Identification of key priority areas under different ecological restoration scenarios on the Qinghai-Tibet Plateau

Systematic conservation planning considering ecosystem services can optimize the conservation system in the Qinling-Daba Mountains

Protected area are the cornerstone of biodiversity and ecosystem service conservation at the local, regional, and global levels. In 2019, China proposed the establishment of a nature reserve system (NRS)centered on national parks, integrating and improving various existing protected areas. This study focuses on the Qinling‒Daba Mountains, an area crucial for both biodiversity and ecosystem services. Through assessments of carbon storage (CS), water yield (WY), soil conservation (SC), and habitat quality (HQ), different conservation scenarios are considered in the context of Systematic conservation planning (SCP). An optimization scheme for the NRS in the Qinling-Daba Mountains is proposed, incorporating ecosystem services and comparing them with the existing system. Research indicates that the main protected areas are concentrated in the Min Mountain‒Motian Mountain‒Longmen Mountain region, the central Qinling region, and the Shennongjia‒Daba Mountain region. Compared with the original system, the area of protected regions in the NRS expanded by 52,000 km2 after the SCP scheme was incorporated. The number of patches decreased to 50, and the patch density reduced from 2.1 × 10-4(/100 ha) to 1.7 × 10-4(/100 ha), thereby reducing the fragmentation of the conservation system. Additionally, the optimized scheme achieved a conservation ratio of over 30% for CS, WY, SC, and HQ, with the conservation efficiency for WY and HQ increasing by 0.18 and 0.22, respectively. The study results provide support for optimizing the Qinling-Daba Mountains NRS and offer a reference for constructing NRSs in other regions. Considering ecosystem services in the optimization of the NRS helps enhance the supply capacity of ecological products, maintain national ecological security, and achieve harmonious coexistence and sustainable development between humans and nature.

Regarding reference state to identify priority areas for ecological restoration in a karst region

Widespread degradation of natural ecosystems around the globe has resulted in several ecological problems. Ecological restoration is considered a global priority as an important means of mitigating ecosystem degradation and enhancing ecosystem services provision. Regarding ecosystem reference state is a prerequisite for ecological restoration. However, there were few studies focusing on how to regard reference state for ecological restoration, especially under a changing climate. Taking Guizhou Province, a typical karst region in China, as a case study area, in this study we firstly assessed ecosystem services under homogeneous climate conditions. Secondly, we defined the optimal ecosystem services as ecosystem reference state, and then evaluated restoration suitability under a comprehensive framework. Finally, ecological restoration priority areas (EPRAs), which included ecological reconstruction areas, assisted regeneration areas and conservation priority areas needing restoration, were identified by integrating restoration suitability and conservation priority areas. The results showed that the services of water conservation and habitat maintenance only increased less than 10% from 2001 to 2018. Identified ecological reconstruction areas and assisted regeneration areas covered 1078 km2 and 1159 km2 respectively. Additionally, 15 conservation priority areas with the total area of 18,507 km2 were identified as conservation priority areas needing restoration. Accounting for 11.78% of the total area, ERPAs were mostly located in the eastern part of Guizhou, including Qiandongnan, Tongren, and Zunyi. The approach proposed here for regarding ecosystem reference state after controlling climate variables and the framework for identifying ERPAs can provide a scientific reference for large-scale ecological restoration planning.

How to synergize ecological restoration to co-benefit the beneficial contributions of nature to people on the Qinghai-Tibet Plateau?

Understanding the magnitude and spatial distribution of ecological restoration requires a precise assessment of the beneficial contributions of nature to people. However, where the restoration areas should be located and whether the natural contribution of a compensation area can satisfy people's needs in the context of ecological degradation remain unclear. To address these issues, we selected the Qinghai-Tibet Plateau as the study areas, utilizing the offset portfolio analyzer and locator model to identify the compensation sites that offset the losses of ecosystem services and biodiversity resulting from ecological degradation. These compensation sites were developed through two offset types: restoration and protection. Then, based on the offset sites, we assessed nature's contribution to people (NCP) under the current status and future scenarios in terms of various aspects, including the habitat (NCP1), climate change (NCP4), and water quantity and flow regulation (NCP6). This study found that the area impacted by agricultural development was 7.15 × 105 ha, and the required compensation area was 5.5 × 106 ha under the current status. The ratio of the impacted area to the required area was approximately 7.0 in the future scenarios. The average habitat qualities were 0.14 and 0.30, while the mean NCP1 values were 2.69 and 0.51 in the protection and restoration offset sites, respectively. Moreover, based on the offset sites, the high-value contributions in NCP4 accounted for 18.64%-22.69% and 38.87%-46.17% of the total offset sites in terms of the restoration and protection offset types, respectively. Additionally, the estimated high-value contributions in NCP6 accounted for 58.35%-59.02% and 84.40%-95.86% of the total offset sites in the restoration and protection offset types, respectively. Our findings highlighted the significance of ecological restoration in showcasing the role of NCPs. These results could aid conservation managers in developing more targeted ecological strategies to enhance human well-being.

