不同类型猴樟混交林种间关系和冠层结构

以贵州人工栽培的猴樟纯林和3种类型的混交林为研究对象,采用Hegyi单木竞争指数模型对其种内、种间及全林分竞争强度进行定量研究,分析了不同混交组成树种的生态位宽度、生态相似系数和生态位重叠并测定了林分的冠层结构参数。结果表明:猴樟纯林的竞争最强,猴樟×杜英×楠木混交林是一个生态相似性较大、生态位重叠较高的混交组合,但目前竞争最小;猴樟×广玉兰×女贞混交林则是一个生态相似性小、生态位重叠较低且竞争比较强的混交组合,需要进行结构调整。研究结果反映出了不同混交组合中物种生态位宽度、生态位重叠和种间竞争关系的复杂性。混交林的冠层结构参数因树种组成、混交比例不同而异,总体上混交林的冠层参数空间异质性大于纯林。

Theintraspecific relationship and canopy structure of different type Cinnamomum bodinieri mixed stand

Pure plantation and three types mixed plantation of Cinnamomum bodinieri in Guizhou was chosen as researh object, and the competition intensities of intraspecific, interspecific and total stand in quantitatively was analyzed by ap-plying Hegyi'Scompetition index model for individual tree. The niche breadth, niche similarity and niche overlap were an-alyzed to determine the canopy structure parameter. The results showed that competition intensities in the pure C. bodinieri stand was the largest. Mixed stand of C. bodinieri,E. sylvestris and P. zhennans was the combinination of high niche simi-larity and niche overlap, but with weak competitiveness. Mixed stand of C. bodinieri,L.lucidum and M.grandiflora was the one with low niche similarity and niche overlap, but competited strongly so that it was necessary to adjust the structure. The results reflected the complexity between niche breadth, niche overlap and interspecific relationship of species for dif-ferent mixed combination. The canopy structure parameters of mixed stand were different with tree composition, mixed rate. The spatial heterogeneity of canopy parameters of mixed stand was obviously larger than pure stand.