Fragile Areas Research Articles

Decoupling the effects of near-surface characteristic change on soil roughness in a dune-meadow cascade ecosystem

As an important indicator of ecological restoration, soil roughness changes exhibit a synergistic evolutionary relationship with near-surface characteristics such as soil and vegetation. However, the main controlling factors for changes in soil roughness in different ecosystems are still unclear. This study was conducted to clarify the changes in soil roughness in different ecosystems and to decouple and quantify the impact of near-surface characteristics on soil roughness in the Horqin Sandy Land (China). Soil roughness was measured using the structure-from-motion (SfM) technique, showing a pattern of farmland (14.08 mm) > semi-mobile dune (12.59 mm) > meadow (6.19 mm) > woodland (5.67 mm). Redundancy analysis (RDA) results showed that the near-surface characteristics of the dune-meadow cascade ecosystem that explained soil roughness, in descending order of importance, were as follows: sand, soil moisture content (MC), silt, plant stem diameter (SD), clay, pH, soil organic matter (SOM), soil shear resistance (SC), litter thickness (LT), water-stable aggregates (WSA), litter density (LD) and bulk density (BD). Specifically, in the semi-mobile dune ecosystem, the order of total effects on soil roughness was as follows: sand (1.311) > pH (0.447) > clay (0.387). In the woodland ecosystem, SC (0.226), pH (|-0.216|), and LD (0.179) were important factors controlling soil roughness. In the farmland ecosystem, MC (0.380), LT (|-0.378|), and SOM (|-0.336|) were the main controlling factors of soil roughness. In the meadow ecosystem, silt (0.574), SOM (|-0.413|), and clay (|-0.380|) significantly influenced soil roughness. Compared to other machine learning models and stepwise regression models, the k-nearest neighbors (KNN) model could predict soil roughness changes more accurately. The findings of this research are of great significance for ecological restoration and sustainable development of the ecologically fragile areas in northern China.

Investigating ‘Land-Use Trajectories’ in Mediterranean Rural Areas with Official Statistics and a Multiway Factor Analysis

While displaying diversified economic values, agro-ecosystems remain a relevant component of rural landscapes in Southern Europe. Coupled with the expansion of ecologically fragile areas because of climate warming, intensification and simplification of rural landscapes—e.g., in lowland—represent frequent trajectories of rural land-use change (RLUC) in the Mediterranean region and demonstrated to harm ecosystem functionality and ecological quality, especially in a context of socioeconomic transformations of landscapes. Additionally, an incipient ‘extensivation’ of geographically remote and economically marginal agricultural systems was also observed, likely following depopulation and land abandonment. The present study elaborated in this direction, providing an integrated RLUC evaluation scheme based on a multivariate analysis of land-use indicators derived from official statistics. This approach was applied to a continuous, long-term RLUC monitoring of a rural landscape in an ecologically complex Mediterranean region (Latium, Central Italy) experiencing multiple trends (e.g., lowland urbanization, crop intensification in gently sloping areas, and land abandonment/depopulation in steep zones) with diversified environmental implications. Based on administrative inventories, such evaluation was carried out over fifty years (1970–2020) in the study area, considering trends over time in selected crop surfaces at the municipal scale as inputs of a multiway factor analysis (MFA). This analysis quantifies stability in the main rural land-use types and possible changes in the dominant farming systems. Simplified indicators of land configuration (namely a crop intensity index and a rural woodland index reflecting ‘intensification’ or ‘extensivation’ of local farming systems) made available at the same spatial and temporal scales completed the informative picture corroborating MFA results. Taken together, our findings delineate multiple changes in rural landscapes, discriminating land-use trajectories in coastal and inland districts. These development trajectories were basically dependent on processes of (i) land abandonment in relict and remote areas, (ii) crop intensification in dynamic rural districts, and (iii) fringe urbanization along the coastal strip.

