Ecological risks (ERs) are external threats to ecosystem structure and function, and the evaluation of ER is valuable for understanding the extent of the disturbance of ecosystems by human activities. An objective investigation of the spatio-temporal characteristics of ER and its affecting elements can contribute to the improvement of the ecological environment and the sustainable development of regional resources. The Funiu Mountains were chosen as the study area, the ecological risk index was built using landscape interference and landscape separation, and the spatial–temporal properties and scale effect of the ER were assessed. The findings of ER may be separated into four distinct zones to study the variations in ER levels from 2000 to 2015: modest, mild, moderate, and high. Furthermore, geographically weighted regression (GWR) was used to ascertain the degree to which environmental factors impact ER and regional disparities. The results show: (1) Ecological risk assessment was sensitive to scale transformation, and there are variations in the spatial pattern of ER on diverse scale units. With the scale following a 1 km grid to the watershed, Global Moran’s I values dropped from 0.53 to 0.04, and 1 km × 1 km was the most suitable unit. (2) The ecological and environmental quality of the Funiu Mountains improved from 2000 to 2015. The extent of the high ecological risk zone dropped by 398.07 km2, but other types of ecological risk regions rose, owing to the execution of policies aimed at restoring cropland to forests. The ER presented a transitional distribution from a high risk in the surrounding area to low risk in the central area. (3) From the perspective of correlations among the influencing factors, altitude and slope had a negative correlation with other influencing factors, while others were positively correlated. The correlation coefficient between land-use degree and human activities intensity and ER was the highest. Each environmental factor had significant effects on the ERs and spatial variation existed, where the land-use degree and human activities intensity were the main obstacle factors limiting ER improvement. Population density, altitude, slope, and maximum temperature all displayed effects on ER with different directions and intensities.
Topographic position indices (TPIs) measure essential impacts on ecosystem service supply capacity. The identification of changes in ecosystem services and value metrics under varying TPIs has become a topical subject of global change research. Multidimensional changes in spatiotemporal and geographical aspects of ecosystem service values (ESVs) are assessed in this article using land cover/use data from 2000–2015. Effects of land-use/cover changes and topographic indices on ESVs are explored using the Chinese terrestrial unit area ecosystem service value equivalence table combined with topographic factors. A sensitivity index is introduced to quantify the robustness of total ESV to land-use/cover and topographic indices. The results show that: (1) The total ESV in the Qihe watershed declined with a change in land-use/cover during the period 2000–2015. The maximum ESV was CNY 1.984 billion in 2005 and the minimum was CNY 1.940 billion in 2010; (2) The response of ESV to land/use cover varied greatly across TPIs, with the most significant change in ESV occurring in the 0.6–0.8 TPI range and the greatest change in a single ecosystem service occurred in water areas; (3) The sensitivity indices of ESVs are all less than 1. The sensitivity indices of unused land and water tended to zero. Woodland sensitivity indices were the highest at 0.53, followed by those of arable land and grassland, owing to the large proportion of arable land and grassland areas in the overall area of land-use categories.
Rapid urbanization and economic development have resulted in a mismatch between the supply and demand of ecosystem services. The theoretical value of ecosystem services (ESTV) is not suitable for determining ecosystem service compensation, posing challenges for integrated regional ecological development. A scarcity value model was used to analyze the influence of changes in supply and demand on the scarcity value of ecosystem services (ESSV) in the context of land-use change. The spatio-temporal distribution characteristics and trends of the ESSV from 2010 to 2020 were assessed in the Yangtze River Delta (YRD) urban agglomeration in China, and the driving factors were analyzed to provide theoretical guidance for horizontal ecological compensation across regions. The results show the following: (1) In the scenario that did not consider the impact of supply and demand changes on the scarcity value, the total ESTV decreased by 8.67% from 2010 to 2020, and high-value areas shifted to the west and south, whereas low-value areas shifted to the central and northern region and the Jiangsu, Zhejiang, and Shanghai Ringbelt. The ESTV was low in Shanghai and Jiangsu and high in Zhejiang. (2) In the scenario that considered changes in the supply and demand of ecosystem services, the ESSV increased from RMB 213 million in 2010 to RMB 1.323 billion in 2020; an increase of 521.13%. The scarcity value showed high variability within the provinces, with a larger difference between Zhejiang and Jiangsu and a smaller difference between Anhui and Shanghai. The ESSV was higher in counties with increased urbanization and high population density and lower in counties with slower economic growth and fewer people. (3) Regional ecological integration planning and management should be strengthened, and the ESSV might be considered as the reference standard for ecological compensation. The ESSV showed that spatio-temporal heterogeneity might guide the conversion from ecological resources to ecological capital and promote the regulatory role of market mechanisms to achieve horizontal payments for ecosystem services across regions.
4 March 2023 in Environmental Science and Pollution Research