Ecological Security Pattern Construction Of Ecotone Between Agriculture And Animal Husbandry Based On The Ecological Protection Red Line

Ecotone between agriculture and animal husbandry of northern China,a fragile ecological environment condition,is very sensitive to changes in climate and human activities.Although the ecological environment in some areas has been partially improved recently,the trend of deterioration has not been contained,and the prolonged exposure from ecological environmental problems has been increasingly acute.There is an urgent need to construct an ecological security pattern to coordinate the contradiction between ecological protection and socio-economic development for ensuring a sustainable socio-economic development.Delineation of the ecological protection red line is a recently proposed national major ecological strategy,implementing at a regional level.Building up a regional ecological security pattern,the purpose of the ecological protection red line is to maintain national ecological security,curb ecological degradation,and promote the coordinated and balanced socio-economic development and ecological environment.The ecological protection red line,as a safety zone and security line of the regional sustainable development,is of great significance for optimizing the scientific and reasonable production,living and ecological spaces,and ensuring the ecological security.Yulin City in the ecotone between agriculture and animal husbandry was chosen as a case study to establish the ecological security pattern system using the ecological protection red line.The multi-thematic data in the national ecological status remote sensing survey and assessment was adopted by analyzing land use and land cover and important ecological parameters.The main findings are as follows:(1)The evolutionary characteristics of ecosystem in Yulin City were systematically analyzed from the perspective of the composition and their changes in land cover,the changes of landscape pattern indexes and the level of spatial conflicts,and the changes of ecosystem system quality.The production-living-ecology space was confirmed in Yulin city.The analysis of land cover and landscape pattern shows the ecological space accounts for 70% of the land use and the grassland is an important element of the ecological space.The dynamic measurement level of the landscape spatial conflict demonstrates that the severe out-of-control areas were mainly distributed in the Wuding River and the middle and lower reaches of the Yuxi River.The river main stream basically belonged to the uncontrolled area.The results of inter-annual variation coefficient,trend slope,and degeneration index of grassland vegetation coverage indicates that the grassland coverage in Yulin City was dominated by low-and lower-coverage grassland in past 16 years,gradually changing to medium-and lower-coverage grassland-based vegetation.Moreover,there is an increasing trend of the coverage degree,and the grassland was recovered by assessing an extremely severe degradation level in 2000 and the moderate degradation level in 2015.(2)The water demand was spatialized by coupling the social water demand forecast data with the land use status and planning data space.Furthermore,the integrated valuation of ecosystem services and trade-offs(In VEST)model was used to simulate the water yield service at the sub-basin scale.The results indicates that the unbalanced supply and demand of the water resources was mainly distributed across the Tuwei River,the Yuxi River,the Luhe River and the Wuding River basins by analyzing of water resources carrying capacity and demand space balance.The water resources constraints were identified by comparing the water-producing functional space of the major rivers with the evaluation results of NPP quantitative index method.The delineation ecological red line can be more accordant with the actual needs of Yulin City under consideration of the regional water resources requirements,and realize the effective protection of important water-producing functional spaces.(3)A method with the feasibility for constructing a scientific and rational ecological security pattern was built in the ecotone between agriculture and animal husbandry.The ecological spaces were identified through assessing the important ecosystem services and ecological sensitivities.The ecological functional and sensitive red lines were identified,and the criteria for the classification of ecological security were constructed as the bottom line,the satisfactory,and the ideal type.The ecological security control measurement for the environmental access management were proposed in the three levels of ecological security.The results shows that the proportions of Bottom Line,Satisfaction and Ideal Type are 17.80%(The total land area of Yulin is 7605.11 km2),39.49% and 55.81%,respectively.The Bottom Line Type is mainly distributed in the northwest wind beach area of the Wuding Basin and the upper right bank of the Wubu Basin.The ecological security pattern of the northwest wind beach area is an important component of the ecological security pattern for the Yulin City.The ecological protection of wind beach area is more important than the hilly gully area.