Effects of coal mining disturbance on spatial and temporal distribution of soil water content in Northwest China‐based on 3D EBK model

AbstractNorthwest China is both an important coal storage base and an ecologically fragile area, and soil water content (SWC) is a key factor limiting the ecological development of Northwest China. Revealing the characteristics of spatial and temporal distribution changes of soil water content in mining areas under coal mining disturbance and the influencing mechanism is crucial for the protection of water resources in mining areas. In this study, the soil water content (depth 0–1000 cm) of a typical coal mine subsidence area in the western part of Shendong Coal Group was monitored in situ for 1 year after mining, and the absolute value, variability, and spatial distribution of soil water content were temporally analysed by combining classical statistics, 2D Ordinary Kriging and 3D Empirical Bayesian kriging spatial interpolation. sequence analysis. The results showed that the shallow SWC (0 ~ 60 cm) was distributed horizontally in bands, and gradually increased along the direction from northwest to southeast; with the increase of coal mining time, the absolute value of SWC decreased by 0.81% ~ 33.58%, and the coefficient of variation decreased and then increased, with the range of variation from 2.19% ~ 34.49%. The deep SWC (100 ~ 1000 cm) was stratified vertically and increased with soil depth, and the shallow and deeper soil moisture would gradually migrate to the middle layer under the influence of coal mining. In addition, this paper accurately portrays the three‐dimensional spatial and temporal distribution of soil water content by the 3D EBK model, which further reveals the mechanism of coal mining's influence on soil water content. This study can provide technical and data support for predicting and evaluating the potential impacts of mining activities on the water cycle, and help mining areas to formulate policies for managing and protecting water resources.

The past and future dynamics of ecological resilience and its spatial response analysis to natural and anthropogenic factors in Southwest China with typical Karst

With the global land use/land cover (LULC) and climate change, the ecological resilience (ER) in typical Karst areas has become the focus of attention. Its future development trend and its spatial response to natural and anthropogenic factors are crucial for understanding the changes of ecologically fragile areas to human behavior. However, there is still a lack of relevant quantitative research. The study systematically analyzed the characteristics of LULC changes in Southwest China with typical Karst over the past 20 years. Drawing on the landscape ecology research paradigm, a potential-elasticity-stability ER assessment model was constructed. Revealing the characteristics and heterogeneity of the spatial distribution, annual evolution, and development trend of ER in the past and under different scenarios of shared socioeconomic pathways and representative concentration pathways (SSP-RCP) in the future. In addition, the spatial econometric model was utilized to reveal the spatial effect response mechanism of ER, and adaptive development strategies were proposed to promote the sustainable development of Southwest China. The study found that : (1) In the past 20 years, the LULC in Southwest China showed an accelerated change trend, the ER decreased declined in general, and there was significant spatial heterogeneity, showing the spatial distribution pattern of “west is larger than east, south is larger than north, and reduction in the west was slower than that in the east.” (2) Under the same SSP scenario, with the increase of RCP emission concentration, the area of the lowest-resilience increased significantly, and the area of the highest-resilience decreased. (3) The woodland was the largest contributor to ER per unit area in the Southwest China, and grassland was the main LULC type, which had a prominent impact on the ER of the study area. (4) The average precipitation and the normalized difference vegetation index (NDVI) were significant natural drivers of ER in the study area, and the economic growth, innovation, and optimization of industrial structure contributed to the ER of Southwest China. Overall, the integration of quantitative assessment and multi-scenario-based modeling not only provides new perspectives for understanding the pattern of change and response mechanisms, but also provides valuable references for other typical Karst regions around the world to achieve sustainable development.

Co-incorporation of wheat straw and hairy vetch reduced soil N2O emission via regulating nitrifier and denitrifier structure on the Qinghai plateau

