密云水库上游不同造林树种叶片-凋落物-土壤生态化学计量特征  

Ecological Stoichiometric Characteristics of Leaf-litter-soil of DifferentAfforestation Tree Species in Upper-river Basin of Miyun Reservoir

作　　者：陈长启 CHEN Changqi(Beijing Miyun District Landscape and Greening Bureau,Miyun Beijing 101500,P.R.China)

机构地区：[1]北京市密云区园林绿化局,北京密云101500

出　　处：《西部林业科学》2024年第2期93-98,共6页Journal of West China Forestry Science

基　　金：2023年度北京市百万亩造林林木养护项目(11011823T000002220096)。

摘　　要：平原生态林作为北京人工林生态系统的重要组成部分,探究其生态化学计量特征是揭示平原造林后森林生态系统物质周转和养分循环等生态功能的关键。本研究以北京市密云水库上游平原生态林区域的刺槐、侧柏、臭椿和白榆4种林分为对象,采用野外取样和室内实验分析相结合的方法,研究4种造林树种叶片-凋落物-土壤的碳(C)、氮(N)和磷(P)生态化学计量特征及其相关性。结果显示:4种树种叶片、凋落物和土壤中C、N和P的含量呈现显著差异,其中白榆的C含量在叶片、凋落物和土壤最高,4种树种鲜叶和凋落叶C︰N︰P化学计量比存在显著差异。4种树种鲜叶C︰N与C︰P均表现为白榆>刺槐>臭椿>侧柏。4种树种凋落叶N︰P表现为刺槐>臭椿>侧柏>白榆,且三者之间存在显著差异性。土壤C︰N,C︰P、 N︰P与SOC和TN含量有非常显著的相关性(P<0.01),说明植物体内的养分需求与土壤的SOC和TN养分供应有一定的关联。该区域刺槐、臭椿、白榆叶片N/P为16~19,说明这3种树种生长可能受P的限制。研究结果表明,在未来北京平原生态林养护管理中,可以通过开展合适的树种混交和提高树种多样性来有效改善养分限制,提高林分养分循环能力,维持林分长期生产力。Plain afforestation may affect the stoichiometry of carbon,nitrogen,and phosphorus in soil due to changes in land use.In order to clarify the spatial distribution,stoichiometric characteristics,and control factors of carbon(C),nitrogen(N),and phosphorus(P),four typical plain afforestation forests,Robinia pseudoacacia,Platycladus orientalis,Ailanthus altissima and Ulmus pumila,were selected in the upstream plain afforestation area of Miyun Reservoir,Beijing.Analyzed the concentrations and stoichiometric relationships of C,N,and P in leaves,litter,and soil.The results showed that the content of C,N,and P in the leaves,litter,and soil of different tree species showed changes.The C content of white elm was highest in the leaves,litter,and soil,and there were significant differences in the C︰N︰P stoichiometric ratio between fresh and fallen leaves of the four tree species.The fresh leaves of the four tree species showed a C︰N and C︰P ratio of Ulmus pumila>Robinia pseudoacacia>Ailanthus altissima>Platycladus orientalis.The N︰P ratio of fallen leaves of four tree species is as follows:Robinia pseudoacacia>Ailanthus altissima>Platycladus orientalis>Ulmus pumila,and there are significant differences among the three.There is a significant correlation(P<0.01)between soil C︰N,C︰P,N︰P,and SOC and TN content,indicating that the content of SOC and TN is a factor affecting the stoichiometric ratio of C,N,and P.The N/P of Robinia pseudoacacia,Ailanthus altissima,and Ulmus pumila leaves in this area is 16-19,indicating that the growth of these three tree species may be limited by P.Therefore,in the management of artificial forest nurturing,understory vegetation should be protected.For coniferous forests,mixed forests should be appropriately developed to promote litter decomposition,improve the nutrient cycling ability of artificial forests,and maintain long-term productivity of the forest.

关 键 词：密云水库 造林树种 化学计量特征 限制元素 

分 类 号：S714.2[农业科学—林学]