Evolution Of Ecological Quality,Functional Zoning,and Ecological Protection Strategies Of Cultivated Land In Mountainous Area Of Southern Zhejiang Province

As a semi-natural and semi-artificial ecosystem,the evolution of cultivated land ecological quality will directly affect grain production,regional ecological environment and sustainable utilization of resources.However,under the current policy system,there is insufficient awareness of the ecological quality and the multi-functionality of the cultivated land ecosystem,and the means of management and protection of cultivated land ecology are not strong enough,so that the problems of ecological environment caused by the decline of the ecological quality of cultivated land have become increasingly prominent.Under the background of ecological civilization construction,how to reveal the evolution characteristics of cultivated land ecological quality,rationally locate the functional zoning of cultivated land ecosystem,and realize scientific and systematic ecological protection and sustainable management of cultivated land has become an important proposition in the new era.On the basis of sorting out relevant studies at home and abroad,combining the actual situation and typical characteristics of the mountainous area of southern Zhejiang,this study took Jinyun County as the research area,constructed a comprehensive evaluation system of cultivated land ecological quality,analyzed the multi-scale spatio-temporal evolution characteristics of ecological quality,and made multifunctional zoning by comprehensive use of correlation analysis,cold hot spot analysis and cluster analysis.The comprehensive management strategy was put forward to provide theoretical and practical basis for improving the protection system of quantity,quality and ecology as well as sustainable utilization of cultivated land resources.The main conclusions of this paper are as follows:(1)The connotation of cultivated land ecological quality was analyzed from three dimensions of "element-structure-function",and a comprehensive evaluation model of cultivated land ecological quality including background quality factor,spatial structure factor and ecological service factor was constructed based on the actual situation of the study area.The results showed that the cultivated land ecological quality showed a trend of first increase and then decline in time series,and the high value area is mainly distributed in the northeast and southeast,while the low value area is mainly distributed in some central urban areas and the areas with large relief degree in terms of spatial distribution.(2)The analysis of multi-scale spatio-temporal evolution characteristics of cultivated land ecological quality shows that: at the plot scale,the cultivated land ecological quality in the northern and eastern parts of the study area has an increasing trend,while that in the central and southern parts of the study area has a decreasing trend.At the scale of topographic units,the ecological quality of cultivated land was the best in the high altitude area and the worst in the middle altitude area.In terms of township scale,the ecological quality profit and loss of Qianlu and Huzhen Township is relatively good,and the change and decline of cultivated land ecological quality in Xiandu Subdistrict is more obvious.(3)Based on the evaluation results of ecological quality,the method of "priority +dominant function" was adopted to develop functional zoning.The spatial agglomeration and distribution characteristics of the three dimensions of cultivated land ecological quality were identified through the cold and hot spot analysis,and the priority was determined according to the superimposed values of multiple hot spots.Based on the trade-off/synergy relationship of ecosystem services,the cultivated land was divided into four main functional areas by K-means clustering analysis method,namely,main grain producing area,comprehensive regulation area,ecological conservation area and cultural recreation area,and it was finally divided into eight functional areas by combining the priority and dominant function identification.(4)Based on the evaluation and evolution characteristics of cultivated land ecological quality,combined with the multifunctional zoning of cultivated land,a cultivated land ecological management and protection strategy of "constraint-incentive-promotion" was proposed.First,it is necessary to construct the constraint mechanism under the evaluation system,monitoring system and responsibility system of cultivated land ecological management based on ecological index evaluation;the second is to build an incentive mechanism for cultivated land ecological management and protection based on ecological grade accounts and ecological profit and loss;the third is to build a differentiated promotion mechanism for cultivated land ecological management and protection based on scale analysis and functional zoning.