Regulating Effect Of Landscape Pattern On Temperature And Precipitation

Global change,especially climatic warming leads to degradation of ecosystem services,water shortages and other environmental problem.It seriously threatens to sustainable development of human society.How to cope with and adapt to climate change effectively has become a common challenge for human.At present,researches on regulating climate change through land use and landscape pattern has not been highly valued.In recent years,studies on landscape ecology have found that the changes in composition and configuration of land use/cover are significantly correlated with temperature and precipitation.The study had found that when the landscape type converted from forest to farmland,the surface air temperature will increase and the precipitation will decrease.The surface biophysical parameters of different landscape patterns are different.The changes of carbon,energy and water in surface fluxes will lead to the change of temperature,precipitation and other climatic factors.Therefore,landscape pattern is one of the important factors affecting temperature and precipitation.Which landscape metrics are the primary factors influence temperature and precipitation?Is it consistent that the influence of landscape pattern on temperature and precipitation in different climatic zones?Does landscape patterns closely related to extreme temperature and precipitation?These are urgent issues that need to be explored.It has great meaning to mitigate climate change by optimizing land use and constructing suitable landscape patterns.In this paper,the relationship between landscape pattern and temperature and precipitation in the hilly regions of southern China and Inner Mongolia were studied by using landscape ecology methods,correlation analysis,remote sensing and GIS technology.The results showed that the optimal scale of landscape pattern influencing annual average temperature is same across the regions with similar climate background and slightly different across different climate backgrounds.In multiple regression models,the number of landscape pattern indexes involved in the optimal regression model is more in the southern region than in northern region.The dominant landscape pattern indices influencing temperature in Inner Mongolia are those of forest,grassland and sandy land.Generally,the larger area and the higher edge density of grasslands,more cooling effects were observed in the northern regions.For southern region,the large area of forest,the lower fragmentation degree and the more complex the shape of grassland,the more significant cooling effects were observed.In order to reveal the mechanism of the influence of landscape pattern on temperature,this paper analyze the correlation between vegetation transpiration and temperature in different landscape patterns in the southern region.The results showed that the effects of the same types of vegetation on temperature have seasonal differences.The relationship between the transpiration of combination of multiple vegetation and temperature is stronger than the effect of single type of vegetation transpiration on temperature in same area.The transpiration of grassland and shrub are more correlated with temperature in autumn,and the transpiration of grassland,Castanopsis fargesii and Oryza sativa L.,Triticum aestivum L.,shrub combination are strongly correlated with temperature in all seasons.Therefore,vegetation transpiration plays an important role in regional climate change in landscape level.In southern region,the environmental factors are complex.There are many factors affecting precipitation like climate background and topography,lead to fail to obtain regression model in some southern areas.Due to the weak influence of monsoons and the flat terrain,three counties in the Inner Mongolia have obtained the significant regression models with the optimal research scale of 5km.In general,the more complex shape of forest,the more number and the more complex shape of grassland patches,the less precipitation in the southern regions.In the northern regions,the complexity shape of forest and sandy land have positively correlated with precipitation,the smaller edge length and number of shrub patch,the more precipitation will be promoted.Based on the above results,the influence of landscape pattern on temperature need to be taken into consideration in response to climate change,and appropriate scale of optimize the landscape pattern in different climate backgrounds should be identified.Some measures like improving the area and shape complexity of forest and water,reducing fragmentation of forest,reasonably selecting plant species for enhancing vegetation transpiration to reduce temperature,should be considered in adapting global climatic change.Meanwhile,it is necessary to consider the occurring mechanism of extreme temperature and precipitation events,and reduce the frequency of extreme events through optimizing the land use and landscape pattern.