| Quantifying the effectiveness of ecosystem conservation policies in degraded oases has always been a hot and difficult scientific issue.It involves ecology as the main subject more over combines the knowledge,methods and means of sociology,agronomy and management sciences.The classical theories include stratified feature and distinct theory of ecosystem management(SFDEM),coupled human and natural systems(CHANS),dryland development paradigm(DDP)and payment for ecosystem services(PES),each of which has formed a relatively mature research system around the sustainable management of ecosystem.However,in previous studies,validity and driving mechanism of most of the ecological conservation policies was remained unclear,and lack in quantitative evaluation.In this thesis,using the Shiyang River Basin in western China as a study case,we evaluated the ecological conservation policies implemented in the past ten years.The Shiyang River Basin is one of the endangered oasis ecosystems of the inland river basin contains the highest degree of water developed resources and is becoming the most serious threat to desertification.The ecological conservation policy has led to multi-scale and multi-level composite effects.Based on the social,economic and natural ecosystem stability indexes,this paper uses the methods of previous literature analysis,questionnaire survey,field investigation,spatial analysis and statistical modeling,and quantitative evaluation of ecological conservation policy in Shiyang River Basin at social,natural and basic ecosystem level:(1)the social ecology level,one part based on the responses of the residents to ecological conservation policy and this policy influences on the residentslivelihood.2)The natural ecological level;on one hand,quantitative evaluation analysis changes the physical and chemical properties of soils by ecological conservation policy while the other hand,quantitative evaluation,analysis the proportion and impacts of human activities and climate change on vegetation cover.Finally,based on the above research results,the effectiveness and sustainability of the ecosystem conservation policy in Shiyang River Basin were comprehensively evaluated.The main conclusions were as follows:1.Quantitatively analyze the residents' opinion and responses to the ecological conservation policyBy using stratified random sampling and the method of structured and semi-structured interviews,we investigated local people's knowledge,attitudes and perceptions towards ecological conservation policies in Shiyang river basin,and the demographic and social economic characteristics of the rural families.Based on the obtained 379 valid questionnaires,we evaluated the relative importance of the various demographic and socioeconomic factors on local people's perceptions using logistic regression equation analyses.1)The level of local people's perceptions about ecological conservation policies is very low and it lacks communication between local people and policy makers/management.We found that local people's knowledge about ecological conservation policies is very limited.Specially,the number of people who know the size and content of the ecological conservation policies is no more than 5%.Besides,we found that the residents' knowledge about the ecological conservation policies was significantly affected by respondents' gender and the water sources for agriculture.Specially,male respondents have more knowledge about ecological conservation policies than females(p<0.05)and the respondents from river irrigated area also have more knowledge about ecological conservation policies(p<0.01).In brief,the limited knowledge of local people about ecological conservation policies means that there is lack of public participation and communication mechanism in local management.2)The low level of local people's perceptions about ecological conservation policies led to a negative response and a high risk of conflict.More than 85% of respondents expressed an objective opinion about ecological conservation policies and about 90% of the respondents believe that the current allocation policy of water resources is unreasonable.Furthermore,we found that the residents' perceptions about the ecological conservation policies were significantly influenced by demographic and socioeconomic factors.For demographic factor,we found that older respondents have more supportive attitudes for ecological conservation policies(p<0.01).For socioeconomic factors,we found that the respondents with bigger household size expressed disagreeing opinion about ecological conservation policies(p< 0.01).3)Under the force of ecological conservation policies,local people had to compromise and change the mode of livelihood.Although most of the respondents were opposed to ecological conservation policies,still they were willing to change the family livelihood model,which means that the respondents' compromise.Totally,34.8% of families were willing to abandoned farmland,47.0% were willing to reduce irrigation,57.8% were willing to change cropping patterns,32.7% were willing to develop animal