Qing Feng

In the context of increasing climate variability and carbon neutrality targets, understanding the relative roles of climate and human activities is essential for accurately assessing vegetation carbon sink dynamics. This study develops a climate-controlled attribution framework to disentangle human-induced effects from natural climatic variability in Guizhou Province, a representative karst region of Southwest China. Using multi-source remote sensing and climate data from 2004 to 2023, net ecosystem productivity (NEP) was estimated, and its spatiotemporal dynamics were analyzed. A two-step attribution approach was applied to isolate climate-driven variability and quantify the contribution of anthropogenic activities. Results indicate that mean NEP increased significantly from 273 gC·m⁻²·yr⁻¹ in 2004 to 369 gC·m⁻²·yr⁻¹ in 2023, with a provincial average of 318 gC·m⁻²·yr⁻¹. Human activities are estimated to contribute a dominant share (approximately 60–75%), although uncertainties remain due to methodological limitations. Spatial analysis reveals pronounced heterogeneity, with stronger human-induced enhancement in eastern regions and mixed restoration–disturbance effects in ecologically fragile western areas. These findings suggest that ecological restoration policies in fragile karst ecosystems can generate amplified carbon sink responses beyond background climatic effects. These findings provide insights into understanding climate–carbon cycle interactions and improving region-specific climate mitigation strategies.

The Poverty Alleviation Relocation (PAR) policy is widely regarded as an effective approach for breaking the cycle of ecological vulnerability and poverty. However, quantitative research on the ecological restoration effectiveness of PAR lacks sufficient experimental data support. This study focuses on the karst region and employs analysis methods such as volume-derived biomass and correlation analysis to evaluate the impact of PAR on carbon storage in forest ecosystems using on-site experimental data. The objective is to enhance and broaden the research framework for assessing PAR’s ecological restoration effectiveness. The findings reveal that, compared to the pre-PAR implementation period in 2015, the study area experienced an 8.16% increase in forest land area and a 6.57% increase in carbon storage after six years of PAR implementation in 2021. Following PAR implementation, carbon storage in the stone desertification area surged by 14.31%, indicating a significant correlation between PAR households and carbon storage variables. In the karst area, carbon storage increased by 4.34%, exhibiting a significant correlation between the two variables. Conversely, in the non-karst area, carbon storage rose by 5.01%, but no significant correlation was observed between the variables. Furthermore, post-PAR implementation, there is a discernible trend of stronger carbon storage enhancement with increasing distance from the relocated PAR households.

Forests, serving as crucial custodians of our planet’s ecological balance, also constitute a significant source of livelihood for humanity. Karst regions, recognized as some of the world’s most susceptible landscapes, grapple with the dual predicaments of ecological restoration and resident impoverishment. To bridge the gap between environmental and economic concerns, this manuscript employs an amalgamation of remote sensing and socio-economic methodologies to devise a comprehensive assessment framework, thereby scrutinizing the alterations in forest ecosystems from 2001 to 2020.The investigation reveals that over the past two decades, forest rehabilitation within the study area has yielded commendable outcomes, substantially mitigating various ecological dilemmas instigated by rocky desertification in this region. The forested area has increased significantly, and the ecosystem service value has more than doubled. These improvements are largely attributed to compulsory forest conservation measures, demonstrating their decisive influence. The study advocates meticulous management and conservation strategies to safeguard these unique ecosystems and ensure their sustainability. This research underscores the significance of striking a balance between maintaining ecological integrity and fostering economic development, thereby contributing to the broader discourse on sustainable forest management in vulnerable landscapes.

During the 13th Five-Year Plan period (2015–2020), the Poverty alleviation relocation (PAR), led by the Chinese government in the karst regions of southwest China, aimed to cope with poverty and ameliorate the ecological environment. Nevertheless, few research results have involved quantitative assessment of the ecological effectiveness of PAR. Moreover, few studies on the ecological effects of migration relocation have distinguished the effects of relocation on climatic factors and other ecological restoration projects concerning the ecological environment. It remains unclear to what extent PAR affects the regional ecological environment. In order to quantitatively assess the extent of PAR’s ecological restoration contribution, we adopted the Remote Sensing Ecological Index (RSEI) model, which integrates the four more intuitive and critical influencing factors of greenness, moisture, dryness, and heat. On the Google earth engine (GEE) platform, utilizing its powerful remote sensing data storage capacity and computational capability, we quantitatively assessed the spatial and temporal distribution characteristics of ecological environmental quality (EEQ). As revealed by our research findings, overall EEQ showed a fluctuating upward trend over the period 1996–2021 in the study area, exhibiting an improvement of 22.66%. Mann–Kendall mutation test curves showed the most significant improvement occurred after 2015, with an improvement of 8.06%. Based on the residual analysis model, in order to remove the influence of climatic factors and other anthropogenic activities, and to assess the driving effectiveness of PAR, PAR was remarkedly effective in ameliorating EEQ, causing the RSEI to improve by 0.0221–0.0422. The LISA correlation model further analyzed that 44.91% of regional PAR implementation exerted a remarkable influence on RSEI change, of which 54.59% belonged to positive correlation. Aside from that, we also found that not all areas involved in PAR experienced ameliorated RSEI. In the western region, where the human–land conflict is prominent and the ecology is more fragile, PAR exhibited a significant effect in ameliorating EEQ, but in the eastern region, where the EEQ foundation is better, PAR did not show significant effect, and, thus, the ecological restoration effect of PAR exhibited noticeable geographical suitability.

Many scholars are skeptical about the poverty reduction effect and the ecological effect of poverty alleviation resettlement (PAR). This study evaluates the spatial and temporal evolution of the ecological environment quality (EEQ) to analyze the effectiveness of ecological restoration from PAR. Based on cloud computing using the Google Earth Engine platform, remote-sensing data were obtained and reconstructed from 2000 to 2020. The remote-sensing ecological index (RSEI) was used to analyze the spatial and temporal evolution of EEQ. The results show that the RSEI of the study area increased by 13.07% after the implementation of PAR, and the rate of increase was higher than that in the period before PAR; the Pu’an and Qinglong areas improved most obviously, in terms of the fragile ecological environment and the prominent contradiction between peasants and land. The residual trends method indicated that the contribution rate of improvement in RSEI due to PAR was 70.56%, 88.38%, and 82.96% in 2017, 2018, and 2020, respectively. An increase in RSEI was more obvious in the area with a greater relocated population and a higher corresponding coupling coordination level. PAR has a promoting effect on EEQ improvement but does not have ecological restoration benefits in every region. It is not satisfactory in terms of the degeneration of the LST indicator and the ecological impact of human wells.

Cultivated land resources are important natural resource assets that are related to food security and sustainable development. Due to the many restrictive factors of the karst landform on agricultural production, the quantity and quality of cultivated land in the karst mountainous areas in Southwest China are poor. Reclaiming cultivated land to develop economy or to avoid transitional reclamation to protect ecology is an important proposition in this area. Analyzing changes in the physical and monetary value of cropland resources can help us to formulate more reasonable policies for the development and utilization of cultivated land resources, and to achieve a win-win scenario for economic development and ecological protection. Using multi-source remote sensing data and 20-year landcover data obtained by the GEE platform, this paper evaluated the cropland resources of the karst mountain areas of China at the pixel level. It was found that under the apparent outflow of the physical account of the cultivated land resources, the monetary value still maintained growth, proving that the current cultivated land-use policy in Guizhou Province has significantly improved the value of local cultivated land resources.