中条山中段生态公益林典型森林群落天然更新特征及其影响因素OA北大核心CSTPCD

[Background]Because of the large amount of soil and water loss in Zhongtiao Mountains and the formation of fragmented topography over the years,the ecological environment has been destroyed,and the vegetation degradation is serious,therefore,the study of understory regeneration is of great significance for vegetation restoration and soil and water conservation.In order to clarify the present situation of natural regeneration of non-commercial forest,we should find out the key factors affecting natural regeneration,promote forest regeneration,and improve the efficiency of water and soil conservation.[Methods]Seven typical forest communities of ecological public welfare forest in the middle section of Zhongtiao Mountains were selected as the research objects,after setting plots,field investigation and data analysis,the characteristics of understory regeneration were analyzed from three aspects:species composition,quantitative characteristics and spatial distribution pattern,and the key factors affecting understory natural regeneration were explored.[Results]1)There was significant difference in species composition among the 7 species of community regeneration(P＜0.05).Quercus wutaishansea was the dominant species,followed by Pinus armandii.Except Q.wutaishansea forest,the regeneration density was only 38 trees/hm2.The understory regeneration showed aggregation distribution on the 2 m ×2 m scale,and the aggregation intensity index was the highest(3.36).2)Litter and soil thickness were the key factors affecting seedling regeneration,while topographic factors,stand density and coverage of shrub and grass only play significant roles in specific stands.In the mixed forest of Populus davidiana and Q.wutaishansea,the density of seedlings was significantly and positively correlated with the thickness of litter(P＜0.05),and the density of seedlings was higher(200-450 trees/hm2)when the thickness of litter was 2.7-3.7 cm,while in the mixed forest of Pinus tabuliformis and Q.wutaishansea,the density of seedlings was significantly positively correlated with the thickness of soil(P＜0.05),and the density of seedlings was higher(250-675 trees/hm2)when the thickness of soil was 15-24 cm.3)In the same stand,the seedlings and saplings responded differently to the change of stand density,and the saplings were more sensitive.[Conclusions]Scientific management measures should be taken in the follow-up forest management,which may accelerate the succession process by clearing litter and replanting gaps.This study may provide reference for adjusting stand structure and improving stand quality,and play an important role in improving protective function and comprehensive benefit of forest land and maintaining regional balance of nature.