Study On Habitat Quality And Restoration Of Forest-Shrub-Grass Diversity In The Karst Rocky Desertification Areas

The restoration of forest-shrub-grass diversity in karst rocky desertification areas is an effective way to restore community vegetation and improve community stability.It is of great significance to explore the response mechanism of forest-shrub-grass functional traits and habitats in rocky desertification areas,and to reveal the mechanism of species coexistence in different habitats,and to restore the diversity of forest-shrub-grass in different habitats and accelerate the recovery process of in the karst rocky desertification communities.Based on the basic principles of plant physiology and ecology,soil nutrients,combined with the theory of species coexistence and community succession theory,this paper selects the typical representative karst plateau gorge moderate-strength rocky desertification comprehensive treatment demonstration zone,karst plateau The mountain potential-light rocky desertification comprehensive prevention demonstration area is used as a research area.Through the vegetation community survey,soil experiment,plant functional traits monitoring and habitat survey,the relationship between soil and plant functional traits and the coexistence of different community species are revealed.At present,the technology of forest shrub diversity restoration is proposed for different habitats.Conclusions as below:(1)There was a significant correlation between plant leaf functional traits and soil alkaline nitrogen,available potassium,and total potassium in potential-mild rocky desertification area of karst plateau mountain.In the moderate-severe rocky desertification area of the karst plateau gorge,plant functional traits were significantly correlated with soil total phosphorus,available phosphorus,and available potassium.(2)There was a significant difference in soil properties between different community types in the two demonstration areas(p<0.05).Considering the plant life forms'changes of different communities in rocky desertification areas,it was found that with the improvement of vegetation restoration,the Margalef richness index,Shannon-Wiener diversity index,Simpson dominance index,and Pielou evenness index of the tree layer showed an increasing trend in different degrees.In process of natural restoration,the species composition of the shrub-grassland varied widely,and the herb plants had a greater advantage.In the early stage of vegetation restoration,habitat conditions were poor and the stability was lower,which intensified the competition for space resources between shrubs and herbs,resulting in frequent species turnover.The structure differentiation of community was gradually significant,and the proportion of large-diameter plants increased.Due to the competition of trees,the proportion of shrub-grass plants decreased.The results of zero model showed that the different community species mainly presented competitive coexistence patterns in the karst plateau mountain and plateau gorge.(3)In the potential-mild rocky desertification area of the karst plateau mountain,the habitat quality of the forest-shrub-grass community was better,and the shrub-grassland poor.In the moderate-severe rocky desertification area of the karst plateau gorge,the habitat quality of the community was generally inferior to the plateau mountain area.For the community types with poor habitat quality,the measures of soil and water conservation was adopted to improve the habitat conditions,which was beneficial to the restoration of vegetation.For the types of communities with better habitat quality,community species diversity could be improved by community structure adjustment and artificial tending.(4)The demonstration project for the restoration of plant diversity was carried out in the karst plateau mountain area and the karst plateau gorge area.In the mountain area,the mixed plantation was mainly used to carry out the demonstration of community plant diversity restoration with a demonstration area of 10 hm~2,which was also applicable to other karst plateau mountain areas.In the gorge area,the method of closing for afforestation was mainly used for demonstration with the demonstration area of 20 hm~2,which could be demonstrated in the terrain of karst gorge.