Land use/cover change (LUCC) is one of the major factors influencing the storage of ecosystem carbon. The carbon storage in Qinghai-Tibet Plateau, the world’s highest plateau, is affected by a combination of many factors. Using MCD12Q1 land classification data, aboveground biomass, belowground biomass, soil carbon and humus carbon data, as well as field sampling data for parameters verification, we applied the InVEST model to simulate the ecosystem carbon storage and the impacts of driving factors. The field survey samples were used to test the regression accuracy, and the results confirmed that the model performance was reasonable and acceptable. The main conclusions of this study are as follows: From 2001 to 2010, carbon storage in the Qinghai-Tibet Plateau increased by 10.39 billion t when assuming that the carbon density in each land cover type was constant. Changes of the land cover types caused carbon storage to increase by 116 million t, which contributed 13.82% of the dynamic carbon storage. Consequently, changes in carbon density accounted for 86.18% of the carbon storage change. In addition, we investigated the soil organic matter and aboveground biomass characteristics between 2012 and 2014 and found that the influences of fencing and dung on carbon storage were positive.
The Eurasian steppe (EAS) is the largest contiguous grassland worldwide. Quantitative evaluations of the relative impacts of climate change and human activities on grasslands are significant for understanding grassland degradation mechanisms and controlling degraded grasslands. In this study, we analyzed the grassland productivity based on multiple forms of net primary productivity (NPP), including climate NPP (CNPP), actual NPP (ANPP), and human-caused NPP (HNPP) during 2000–2014. The results demonstrate that the average value of annual ANPP in the EAS was 47.36 gC/(m2·year), with a weak decrease (−0.02 gC/(m2·year)) during the study period. The area of grassland degradation account for 48.52% of the total grassland area in EAS, while the area of grassland recovery account for 51.48%. Restorative grassland was mainly distributed in Mongolia and China, while worse grassland was mainly distributed in the Kazakh steppe regions. Grassland degradation in China was mainly caused by climate change, whereas it was mainly caused by human activities in Mongolia. Grassland recovery in Kazakh steppe regions was mainly caused by human activities, but in Mongolia, it was mainly caused by climate change. Compared with temperature, precipitation played a more significant role on grassland productivity.
Determining the carrying capacity of ecological resources is the key to finding contradictions between human activities and the environment, as well as the links between economic growth, environmental protection and social development. In recent years, the carrying capacity of the ecological environment has been extensively studied at home and abroad. Through extensive literature research and analysis, this paper discusses the current status and main problems of recent research on the carrying capacity of the ecological environment in China. For example, two of the main problems are that: 1) the concepts and connotations are not clear enough, and 2) the research content is not systematic enough. This is followed by a summary of the evaluation index system and main calculation methods. Finally, according to the research status and development trends at home and abroad, the possible direction for the development of this research field in the future is proposed.
1 November 2019 in Journal of Resources and Ecology
Since the 1970s, resource crisis, environmental pollution and ecological degradation have become prominent globally, and the limits to growth have always been an important theoretical and policy issue. The technological system of early warning and regulation based on carrying capacity evaluation has great potential in natural resource utilization, environmental management and ecosystem conservation. In this paper, the evolution of carrying capacity research and the concept of ecological carrying capacity are summarized, and the existing evaluation methods of ecological carrying capacity are classified into ecological footprint method, comprehensive index system method, ecosystem service analysis method and human appropriation of net primary productivity method. The current problems in ecological carrying capacity study were analyzed and the trend was outlooked. Combined with the special issue, the recent proceeding of ecological carrying capacity study in the Belt and Road Initiative (BRI) region was narrated, from the aspects of ecological carrying capacity evaluation method and application, the supply and consumption of ecosystem services, and the resources use and environment change. Some suggestions have been proposed to improve the accuracy and reliability of ecological carrying capacity evaluation: 1) the spatial heterogeneity and temporal dynamic change of ecological carrying capacity should be explored furtherly; 2) the interaction between ecological process and human activities should be simulated; 3) factors such as climate change, human activities and ecological products and ecological service flows should be integrated into the evaluation system of ecological carrying capacity.