Introducing green manure is considered a sustainable practice in wheat production on the Qinghai plateau, an ecologically fragile area. However, the regulatory mechanisms governing N2O emission through green manure and wheat straw co-incorporation in nitrifiers and denitrifiers communities remain unclear. Herein, a microcosm experiment was conducted, including no-addition (CK), hairy vetch (VS), wheat straw (WS), and the mixture of hairy vetch and wheat straw (VWS), to investigate soil N2O emission and functional microbes communities. Compared with CK, cumulative N2O emission decreased by 19.1 % and 74.8 % in WS and VWS, whereas it increased by 60.4 % in VS. Residues incorporation increased absolute abundances of denitrifier (narG, nirK, and nosZ genes) by 39 %–139 % than CK. However, the contribution of structures of functional microbes on N2O emission overweighed their absolute abundances. The reduced N2O emission was mainly associated with the decreased relative abundance of M5 and M7 (key ecological cluster, gained from co-occurrence network of narG- and nirK-types denitrifier, dominant genera were Pseudomonas and Bradyrhizobium), and with the increased M13 (from nosZ-type denitrifier, dominant genus was Tardiphaga). In N2O emission peak (the 6th day of incubation), VWS reduced the relative abundance of Pseudomonas by 9.9 % and 11.2 % and Bradyrhizobium by 39.7 % and 49.2 % compared with CK and VS, respectively. Additionally, VWS increased the relative abundance of Tardiphaga by 134.1 % and 172.1 % compared with CK and WS. Our results suggest that wheat straw and hairy vetch co-incorporation is an effective practice to mitigate N2O emission via regulating key denitrifier taxa on the Qinghai Plateau.

The Assessment of Green Poverty Reduction Strategies in Ecologically Fragile Areas: A Case Study of Southern Xinjiang in China

Green poverty reduction is a strategic choice for China to bring ecological benefits as well as economic and social benefits. This study examines three typical models of green poverty reduction strategies in Southern Xinjiang, which is an ecologically fragile region. The data for calculating the comprehensive benefits of the three models were derived from satellite remote sensing data, regional forestry bureau statistics, and survey data from 2021. The economic benefits are calculated to measure the net profit of a certain type of cover such as the supply of timber, forest products, and crops. The ecological benefits are calculated to measure the improvement in water resource regulation, soil conservation, carbon sequestration, windbreak and sand fixation, biodiversity conservation, and landscape recreation. The social benefits include providing employment opportunities and government subsidy. The comprehensive benefits are a weighted average over individual benefit categories. We found that the comprehensive benefits of the composite forest model, the drought-resistant crop model, and the industrial transformation model are CNY 288 million, CNY 50 million, and CNY 545 million, respectively. The composite forest model and the industrial transformation model have greater ecological benefits, while the drought-resistant crop model has greater economic benefits.

Spatio-temporal evolution characteristics and driving mechanisms of Urban–Agricultural–Ecological space in ecologically fragile areas: A case study of the upper reaches of the Yangtze River Economic Belt, China

Ecologically fragile areas, which are vulnerable to human disturbances, are facing development dilemmas due to the contradiction between economic development and environmental degradation. Examining the driving mechanism and future trends of land use transitions can inform territorial planning and land use policies to address the contradiction. However, research into the mechanisms governing the interaction between ecological and social factors driving land use transitions in ecologically fragile areas is currently limited. Considering the Upper Reaches of the Yangtze River Economic Belt (URYREB), a typical ecologically fragile area in China, as an example, this study discussed the spatio-temporal evolution characteristics and driving mechanisms of Urban-Agricultural-Ecological Space. The results indicated that ecological factors influence the direction, location, and scale of spatial evolution, while social factors dominate the direction and scale of spatial evolution. The interaction between ecological and social elements drives spatial evolution due to the endogenous development needs of the social-ecological system (SES), in conjunction with external policy guidance and economic development. In the future, urban function space may continue to expand and threaten surrounding agricultural function space, thus, corresponding land use policies are necessary to ensure food security. This study unveils the impact of multifactor interactions on land use transitions and offers insights for optimizing territorial space planning in ecologically fragile areas.

