Spatial heterogeneous relationship between ecosystem services and human disturbances: A case study in Chuandong, China.

Goal 15 of the UN Sustainable Development Goals (SDGs) has highlighted the importance of maintaining a sustainable relation between ecosystem services and human activities. Ecosystem services are heterogeneous across landscapes. However, how human activities, which cause disturbances to ecosystem services, relate to such heterogeneity has not been well studied and thus necessarily constraining our ability to manage ecosystems sustainably. Based on land use/land cover data, this study addressed the research gap by running two inter-related analyses on the datasets of the study area, i.e., Chuandong, China. The first analysis involves identifying distinctive heterogeneous units of ecosystem service values using Getis-Ord Gi⁎. The second analysis involves measuring the impacts of human disturbances on ecosystem service values and their variations over every five years between 1990 and 2015, using linear regression and spatial regression models. The result of the first analysis identified heterogeneous ecosystem service units of hot-spots, cold-spots, and random areas. The hot-spots mainly clustered in relative inaccessibility land at higher terrain gradients in the east of the study area. The cold-spots overlapped extensively with built-up areas and farmland at lower terrain gradients in the west of the study area. Random areas distributed mainly in the middle part of the study area. This heterogeneity also existed temporally. Ecosystem service values in the study area decreased from 1990 to 2000 but reversed the trend after 2000. The result of the second analysis revealed that the impacts of hot-spots, cold-spots, and random areas on the relationship between ecosystem service values and human disturbances vary. Specifically, there was a negatively linear relationship between ecosystem service values and the integrated indicator of human disturbances, which was the strongest in random areas, followed by cold-spots and hot-spots. In addition, spatial spillover effect is explicit in the relationship between ecosystem service values and three specific factors of human disturbances, i.e., terrain index, population, and gross domestic product. They varied significantly between units: the terrain index had a positive externality on ecosystem service values with cold-spots and random areas but negative externality with hot-spots; population imposed a more negative externality on ecosystem service values when in proximity to random areas than cold-spots and hot-spots; the externality between gross domestic product and ecosystem service values exhibited irregular inverse 'U' shape, which was below the 'X-axis' in cold-spots but throughout the 'X-axis' in hot-spots and random areas. The findings of this study have potential policy implications in improving ecosystem sustainability through harmonizing the environment and human activities.

Quantifying the Impact of Grain for Green Program on Ecosystem Service Management: A Case Study of Exibei Region, China.

Evaluating the impact of an ecological restoration program on ecosystem services is crucial, given the role of such a program in boosting sustainable ecosystem management. This study examines the impact of one of the large-scale ecological restoration programs in China, the Grain for Green Program (GGP), on ecosystem service management in the Exibei region of China. This region is studied, as it is a key source water area with rich biodiversity and has been experiencing GGP for 20 years. To achieve the stated goal the changes of land use and ecosystem services value (ESV) and the ecosystem services scarcity value (ESSV) in the Exibei region were quantified and assessed based on remote sensing images from 1990, 1995, 2000, 2005, 2010, 2015 and field survey data. The results indicated that the expansion of construction land and the increase of water body were the dominant land use changes throughout the study period. Farmland, forestland and grassland decreased by 2.61%, 0.47% and 1.41% after the GGP, respectively. The ESV of the entire Exibei region increased slightly in response to land use change during 1990-2015, with an annual loss of 0.08% before the implementation of GGP and an annual growth of 0.03% after the implementation of GGP. Moreover, forestland was the dominant contributor to ESSV after the implementation of the GGP. Its annual growth rate was four times higher than before the commencement of GGP. The results of this study contribute to the protection of the Exibei region ecosystem, and more importantly, the future management of the ecosystem service in the hilly regions of southern China.

The Effect of the Grain for Green Program on Ecosystem Health in the Upper Reaches of the Yangtze River Basin: A Case Study of Eastern Sichuan, China.

The Eastern Sichuan Region (ESR) is one of the key pilot regions for Grain for Green Program (GGP) implementation in the upper reaches of the Yangtze River basin in China. Therefore, monitoring the effect of the GGP on the ecosystem in the ESR is important. In this study, the Mann-Kendall Trend Test Model was used to ascertain the changes in vegetation coverage. The transfer matrix was used to explore the changes in Land Use/Land Cover (LULC). LULC change direction model (LCDM) was used to preliminarily assess the impact of LULC changes on the ecosystem. The Pressure-State-Response model (PSR), reflecting the human pressure and the ecosystem state, was applied to analyze the spatial-temporal characteristics of the ecosystem health index (EHI). The time span of this study was from 1990 to 2015. The results show that the vegetation coverage changed significantly (p < 0.05), and ecosystem function developed towards positive because of the increase in the coverage of forestland and water land and decrease in the coverage of farmland. The spatial distribution of the EHI was influenced by the pattern of land use. The eastern region, associated with a large area of forestland and grassland, has a low population density and a low degree of land use exploitation, resulting in a high EHI value. The situation was completely opposite in the western region. Regarding the temporal scale, in spite of the decreasing pressure indicator, most counties had experienced an increase in the EHI. There was a clear correlation between the increased EHI values and the restored areas at the third stage (2000-2005) (p < 0.05, r2 = 0.164), but this correlation disappeared at the latter stage (2005-2015) (p > 0.05). The changes showed significant variations in time and area because of differences in the process and the intensity of the implication of the GGP.