Changes in Ecological Environment of the Tarim River Confirmed by Tree Rings

The tree ring is an important carrier of the evolution of climate in the study of global change.It enjoys advantages of accurate dating,strong continuity,high resolution ratio and high reconstruction precision.This paper tested the changes of Populus euphratica tree ring and the runoff in the upper and middle reaches of the Tarim River through the monotonic trend and analyzed the response of the tree ring in the lower reaches of the Tarim River to the water supply through the combined tree ring data and the historical literature,so as to confirm the accuracy of the response of Populus euphratica tree ring to river diversion.The results were included as follows.(1)From 1957 to 2010,the radial growth of Populus euphratica in the upper and middle reaches of the Tarim River decreased gradually in the time series,which was the same as the runoff.The downtrend was significant,and|Zc|was more than 0.96.(2)From1913 to 2000,the radial growth of Populus euphratica as a whole in the lower reaches of the Tarim River decreased.The downtrend was significant between 1973 and 2001,reaching the lowest level in the past 100years.The formation and diversion of the Layi River was as described in the historical literature.(3)The development of the ecological water delivery project has improved the ecological environment of the lower reaches,which has been verified from the Populus euphratica tree ring in the lower reaches.However,despite the ecological water delivery project in recent years,the growth of Populus euphratica tree ring has not reached to the level before 1920,indicating that the existing ecological water delivery is of limited value in recovering desert riparian forest.(4)In the analysis of the response of the Populus euphratica to the water resources,the wavelet analysis method and the historical literature review method have drawn the same conclusion.

The Analysis of NGOs' Organizational Ecosystem in Participating in Climate Change Issues in the United States

How many NGOs were there in the climate change field in the United States？ Who were they？ And what was the relationship between them？ In the United States,climate change was only a branch of environmental issues at the beginning; therefore there were no specific quantitative statistics and network analysis of NGOs in climate change. Diversity was an important feature of NGOs in American climate change fields,and it showed a complex organizational ecology through varieties of networks and interaction among organizations. In order to make a difference in climate field,Chinese NGOs firstly needed to improve and enhance their own abilities.

Ecological health analysis of wetlands in the middle reaches of Yangtze River under changing environment

Changes in wetland ecosystems have a critical impact on the local ecology and species diversity.Different development scenarios and policies are key factors influencing their changes.Therefore,we studied changes of wetlands in the middle Yangtze River basin(MYRB)in 2001-2020,and a patch-generated land use simulation(PLUS)model and random forest(RF)method were applied to predict and analyze the changes under different scenarios in the MYRB in the future(i.e.2035-2095).The results indicated that:(1)The regions with high wetland proportions were concentrated in the central and eastern MYRB in 2001-2020,with a 1.5%decrease in overall wetland area;(2)The RF could simulate the future ecological quality with training and testing accuracies of 0.98 and 0.92,respectively;(3)Remote Sensing Ecological Index(RSEI)less than 0.5 in the central and eastern regions and 13.3%reduction in the northwest in the SSP245 scenario.In general,the study provides a basis for future regional studies of ecosystem quality and provides data to support wetland conservation and management.

Spatial quality： analysis of China＇s eco-environmental 1990-2010

Over the past two decades in China, stress on the environment has increased continuously. This paper will assess the change in environmental quality over time, and its spatial variation using data from the statistical yearbooks of 31 provincial administrative regions in 1990, 1995, 2000, 2005, and 2010. These books provide a general assessment of the environment at the provincial level, and the three major economic regions from western to eastern China. By using the geographic information system （GIS） and SPSS, we analyzed the changing trend of China＇s eco-environment and calculated the changing trajectory in the gravity center of the eco-environmental quality. We conclude the following. （1） From 1990 to 2010, the rate of deterioration of the environment went down. We argue that the cause of this trend was neither the result as ＂the deterioration trend was under control＂ noticed by the government departments concerned, nor ＂the deterioration rate of the environment was increasingly intensified＂ suggested by many researchers. （2） Since 1990, the general environment has been worsening in China, but it was improved in some regions; however, the ecological deficit is still expanding and will last for a long time. （3） From western to eastern China, the deterioration rate of environmental quality was slowed down. The reasons include a good natural environment, a developed regional economy, and technology and finance in eastern China. （4） After extensive economic development in China, there are imbalances of population, economy, society, and the environment in the 31 provincial regions. The governments at all levels should play an important role in research and protecting the environment. In addition, it is imperative to implement positive measures such as controlling population, improving the environment, and promoting smart development to balance the socio-ecological system.