天目山国家级自然保护区毛竹扩散过程的林分结构变化研究

为了弄清毛竹在自然条件下的扩散过程,通过样带法在天目山国家级自然保护区对毛竹扩散过程的立竹度、胸径、竹高及年龄结构进行了调查研究。结果表明,毛竹在扩散过程中其立竹度无论在垂直方向还是在水平方向上都随着扩散距离增加逐渐减少,立竹度由最大5 600株.hm-2减少到200株.hm-2;在毛竹纯林中由各种年龄的竹子组成(1～11年),年龄结构呈现不均匀性;随着距周边林分越近,主要由年龄较小的竹子组成,一般为1～3年;扩散到周边林分地带的毛竹胸径、株高均比纯林里的生长好。因此,在自然条件下毛竹林正向周边林分扩散,逐渐形成以毛竹为优势种的林分。研究结果为合理科学地经营自然保护区毛竹提供理论依据。

Stand Structure Change of Phyllostachys pubescens Forest Expansion in Tianmushan National Nature Reserve

In order to explore the expansion process of Phyllostachys pubescens population under natural conditions,through setting belt transects in Tianmushan National Nature Reserve,the culm density,DBH,height and age of P.pubescens were investigated and studied.The results showed that as the expansion distance increased,the culm density decreased,from the highest density of 5 600 individuals/hm2 to the lowest density of 200 individuals/hm2.Within the pure stand,the age of P.pubescens individuals varied from 1 to 11 years,while the P.pubescens at the edge and far from the pure forest were mostly 1 to 3 years old.It was found that the P.pubescens expanded to the surrounding stand had better growth performance that those in pure stand.The results of this study implies that the P.pubescens population in Tianmushan National Nature Research are ongoing the course of expanding to the surrounding stand,the stands dominated by P.pubescens are gradually forming.