Yunnan Province Yongren Forest Landscape Pattern Analysis

The Jinsha River Basin is the most ecologically fragile area along the Yangtze River. However, being abundant in forest ecosystem diversity, it is the most important area for the economic and ecological sustainability of the entire Yangtze River Basin. Therefore restoring and reconstructing the degraded forest ecosystem and its restoring ecology research, has practical and theoretical significance in restoration ecology. Through the landscape pattern analysis, understanding the degenerated actuality of the forest ecosystem in this area, the characteristic of the various forest landscape essential factor type and the spatial.distribution situation, is the precondition of finding out the factors of producing and controlling the spatial pattern and its function mechanism, which can provide the valuable information for the restoration and reconstruction measure research of the degenerate forest ecosystem in this area.This paper took the county of Yongren, which locates in the Jinsha River Basin in Yunnan, as the study background and the forest landscape of this county as the study object. With the help of remote sensing, geographic information system and the landscape pattern analysis software of Fragstats3.3, I applied related principle, method and index system of landscape ecology to carry out forest landscape pattern analysis from such aspects as landscape composition and structures, patch characteristics, spatial relations, distribution patterns, etc. The results showed:(1) The landscape of Yongren was a tessera which was mainly composed of the forest landscape patches. The coniferous was the main constituent in the forest landscape and supremely occupied the majority of this landscape. It was the key factor that substantially influenced forest landscape pattem of this county.(2) Both the landscape diversity index and the landscape evenness index were low in this area. Therefore, the uniformity of landscape distribution was poor and the overall landscape diversity was not so optimal. The entire study area was made up of only a few large patches and lack of landscape heterogeneity.(3) The average patch size of forest landscape elements and patch grain-level structure differed very much, which reflected that they were in different ecological processes and disturbance conditions. The shape of the forest landscape patch affected by human activities was more normal than that of the natural ones. Natural landscape had more complicated patches. Considered from the spatial relations among the forest landscape essential elements, the distribution of the coniferous forest and the bush was almost reunitable while the distribution of the broad-leaved forest and the economic forest was mostly scattered.(4) The landscape differed greatly with the changes of altitude, inclination and aspect of slopes. Generally speaking, the forest landscape essential elements were mainly distributed at the vertical zone of 1500-1800m altitude, with slope inclination of 0～25°and aspect of east, northwest, southeast, west south or southwest. However they scarcely distributed at the steep slope over 25°.On the basis of the previous analysis, the paper carried on a more detailed analysis and discussion about the formation factor of the forest landscape pattern in Yongren County, and the results can serve as the basis of establishing the restoration and reconstruction measure about the degraded natural forest ecosystem. Meanwhile, the study will provide a new chain of thought and a scientific basis for establishing the dynamic monitoring and predictive model during the restoration of the forest ecosystem and the implementation of forest landscape planning.