Mapping and Evaluating Human Pressure Changes in the Qilian Mountains

Evaluation of ecosystem quality and stability based on key indicators and ideal reference frame: A case study of the Qinghai-Tibet Plateau

China has explicitly prioritized the enhancement of ecosystem quality and stability(EQS) as a governmental objective. However, our understanding of systematic and comprehensive assessment methods for EQS remains limited. The development and investigation of corresponding evaluation frameworks and their underlying mechanisms remain insufficiently explored. This study employs the concept of an "ideal reference system and key indicators," integrating diverse ecosystem and human activity characteristics from perspectives such as ecosystem structure, function, and landscape vulnerability, to determine indicator weights using the Analytic Hierarchy Process(AHP) and entropy weight method, thereby constructing an evaluation framework for assessing the quality and stability of the Qinghai-Tibet Plateau(QTP) ecosystem. The spatiotemporal variations in EQS from 2000 to 2018 were examined, and the key driving factors were identified using the optimal parameter-based geographical detector (OPGD). The results indicate that the EQS of the QTP exhibit a spatial distribution pattern characterized by higher values in the southeast and lower values in the northwest. From 2000 to 2018, there has been a consistent improvement in the overall ecosystem quality and stability across the QTP. The EQS exhibit a significant synergistic effect, with high-high(26.59 ± 1.26%) and low-low(32.61 ± 1.45%) matching combinations becoming the predominant regional patterns. However, in climatic transition zones and glacial areas, the relationship between these factors is particularly distinctive, indicating ecosystem response mechanisms specific to certain natural environmental conditions. Vegetation cover(>0.697), evapotranspiration(>0.620), and precipitation(>0.688) are the primary natural factors influencing EQS, while the impact of human activities has become increasingly significant. Furthermore, the research findings underscore the positive effects of the variable climatic conditions of the QTP on ecosystems within the context of global climate warming, while the stringent implementation of ecological protection measures has collectively contributed to the enhancement of EQS. The proposed evaluation framework not only facilitates a comprehensive and precise assessment of regional EQS, but also provides a scientific basis for understanding and managing the adaptive responses of plateau ecosystems under the complex interplay of natural and anthropogenic factors.

Identifying carbon sequestration's priority supply areas from the standpoint of ecosystem service flow: A case study for Northwestern China's Shiyang River Basin

Finding important supply areas helps maintain the ecological security of the region and promotes the creation of healthy ecosystems. By considering the ecosystem service flows (ESF), priority provisioning area studies can be approached from a new perspective. This study describes the real supply in terms of flows. The goal was to reveal the priority-ranked supply pattern of ecosystem carbon sequestration services (ECSS) in the Shiyang River Basin (SRB). First and foremost, soil respiration models and Carnegie-Ames-Stanford Approach (CASA) model were used to examine the supply of ECSS, and a combination of natural and human factors was used to determine the demand for ECSS. Second, Python was used to illustrate the ECSS flow trajectories and flows. Lastly, and utilized in conjunction with System Conservation Planning (SCP) to determine supply regions of importance. The results show that, first, the spatial distribution of ECSS supply and demand clearly demonstrates heterogeneity. This is reflected in the spatial characteristics of supply, which are "high in the south and low in the north," and demand, which is "high in the urban areas and low in the suburbs." Second, the middle and lower portions of the basin, where there is little precipitation and little vegetation, are home to the majority of the locations with poor carbon sequestration fluxes. These areas accounted for almost 60 % of the entire watershed area over time. Third, the first priority area of ECSS occupies 19.3 % of the basin's total area, while the second priority area occupies 21.46 %. For the major supply regions, strict ecological protection laws must be implemented going forward in order to ensure the ability to sustain ECSS supply. The long-term growth of SRB as well as ecological and environmental management can benefit from this research's foundational role in policymaking.

The dominant influencing factors of desertification and ecological risk changes in Qinghai Area of Qilian Mountains National Park: Climate change or human activity?

Transitional features of desert environments partially determine the risks associated with ecosystems. Influenced by climate change and human activities, the variability and uncertainty of desertification levels and ecological risks in the Qinghai Area of Qilian Mountain National Park (QMNPQA) has become increasingly prominent. As a critical ecological barrier in northwest China, monitoring desertification dynamics and ecological risks is crucial for maintaining ecosystem stability. This study identifies the optimal monitoring model from four constructed desertification monitoring models and analyzes spatiotemporal changes in desertification. The spatial and temporal changes in ecological risks and their primary driving factors were analyzed using methods such as raster overlay calculation, geographic detector, cloud model, and trend analysis. The main conclusions are as follows: The desertification feature spatial model based on GNDVI-Albedo demonstrates better applicability in the study area, with an inversion accuracy of 81.24%. The levels of desertification and ecological risks in QMNPQA exhibit significant spatial heterogeneity, with a gradual decrease observed from northwest to southeast. From 2000 to 2020, there is an overall decreasing trend in desertification levels and ecological risks, with the decreasing trend area accounting for 89.82% and 85.71% respectively, mainly concentrated in the southeastern and northwestern parts of the study area. The proportion of areas with increasing trends is 4.49% and 7.05% respectively, scattered in patches in the central and southern edge areas. Surface temperature (ST), Digital Elevation Map (DEM), and Green normalized difference vegetation index (GNDVI) are the most influential factors determining the spatial distribution of ecological risks in QMNPQA. The effects of management and climatic factors on ecological risks demonstrate a significant antagonistic effect, highlighting the positive contributions of human activities in mitigating the driving effects of climate change on ecological risks. The research results can provide reference for desertification prevention and ecological quality improvement in QMNPQA.

