基于树冠重叠面积的天然混交林林木竞争指数  

Competition index of natural mixed forests based on canopy overlap area

作　　者：廉琪 张弓乔 萨日娜 卢彦磊 刘文桢 胡艳波[1] 赵中华[1] LIAN Qi;ZHANG Gongqiao;Sarina;LU Yanlei;LIU Wenzhen;HU Yanbo;ZHAO Zhonghua(State Key Laboratory of Efficient Production of Forest Resources,Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration,Research Institute of Forestry Chinese Academy of Forestry,Beijing 100091,China;Key Laboratory of Oak Secondary Forest Ecosystem of Gansu Province,Xiaolongshan Research Institute of Forestry in Gansu Province,Tianshui 741022,China)

机构地区：[1]中国林业科学研究院林业研究所,林木资源高效生产全国重点实验室,国家林业和草原局林木培育重点实验室,北京100091 [2]甘肃省小陇山林业试验局林业科学研究所,甘肃省栎类次生林生态系统重点实验室,天水741022

出　　处：《生态学报》2024年第5期2057-2068,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金面上项目(32171780)。

摘　　要：构建基于树冠重叠面积和林木混交关系的竞争指数,探究天然混交林林分及主要树种竞争的表达方法,并以甘肃省小陇山林区锐齿槲栎天然混交林为研究对象,采用胸径、树高、冠幅、距离等信息的2期调查数据,对新构建的基于树冠重叠面积的天然混交林林木竞争(CIM)指数进行验证,并选取Spearman系数,对CIM竞争指数和传统竞争指数进行相关性分析。结果表明,采用树冠投影重叠和考虑树高关系确定竞争木的方法能有效避免竞争木多选或漏选;CIM1、CIM2、CIM3能够表达出混交林竞争压力变化,表现出竞争压力越大林木蓄积生长量越小的趋势,将树种混交因子引入竞争指数能够提高蓄积生长量与竞争指数的相关性,更加客观的描述林分中竞争状况。竞争指数与蓄积生长量相关性由大到小排序为CIM2>CIM3>CIM1>Bella竞争指数(CIO)>简单竞争指数(CI)>CIO_(2)>CIO1,表明竞争指数CIM2对混交林竞争表达更具参考意义。林分中主要树种锐齿槲栎由于相邻木中同树种相邻木增加,导致竞争压力增大。天然混交林中树种组成复杂多样,林木分布不均匀,在竞争指数中引入树种混交因子能够较为真实的反映林木竞争状况。Competition in forests plays a significant role in the process of tree growth,and the competition indices were typically used to quantify the intensity of competition among individual trees.However,due to the rich composition of tree species and the patchy distribution in natural mixed forests,there were still few studies on tree competition in natural mixed forests.In this study,we constructed a competition index based on the overlapped area of tree crowns and interspecies interactions,which allowed us to investigate the intensity of competition in natural forests and among major tree species.Specifically,we focused on the Quercus aliena natural forest in Xiaolongshan Forest District of Gansu Province and used data of DBH(breast height diameter),tree height,crown size,and distance from two surveys to validate the newly developed CIM(Competition Index based on Overlapping area and Mixing)index.To evaluate the effectiveness of our index,we utilized the CIM and conventional competition indices,such as CIO(Competitive Influence⁃Zone Overlap)and CI(Competition Index),and employed the Spearman coefficient to analyze their correlation with growth accumulation.We found that our method of determining competing trees using crown projection overlaps and tree height was an effective tool that could help prevent excessive selection or omission of competing trees.The results indicated that CIM1,CIM2,and CIM3 could effectively capture changes in competition pressure across natural forests and demonstrated that as competition pressure increased,tree growth accumulation decreased.In addition,by introducing the tree species mixing factor into our competition indices,we improved the correlation between growth accumulation and competition indices and provided a more objective representation of competition status in the natural forest.Specifically,our study found that the correlation between competition indices and growth accumulation was the highest for CIM2,followed by CIM3,CIM1,CIO,CI,CIO2,and CIO1.The competition index CIM2 pr

关 键 词：竞争指数 锐齿槲栎 天然混交林 树冠重叠面积 

分 类 号：S71[农业科学—林学]