荒漠草原不同自然种群蒙古冰草生物量和养分权衡特征  

Trade-off relationships between biomass and nutrient allocation in different natural populations of Agropyron mongolicum on the desert steppe

作　　者：常怡然 史佳梅 许冬梅[1,2] 康如龙 马媛 CHANG Yi-ran;SHI Jia-mei;XU Dong-mei;KANG Ru-long;MA Yuan(College of Forestry and Prataculture,Ningxia University,Yinchuan 750021,China;Ningxia Grassland and Animal Husbandry Engineering and Technology Research Center,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

出　　处：《草业学报》2024年第11期186-197,共12页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(32060405);宁夏高等学校一流学科建设(草学学科)项目(NXYLXK2017A01)资助。

摘　　要：为了解荒漠草原蒙古冰草是否可以通过调整不同构件生物量及养分分配适应环境的变化,本研究基于宁夏盐池县自南向北气候由半干旱向干旱过渡、地形由黄土丘陵向鄂尔多斯缓坡丘陵过渡的自然特征,考虑到降水和土壤的时空变异,分别选取盐池县大水坑镇、青山乡、花马池镇和高沙窝镇不同自然种群的蒙古冰草为对象(分别以D、Q、H和G种群表示),研究了其个体生物量及养分在根、茎、叶、穗各构件的分配和权衡关系,以探讨蒙古冰草对荒漠草原异质生境的资源权衡适应策略。结果表明:1)H种群的蒙古冰草个体总生物量和根冠比分别为24.69 g·株^(-1)和0.85,显著高于D、Q和G种群(P<0.05);除H种群外,其他种群的蒙古冰草构件生物量均表现为茎>根>穗>叶。2)不同自然种群的蒙古冰草叶-穗、叶-根之间均呈显著的异速生长关系,在D和H种群中各构件生物量累积速率表现为根>叶>穗>茎。3)蒙古冰草各构件氮含量和N/P以H种群较高,C/N则以H种群较低;碳、氮、磷含量在各自然种群均以根部最低,N/P以叶部最高,C/N、C/P以茎部最高(P<0.05)。4)蒙古冰草主要通过根、茎、叶之间的生物量权衡、叶部碳含量和C/P、穗部氮含量的可塑性变化适应环境的改变,土壤全氮和全钾是影响其生物量和养分分配的主要环境因子。综上所述,荒漠草原蒙古冰草各构件之间的资源权衡和异速生长关系有其固有的特征,同时,其在一定程度上又可以调节自身资源分配以应对特化的生境,体现了不同自然种群对异质环境的可塑性适应对策。In this study,we explored whether Agropyron mongolicum growing on the desert steppe can adapt to environmental changes by adjustments in biomass and nutrient allocation to different plant organs.Across this area,there is a climate transition from semi-arid to arid,and a terrain transition from the Loess plateau to the gently sloping hills of Ordos moving from south to north in Yanchi County,Ningxia.Taking into account the spatio-temporal variations in precipitation and soil across this region,we selected different natural populations of A.mongolicum(populations D,Q,H,and G)sourced from the towns of Dashuikeng,Qingshan,Huamachi,and Gaoshawo,respectively.The allocation to,and trade-off relationships among individual organ biomass and nutrients in roots,stems,leaves,and spike were determined to explore the resource trade-off adaption strategy of A.mongolicum to heterogeneous habitats on the desert steppe.The results showed that:1)The total individual biomass and root-shoot ratio of A.mongolicum in the H population were 24.69 g·plant^(-1)and 0.85,respectively,significantly higher than their corresponding values in the D,Q,and G populations(P<0.05).In the D,Q,and G populations,the organs were ranked,from largest to smallest proportion of total biomass of A.mongolicum,as follows:stem>root>spike>leaf.2)The leaf-spike and leaf-root relationships of A.mongolicum in different natural populations showed significant allometry.In the D and H populations,the organs were ranked from highest rate of biomass accumulation to lowest,as follows:root>leaf>spike>stem.3)The nitrogen(N)content and N∶phosphorus(P)in each organ were higher,and the carbon(C)∶N in each organ was lower,in the H population than in the other populations.In each natural population of A.mongolicum,the C,N,and P contents were the lowest in roots,N∶P was the highest in leaves,and C∶N and C∶P were the highest in the stem(P<0.05).4)A.mongolicum adapted to environmental changes mainly through biomass trade-offs among roots,stems,and leaves,and plasticity c

关 键 词：荒漠草原 自然种群 蒙古冰草 构件生物量 异速生长 资源权衡 

分 类 号：S543.9[农业科学—作物学]