husbandry and 38.8% were willing to work as migrant.The above results show that the implentment of ecological conservation policies should indeed take local people's needs,wishes and attitudes into consideration,and the government should constantly improve the ecological conservation policies according to the social-economic and demographic characteristics.2.Quantifying the impact of ecological conservation policies on the livelihood of residentsIn the questionnaire of 1),we also investigated livelihood capital,livelihood activities(especially,whether the mode of agricultural production changed,namely whether agricultural produced in greenhouses)and family net income of rural families.Using the multivariate linear regression analysis,quintile regression analysis and income unequal analysis to investigate rural household income and inequality with greenhouses.4)Greenhouse agriculture has a significant positive impact on the rural household's net income in the survey area.The net income of households with greenhouses agriculture was significantly higher than that of households without greenhouse agriculture(p<0.01),especially for agricultural income.However,the multiple linear regression analysis showed that the interaction between greenhouse and farmland area(p<0.05)and outworking time(p<0.05)had some negative effects on family net income.The interaction of greenhouse agriculture with demographic features is not significant.In the five quintile regression models,participation in the SLCP has a significant positive impact upon household income,but the impact decreases from households at low income levels to those at high income levels.Furthermore,participation has a significant negative impact on low-income families(p<0.05)and middle-income families(p<0.05),but the effect on high-income families was not significant.5)The Gini coefficient for total net income of households with greenhouse agriculture is 0.174.Ck of income from husbandry and wages are both >0.174.Wages(Ck=0.432)contributes most to inequality of total income,followed by husbandry income(Ck=0.393).The Gini coefficient of households without greenhouse agriculture is 0.363,higher than for those with greenhouse agriculture.Similarly,for households without greenhouse agriculture,wages(Ck=0.491)and husbandry(Ck=0.432)both contributes to the inequality of total income.Besides,we found similar results when there is a 1% increase in the different sources of income for households with and without greenhouse agriculture.That includes,(i)increase in income from crops causes decrease in the Gini coefficient,specifically,40%;(ii)income from husbandry causes increase in the Gini coefficient,specifically 8.4% and(iii)wage income causes the largest increase in the Gini coefficient,specifically 23%.The above results show that greenhouses not only have a significant positive role in improving rural household's income,but also can reduce income inequalities between farmers.Therefore,it is necessary to further generalize the greenhouses in the whole Shiyang river basin.However,greenhouses need to spend a lot of labors and have higher technical requirements,while households need to reduce the time to engage in other livelihood activities.Based on the above issues,the local government should promote greenhouses and support local farmers to build greenhouses.3.The impact of ecological conservation policies on soil physical and chemical propertiesReducing the irrigation area is one of the main measures of ecological conservation policy.As a result,the soil quality of abandoned farmland will change accordingly.We first identified the samplings with different abandoned periods through interviews and history data,and then based on the spatial instead of temporal analysis methods;differences in soil characteristics were analyzed using two-way analysis of variance(ANOVA)with the year of land abandonment,location and their interaction as the classificatory(independent)variables.Principal component analysis(PCA)was to distinguish periods of land abandonment and to determine the most important parameters for characterization.6)The quality of land abandonment soil decreased.The soil total phosphorus(0.869 ? 0.263 g Kg-1)in abandoned farmland was significantly lower than that in natural farmland(1.225 ? 0.242g·Kg-1).The soil alkalinity(8.026 ? 0.129)in abandoned farmland was significantly higher than that in natural farmland(7.840 ? 0.113).The soil bulk density(1.514 ? 0.108)of abandoned farmland was also significantly higher than that of natural farmland soil(1.456 ? 