摘要
在西藏自治区林芝市分别设置急尖长苞冷杉、林芝云杉和高山松天然林样地各一块,调查样地内的竞争木和对象木,采用Hegyi单木竞争模型对这3种植物进行种内竞争分析;运用幂函数、对数函数、指数函数、二项式、Logistic五种模型对整个林分竞争指数与对象木胸径间的关系进行回归拟合,并选择最优函数。通过对藏东南3种典型针叶林-急尖长苞冷杉、林芝云杉和高山松林的竞争强度定量分析,揭示出不同树种之间的种内竞争差异,为其可持续经营和合理利用提供科学依据。得出结果:(1)3个样地均为纯林,因此急尖长苞冷杉、林芝云杉、高山松的种内竞争指数分别为92.417、74.668、29.613。(2)急尖长苞冷杉、林芝云杉、高山松的胸径与整个林分的关系呈负相关关系,即随着胸径的增加,竞争指数在不断降低。(3)当急尖长苞冷杉胸径达到35 cm时,高山松胸径超过30 cm时,其对应所受的竞争强度下降幅度趋缓。急尖长苞冷杉受到的种内竞争压力最大,其次就是林芝云杉,种内竞争压力最小的是高山松。竞争强度随个体胸径的增大而减小最后趋于平缓,二者符合幂函数关系,所得模型能有效预测3种典型针叶林的种内竞争强度。
This study conducted a quantitative analysis of intraspecific competition in three typical coniferous forests in southeast Tibet:Abies georgei var.Smithii,Picea likiangensis var.linzhiensis,and Pinus densata.Sample plots were established in Nyingchi City,Tibet Autonomous Region,and the competitive and objective trees within the plots were investigated.The Hegyi single tree competition model was employed to analyze the intraspecific competition of the three plant species.Additionally,five regression models,including power function,logarithmic function,exponential function,binomial,and logistic,were used to examine the relationship between the competition index of the entire stand and the diameter at breast height(DBH) of the target tree,and the optimal model was selected.The findings revealed the differences in intraspecific competition among different tree species,providing a scientific basis for their sustainable management and rational utilization.The results indicated that all three plots consisted of pure forests,with intraspecific competition indexes of A.georgei var.Smithii,P.likiangensis var.linzhiensis,and P.densata being 92.417,74.668,and 29.613,respectively.A negative correlation was observed between the DBH of A.georgei var.Smithii,P.likiangensis var.linzhiensis,P.densata,and the entire stand,indicating that the competition index decreased with increasing DBH.Furthermore,the decline in competition intensity slowed down when the DBH of A.georgei var.Smithii reached 35 cm and the DBH of P.densata exceeded 30 cm.Among the three species,A.georgei var.Smithii experienced the highest intraspecific competition pressure,followed by P.likiangensis var.linzhiensis,while P.densata exhibited the lowest intraspecific competition pressure.The competition intensity decreased with increasing DBH,eventually reaching a gentle plateau,and both species conformed a power function relationship.The developed model effectively predicted the intraspecific competition intensity in the three typical coniferous forests.
作者
姚慧芳
屈兴乐
卢杰
王超
郑维列
YAO Huifang;QU Xingle;LU Jie;WANG Chao;ZHENG Weilie(Research Institute of Tibet Plateau Ecology,Tibet Agriculture&Animal Husbandry University;Key Laboratory of Forest Ecology of Tibet plateau,Ministry of Education;National Key Station of Field Scientific Observation&Experiment of Alpine Forest Ecology System in Nyingchi Tibet;Key Laboratory of Alpine Vegetation Ecological Security in Tibet,Nyingchi Tibet,860000,China)
出处
《高原农业》
2023年第4期409-417,共9页
Journal of Plateau Agriculture
基金
科技部国家野外科学研究观测站(生态系统)运行补助项目(西藏林芝高山森林生态系统国家野外科学观测研究2015-2020)
西藏农牧学院研究生创新计划项目(YJS2020-29)。
关键词
急尖长苞冷杉
林芝云杉
高山松
竞争指数
藏东南
Abies georgei var.Smithii
Picea likiangensis var.Linzhiensis
Pinus densata
competition index
southeast Tibet
