集约经营模式下毛竹的空间分布格局

为了解集约经营模式下,环境条件和自身密度法则对毛竹(Phyllostachys edulis)空间分布格局及其种群动态、品质与产量的影响,笔者在福建省永安市上坪山地长期集约性经营的毛竹林选择一块样地(40 m×15.5 m),对2008、2010、2012和2014年出土的毛竹进行区分,测定其空间位置,以异质性空间点格局分析方法重点研究2014年新竹相对于其余老竹的空间分布特点,同时测量了研究区域内毛竹个体的胸径,并采用广义可加模型分析了胸径在空间的分布类型是否呈现出随机化的特点。研究结果表明:毛竹在给定的距离尺度下表现为随机分布,同时毛竹胸径大小与毛竹的空间位置有关,毛竹分布的环境是异质性的,使用异质性空间点格局分析较为稳妥可靠。野外集约化经营模式下毛竹空间分布格局同样呈现出随机化分布的特点,而不是聚集性分布。毛竹在空间上出现是随机的,但是个体生物量大小的出现则与环境有关,提高毛竹产量和竹笋品质的关键在于改善土壤条件和选择毛竹的种植环境。

Spatial distribution pattern of Phyllostachys edulis under the pattern of intensive farming

The spatial distribution pattern of moso bamboo(Phyllostachys edulis)is generally limited by environmental conditions and self-thinning rule by itself. In order to understand the influences of the environment conditions and self-thinning rule on spatial distribution pattern, population dynamics, the productivity and quality of moso bamboo under the pattern of intensive farming, we sampled a 40 m×15.5 m plot on a mountain of Yongan City, Fujian Province, which was reckoned as a representative moso bamboo forest, used the heterogeneous spatial point pattern analysis method to check the distributional type of new moso bamboos in 2014 relative to old moso bamboos in 2008, 2010 and 2012, measured the spatial locations and the diameters at breast height(DBH)of moso bamboos, meanwhile used the generalized additive model(GAM)to check whether there was a relationship between the DBH of moso bamboos and the corresponding spatial locations. The results showed that the spatial distribution type of moso bamboo was random in a particular distance scale, and the DBH was significantly affected by the spatial locations of moso bamboo, which meant that the distributing environment of moso bamboo were heterogeneous. The biomasses of moso bamboo were related to environmental conditions, which implicated that it is important to improve the soil conditions and choose the plantation of moso bamboo for enhancing the productivity of moso bamboo and the quality of bamboo shoots. Thus, to use the inhomogeneous spatial point pattern analysis method is reasonable. The present study is of theoretical value for exploring the spatial distribution rule of moso bamboos, and it is also of practical value for operating moso bamboo forests.