晋西黄土区不同密度刺槐林天然更新方式与更新苗木空间分布格局OACHSSCD

This study aimed to clarify the natural regeneration patterns and spatial distribution of seedlings in Robinia pseudoacacia forests across different stand densities(775-3300 trees/hm2)in the loess region of western Shanxi.Through vegetation surveys combined with spatial point pattern analysis(using Ripley's K and bivariate K12 functions),the spatial characteristics of regenerated seedlings were systematically quantified.The findings provide scientific reference for local vegetation restoration and sustainable forest management.The results indicated that natural regeneration of R.pseudoacacia is predominantly asexual,with the combined proportion of root suckering and sprouting regeneration accounting for 80%to 100%,whereas seedling regeneration capacity is very limited,with a maximum density not exceeding 125 trees/hm2.Stand density significantly regulated the composition of regeneration modes:root suckering dominated at low to medium densities(2225 trees/hm2),peaking at 600 trees/hm2 at the density of 2225 trees/hm2,while sprouting became the dominant mode at high densities(＞2225 trees/hm2).Spatially,seedlings exhibited suppressed distribution near adult trees but showed aggregation at farther distances,displaying a dispersed pattern within 0-1 m from adult trees and an aggregated distribution at distances of 1-3.5 m.The study demonstrates that medium-density stands(1300-2225 trees/hm2)support superior regeneration capacity and more desirable spatial distribution characteristics for seedlings,maintaining a higher proportion of root suckering while forming an appropriate spatial structure,which is conducive to the stability and sustainable management of the forest ecosystem.