The Temporal-Spatial Variation Of Trade-Offs And Synergies Among Cultivated Land Multi-Functions

The cultivated land has the multi-function characteristic.Under the drive of the human society,the cultivated land multi-function is not independent existence,but has the complex interaction,which generally exhibit as trade-offs and synergies.Researches on the temporal and spatial variation of trade-offs and synergies among multi-functions have important significance to develop differentiated cultivated land management policy,enhance the coordinated development of multi-functions,Improve the efficiency of cultivated land protection.In this paper,the cultivated land multi-function in Hubei province is divided into six kinds of functions,material output,net carbon sequestration,water conservation,habitat maintenance,labor capacity,landscape scenery function,and we construct the evaluation index system and ecological economics model to evaluate the cultivated land multi-function.From the aspects of without considering the interaction of adjacent space and considering the interaction of adjacent space,we use the correlation analysis and spatial correlation analysis to study temporal and spatial variation of trade-offs and synergies and the spatial association of trade-offs and synergies among multi-functions.The results show that:(1)during the 2000-2013,the functions of material production,net carbon sequestration,landscape scenery were all enhanced.The function of labor capacity and habitat maintenance were weakened,while the function of water conservation is stable.The temporal variation of trade-offs and synergies among multi-functions show that: The material output function and net carbon sequestration,water conservation,labor capacity and landscape scenery function present synergy over the years,but the synergistic level is weakening.Net carbon sequestration function and water conservation function present synergy over the years,but the synergistic effect is weakening.Net carbon sequestration function and habitat maintenance,labor capacity present synergy in 2000,thereafter present independent existence with the former,present trade-offs with the latter.Water conservation function and landscape scenery function present synergy over the years,water conservation function and habitat maintenance function were independent existence before 2013,present trade-offs in 2013,water conservation function and labor capacity function present synergy in 2000,thereafter present independent existence.Habitat maintenance function and labor capacity function present trade-offs over the years.(2)The material output function is gradually enhanced,enhancement region mainly distributed in Jingmen,Xiangyang and Wuhan city circle except for Xian ning;net carbon sequestration function is generally enhanced,shows a “low in east and west-high in middle” pattern.Water conservation function remained stable,shows a “low in northwest-high in southeast” pattern.Habitat maintenance function kept weakened and mainly distributed in shennongjia area and north of Hubei.Labor capacity function kept weakened and mainly distributed in part of east and west area.Landscape scenery function is strong in the area around the city.The study area is divided into four types: central Hubei Province,Western Hubei and eastern areas and metropolitan areas.Analyses of the trade-off and synergy among multi-functions on each type of area show that: The material output and net carbon sequestration function present synergy on Western Hubei over the years,but the synergistic level is weakening.The material output and water conservation function present synergy on central and Western Hubei in 2000.The material output and labor capacity present synergy on central and eastern areas of Hubei over the years.The material output and landscape scenery function present synergy on Western of Hubei and metropolitan areas since 2010.Net carbon sequestration and water conservation function present synergy on all types of areas over the years.Net carbon sequestration and landscape scenery function present synergy on central and western of Hubei over the years.habitat maintenance and water conservation,labor capacity function all present trade-offs on eastern of Hubei over the years.The labor capacity and landscape scenery function present trade-offs on eastern of Hubei since 2010.(3)Univariate analysis considering the interaction of adjacent space shows that: the number of areas with synergistic enhance and weaken of the function of material output gradually decreased,the former is distributed in Wuhan city,the latter changed to Enshi city;the number of areas with synergistic enhance and weaken of the function of net carbon sequestration gradually decreased,the former is distributed in north of Hubei,the latter is changed to Enshi city;the number of areas with synergistic enhance and weaken of the function of water conservation tends to be stable.The former is distributed in Ezhou and Huanggang,the latter is distributed in Shiyan and Yichang city.The number of areas with synergistic enhance and weaken of the function of habitat maintenance is reduced.The former is distributed in Suizhou City,the latter changed to Huanggang city;the number of areas with synergistic enhance of the function of labor capacity less,mainly distributed in some districts and counties of Huanggang city;the number of areas with synergistic weaken of the function of labor capacity gradually increased in Jianghan plain area extending northward;the number of areas with synergistic enhance and weaken of the function of landscape scenery tend to be stable,the former is distributed in Wuhan city,the latter is distributed in Enshi city.Bivariate analysis analysis considering the interaction of adjacent space shows that: the number of areas where net carbon sequestration and labor capacity present trade-offs in space is more,and mainly distributed in most areas of central Hubei Province;the number of areas where net carbon sequestration and water conservation synergistic enhance in space is more,and Mainly distributed in the southeast of Hubei Province;the number of areas where material output and labor capacity synergistic weak in space is more,and mainly distributed in most areas of central Hubei Province;the number of areas where material output and landscape scenery synergistic weak in space is more,and Mainly distributed in Enshi city;the number of areas where material output and water conservation synergistic enhance and weak in space is more,the former is distributed in Huanggang city,the latter is distributed in Shiyan and Yichang city;the number of areas where labor capacity and habitat maintenance present trade-offs in space is more,and mainly distributed in Suizhou and Huanggang city.