Sand fixation and human activities on the Qinghai-Tibet Plateau for ecological conservation and sustainable development

The sand fixation ecosystem services and human activities on the Qinghai-Tibet Plateau (QTP) play a crucial role in local sustainable development and ecosystem health, with significant implications for surrounding regions and the global ecological environment. We employed an improved integrated wind erosion modeling system (IWEMS) model for the QTP to simulate sand fixation quantities under the unique low temperature and low pressure conditions prevalent on the plateau. Using the human footprint index (HFI), the intensity of human activities on the plateau was quantified. Additionally, an econometric model was constructed to analyze the impacts of the natural factors, the HFI, and policy factors on the sand fixation capacity. The results revealed that the average sand fixation quantity was 1368.0 t/km2/a, with a standard deviation of 1725.4 t/km2/a, and the highest value during the study period occurred in 2003. The average value of the HFI for 2020 was 6.69 with a standard deviation of 6.61, and the HFI exhibited a continuous growth trend from 2000 to 2020. Despite this growth, the average human activity intensity remained at a low level, with over 50 % of the area having an index value of <4.84. Overall, a strong negative correlation was observed between the sand fixation ecological capacity and the HFI on the QTP. However, extensive regions exhibited high values or low values for both indicators. The sand fixation capacity on the QTP is influenced by both natural and human factors. In light of these findings, suggestions are made for optimizing protected area design, rational control of human activity scales, and targeted human activity aggregation within certain regions as part of ecological conservation strategies. This study has implications for assessing sand fixation ecological functions in high-altitude regions and enhancing sand fixation capacity within the region, providing valuable practical guidance.

Evaluation and prediction of ecological carrying capacity in the Qilian Mountain National Park, China

With increasing human impacts on the ecosystem in natural protected areas, there is an urgent need to undertake an assessment of ecological carrying capacity taken as a benchmark for assessing regional sustainability. Based on satellite remote sensing and socio-economic statistical data from 2000 to 2019, this study distinguished the controlling factors for the spatial and temporal patterns of ecological carrying capacity in the Qilian Mountain National Park, one of the 10 pilot national parks in China. The ecological carrying capacity index (ECCI) was developed by using the Driver-Pressure-State-Impact-Response framework and a comprehensive weight method. The results showed that the multiyear averaged ECCI was low in the south and west but was high in central and eastern regions. The spatial distribution of the ECCI was constrained by soil resources, ecosystem quality, land use/cover and water environment. At the regional scale, the ECCI decreased from 2000 to 2014, especially in Tianzhu, where farmland expansion and severe droughts reduced habitat quality and ecosystem function. However, the ECCI increased significantly from 2014 to 2019, which was attributed to a warm moist climate and the implementation of eco-environmental protection policies. Forest and grassland coverage, soil and water conservation, waste water treatment amount and terrestrial water reserves accounted for 35%, 26%, 20% and 8%, respectively, of the temporal variability in the ECCI. Concurrent with national park development, the ECCI is predicted to increase in most areas from 2020 to 2029 by back-propagation artificial neural networks, except for Sunan, Shandan and Menyuan, possibly owing to increasing conflicts between humans and the environment. The findings of this study provide evidence about the effectiveness of government policies in promoting regional sustainability by altering ecosystem composition and function. In addition, the dominant drivers for the temporal variability of ecological carrying capacity varied in space according to stepwise regression analysis, calling for region-specific management strategies in mountain protected areas and their surroundings.

