Ecosystem changes revealed by land cover in the three-river headwaters region of Qinghai,China(1990–2015)

The Three-River Headwaters Region(TRHR) of Qinghai Province, in the Tibetan Plateau of China, is the main source of the Yangtze, Yellow, and Lancang rivers, and is very significant to the security of freshwater resources for China and southeastern Asia. It is a critical ecological region of China for its ecological functions, and has been changed or even degraded in recent decades owing to climate change and human pressure. To effectively protect and restore the degraded ecosystems, the Chinese government initiated a series of ecological conservation projects in TRHR. It is essential to quantitatively assess ecosystem changes and their relationship to driving factors for indepth understanding of long-term changes of ecosystems and effects of ecological restoration policies and offer practical insights for ecological restoration. Here, land cover data has been interpreted with the series data of Landsat during 1990–2015. The patterns of different ecosystems and their developing process have been derived from land cover change. The results show that ecosystem types in TRHR include forest, grassland, cropland,wetland, artificial surface and barren land, accounting for 4.51%, 70.80%, 0.15%, 9.47%, 0.16% and 14.90%,respectively. Barren land converted to wetland was the significant ecosystem change from 1990 to 2015. Increases in temperature and precipitation and implementation of ecological rehabilitation helped maintain relatively stable ecosystem patterns. It is necessary to continue ecological projects to improve and/or maintain the ecosystems in TRHR because there is still a risk of land degradation under increasing climate change and human activity.

Research Agenda for Understanding Transboundary Ecosystem Changes and Eco-security in Southwestern China

The longitudinal range-gorge region (LRGR) in Southwestern China, characterized by longitudinal mountain ranges and deep valleys, includes the basins of four major international rivers: the Yuanjiang-Red, Lancang Mekong, Nujiang Salween and Irrawaddy. This region is classified as one of the world’s biodiversity hotspots, and provides an important ecological and economic corridor linking China and Southeast Asian countries. Over the past half century, it has served as a resource base for timber and minerals needed to fuel economic development, which resulted in rapid and drastic changes in ecosystem and species diversity. Proposed and ongoing development programs, such as China’s Great Western Development campaign, Greater Mekong Subregional Economic Cooperation (GMS) and China-ASEAN free trade zone development (“10+1”), threaten to bring unprecedented disturbance to the region’s ecosystems. Present and emerging threats to eco-security have caught tremendous attention worldwide. Therefore, studies on such problems are critical for enhancing ecosystem health and transboundary eco-security. This paper indicates several multi-disciplinary and cross-sector studies on transboundary resources in this region that will meet three major national needs: 1) identifying core scientific issues of ecological development and infrastructure construction in highplateau and mountainous areas for the Western Development campaign; 2) developing maintenance mechanisms and control methodologies for transboundary eco-security and resource base development; 3) providing scientific grounds for multi-lateral diplomacy, trade and economic cooperation, and conflict resolution as part of China’s opening-up to south Asia. The key subjects to be solved include dynamics and major drive forces of this area, ecological effects caused by major projects construction, and transboundary eco-security and its controlling. The research projects proposed in this article will develop theories on ecosystem change and transboundary eco-security, and provide a scientific basis for national and international development strategies.

Scientific Frontier on Human Activities and Ecosystem Changes

'Scientific Frontier on Human Activities and Ecosystem Changes' compiled by the innovation team 'Human Activities and Ecosystem Change',one of International Partnership Programs of Chinese Academy of Sciences(CAS),was published by Higher Education Press

Limnological Changes in the Lake Kinneret (Israel) Ecosystem: The Beginning and Its Significance

The Lake Kinneret (Israel) ecosystem has undergone limnological changes. The trend of changes started in the mid 1990’s. The deviation from the previously known as stable long-term structure of the ecosystem included, among others, phytoplankton community structure, nutrient dynamics, zooplankton densities, water temperature increase, water level decline, and fishery management. This study is aimed at identifying ecosystem stability by focusing on three major compartments of the ecosystem: Total Dissolved Solids (TSS), Plankton (Phyto and Zoo), and Detritus (TSS minus plankton). It is suggested that although significant temporary changes of biotic and abiotic parameters were recorded and despite the existence of the normal seasonal fluctuations, the major compartments’ structural relations were not modified. The objective of the study is to analyze the process initiation of the modification trend. Previous studies and reports were focused on descriptive evaluation of the modified parameters. The expected outcome is a comprehensive evaluation of the modification process. Consequently, resulted prediction might be a tool for managers to improve management design.

CHINA'S VEGETATION/ECOSYSTEM RESPONSE TO GLOBAL CHANGE: RESEARCH PROGRESS & PROSPECTS

This paper presents the latest developments in the re search progress on mechanisms by which natural plants and crops respond to the doubled concentration of CO2 in the atmosphere, resultant climatic change and the modeling of vegetation and eco-systems in China. In addition, it points out that the future study on global change and terrestrial ecosystems should stress m(?)iti-disciplinary teamwork and inter-discipline penetration. Finally, the paper emphasizes 10 research realms in the field to be enhanced in the future.

Landscape dynamitic change in Mu Us Desert derived from landsat TM data

Landscape ecology emphasizes large areas and ecological effects of the spatial patterning of ecosystem. Recent developments in landscape ecology have emphasized the important relationship between spatial patterns and many ecological processes. Quantitative methods in landscape ecology link spatial patterns and ecological processes at broad spatial and temporal scales. In turn the increased attention on temporal change of ecosystem has highlighted the need for quantitative methods that can analyze patterns. This research applies quantitative methods——change detection to assess the ecosystem temporal change in the arid and semiarid area. Remote sensing offers the temporal change of ecosystem on landscape characteristics.

Progress and Perspectives of Ecosystem Services: A Review

According to the latest research of ecosystem service（ ES）,the background and connotation of ecosystem services were briefly summarized,the relationship among human activity,climate change,and biodiversity and ecosystem service function（ ESF） was synthetically analyzed,the research trends of ecosystem services function assessment（ ESFA） were discussed from multi-scale,and the perspectives was given based on the past studies. The ecological long-term location monitoring method based on the ESFA should be studied,evaluation index of ESFA should be further improved,and the ESF research on the arid region should be reinforced.