Study On Vegetation Pattern And Structure Of Goat Road Landscape In Semi-arid Loess Plateau

Goat road landscape is widely distributed in semi-arid Loess Plateau. In this paper we selected five sunny slopes and five shady slopes as sample plots from northeastern hillys of Jin'ai Cown, Yuzhong Country, Lanzhou City, Gansu Province, based on methods from GIS and landscape ecology, a study on vegetation pattern and structure of goat road landscape was done. The results were as follows:(1) Vegetation coverage in sunny slopes was extremely lower than that in shady slopes, but soil crust coverage in sunny slopes showed no significant difference with that in shady slopes. The coverage of three cover types was in the sequence of soil crust> bare land> vegetation in sunny slopes, and soil crust> vegetation> bare land in shady slopes (except one sample plot). The main cover types in sunny slopes were soil crust and bare land, and in shady slopes were soil crust and vegetation.(2) Largest vegetation patch area in sunny slopes was extremely lower than that in shady slopes, but there was no significant difference between largest soil crust patch area in sunny slopes and that in shady slopes. Vegetation patch average area in sunny slopes was extremely lower than that in shady slopes, but there was no significant difference between soil crust patch average area in sunny slopes and that in shady slopes. Standard deviation of vegetation patch area in shady slopes was extremely lower than that in shady slopes, which means vegetation patch size evenness in sunny slopes was higher than that in shady slopes. There was no significant difference between standard deviation of soil crust patch area in sunny slopes and that in shady slopes, but both of them were very high, which means soil crust patch size evenness in sunny slopes and that in shady slopes were both very low.(3) Bare land patch density in sunny slopes was significantly higher than that in shady slopes, but vegetation patch density, soil crust patch density and landscape patch density respectively showed no significant difference between sunny slopes and shady slopes. There was no significant difference between goat road density in sunny slopes and that in shady slopes. Vegetation patch density in sunny slopes was higher than bare land patch density and soil crust patch density in sunny slopes. Patch density in shady slopes was in the sequence of vegetation> soil crust> bare land (except one sample plot).(4) There was no significant difference between landscape fragmentation index in sunny slopes and that in shady slopes. There was no significant difference between vegetation patch fragmentation index in sunny slopes and that in shady slopes, but bare land patch fragmentation index in sunny slopes was extremely higher than that in shady slopes, and soil crust patch fragmentation index in sunny slopes was significantly lower than that in shady slopes.(5) Average fragmentation index of vegetation patch shape and area weighted average fragmentation index of vegetation patch shape in sunny slopes were significantly lower than those in shady slopes respectively, which means vegetation patch shape in sunny slopes was more regular than that in shady slopes. Average fragmentation index and area weighted average fragmentation index of bare land patch shape and soil crust patch shape showed no significant difference between sunny slopes and shady slopes.(6) Vegetation patch separation index in sunny slopes was extremely lower than that in shady slopes, but bare land patch separation index and soil crust patch separation index showed no difference between sunny slopes and shady slopes. Vegetation on sunny slopes, and the vegetation patches are smaller than these in shady slopes, so vegetation patches on sunny slopes were farther apart from each other than those on shady slopes, and distribution of vegetation patches on sunny slopes was more disperse than that on shady slopes.(7) Vegetation of goat road landscape was trend to locate below goat road, soil crust was trend to locate between goat roads.