陇东黄土高原刺槐林分特征和林下灌草多样性对林分密度的响应  

Stand Characteristics of Robinia pseudoacacia and Responses of Its Understory Shrub-herbs Diversity to Stand Density in Loess Plateau of Eastern Gansu

作　　者：李志鑫 LI Zhixin(Guanshan Forest Farm of Jingchuan County,Pingliang Gansu 744306,China)

机构地区：[1]泾川县官山林场,甘肃平凉744306

出　　处：《甘肃林业科技》2024年第3期45-50,83,共7页Journal of Gansu Forestry Science and Technology

基　　金：甘肃省公益林生态效益监测。

摘　　要：研究陇东黄土高原刺槐Robinia pseudoacacia人工林不同密度条件下林分特征和林下灌草植物多样性特征,为陇东黄土高原生态效益发挥和生态功能提升提供科学依据。在甘肃泾川中沟小流域选取6种林分密度(975株/hm^(2)、1 200株/hm^(2)、1 450株/hm^(2)、1 650株/hm^(2)、1 875株/hm^(2)和2 100株/hm^(2))的刺槐纯林,分析其林分特征、林下灌草植物组成和植物多样性指标。结果表明:(1)刺槐密度1 650株/hm^(2)是刺槐林平均胸径、树高和冠幅的生长临界密度;(2)6种林分密度刺槐林下共有植物28科39属44种,其中灌木层植物共12科13属13种,草本层植物共16科26属31种,灌木层和草本层植物种数均在1 650株/hm^(2)时最多;随林分密度增加,林下灌草表现出阳生—中生—阴生的变化规律,茅莓为研究区主要适生植物;(3)随林分密度的增加各植物多样性指标整体呈现先增加再减小的变化规律,1 650株/hm^(2)时出现峰值,1 450株/hm^(2)时次之。建议通过人工抚育向中密度刺槐林进行改造,创造适合林下灌草生长的环境,以充分发挥研究区生态效益,提升其生态功能。To study the stand characteristics of Robinia pseudoacacia artificial forests and its understory shrub-herbs diversity under different stand densities in the loess plateau of eastern Gansu,eventually providing a scientific basis for the utilization of ecological benefits and the enhancement of ecological functions for the loess plateau of eastern Gansu.Six kinds of pure R.pseudoacacia forests with different stand densities(975 plants/hm^(2),1200 plants/hm^(2),1450 plants/hm^(2),1650 plants/hm^(2),1875 plants/hm^(2) and 2100 plants/hm^(2))were selected from Jing Chuan Zhong Gou sub-watershed of Gansu Province to analyze the stand characteristics,analyzing the understory shrub-herb plants composition and the indicators of plants diversity.The results showed that:(1)The density of R.pseudoacacia is 1650 plants/hm^(2),which is the growth critical density of average DBH,average tree height and average crown width of R.pseudoacacia forest;(2)There were a total of 44 species in 28 families and 39 genera in the understory of R.pseudoacacia forests of the six stand densities,among which there were 13 species in 12 families and 13 genera in the shrub layer,and 31 species in 16 families,26 genera and 26 genera in the herb layer.Especially the number of species in both the shrub layer and herb layer was the highest at the stand dentity of 1650 plants/hm^(2);Besides,with the increase of stand density,the understory plants showed the regular change from the law of Yang-middle-Yin,Rubus parvifolius was the typical plant in the study area;(3)With the increase of stand density,the plant diversity indexes showed an overall pattern of increasing and then decreasing,with a peak at 1650 plants/hm^(2),followed by 1450 plants/hm^(2).Overall,it is suggested that the medium-density of R.pseudoacacia forests should be transformed through artificial cultivation to create a suitable environment for the growth of understory shrub and herb,so as to activate the ecological benefits of the study area and enhance its ecological functions.

关 键 词：刺槐林 林分密度 林分特征 植物组成 植物多样性 陇东黄土高原 

分 类 号：S792.99[农业科学—林木遗传育种]