0.089),while there was no significant difference between abandoned farmland and the farmland regarding the total nitrogen content,available nitrogen,available potassium and organic carbon the content and farmland.The soil fertility of abandoned farmland is significantly lower than farmland.7)Soil composition was significantly different in between abandoned farmland and farmland.Through the principal component analysis of soil composition between abandoned and natural farmland,the soil composition was significantly different.The two principal component axes,which are composed of soil total nitrogen,total phosphorus,organic carbon,pH and soil bulk density,can distinguish farmland from abandoned farmland.This means that these five variables can be used to assess land type in the future.It also means that PCA may be a suitable method to evaluate the impact of abandoned land on soil fertility.The above results show that,compared with the cultivated farmland,the soil fertility of the abandoned farmland declined significantly,and the soil composition have also changed significantly.Therefore,abandoning farmland is not conducive to vegetation restoration,and adjustments must be made to relevant policy,or the soil fertility of abandoned farmland will further decline.4.Quantitative analysis of the relative roles of the driving factors of vegetation covers change before and after the ecological conservation policyBy using remote sensing observations,spatial analysis and residual trend method,we investigate the relative roles of climate variations and human activities in vegetation change in Liangzhou.8)From 2000-2006,climate change was the dominant factor that induced the increasing in vegetation variation.The area of the vegetation increased by 88% of the total area by vegetation increased with the climate change(relative to 50%).Human activities were the dominant factor that induced the declining of vegetation variation,the area of vegetation reduction with human activities is 69.2% of the total vegetation reduction area.For different land cover types,climate change was the dominant factor that induced the increasing in vegetation variation in forest,grass,farmland,Urban,water and bare land,the area of the vegetation increased by 88.7%,83.8%,85.9%,81%,77.6% and 89.6%of the total area in each land cover type by vegetation increased with the climate change,respectively.At the same time,climate change was also the dominant factor that induced the decreasing in vegetation variation in grass,Urban and water,the area of the vegetation decreased by 53.8%,62.3% and 67.2%of the total area in each land cover type by vegetation decreased with the climate change,respectively.However,human actives were the dominant factor that induced the decreasing in vegetation variation in forest,farmland and bare land,the area of the vegetation decreased by 54.5%,50.3% and 77.5%of the total area in each land cover type by vegetation decreased with human actives,respectively.9)From 2006 to 2013,human activities were the dominant factor that induced the enhancement in vegetation variation.The area of vegetation increased by human activities was 80.1% of the total vegetation area.Climate change was the dominant factor that induced the declining of vegetation variation,the area of vegetation decreased by 57.1% of the total vegetation area.For different land cover types,human activities were the dominant factor that induced the increasing in vegetation variation in forest,grass,farmland,Urban,water and bare land,the area of the vegetation increased by78.9%,77.5%,80.8%,75.6%,80.4% and 80.1%of the total area in each land cover type by vegetation increased with the human activities,respectively.At the same time,human activities were also the dominant factor that induced the decreasing in vegetation variation in grass and Urban,the area of the vegetation decreased by 52.4% and 56%of the total area in each land cover type by vegetation decreased with human activities,respectively.However,climate change was the dominant factor that induced the decreasing in vegetation variation in forest,farmland,water and bare land,the area of the vegetation decreased by 55.7%,56%,56.3% and 57.7%of the total area in each land cover type by vegetation decreased with the climate change,respectively.10)From 2000 to 2013,human activities were the dominant factor that induced the increasing of vegetation variation,the area of human vegetation increased by 62% of the total vegetation area;Human activities were also the dominant factor that induced the declining of vegetation variation,the area of vegetation reduction with human activities is 59.7% of the total vegetation reduction area.For different land cover types,human actives were the dominant factor that induced the increasing in vegetation variation in forest,grass,farmland,Urban,water and bare land,the area of the vegetation increased by 60%,60.5%,53.6%,54.8%,59.8% and 66.2%of the total area in each land cover type by vegetation increased with the climate change,respectively.At the same time,human activities were also the dominant factor that induced the decreasing in vegetation variation in forest,grass,farmland and bare land,the area of the vegetation decreased by 58.7%,55.4%,62.5% and 62.3%of the total area in each land cover type by vegetation decreased with the human activities,respectively.However,climate change were the dominant factor that induced the decreasing in vegetation variation in urban and water,the area of the vegetation decreased by 64.7% and 66.5%of the total area in each land cover type by vegetation decreased with the climate change,respectively.The above results