Planning a water-constrained ecological restoration pattern to enhance sustainable landscape management in drylands

Ecological restoration is an important approach to improving landscape sustainability. However, ecological restoration in drylands is strongly limited by water resources. Therefore, a technical route for ecological restoration in drylands that creates sustainable landscapes based on those water constraints is needed. In this study, we develop a spatially explicit framework named "Constraint-Pattern-Benefit" to plan ecological restoration patterns in Inner Mongolia, China. Based on a prediction of the ecosystem service (ES) increase under limited evapotranspiration as a water constraint, we constructed 5 landscape sustainability-related strategies with 100 ecological restoration scenarios, which considered fragmentation of restoration locations, distance to city, water consumption, and the allocation scale to determine the spatial arrangement of ecological restoration. Results show that the ES increase potential of ecological restoration under water constraints is distributed in the center of Inner Mongolia. The multi-objective scenario simultaneously achieves 59.1% water yield, 74.2% soil conservation, 57.2% sand fixation, and 52.8% carbon sequestration with 50% restored landscape. Considering the indicators of fragmentation, water consumption, and distance to city decreases the restored landscape fragmentation from 0.44 to 0.26, improves the restoration efficiency by 14.41%, and increases the beneficiary population by 35.5%, respectively. Small-scale allocation can further increase the ES realization efficiency, which is on average 4.8% higher at the city scale than at the provincial scale. Moreover, this approach focuses on the sustainable effect of the spatial arrangement on dryland landscapes at different scales, which provides methodological support for improving the sustainability of drylands.

Reduced soil multifunctionality and microbial network complexity in degraded and revegetated alpine meadows

Understanding how microbial processes develop and change in alpine meadow soils is key to global initiatives toward environmental sustainability and local land management. Yet, how microbial interactions mediate soil multifunctionality in disturbed and managed alpine meadows remains understudied. Here, we investigated multiple community metrics, particularly microbial network properties and assembly processes, of soil bacterial and fungal communities and their links to certain soil functions along a degradation-restoration sequence of alpine meadows in the Qinghai-Tibetan Plateau. Meadow degradation caused significant declines in soil hydraulic conductivity (e.g., higher bulk density, reduced soil porosity and water content) and nitrogen availability, leading to lowered soil multifunctionality. Meadow degradation only caused weak changes in microbial abundance, alpha diversity, and community composition, but remarkably reduced bacterial network complexity, to a less extent for fungal network properties. Short-term artificial restoration with productive grass monocultures did not restore soil multifunctionality, in turn even destabilized bacterial network and favored pathogenic over mutualistic fungi. Soil fungi community are more stable than bacteria in disturbed alpine meadows, and they evolved with distinct assembly strategies (stochastic-dominant versus deterministic-driven processes, respectively). Further, microbial network complexity, positively and better predicts soil multifunctionality than alpha diversity. Our work shows how microbial interaction complexity may enhance soil multifunctionality in degraded alpine meadow ecosystems, noting that meadow restoration with low plant species diversity may failed in restoring multiple ecosystem functions. These findings would help predict the outcomes of global environmental changes and inform management strategies in regional grassland conservation and restoration.

Construction of Ecological Security Pattern and Identification of Ecological Restoration Zones in the City of Changchun, China

Identification of crucial regions in need of ecological conservation and restoration based on ecological security patterns is of utmost importance for ecological restoration across national land space with regard to China's promotion of ecological civilization. Using Changchun, the capital of northeast China, as an illustration, the study chooses ecological sources based on the importance of ecosystem services, builds an ecological security pattern using circuit theory, and organizes critical regions for ecological conservation and restoration. The findings reveal that the 20 ecological sources chosen based on ecosystem services are more concentrated on the eastern side of the city, whereas the western side of the city has a smaller overall area; 41 ecological corridors show a network distribution, among which the southeast is relatively densely distributed; 31 ecological pinch points and 15 ecological barrier points are also identified. Prioritized restoration zones, prioritized protection zones, key conservation zones, and general conservation zones were the four different types of ecological restoration regions identified by the study. Each district's prioritized restoration zones in the main metropolitan area are larger than the others; Gongzhuling's priority protection zones are the largest, and Yushu's natural substrate is the best. According to the grading, targeted solutions are suggested, offering helpful advice for the improvement of ecological patterns and ecological restoration of the aforementioned national areas.

Analysis of Landscape Characteristics and Influencing Factors of Residential Areas on the Qinghai-Tibet Plateau: A Case Study of Tibet, China

The Qinghai-Tibet Plateau is the largest ecological barrier and one of the most vulnerable areas of the ecological environmental system. However, the increasing frequency of human activities in the Qinghai-Tibet Plateau has led to strong interference. Residential areas are the main places in which human activities are carried out and, as such, can effectively reflect the intensity of activities. Based on this, this research takes the Tibet Autonomous Region as the study area and analyzes the distribution characteristics of Tibetan residential areas using Zipf's law and various landscape indices, as well as discussing the influences of altitude, hydrology, ecological environment, and location on residential area distribution. The obtained results indicate the following: (1) The residential areas in Tibet basically conform to the rank-size principle. The residential areas in central and northwest Tibet are concentrated in size distribution, and the relatively large residential areas are prominent, while the residential areas in the eastern Hengduan mountain region are relatively balanced in size distribution. (2) The landscape index results demonstrate that the counties with an unbalanced distribution of residential areas are mainly concentrated in the northwest of Tibet, while the residential areas in the counties and regions where the administrative stations of each prefecture-level city (or region) are located tend to present a polarization phenomenon, with large patches. The area distribution of residential areas showed a "medium-high-low" pattern from southeast to northwest. The residential areas in eastern Tibet have a high degree of fragmentation and a low degree of aggregation, while the residential areas in northwest Tibet have a low degree of fragmentation and a relatively high degree of aggregation. (3) The residential areas in Tibet are most concentrated in the altitude range of 3000-5000 m above sea level and their water affinity and road-affinity are strong, with the distribution of residential areas within 500 m of roads and water networks accounting for more than one-quarter. The vegetation coverage in the residential areas is low, inconsistent with the surface vegetation coverage rate over the whole of Tibet.