| The value orientation of space and food production of land use and the understanding insufficiency about natural ecological function of land made that a large number of ecological lands with important ecological functions have been transformed into building lands,such as,forest lands,wetland lands and farmlands have been transformed into urban residential lands,commercial lands and industrial lands.which caused great changes in land use / cover,especially the hardened land changed the earth's cover and biogeochemical cycles,caused to inconsistencies between the elements of the ecosystem,Leaded to regional hydrothermal cycles and local climates disturbances,triggered regional "heat island effect",floods,soil erosion and biodiversity damage and a series of ecological problems,And eventually resulted to the degradation of regional and global ecological function and the occurrence of ecological crisis.In the period of national advocacy of new urbanization and ecological civilization construction,from the perspective of landscape ecology,discusse the landscape ecological effect of land use / cover change(LUCC)in Jiangnan New Town,Banan District,Chongqing,analyse the impact of LUCC on regional ecosystems from the perspective of landscape,and then guide the ecological allocation of land use with the objective of landscape ecology optimization,and ultimately from the perspective of land use to maintain regional ecological functions and to protect the regional ecological security,This is of great value and significance to the construction of ecological city and ecological civilization for the study area.The main conclusions are as follows:(1)The features of LUCCLUCC has showed some features that the building landscape area gradually increased,the area of farmland landscape,natural landscape and other landscape gradually narrowed,and urban lands massively occupied cultivated lands,garden lands,forest lands and other lands from 2010 to 2015,moreover,these changed features are more concentrated in the low hilly region of the study area.At the same time,this paper also found that there was no increase in the ecological landscape,especially the natural ecological landscape for the study area during this period.And this showed that the land use shows typical characteristics of urbanization in the study area.(2)The influence of LUCC on landscape indexFor landscape index of patch type level,a large number of landscape patches were occupied in the natural landscape,especially small patches,which led to the decrease of the remaining patch area and quantity,the regularity of the patch shape,and the increase of the accumulation but the decrease of connectivity of remaining patches;the decrease of the number and area of farmland landscape patches was greatest in all types during the study period,and the fragmentation and decentralization phenomenon of the cultivated land is obvious after the large-scale occupation;then the number and area of the village patches greatly reduced,the density and aggregation degree of the village patches decreased,and the separation degree of the village patches increased,in addition,the number,area and density of urban lands,roads land and other construction land greatly increased,but the aggregation of urban lands reduced,and the aggregation and connectivity of roads land and other construction lands increased,moreover,the separation degree of roads land and other construction lands reduced;only 3 patches were converted into urban lands and villages lands about disease landscape during the study period,and the separation degree of disease landscape increased,while other indexes decreased.For landscape index of landscape level,the quantity,area and fragmentation degree of overall patches decreased,and this is mainly related to small patches of ecological landscape that transformed into large patches of the building landscape;edge density and edge length of overall patches decreased,and the exchange potential and interaction strength of substances,energy,species and other information among patches were Weakening;the decrease of fractal dimension and the regularization of patch shape of patches explained that the impact of human enhanced;at the same time,the aggregation index increased but the separation degree enlarged,that is to say,large patches were enhanced,but the connectivity of patches decreased,and the ecological relationship between patches is weakened;eventually,the diversity index and evenness increased,because the improvement of the area proportion of building landscape narrowed the area gap with farmland landscape and natural landscape,further resulting in the increase of the balance and the landscape heterogeneity,meanwhile,the heterogeneous and homogeneous development showed that the internal stability of landscape ecological system reduced.(3)The influence of LUCC on Landscape ecological qualityFor the landscape ecological components,the occupation of high-level functional ecological landscape,woodland and river channel decreased the average ecological service equivalent of ecological landscape,and further damaged the landscape ecological function in a certain extent.For the landscape ecological pattern,the separation degree of ecological landscape increased,the connectivity of landscape distribution weakened,landscape distribution also tended to be scattered and fragmented,the marginal ecological effect of landscape also weakened and the shape of patches tended to be regular.More importantly,these changes will hinder the exchange among material,energy and information of patches,weaken the function of the ecological ecosystem,cause the decline of habitat quality and make the ecological landscape pattern become poor.For the landscape disturbance,although the bare land of disease landscape and farmland landscape were under control in a certain extent,it will have an adverse effects on ecosystem for the study area,especially on bare land and soil erosion of sloping land;inevitably,the great improvement of the interference intensity of artificial buildings enhanced the ecological disturbance for natural ecosystem,and further Strengthened the pressure of regional landscape ecology.(4)Landscape ecological effect and Landscape ecological OptimizationThis paper found that LUCC had a negative ecological influence on regional landscape ecosystem for study area through the change analysis of landscape index and landscape ecological quality,and that influence caused the ecological condition of landscape ecosystem to be worse.In view of this,based on the landscape ecological thinking and regional practice,we can take the following optimization measures: Firstly,we should protect the important ecological land components through the strengthening of ecological land management,the delineation of ecological red line,the formulation of ecological compensation mechanism and other methods.And then it is necessary to strengthen the construction of high standard basic farmland,to improve agricultural productivity and to alleviate the tense situation of cultivated resources.At the same time,we need to use the building land economically and intensively and to reduce the occupation of the natural ecological landscape.Secondly,based on "centralized and decentralized principle" of landscape ecology and actual situation of study area,we should construct the security pattern of ecological land.Finally,it is necessary to restore the bare land of natural diseases and slope farmland reasonably.And we could construct the ecological buffer zone between the building landscape and natural ecological components in order to reduce the interference intensity of the natural ecosystem. |
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