Analysis And Evaluation Of Damage Status Of Key Species In Wild Fruit Forest In Western Mountainous Area Of Xinjiang

Wild fruit forest in western mountainous areas of Xinjiang is a valuable product of the combination of Tertiary paleo-temperate broad-leaved forest and northern forest meadow in Tianshan Mountains.It is also the origin center of cultivated deciduous fruit trees in the world.It plays an important role not only in the development history of agriculture,forestry and animal husbandry in China,but also in the gene pool of biological resources.As key species of wild fruit forest community,Malus sieversii,Armeniaca vulgaris,Prunus divaricata,Crataegus cuneata,Juglans cathayensis and Amygdalus communis play a vital role in the health and stability of wild fruit forest ecosystem in Xinjiang.In recent years,the climate change caused by global warming,the increase of grazing pressure,the destruction of tourism development,the expansion of agricultural area and the frequent occurrence of diseases and insect pests have caused direct damage to the wild fruit forest ecosystem,leading to the endangered germplasm resources of wild fruit trees.The investigation of forest damage status is an essential part of forest health monitoring and research,which can better realize the protection and utilization of forest resources.However,the damage status of wild fruit forest is still unclear and there is no unified evaluation standard.Therefore,according to the distribution of wild fruit forest in western mountainous areas of Xinjiang,the typical distribution areas of key species of wild fruit trees in seven counties of Yining,Huocheng,Gongliu,Xinyuan,Yumin,Ermin and Tuoli were selected as the research areas,and the key species of Malus sieversii,Armeniaca vulgaris,Prunus divaricata,Crataegus cuneata,Juglans cathayensis and Amygdalus communis population in wild fruit forest in Xinjiang were selected as the research objects.Through field investigation,the damage status of key species of wild fruit forest in western mountainous areas of Xinjiang was investigated,analyzed and evaluated,so as to provide scientific theoretical basis for the protection and development and utilization of wild fruit forest resources in western mountainous areas of Xinjiang,and realize the sustainable utilization and healthy development of forest ecological resources.The main research results are as follows:1.Extreme high temperature weather occurred frequently in Xinjiang wild fruit forest counties since1995,and extreme gale weather occurred highly concentrated after 2005.The population of wild fruit forest in Xinjiang has been increasing year by year since 1989.Since 2000,the number of tourists in Yili has increased rapidly.The occurrence of extreme weather and disturbance of human activities have affected and damaged the ecology and environment of Yili wild fruit forest.2.At present,66.00%of Malus sieversii,89.20%of Armeniaca vulgaris,57.59%of Prunus divaricata,88.94%of Crataegus cuneata,37.43%of Juglans cathayensis and 87.14%of Amygdalus communis individuals in 57450 m~2wild forests in Xinjiang were damaged to varying degrees.The main damage type was grade 3 severe damage,and the main branch of the tree was split or died.3.Principal component analysis of community damage and species diversity of key species in wild western mountainous areas of Xinjiang showed that forest damage index was an important index reflecting the damage status of wild fruit trees in Xinjiang.Among the key species of wild fruit trees in different regions,Amygdalus communis community was the most seriously damaged and Armeniaca vulgaris community was the least damaged.Among the wild fruit trees in different counties,Yining County suffered the most serious damage while Gongliu County suffered the least.4.Using gray correlation analysis method to select altitude,aspect and slope of the key species in the western wild mountain terrain factor analysis found that altitude has the greatest influence on the damage of wild fruit trees in Xinjiang.