By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to th...By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longi- tude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study con- tained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analy- sis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to tree growth would increase, and the response of tree growth to environmental changes would also increase. This study emphasizes the importance of regional-scale investigations into the biosphere-climate interac- tions. The results of this research indicated a substantial increment of tree-ring radial growth as a re- sult of warmer and wetter climate in the eastern regions. However, climate change will have less effect on forest growth and primary production in the western regions.展开更多
Willingness to Pay(WTP),Willingness to Work(WTW)and Willingness to Accept Compensation(WTA)are the three quantitative criteria for assessing local ecological asset values for the social aspects of ecosystem services a...Willingness to Pay(WTP),Willingness to Work(WTW)and Willingness to Accept Compensation(WTA)are the three quantitative criteria for assessing local ecological asset values for the social aspects of ecosystem services and residents’willingness to contribute to and receive compensation for tourism ecology.The objectives of this study are to estimate the residents’willingness to pay,work and accept compensation for conservation at Sanjiangyuan National Park,and to analyze the relationship between residents’attitude towards tourism ecology and the ecological assets of the National Park based on a standard questionnaire survey.The dichotomous choice Contingent Valuation Method(CVM)was employed to determine the willingness.The survey conducted in 2018 collected WTP,WTW,WTA,socio-demFographical information,social trust and resident perceptions toward tourism impacts and relevant management strategies from 244 residents in two counties.Based on generalized linear modeling,income and education level are important for residents’WTP and WTA,but other social characteristics,such as gender and age,do not have significant effects.The social trust is found to be a significant factor on residents’willingness,despite the limitation on education level.Also,government funding is associated with residents’inclination to WTP,WTW and WTA,but the support levels differ among the two counties due to geographical and social heterogeneities.The estimated WTP,WTW and WTA for the Sanjiangyuan National Park in 2018 were 1.2448×10^(7) yuan,1.247×10^(6) hours and 2.3232×10^(7) yuan yr^(-1) based on the survey and published demographics.This study,for the first time,estimates the WTP,WTW and WTA for the Sanjiangyuan National Park and informs ecological conservation managers and policy makers.Ultimately,to maintain the long-term benefits arising from sustainable development,compensation should be specifically tailored and site-dependent,and development measures based on local resources should be adopted by governments to actively support eco-tourism activities.展开更多
基金Supported by Knowledge Innovation Project of Chinese Academy of Sciences (Grant No. KZCX1-10-05) Key Program from the National Natural Science Foundation of China (Grant No. 90102009)
文摘By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longi- tude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study con- tained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analy- sis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to tree growth would increase, and the response of tree growth to environmental changes would also increase. This study emphasizes the importance of regional-scale investigations into the biosphere-climate interac- tions. The results of this research indicated a substantial increment of tree-ring radial growth as a re- sult of warmer and wetter climate in the eastern regions. However, climate change will have less effect on forest growth and primary production in the western regions.
基金The National Key Research and Development Program(2017YFC0506501)The Program for Ecological Innovation Team in Minzu University of China(2020CXTD02)。
文摘Willingness to Pay(WTP),Willingness to Work(WTW)and Willingness to Accept Compensation(WTA)are the three quantitative criteria for assessing local ecological asset values for the social aspects of ecosystem services and residents’willingness to contribute to and receive compensation for tourism ecology.The objectives of this study are to estimate the residents’willingness to pay,work and accept compensation for conservation at Sanjiangyuan National Park,and to analyze the relationship between residents’attitude towards tourism ecology and the ecological assets of the National Park based on a standard questionnaire survey.The dichotomous choice Contingent Valuation Method(CVM)was employed to determine the willingness.The survey conducted in 2018 collected WTP,WTW,WTA,socio-demFographical information,social trust and resident perceptions toward tourism impacts and relevant management strategies from 244 residents in two counties.Based on generalized linear modeling,income and education level are important for residents’WTP and WTA,but other social characteristics,such as gender and age,do not have significant effects.The social trust is found to be a significant factor on residents’willingness,despite the limitation on education level.Also,government funding is associated with residents’inclination to WTP,WTW and WTA,but the support levels differ among the two counties due to geographical and social heterogeneities.The estimated WTP,WTW and WTA for the Sanjiangyuan National Park in 2018 were 1.2448×10^(7) yuan,1.247×10^(6) hours and 2.3232×10^(7) yuan yr^(-1) based on the survey and published demographics.This study,for the first time,estimates the WTP,WTW and WTA for the Sanjiangyuan National Park and informs ecological conservation managers and policy makers.Ultimately,to maintain the long-term benefits arising from sustainable development,compensation should be specifically tailored and site-dependent,and development measures based on local resources should be adopted by governments to actively support eco-tourism activities.
