Understanding the relationships between ecosystem services supplies and demands is of vital importance for sustainably utilizing natural capital and coordinating ecosystem services supplies and demands. According to the previous research on ecosystem services at home and abroad, the research framework of the relationships among ecosystem services supplies and demands was put forward in this study. Within this framework, the formation mechanisms and representations of the relationships between ecosystem services supplies and demands were explained, the basic characteristics of the relationships between ecosystem services supplies and demands were summarized, and the potential research focuses were proposed, which could provide a guidance for the studies on the ecosystem services and the governance of ecosystem services. In general, there were two non-exclusive mechanisms that formed the relationships between ecosystem services supplies and demands. On the basis of these formation mechanisms, the representations of the relationships between ecosystem services supplies and demands included bundles, trade-offs, synergies and no-effect relationships. In terms of the characteristics, the relationships between ecosystem services supplies and demands could be spatially heterogeneous, temporally variable and scale dependent. The construction and evaluation of indexes, statistical analysis of indicators, development and simulation of scenarios, and spatial mappings and analysis were the four main methods to study the relationships between ecosystem services supplies and demands.
Recreation oriented ecological restoration (ROER) of national territorial space is an important mean of integrating the protection of damaged ecological space with human leisure function. It is also an important content in building a life community of common destiny of mountains, rivers, forests, farmlands, lakes and grasslands, and improving human well-being. Based on the present research at home and abroad, this paper defined the concept of ROER of geographical space, and pointed out that this kind of ecological restoration should follow the guidance of five theories: ecosystem services theory, man-land relationship areal system theory, location theory, landscape gene theory and earth art theory. Based on practical cases, we summarized the types, characteristics and problems of ROER of land space. Then, we put forward five optimization paths for the practice patterns to identify the restoration orientation with appropriate functions and optimal benefits, to establish a multi-level space scale of transmission mechanism, to promote the local embeddedness of ROER, to strengthen the dynamic monitoring and evaluation of the restoration effects, and to build a sustainable construction and operation management mode, which can provide theoretical and practical references for the ROER and protection of national territorial space.
Evaluation of biodiversity maintenance function is an essential precondition for ecosystem assessment. In this study, we modified and improved the biodiversity maintenance service capability model based on the law of species richness vertical zonality. Then, we further quantified the responses among three spatial scales of provincial, municipal and priority zones. The main conclusions in this study are as follows: (1) There are significant distribution differences in the scales of provincial, municipal and priority areas of biodiversity conservation (PABC). The most important areas in the provincial scale are concentrated in the Qinling-Daba mountains, while they are scarcely distributed at the municipal scale. There is a high consistency of distribution between nature reserves and the most important areas at the priority area scale. (2) The accuracy of identification from high to low in the three scales was: the priority area scale (19.5%), provincial scale (11.7%), and municipal scale (11.2%). The priority area scale assessment is more accurate than that of the administrative area scale. (3) The most important area identified by the scale assessment of the priority area is 28032.3 km2, accounting for 13.7% of Shaanxi province. Comprehensive evaluation results of land use structure and species importance in extremely important areas are superior to those in the administrative area scale.
Remote sensing data can provide long-term sequences for replenishing wetlands in changing environments under the context of scarce data. The accurate identification of wetland systems in arid regions is important to the comprehensive regulation and feedback mechanism of water and soil resources. However, we lack long-term data accumulation in the national wetlands in the context of the complex underlying surface of the Belt and Road region. In this study, random forest (RF) classification model was used to map the spatial distribution pattern of the typical terminal lake wetland in the arid regions over the past 30 years. Through the accurate wetland mapping, the spatial conversion rule of the wetland landscape is calculated, and the spatial connectivity of the wetland landscape is determined. We present the results of a high-precision classification study conducted in the Ebinur Lake National Wetland Reserve (Kappa coefficient is greater than 0.9). The spatial and temporal changes in the Ebinur Lake wetland during 1991-2017 was extremely significant, especially in different seasons of the year. From 1991 to 2017, the total area of wetlands, rivers, lakes, constructed wetlands, and salt marshes increased by 425.06 km2, 47.97 km2, 233.95 km2, 48.74 km2, and 109.41 km2, respecctively, while the total area of marshes decreased by 15.01 km2. The annual change in salt marsh conversion is the largest, and the lake wetlands were shrinking gradually from spring to autumn, mainly into swampy wetlands. In addition, the ideal spatial connectivity of Ebinur wetland is listed in the order of spring > summer > autumn. The connectivity between lake wetlands, marsh wetlands and non-wetlands is better than that of other types of wetlands. The connectivity of wetland landscapes depends on the wetland patches with larger areas. To a certain extent, this research compensates the basic wetland data in the scarce data area, and provides a typical demonstration for the long-term mechanism of ecological water replenishment in the Belt and Road region.
The impact of landscape changes on the quality and connectivity of habitats for multiple wildlife species is a global conservation concern. Zhalong Wetland is not only the priority areas of biodiversity conservation in China, but also the largest haibitat in the world with a large number of red-crowned cranes (Grus japonensis) breeding. The red-crowned crane was listed as a globally endangered species by the IUCN Red List of threatened species (IUCN, 2012), which is the umbrella species and the most sensitive biological indicator species of ecological changes in Zhalong Wetland. The selection of breeding habitat and the dispersal between suitable habitats in the study area are of great significance to the protection of wild red-crowned cranes. Firstly five variables (distance to water, soil wetness, NDVI, distance to roads and distance to buildings) were derived, which was hypothesized to influence the quality of habitat for red-crowned cranes according to the actual investigation within an area encompassing the entire Zhalong Nature Reserve. The MAXENT model was used to predict the suitable habitat distribution of red-crowned crane and analyze the response curve of each factor. The results showed that the red-crowned cranes were more likely to inhabit far away from roads and residents, and the breeding habitat might be close to water with more vegetation in a higher soil moisture condition. Finally, 38 suitable habitat patches were extracted from MAXENT model to simulate the multipath dispersal of red-crowned cranes when they lost flight ability based on circuit theory in landscape connectivity. Our map of maximum current flow between patches highlighted the possible pinch points, which can be used for red-crowned cranes moving directly between patch pairs. Current flow summed across all pairs of patches highlighted areas important for keeping the entire network connected. The results show that based on the suitable habitat patches predicted by MaxEnt model, considering the migration and diffusion behavior of the red-crowned crane in the breeding period, the comprehensive importance of the suitable habitat patches is evaluated by using the area weighting of the cumulative current density, and the suitability level is more consistent with the real nest distribution of the red-crowned cranes. Map results can be used to support the planning efforts concerned with the maintenance of red-crowned cranes metapopulation structure, as well as to protect the landscape features that facilitate the dispersal process.