摘要
【目的】研究对比油松和刺槐林在不同密度下土壤养分及其化学计量比的变化规律及差异性,以加强黄土区人工林的林分管理和生态恢复建设。【方法】以油松和刺槐人工林为研究对象,分别将其划分为高(2000~2700株/hm^2)、中(1100~1600株/hm^2)、低(800~1100株/hm^2)3组林分密度类型,每组挑选4个不同林分密度的林地,分别分层采取土样,测定土壤理化性质。【结果】(1)双因素方差分析显示,林分类型对全磷含量(TP)、碳磷比(C∶P)、氮磷比(N∶P)均有显著影响,林分密度仅对TP有显著影响,林分类型与林分密度的交互作用对有机碳含量(SOC)、全氮含量(TN)、TP、C∶P、N∶P均有显著影响。(2)不同林分密度的油松林和刺槐林的SOC和TN表现为:高密度油松林(油H)>中密度油松林(油M)>低密度刺槐林(刺L)>高密度刺槐林(刺H)>低密度油松林(油L)>中密度刺槐林(刺M),全P表现为:刺M>油H>刺L>刺H>油M>油L;随林分密度增加,油松林各土层SOC和TN逐渐增加,TP变化相对稳定且无显著性差异,刺槐林各土层SOC和TN先减少后略有增加,TP则是先增加后减少;同一密度在不同林分类型下,油松林土壤养分含量在高密度和中密度时均优于刺槐林,低密度时则相反。(3)不同林分密度的油松和刺槐林的C:N比值表现为:油H>刺H>刺L>油M>刺M>油L,C∶P和N∶P比值均表现为:油H>油M>刺L>刺H>油L>刺M;随林分密度的增加,油松林土壤C∶P和N∶P逐渐增大,磷的有效性逐渐减小,刺槐林土壤C∶P和N∶P先减小后增大,磷的有效性先升高后降低,油松林土壤磷的有效性在高和中密度下低于同等密度的刺槐林,低密度下则相反;土壤SOC和TN分别在很大程度上决定了C∶P和N∶P水平;不同林分密度下土壤C∶N比较稳定,土壤氮含量较缺乏,林分生长过程受氮素的限制。(4)油松和刺槐林在不同林分密度下的土壤各养分含量呈现出"表聚现象"且随土层深度增加
[Objective]This paper aims to study the changes and differences of soil nutrient and stoichiometry of Pinus tabuliformis and Robinia pseudoacacia plantations under different densities to strengthen the stand management and ecological restoration of artificial forests in the Loess Plateau of northern China.[Method]P.tabuliformis and R.pseudoacacia plantations were taken as research objects,and they were divided into three groups of stand density:high(2000-2700 plant/ha),medium(1100-1600 plant/ha)and low(800-1100 plant/ha).Four kinds of stands with different densities were selected for each group,and soil samples were taken in layers respectively to measure the physical and chemical properties of soil.[Result](1)Two-factor analysis of variance showed that the stand type had a significant effect on total P,C:P,N:P,the stand density only had a significant effect on total P,and the stand type and stand density had a jointly significant effect on organic carbon,total N,total P,C:P,N:P.(2)The organic carbon and total N of P.tabuliformis and R.pseudoacacia forests with different stand densities were as follows:high density P.tabuliformis forests(Pinus H)>medium density P.tabuliformis forests(Pinus M)>low density R.pseudoacacia forests(Robinia L)>high density R.pseudoacacia forests(Robinia H)>low density P.tabuliformis forests(Pinus L)>medium density R.pseudoacacia forests(Robinia M),and the total P is as follows:Robinia M>Pinus H>Robinia L>Robinia H>Pinus M>Pinus L.With the increase of stand density,the contents of organic carbon and total N in all soil layers of P.tabuliformis forest showed gradual increase,while the changes of total P content were relatively stable and had no significant difference.The contents of organic carbon and total N in all soil layers of R.pseudoacacia forest first decreased and then slightly increased,while the contents of total P first increased and then decreased.Under the same density and different stand types,the soil nutrient content of P.tabuliformis forest was better than R.pseudoacacia
作者
王岩松
马保明
高海平
王百田
李莎
董秀群
Wang Yansong;Ma Baoming;Gao Haiping;Wang Baitian;Li Sha;Dong Xiuqun(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Forestry and Grassland Bureau of Fangshan County,Shanxi Province,Lüliang 033199,Shanxi,China;Tianjin Water Conservation Engineering Consulting Co.,Ltd,Tianjin 300022,China)
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2020年第8期81-93,共13页
Journal of Beijing Forestry University
基金
国家重点研发计划“黄土残塬沟壑区水土保持型景观优化与特色林产业技术及示范”(2016YFC0501704)。
关键词
林分密度
油松
刺槐
土壤养分
化学计量比
stand density
Pinus tabuliformis
Robinia pseudoacacia
soil nutrient
stoichiometric ratio