Prevention Behavior and Awareness of COVID-19 Pandemic of People in Thai-Myanmar Border Area, Mae Hong Son Province, Thailand

Due to the emergence of the COVID-19 pandemic, affords have been made to block the movement of people and goods. It believed to stop the spread of germs from people and goods in the border area. Nevertheless, the people and goods there do not stand still as specified. This study employed quantitative research to investigate prevention behavior and awareness of the COVID-19 pandemic of people in the Thai-Myanmar border area, Mae Hong Son province, Thailand. A set of questionnaires was used for data collection and administered to a sample group of 406 people living near the border trade relief of Mae Hong Son province. Obtained data were analyzed using descriptive statistics, mean, and standard deviation. Based on behavior and awareness of the prevention of the COVID-19 pandemic, it was found that, as a whole, the respondents had the highest level of COVID-19 prevention behavior (x̅ = 4.24). This included the following instructions for public health personnel: social distancing, wearing a hygienic mask, hand washing, and temperature measurement. For the awareness of the prevention of the COVID-19 pandemic, it was also found at the highest level (x̅ =4.28). This included all people’s participation, communication within the household/community to prevent the COVID-19 pandemic, and strict compliance with the community’s regulations to prevent the disease. The border is a fragile area. There is a chance of transmission of pathogens caused by the movement of people and goods in border areas. The prevention of the COVID-19 pandemic of people in the Thai-Myanmar border area under behavior and awareness of disease prevention. Meanwhile, people worldwide are taking measures to reduce the risk of contracting COVID-19.

Three-dimensional model and environmental fragility in the Guarani Aquifer system, SE-Brazil

The Guarani Aquifer System (GAS) is a vast transboundary continental sedimentary basin in southern South America, encompassing sedimentary rocks and basalt flows across Uruguay, Paraguay, Argentina, and Brazil. It serves as a crucial water resource for urban supply and irrigation. This study aims to propose geophysical, geometric, and fragility models of the GAS in a critical exploitation area, utilizing geological data, geophysical logs, geomorphometry, and information from tubular wells. The models define distinct geophysical ranges for each formation and identify contacts between sedimentary and basaltic rocks. Integration of horizontal and vertical spatial distributions of geophysical and geological data forms a 3D model, revealing basaltic flows and intrusions distribution in fragile areas between formations, and potentially connecting aquifer layers. Natural fragility zones, characterized by high fracture densities, are observed in the central-east region, while outcrop and recharge areas of the main aquifer hydrofacies are found in the north. The 3D model highlights similarities between the topography of the Botucatu Formation (KJb – eolian sandstones) and the potentiometry of GAS at local scales, and overexploitation zones in Ribeirão Preto's city center. The assessment prioritizes areas at risk and conservation strategies for sedimentary aquifers, emphasizing interactions between surface and groundwater and addressing issues of overexploitation, identifying high-impact risks on GAS hydrodynamics and water quality.

Spatiotemporal Characteristics of Typical Ecosystem Services and Their Spatial Responses to Driving Factors in Ecologically Fragile Areas in Upper Yellow River, China

Spatiotemporal Characteristics of Typical Ecosystem Services and Their Spatial Responses to Driving Factors in Ecologically Fragile Areas in Upper Yellow River, China

Mental well-being of children and adolescents during COVID-19: evidence from the Italian context and possible future developments.

The article aims to discuss the increased emergence of mental health problems among children and adolescents, as an outcome of the COVID-19 pandemic.The results of a research study conducted among various professionals, such as psychiatrists and psychologists specialized in childhood and adolescence, are presented. The study, which uses both qualitative and quantitative methods, investigates the main consequences of the physical social distancing measures undertaken by the Italian government during the pandemic. The results are in line with the main evidence highlighted by international research and underline the particularly negative effects of the pandemic emergency on the mental health of minors. It reports how the limitation of intersubjective relationships and the forced digitalization of relationships has triggered or caused the emergence of multiple and varied disorders of the psyche, also linked to the area of reference (e.g., metropolitan, urban o remote areas), the socio-economic and cultural fragility of families, as well as the presence of previous mental issues within them. Finally, the research emphasizes how the understanding and management of the psychic health of these population groups, also from a health organization point of view, will be crucial to address the medium and long-term effects of such emerging issues among younger cohorts.

