Characteristics of Soil Seed Bank of Desert Plant Eremosparton songoricum and Their Effects on Seed Germination
Global warming has brought immense effect on ecological environment. On the background of global warming, the change of oasis thermal field has heavily affected the ecological stability of oasis. Using RS images to observe the pattern of thermal field has a great significance. Landsat7 ETM+ thermal infrared band was used to quantitatively invert land surface temperature of a typical oasis in arid region, south Xinjiang of China, under the clear sky condition, and image overlay analysis, histogram comparison, buffer a-nalysis, spatial auto analysis and profile-line analysis methods were adopted to analyze the thermal field pattern. The results show that oasis thermal field pattern presents a positive spatial correlation, and Moran's / value is 0. 5189 and Z value (from Z-test method) is 18. 44. At the same time, there are notable spatial cluster phenomena at local scale. For the whole study area, the rule of the thermal field pattern is water tem-perature<Ccultivated land temperature < woodland and grassland temperature < urban temperature< bare land temperature<saline-alkali soil temperature, and their average temperatures are 21. 65 ℃ , 27. 86 ℃. 35. 59 ℃ , 36. 52 ℃ . 40. 06 ℃ and 42. 07 ℃ respectively. For the local area, the average temperature of saline-alkali soil is lower than that in surrounding bare lands at 300 m, 900 m, 1 500 m distance buffer zones by 0. 59 ℃ , 0. -11℃ , 0. 26 ℃ respectively. Temperatures of water body, urban land, saline-alkali land and bare land have few spatial fluctuations, and their thermal landscapes are single and thermal field pattern is uniform. While the temperatures of cultivated land and woodland and grassland have large spatial gradient, and their thermal landscapes are complex and their thermal field pattern is very uneven. The area of ecotone between oasis and desert is large, and it can reduce the heat influence of desert to the oasis
thermal fieldLandsat7 ETM+ : oasisthe delta of Weigan River and Kuqa Riverarid region
NETL
NSTL
万方数据
维普
