Dynamic Changes Of Forest Landscape Point Patterns In Qinling Mountains Of Shaanxi Province

In recent years,with the promotion and implementation of the“13th Five-Year Plan”,the ecological environment protection and planning of the Qinling Mountains has also received high concern and attention.How to maintain the balance of ecological functions and processes of forest landscapes,protect biodiversity,and coordinate economic and social development has become an urgent problem to be solved.Based on the remote sensing data of the Qinling Mountains in Shaanxi Province(hereinafter referred to as"Qinling Mountains")in2000,2005,2010,and 2017,this paper using the landscape index and spatial point pattern analysis method to analysis the spatial and temporal dynamics change of forest landscape pattern and the driving factors of forest landscape pattern were qualitatively studied in Qinling Mountains.In order to provide reference for the rational planning and sustainable management of the forest landscape.The main conclusions are as follows:(1)Qinling Mountains are covered with dense vegetation and forests.The vegetation coverage index is over 94%.Generally speaking,the vegetation coverage decreased by 101.56km~2/a in 2000-2017.The reduced area was shifted from medium-low and low vegetation coverage with shrub and broad-leaved forest as the main vegetation types to no and low vegetation coverage with the arable and meadow land and artificial surface as the main vegetation types show that the vegetation coverage is reduced from the area with weak human disturbance to the strong one.Besides the high vegetation cover type,which is dominated by coniferous and broad-leaved mixed forests and coniferous forests,fluctuates within a stable range.The impact of human disturbance on the forest landscape is evident.It can be seen that the impact of human disturbance on forest landscape is obvious.(2)From the patch characteristics,the proportion of landscape types remained basically unchanged from 2000 to 2017.Broad-leaved forests and coniferous forests with high degree of aggregation and neat patch shape are the dominant landscapes in the study area.Shrubs and coniferous and broad-leaved mixed forests are loosely distributed throughout the landscape,inlaid or scattered between other landscape types.From the perspective of heterogeneity,the heterogeneity of landscape types is basically consistent with the patch characteristics.The heterogeneity of shrub forests and coniferous and broad-leaved mixed forests is high,and the connectivity between similar landscapes is poor.On the whole,the Qinling landscape has various types of landscapes,and the level of heterogeneity is high.The quality of forest landscapes is decreasing year by year.(3)It can be obtained from the spatial point pattern analysis that the spatial scale characteristics of landscape types have not changed significantly in the past 17 years,and the distribution characteristics have remained stable.The characteristic scales of broad-leaved forest,coniferous forest,coniferous and broad-leaved mixed forest,shrub forest and the arable and meadow land are:30.2km,28.3km,35km,31.2km and 36.4km.The aggregation of broad-leaved forest,coniferous-broad-leaved mixed forest and shrub forest is not obvious,and they were close to randomly distributed.The aggregate distribution of the arable and meadow land and coniferous forest was very significant.It can be seen that the results are consistent with the results of the landscape index analysis and complement the lack of landscape index analysis on spatial scale.(4)The spatial distribution structure of the landscape pattern in Qinling Mountains is greatly affected by the two natural driving factors of geomorphology and climate,which is characterized by the vertical distribution characteristics along with elevation and climate change.From the perspective of time distribution pattern,related to the shorter time scale the landscape pattern change in the Qinling Mountains is not very obvious during the 17 years.However,the changes in some landscape types are relatively large,which is mainly related to the policy factors.Through the scientific means of human interference to restore the ecological balance and rational optimization of the forest landscape pattern in the Qinling Mountains has become the main way for people to coexist harmoniously with nature.