Exploring the Spatiotemporal Evolution Patterns and Determinants of Construction Land in Mianning County on the Eastern Edge of the Qinghai–Tibet Plateau

Studying the spatiotemporal evolution and driving forces behind construction land amidst the intricate ecological and geological setting on the eastern edge of the Qinghai–Tibet Plateau offers invaluable insights for local sustainable development in a landscape transition zone and ecologically fragile area. Using construction land data from four phases, spanning 1990 to 2020, in Mianning County, this study employs methodologies like the Landscape Expansion Index (LEI) and land use transfer matrix to delineate the spatiotemporal evolution characteristics of construction land. A comprehensive set of 12 influencing factors across five categories—geomorphology, geological activity, climate, river and vegetation environment, and social economy—were examined. The Geographically Weighted Regression (GWR) model was then employed to decipher the spatial distribution pattern of construction land in 1990 and 2020, shedding light on the driving mechanisms behind its changes over the three decades. The research reveals distinct patterns of construction land distribution and evolution in Mianning County, shaped by the ecological and geological landscape. Notably, the Anning River wide valley exhibits a concentrated and contiguous development mode, while the Yalong River deep valley showcases a decentralized development pattern, and the Dadu River basin manifests an aggregation development mode centered around high mountain lakes. Over the study period, all three river basins witnessed varying degrees of construction land expansion, transitioning from quantitative expansion to qualitative enhancement. Edge expansion predominantly characterizes the expansion mode, complemented by leapfrog and infilling modes, accompanied by conversions from cropland and forest land to construction land. An analysis of the spatial pattern and drivers of construction land change highlights human-induced factors dominating the Anning River Basin, contrasting with natural factors prevailing in the Yalong River Basin and the Dadu River Basin. Future efforts should prioritize climate change considerations and environmental capacity, aiming for an ecologically resilient spatial pattern of construction land.

Construction and Optimization Strategy of Ecological Security Pattern in County-Level Cities under Spatial and Temporal Variation of Ecosystem Services: Case Study of Mianzhu, China

Climate change and human activities are seriously affecting the ecological level and economic development of county-level cities. Mianzhu City is a typical county-level city located within the Chengdu-Chongqing Economic Circle and the Yangtze River Economic Belt. The study selected primary ecological sources by analyzing high-level ecosystem service functions over time, using Morphological Spatial Pattern Analysis (MSPA). Ecological resistance surfaces were constructed using natural factors to address ecological risks associated with future urbanization. The construction of the ecological security pattern (ESP) followed the source–corridor–node paradigm, incorporating changes in ecosystem service risks. From 2010 to 2020, ecosystem service functions and values in Mianzhu City declined overall, with significant spatial variations. Human activities increased in ecologically fragile areas, aggravating exposure to ecological risks from climate change and urban expansion. Ecological protection and restoration zones were identified, with nature reserves in the north and the southern center as the core. In 2020, 19 ecological sources and 46 ecological corridors were identified, with a spatial distribution pattern of “more length and short resistance in the north, less length and long resistance in the south”. Additionally, 41 ecological pinch points and 16 ecological barrier points were determined. Considering the spatial distribution of the core areas of ecosystem services and lands with human-intensive activities, setting up the general idea of the ecological restoration pattern centered on forests, river corridors, and natural and artificial landscapes. The study provides new insights into constructing and optimizing the ESP, offering crucial references for the rapid urbanization of ecological restoration and development planning in urban regions.

Coupling Coordination Relationship and Spatiotemporal Heterogeneity between Urbanization and Ecosystem Services in the Songhua River Basin

