| The global ecosystem,as the important property of mankind,are frequently taken by the human beings,which lead to the degradation of more than half of the current global ecosystem and the reduce of ecosystem service and threaten the human well-being and sustainable development.Ecosystem services and its management have become the key and scientific issues in international.Although there have been a lot of researches on trade-off and synergy,the tradeoff and synergy relationship between ecosystem services and its mechanism is still not clear.Especially in the study of trade-off relationship,few studies have taken the negative ecosystem services into consideration.The ecosystem provides positive services for human,also provides negative services at the same time.Considering the positive and negative services comprehensively,will make the trade-off and synergy relationship between ecosystem services more scientific and complex.At present,there are few studies on the trade-off and synergy relationship of agro-ecosystem.While agro-ecosystem as one of the ecosystem controlled by human beings,generates negative services more prominent.Taking agricultural ecosystem as an example to reveal the relationship between ecosystem services is more typical,is also the key issue of managing agro-ecosystem services scientifically,which has important scientific significance.Therefore,based on theory and method of geography and ecosystem service,this paper took the agro-ecosystem of Xi’an Metropolitan zone as the study object,with the 13 positive and negative ecosystem service measurement indexes were selected.The quantitative indexes and models of agricultural ecosystem services were established,and the 13 indexes were evaluated and analyzed based on pixel scale.The division of agricultural function zone was carried out by cluster analysis from the perspective of ecosystem services,and the trade-off between the services of each service zone was studied,corresponding countermeasures and suggestions according to the concrete conditions of each service zone were also put forward.The main conclusions are as follows:(1)In 1999-2015,the changes of each positive ecosystem service had obvious differences in Xi’an Metropolitan zone,the economic output function had the fastest growth rate,the basic living guarantee and the tourism and leisure function took the second place.The air purification,carbon sequestration,oxygen release,the climate regulation and water conservation showed a downward trend;Water consumption and fertilizer pollution showed a significant increase while greenhouse gas emission growth is relatively slow.Among the the increase of the positive and negative services of the agricultural land type,orchard land is the fastest,followed by the arable land.(2)In Xi’an Metropolitan zone,the high-value area of the total positive ecosystem service was expanding in the period from 1999 to 2015,and the output of the Qinling forest area was always at a low level,while the total positive ecological services in the central and northern plains were higher area.The spatial distribution of the high,medium and low value areas of the single positive service was very different.The supply services showed the value of central and northern plain areas was higher than the Qinling area,while the regulating services,the cultural services and the supporting services showed the opposite trend.The distribution range of the high-value area of the total negative ecosystem service was gradually expanding.The spatial distribution pattern of the high,medium and low value areas of the single negative ecosystem service was consistent,and the central and northern plains were generally larger than the Qinling area.(3)Economic output and basic living guarantee of agro-ecosystem always maintained a strong synergistic relationship in Xi’an Metropolitan zone.Supply services and cultural services,regulating services showed a negative correlation.There was a synergistic relationship between cultural services and each supporting service,each regulating service.Cultural services,supporting services and each regulating services and the internal regulating service remained a significant synergistic relationship;the synergistic relationship always maintained between the each of the negative services.Negative services and each of positive services showed trade-off relationship.(4)In regulation-support agricultural function zone,supply services and the culture services,regulating services,supporting services showed a trade-off relationship.Culture services,regulating services,supporting services each other showed synergistic relationship.There was a synergistic relationship between supply services and negative services and the internal of negative services.Negative services and supporting services,regulating services showed a trade-off relationship;In supply-regulation service area,supply services and cultural services,regulating services,supporting services showed a negative correlation in 1999,while there was an opposite relationship(except for cultural and air purification services)in 2006,2015.Culture services,regulating services,and supporting services each other showed synergistic relationship.There was a positive correlation between supply services and negative services and the internal of negative services.Negative services and supporting services,regulating services almost showed a trade-off relationship,while that went to an opposite correlation in 2006,2015;In supply-negative agricultural function zone,supply services showed a negative correlation with cultural services,while air purification services and showed a synergistic relationship with Carbon sequestration,oxygen release and Climate regulation service.Culture services,regulating services,supporting services each other showed synergistic relationship.There was a synergistic relationship between supply services and negative services and the internal of negative services.The correlation between the positive and negative services was more complex,but most of them were cooperative relationship.(5)Based on the trade-off and synergistic relationship of each agricultural function zone,the corresponding ecological system management policies were put forward from the local residents,government departments and enterprises respectively.The management policies of regulation-support agricultural function zone are mainly carried out under the protection policies,such as "slope changed into ladder",rectifying quarry and mining enterprises,etc.The management policies of supply-regulation and supply-negative agricultural function zone mainly include reducing agricultural pollution,adjusting the agricultural structure. |
PDF Full Text Request