litter was faster.According to the exponential decay model,the predicted decomposition rate for L.secalinus litter is greater than for S.breviflora litter.The

关 键 词：荒漠草原 凋落物 分解特征 养分添加 

分 类 号：G63[文化科学—教育学]