Rapid urbanization in the Songhua River Basin (SRB), a crucial ecological barrier in China and Northeast Asia, has led to the degradation of ecosystem service functions and a decline in their value, thereby posing a significant threat to regional ecological security. Clarifying the complex coupling coordination relationship between urbanization and ecosystem services (ESs) and identifying the spatiotemporal heterogeneity of their interactions will facilitate the high-quality and coordinated development of urbanization and ESs in the SRB. This study employed a systems approach, treating urbanization and ESs as overarching systems and delineating different aspects of urbanization and ecosystem service functions as subsystems within these systems. The spatiotemporal characteristics of urbanization and the ecosystem service value (ESV) in the SRB from 1985 to 2021 were revealed. The coupling coordination relationship and the spatiotemporal heterogeneity of the interactions between urbanization and ESs in the SRB at both the system and subsystem levels were analyzed using the coupling coordination degree (CCD) model and the spatiotemporal geographically weighted regression (GTWR) model. The findings indicated that during the study period: (1) The urbanization index of SRB rose from 0.09 to 0.34, while the ESV experienced a decrease from 2091.42 × 107 CNY to 2002.44 × 107 CNY. (2) The coupling coordination degree (CCD) between urbanization and ESs in the SRB at both the system and subsystem levels increased significantly, generally transitioning from the moderately unbalanced to the basically balanced stage. Areas with high CCD values were mainly distributed in ecological function areas and low-level urbanized areas, while areas with low CCD values were mainly distributed in grassland ecological degradation areas, ecologically fragile areas, resource-dependent old industrial cities, and highly urbanized areas. (3) The subsystems of urbanization had an overall negative impact on Ess, with varying trends, but the spatial distribution pattern of the interactions remained relatively stable. Conversely, the subsystems of ESs all exhibited a trend of initially strengthening and then weakening their negative impacts on urbanization, and the spatial distribution pattern was highly correlated with the spatial distribution pattern of ESV in the SRB.

Responses of precipitation and water vapor budget on the Chinese Loess Plateau to global land cover change forcing

There have been notable changes in precipitation patterns on the Loess Plateau (LP) of China in recent decades, and numerous attribution studies have focused on sea surface temperature anomalies and atmospheric circulation changes induced by aerosols and greenhouse gases emission. However, the influences of global land use and land cover change (LULCC) as an important forcing factor in the climate system on regional precipitation remains poorly understood. In this study, we quantified the impacts of LULCC on precipitation and the water vapor budget in the LP region, utilizing data from LULCC forcing experiments conducted by the sixth phase of the Coupled Model Intercomparison Project (CMIP6). Although global LULCC forcing exerted a negative effect on long-term mean precipitation on the LP region from 1850 to 2014, the different response characteristics were detected during different time periods. The global LULCC caused a decrease of 14 mm in annual precipitation during the period of 1850–1960. Conversely, from 1961 to 2014, it led to an increase of 6.4 mm, which is largely attributed to the enhanced water vapor transport along the southern boundary and westerly belt of the LP region. Moreover, from the perspective of the net water vapor balance of the entire LP, although LULCC caused net water vapor export during both periods 1850–1960 and 1961–2014, the export during the latter period (0.20 × 104 kg s−1) was smaller than that during the former period (0.28 × 104 kg s−1), indicating that the global expansion of grassland and cropland, along with the continuous rise in the leaf area index from 1961 to 2014, contributed to retaining more water vapor within the LP, which in turn was more favorable for precipitation. These findings provide valuable insights into the reasons behind precipitation variations in the LP region, emphasizing that global vegetation restoration and greening play a significant role in improving precipitation in ecologically fragile areas.

Projecting the response of carbon sink potential to land use/land cover change in ecologically fragile regions

Introduction: The carbon storage service of ecosystems in ecologically fragile areas is highly sensitive to regional land use/land cover (LULC) changes. Predicting changes in regional carbon storage under different LULC scenarios is crucial for land use management decisions and exploring carbon sink potential. This study focuses on the Luan River Basin, a typical ecologically fragile area, to analyze the impact of LULC changes on carbon storage.Methods: The PLUS-InVEST model was employed to simulate LULC patterns for the year 2030 under three scenarios: natural development, cropland protection and urban development, and ecological protection. The model projected the future carbon sink potential of the basin under these scenarios.Results: From 2000 to 2020, carbon storage showed a trend of decrease followed by an increase. By 2030, compared to 2020, carbon storage is projected to increase by 16.97% under the ecological protection scenario and decrease by 22.14% under the cropland protection and urban development scenario. The increase in carbon storage was primarily due to the conversion of cropland and grassland to forestland, while the decrease was mainly associated with the conversion of forestland to grassland and cropland, and the transformation of grassland to cropland and construction land. In the potential LULC scenarios of 2030, certain regions within the basin exhibited unstable carbon sink potential, strongly influenced by LULC changes. These areas were predominantly characterized by artificially cultivated forests, shrubs, and agricultural land. Implementing appropriate forest management measures and optimizing agricultural land management practices are essential to enhance carbon sink potential in these regions. Population density, annual average temperature, and DEM (Digital Elevation Model) were the dominant factors driving the spatial variation of carbon sink potential in the Luan River Basin.Discussion: The research results provide a theoretical basis for rational planning of land use and the enhancement of carbon sink potential in ecologically fragile regions.

