Study On Formation Of Forest Scenery Aesthetic Quality And Natural Fire Disturbance Regime Of Forest In Kanas, Xinjiang

Altaic Mountain forest not only is extension of West Siberia southern taiga in the south, but also is the characteristic of dark-coniferous boreal forest which extended grassland district. Forest of Kanas National Nature Reserve, acting as the most famous noted sights of Altaic Mountain, condenses essence of Altaic Mountain natural ecosystem and scenery, and conserves virgin taiga ecosystem. Kanas National Nature Reserve is the unique Europe-Siberian plants and animals region within palaearctic distribution in China and has obvious value of protection and research. Like other forests lied in cold temperate district, natural fire disturbance, one of the most important disturbance factors in taiga, improves continually the succession of forest in Kanas National Nature Reserve. As to forest scenery of Kanas National Nature Reserve, natural fire disturbance has double effects of"creation"and"destruction". What is more, natural fire disturbance plays a significant role in formation and maintenance of forest community structure and scenery aesthetic quality. Therefore, study about formation of forest scenery aesthetic quality and natural fire disturbance regime of forest is an invoided scientific problem in forest management of Kanas National Nature Reserve. From the originating mechanism viewpoint, to explore the formation regime and dynamic of forest scenery aesthetic quality based on structure is the most main content. On the basis of the above recognition, this thesis regarding virgin taiga ecosystem in tourism district of Kanas National Nature Reserve as research objection, descripts quantitatively quantitative characteristic of historic fire disturbance in dark-coniferous forest, and explores the formation regime of forest scenery aesthetic value based on the temporal and spatial dynamic response of forest structures of tree species to fire disturbance. The methods of this study include typical transect investigation, typical community sampling plot method, the analysis of fire scars and scenic beauty estimation method(SBE). Structures of tree species are composed of horizontal structure, vertical structure, seasonal structure, composition structure and include seven indexes. The main results show:(1)Structures of tree species in forest community was complicated and various, colorful forest community is material basis of forest scenery visual quality in Kanas. The main arbor tree species in forest community in Kanas are Larix sibirica Ldb., Picea obovata Ldb., Pinus sibirica Ldb. and Betula pendula Roth.. With altitude increasing, the main composition pattern of tree species is formed by broadleaf-conifer mixed forest at the lower of altitude 1900m, species richness of tree is higher. Tree composition structure is conifer mixed forest at the higher of altitude 1900m; species richness of tree is lower. The changes of percentage of different species with increasing elevation are different. And tree seasonal structure and composition structure display distinct downtrend along altitudinal gradient across all scales. But in whole downtrend, tree seasonal structure and composition structure along altitudinal gradients show regional characteristic, altitude 1900m as a division. Species richness of trees and proportion of tree species at the lower of altitude 1900m is higher than that at the higher of altitude 1900m. Furthermore, spatial autocorrelation of tree seasonal structure and composition structure are obvious at middle or small scales, spatial heterogeneity along altitudinal gradients in the same scale ranges are distinct.(2)Terrain is complex, hydro-thermal characteristic is diverse in Kanas. Furthermore, there are many natural fire affairs. Special ecological environment and frequency natural fire disturbance improve the formation of structures of tree species. In large scale, the elevation is the fundamental factor to influence the altitudinal pattern of tree seasonal structure, composition structure. Slope, aspect and soil nutrients also dominant the pattern of Kanas forest vegetation. But in middle or small scale, natural fire disturbance is the main factor which controls structures of tree species. The analysis of temporal and spatial distribution of fire disturbance show that the fire affair mainly occurred at the lower of altitude 1900m. The time of fire affair and severity of each natural fire disturbance is different. Forest scenery is various with fire disturbance. But at the higher of altitude 1900m, there is little fire affair and the trace of fire disturbance is unusual. There is distinctly different between stand with natural fire disturbance and stand without natural fire disturbance as for structures of tree species in Kanas. Forest seasonal structure and tree composition structure are markedly affected by natural fire disturbance. And the indexes of structures of tree species are higher in disturbance plot than ones in stand without disturbance in Kanas. What is more, proportion of tree species and species richness of tree have obvious variance to different period fire disturbances,but they have not significant difference to different fire disturbance severity. Fire disturbance is one of the main factors which control the structures of tree species.(3)In Kanas, natural fire disturbance controls formation of forest scenery structure and affects the scenic beauty of forest scenery value. The scenic beauty of forest scenery value in Kanas is universally higher. However, people prefer the forest scenerys with richer tree species and orderly storey. And these forest scenerys represent higher aesthetic value. There is a close relationship between forest scenery visual quality and the occurring time of natural fire disturbance. The forest scenery which is impacted by the early natural fire disturbance has lower aesthetic value, vice versa. It also can be confirmed by radial basis function. Fire disturbance is one of the main factors which influence the forest scenery visual quality by controlling the formation of structures of tree species. In sum, in the process of forest succession, natural fire disturbance is useful to embodiment of forest scenery visual quality and the sustainable development of tourism in Kanas.