杉木近成熟林林分密度对林下套种闽楠根系生长的影响

[Objective]In order to study the effect of stand density on the root growth of interplanting Phoebe bournei in the multi-layer forest of Phoebe bournei.[Method]by measuring the root biomass,fine root morphological characteristics and soil physical properties of Phoebe bournei in different soil layers under different Chinese fir stand densities,the root distribution,average root diameter and soil water holding capacity of Phoebe bournei in different Chinese fir stand densities were analyzed and compared.[Result]Under the same stand density of Chinese fir,the root biomass of Phoebe bournei increased with the deepening of root distribution in vertical soil layer.In the appropriate Chinese fir stand density,with the increase of Chinese fir stand density,the biomass of Phoebe bournei decreased first and then increased.Within the appropriate Chinese fir stand density,different Chinese fir densities have little effect on soil physical properties such as soil bulk density,soil maximum water holding capacity,soil capillary porosity and soil non-capillary porosity,but in general,the soil water holding capacity and nutrient supply capacity are improved to a certain extent,and the soil is improved to a certain extent. [Conclusion]under the premise of reasonable control of stand density,the construction of Chinese fir and Phoebe bournei multi-layer forest can increase the distribution of forest roots and effectively improve the water holding capacity of forest land,thus providing a scientific basis for the healthy development of Chinese fir and Phoebe bournei multi-layer forest ecosystem.