Mixed planting mode is the best measure to restore soil quality in alpine mines

In ecologically fragile areas heavily affected by human disturbance, it is imperative to restore soil quality to preserve nutrient cycling and ensure ecosystem stability. However, our understanding about the underlying mechanisms of dynamic change in soil quality associated with revegetation in alpine areas remains incomplete. In this study, data from 96 plots were collected to reveal the response of soil quality to vegetation restoration in alpine mines. The soil quality index (SQI) was developed utilizing 19 measured indicators to assess differences in soil quality between various vegetation restoration modes (natural restoration (CK), planting with Elymus dahuricus (ED), Medicago sativa (MS), and multi-plant mixed (Avena fatua L. + Elymus dahuricus + Medicago sativa + Oxytropis coerulea, MM)) and restoration periods (1, 3, 4, and 6 years). A partial least squares structural equation model (PLS-SEM) was constructed to recognize the impact of 14 variables related to topographical features, plant biodiversity and community stability, aboveground plant productivity characteristics, root functional traits, and soil erosion on soil quality. The results revealed significant variations in soil quality among different vegetation restoration modes. Within the initial four years following vegetation restoration, the discernible discrepancies in SQI values were as follows: ED > MM > MS > CK; by the sixth year, the order shifted to MM > ED > MS > CK. Aboveground plant productivity characteristics and functional root traits significantly contribute to soil quality. In contrast, plant biodiversity and community stability had no significant effects on soil quality. Topographical features and soil erosion adversely affected soil quality, with soil erosion exerting the most prominent effect.

Research on the Capability to Prevent Returning to Poverty and Its Enhancement Path for the Ecologically Fragile Areas: A Case Study of Enshi Prefecture

According to the strategic plan for rural revitalization and the consolidation of poverty alleviation achievements, this research has developed an evaluation indicator system encompassing three dimensions: environment, social support, and economic resilience, viewed through a sustainable development lens. This system is designed to gauge the capacity to forestall a relapse into poverty in ecologically fragile regions and can also serve as a foundation for the government to establish a comprehensive early-warning and monitoring system. An integrated approach, combining the TOPSIS and entropy methods, was employed to assess the capability to prevent a recurrence of poverty based on data from Enshi Tujia and Miao Autonomous Prefecture spanning 2016 to 2022. Subsequently, the obstacle degree model was utilized to pinpoint critical barriers to enhancing its capability to mitigate the risk of reverting to poverty. The findings clearly indicated that, compared to other regions, Enshi City and Lichuan City maintained the most robust comprehensive capabilities to avert poverty recurrence between 2016 and 2022. Furthermore, the evaluation of capabilities across various dimensions revealed that, with the exception of Enshi City, other counties and cities demonstrated lower capacities in the environmental, social support, and economic resilience dimensions. Moreover, in 2020, the capabilities of all counties and cities deteriorated, and the capabilities under the dimensions of social support and economic resilience had not returned to their former levels by 2022, suggesting that the social and economic systems are susceptible to emergency public crises. A spatiotemporal analysis of the factors impeding the enhancement of capabilities in the counties and cities of Enshi Prefecture showed that the inhibiting factors varied by region, with the most prevalent obstacles stemming from economic resilience. In terms of environmental dimensions, the total regional water supply played a pivotal role in Enshi Prefecture. There was a pronounced regional disparity in the development of capabilities to prevent the recurrence of poverty, and the evolution of systems, such as the environment, social support, and economic resilience, was markedly uncoordinated. Finally, strategic recommendations and measures were formulated to bolster the capabilities to avert returning to poverty in ecologically fragile areas across these three dimensions.