show that,before and after the implementation of ecological conservation policies in shiyang River basin,the role of human activities in vegetation change changed,that is,before policies implementation human actives were the dominant factor that induced the decreasing in vegetation variation and after policy implementation human actives were the dominant factor that induced the increasing in vegetation variation.These results reflect the effective of the implementation of conservation policies in improving local ecological environment.5.Quantitative analysis of ecological conservation policy effectiveness and sustainabilityUsing a range of methods,including GIS-based landscape analysis,field survey,historic document analysis and the eco-economic model,our objective was to summarize the validity of these policies and offer an integrated paradigm for endangered ecosystem conservation in the Shiyang River Basin.11)Ecological conservation policy have played critical roles in water-saving,natural resource management and stabilizing the tendency of groundwater reduction.Over all in our study period,total water consumption decreased from 12.42 ? 108m3 to 10.51 ? 108m3.Agricultural,domestic,industrial and ecological water accounted for 81%,4%,8% and 4% in 2006.Instead,agricultural,domestic,industrial and ecological water accounted for 72%,5%,14% and 6%,respectively.The depth of groundwater degree tended to be worse year by year.However,the circumstance was different from 2000 to 2006 and then 2006 to2013.The decrease in groundwater table was 2.44 m from 2000 to2006 and 1.51 m from 2006 to 2013 respectively.12)Ecological conservation policies improved biological capacity,but sustainability remains a question.The accounting tools for quantifying humanity's nature use are essential for the overall assessments of human impact as well as for planning specific steps towards a sustainable future and ecological footprint(abbreviated as EF hereafter)methodology.Our results indicate that the biological capacity showed an increasing trend,with an increase of 0.106 ha and 0.0005 ha only from 2000 to 2006 and 2006-2013 respectively.The ecological footprint was increased1.606haperin2000 to 2013.The farmland was expanded 2.95 ? 104 ha in 2000-2006 and expansion farmland led to the increase of biological capacity.In 2006-2013,the area of farmland was reduced by 0.44 ? 104 ha and the area of forest and grassland increased by 1.06 ? 104 ha and 0.20 ? 104 harespectively,which was the main factor to stabilize the biological capacity.But increasing the area of forest and grassland is conducive to improving the stability of ecosystem.The ecological deficit was-1.08 ha,-1.14 ha,and-2.58 ha in 2000,2006 and 2013,respectively.The sustainable development of the local ecological system is still at a low level.The above results showed that although the ecological conservation policy in shiyang River basin initially achieved the expected goals of the rational use of water resources,but the ground water is still declining,and ecological deficit continues to increase.Therefore,the ecological conservation policies in shiyang River basin should be implemented continually until achieving the sustainable development of human beings and the environment.In general,for social-ecological systems,the low level of residents' perception towards conservation policy led to a negative response and a high risk of conflict and under the force of ecological conservation policies,local people had to compromise and change the mode of livelihood.With the goal of improving water use efficiency,greenhouse can significantly increase rural household income and reduce income inequalities between farmers,which help to improve residents ' conservation policy response.For natural ecosystems,involving human activities as the main body,ecological conservation policy also play very important role.From the point of view of vegetation cover change,policies implementation deviate significantly from the effects of human activities on vegetation cover change,reflects the conservation policy has effectively improved the local ecological environment.However,the soil composition of abandoned farmland caused by reducing irrigation area changed,especially,the soil fertility declined signifantly,which is not conducive to effective recovery of the natural vegetation.It also reflects the farming conservation projects are not conducive to improve the local ecological environment,and should be made appropriate adjustments.In addition,based on shiyang River basin's ecological footprint and ecological carrying capacity analysis,the results showed that the sustainability of the ecosystem is still inadequate in shiyang River basin.Overall,the conservation policy in shiyang River basin played a role in improving local environment,and should be continue to strengthen enforcement of policy,but it should be part of the policy to make the appropriate adjustments,in order to achieve the objectives of harmonious development between man and nature in shiyang River basin. |
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