Integrating decision-making preferences into ecosystem service conservation area identification: A case study of water-related ecosystem services in the Dawen River watershed, China

The degradation of ecosystems and their services is threatening human wellbeing, making ecosystem service (ES) conservation an urgent necessity. In ES conservation planning, conservation area identification is crucial for the success of conservation initiatives. However, different decision-making preferences have not been fully considered and integrated in ES conservation area identification. This study takes the Dawen River watershed as the study area and considers three water-related ESs to be conserved. We aim to integrate the decision-making preferences of cost-effectiveness, ES sustainable supply, and ES social benefit into identifying ES conservation areas by using conservation cost, ecosystem health, and ES social importance as spatial constraints, respectively. We identified ES conservation area alternatives under the scenarios set according to different decision-making preferences. Specifically, ES conservation targets, i.e., the expected proportion of each ES in conservation areas, are designed to be met where there is low conservation cost (cost-oriented scenario), high ecosystem health (ES sustainable supply scenario), or high ES social importance (ES social benefit scenario). A balanced scenario considering all three decision-making preferences together is further established. The results show that under each scenario, the identified conservation areas can concurrently meet the conservation targets and decision-making preferences. The consideration of different decision-making preferences can greatly influence the spatial distributions of ES conservation areas. Moreover, a severe trade-off between conservation cost and ES social importance is observed under the ES social benefit scenario, and the balanced scenario can achieve a synergy of decision-making preferences. Our study provides a method to integrate the decision-making preference into ES conservation area identification, which can improve the rationality and practicality of ES conservation planning.

Identifying ecosystem service value and potential loss of wilderness areas in China to support post-2020 global biodiversity conservation

Preserving wilderness areas is one of the key goals in the Post-2020 Global Biodiversity Framework(GBF). However, far too little attention has been paid to identifying wilderness conservation priorities on the national scale. In this study, we developed a methodological framework to evaluate the ecosystem service values, potential loss and conservation priorities of wilderness areas in China, providing guidance for wilderness conservation. First, we assessed the conservation value of wilderness areas and found that wilderness areas provided more ecosystem services than non-wilderness areas per unit area in most ecoregions. Then we identified threatened wilderness areas under multiple scenarios due to land use and land cover change. We found that 5.82 % of the existing wilderness areas were projected to be lost by 2100. Finally, wilderness conservation priorities were identified considering both conservation values and potential loss, and 11.24 % of existing wilderness areas were highlighted as conservation priorities. This methodological framework could be applied to other countries to support post-2020 global biodiversity conservation.

Impacts of climate change and human activities on different degraded grassland based on NDVI

Grassland degradation has emerged as a serious socio-economic and ecological problem, endangering both long-term usage and the regional biogeochemical cycle. Climate change and human activities are the two leading factors leading to grassland degradation. However, it is unclear what the degradation level caused by these two factors is. Using the normalized difference vegetation index (NDVI) and coefficient of variation of NDVI (CV_NDVI), the spatial distribution features of grassland degradation or restoration were analyzed in Qilian County in the northeast of the Qinghai–Tibet Plateau. The dominant climate variables affecting NDVI variation were selected through the combination of random forest model and stepwise regression method to improve the residual trend analysis, and on this basis, twelve possible scenarios were established to evaluate the driving factors of different degraded grasslands. Finally, used the Hurst index to forecast the trend of grassland degradation or restoration. The results showed that approximately 55.0% of the grassland had been degraded between 2000 and 2019, and the area of slight degradation (NDVI_slope > 0; CV_{NDVI (slope)} > 0; NDVI_value > 0.2) accounted for 48.6%. These regions were centered in the northwest of Qilian County. Climate and human activities had a joint impact on grassland restoration or degradation. Human activities played a leading role in grassland restoration, while climate change was primarily a driver of grassland degradation. The regions with slight degradation or re-growing (NDVI_slope > 0; CV_{NDVI (slope)} > 0), moderate degradation (NDVI_slope < 0; CV_{NDVI (slope)} > 0), and severe degradation or desertification (NDVI_slope < 0; CV_{NDVI (slope)} < 0) were dominated by the joint effects of climate and anthropogenic activity accounted for 34.3%, 3.3%, and 1.3%, respectively, of the total grassland area. Grasslands in most areas of Qilian County are forecasted to continue to degrade, including the previously degraded areas, with continuous degradation areas accounting for 54.78%. Accurately identifying the driving factors of different degraded grassland and predicting the dynamic change trend of grassland in the future is the key to understand the mechanism of grassland degradation and prevent grassland degradation. The findings offer a reference for accurately identifying the driving forces in grassland degradation, as well as providing a scientific basis for the policy-making of grassland ecological management.

Effectiveness of the Qilian Mountain Nature Reserve of China in Reducing Human Impacts

The management effectiveness of protected areas plays a key role in biodiversity and ecosystem services conservation. We evaluated the effectiveness of Qilian Mountain Nature Reserve (QMNR) in reducing human footprint (HF). Four dominant human activity factors, including population density, land use, road distribution, and night light, were incorporated for HF mapping. Comparisons of the HF value between inside and outside QMNR and its four functional zones were conducted. The results show that both the HF inside and outside of QMNR were increasing, but the difference between them was increasing, indicating partial management effectiveness. The north part of the central reserve has a good effect in reducing human impacts, while the effectiveness was poor at both ends of the reserve. The HF value of the most strictly managed core and buffer zones increased by 10.50 and 6.68%, respectively, for 2010–2020. The QMNR was effective in controlling population density and land use, but ineffective in reducing road construction, mining, and construction of hydropower facilities.