Genetic Diversity, Mating System, and Seed Viability Reveal a Trade-Off between Outcrossing and Inbreeding in Pinus yunnanensis var. tenuifolia, an Ecologically Important Conifer Species Growing in a Hot-Dry River Basin Habitat in Southwest China

Revealing the relationship between the mating system (i.e., the outcrossing/inbreeding degree) and the fitness of seeds in tree species under wild conditions is essential for understanding the ecological adaptability and evolutionary stability of the species. This study collected open-pollinated seeds from seven wild populations of Pinus yunnanensis var. tenuifolia that exhibited fragmentation in the Nanpan–Hongshui River basin, an ecologically fragile area in China. The seeds and sprouts (germinated seeds) from 20 families were genotyped (24 seeds and 24 sprouts per family) using twelve microsatellite loci to reveal the genetic diversity, mating status, and effect of inbreeding on the three seed quality indicators (thousand-seed weight, germination rate, and germination potential). The three seed quality indicators differed significantly between families (p < 0.001). Higher values of genetic diversity (except the observed heterozygosity) were observed in the sprout group than those in the seed group. Families from different populations showed a notable genetic differentiation (Φst = 0.12), and a large part of families from the common populations had a high degree of coancestry, which signified that the current habitat fragmentation is limiting gene flow between populations. High levels of outcrossing rates (tm) were observed in both the seed group (tm = 0.974) and the sprout group (tm = 0.978), indicating that a low proportion of seeds were self-fertilized. Although there was a slightly higher single outcrossing rate (ts = 0.888) and a lower proportion of biparental inbreeding (tm − ts = 0.077) in sprouts compared to the seeds (ts = 0.871, tm − ts = 0.091), indicating that a part of inbred seeds were purged during the germination stage, curve fitting between the outcrossing rate and seed quality indicators showed that a certain degree of biparental inbreeding (ts between 0.89 and 0.91 and tm − ts between 0.09 and 0.11) did have a positive effect on seed germination ability. This highlights that excessive inbreeding or outbreeding seems to be unfavorable to seed viability. The peculiar relationship between seed viability and the mating system in P. yunnanensis var. tenuifolia was likely an evolutionary consequence of a trade-off between the nature of mixed mating and its specific ecological niche.

Bacteria, Fungi, and Protists Exhibit Distinct Responses to Managed Vegetation Restoration in the Karst Region.

Bacteria, fungi, and protists occupy a pivotal position in maintaining soil ecology. Despite limited knowledge on their responses to managed vegetation restoration strategies in karst regions, we aimed to study the essential microbial communities involved in the process of vegetation restoration. We compared microbial characteristics in four land use types: planted forests (PF), forage grass (FG), a mixture of plantation forest and forage grass (FF), and cropland (CR) as a reference. Our findings revealed that the richness of bacteria and protists was higher in FF compared to PF, while fungal richness was lower in both PF and FF than in CR. Additionally, the bacterial Shannon index in FF was higher than that in CR and PF, while the fungal and protist Shannon indices were similar across all four land use types. Significant differences were observed in the compositions of bacterial, fungal, and protist communities between FF and the other three land use types, whereas bacterial, fungal, and protist communities were relatively similar in PF and FG. In FF, the relative abundance of bacterial taxa Acidobacteria, Firmicutes, and Gemmatimonadetes was significantly higher than in PF and CR. Fungal communities were dominated by Ascomycota and Basidiomycota, with the relative abundance of Ascomycota significantly higher in FF compared to other land use types. Regarding protistan taxa, the relative abundance of Chlorophyta was higher in FF compared to CR, PF, and FG, while the relative abundance of Apicomplexa was higher in CR compared to FF. Importantly, ammonium nitrogen, total phosphorus, and microbial biomass nitrogen were identified as key soil properties predicting changes in the diversity of bacteria, fungi, and protists. Our results suggest that the microbial community under FF exhibits greater sensitivity to vegetation restoration compared to PF and FG. This sensitivity may stem from differences in soil properties, the formation of biological crusts and root systems, and management activities, resulting in variations in bacterial, fungal, and protist diversity and taxa in PF. As a result, employing a combination restoration strategy involving plantation forest and forage grass proves to be an effective approach to enhance the microbial community and thereby improve ecosystem functionality in ecologically fragile areas.