Rock Desertification Research Articles

Zoning strategies for ecological restoration in the karst region of Guangdong province, China: a perspective from the “social-ecological system”

Ecological restoration holds great significance in addressing environmental degradation and rock desertification in karst areas. Zoning strategy is a fundamental task in understanding the interrelationship between human-environment to foster sustainable development. We explore “social-ecological” system and conduct a case study on the karst region in Guangdong Province, China. An evaluation framework consists of “development pressure”, “sensitivity status”, and “resilience potential” was established. The results show that: regions with high pressure of development are predominantly located in high-density urban areas. The generally distribution of the comprehensive status index exhibits significant spatial heterogeneity. Regions with low sensitivity are found on the eastern and western sides of the study area. The comprehensive resilience values are largely influenced by per capita energy-saving and environmental protection expenditures. The restoration zones mainly concentrated in the contiguous regions of the northwestern and southern parts, covering more than half of the total area. The conservation zones are more numerous and primarily situated in the northern and eastern parts. By integrating socio-economic and ecological factors, this study proposes ecological restoration strategies for specific zones. It helps for improve development issues arising from complex interactions between human-environment, facilitating the implementation of restoration practices.

Carbon Sink Trends in the Karst Regions of Southwest China: Impacts of Ecological Restoration and Climate Change

Southwest China (SWC) holds the distinction of being the world’s largest rock desertification area. Nevertheless, the impacts of climate change and ecological restoration projects on the carbon sinks in the karst area of Southwest China have not been systematically evaluated. In this study, we calculated carbon sinks by utilizing the Carnegie–Ames–Stanford Approach (CASA) model, and the actual measurements, including the net primary productivity (NPP) data and soil respiration (Rs,) were calculated to obtain carbon sink data. Our findings suggest that the carbon sinks in the karst areas are displaying increasing trends or positive reversals, accounting for 58.47% of the area, which is larger than the overall average of 45.08% for Southwest China. This suggests that the karst areas have a greater carbon sequestration potential. However, approximately 10.42% of carbon sinks experience negative reversals. The regions with increasing and positive reversals are primarily located in the western parts of Guizhou and Guangxi, while negative reversals are observed in the eastern parts of Chongqing, Guangxi, and Guizhou. Ecological restoration projects are the main driving factors for the carbon sinks with increasing trends. Increased humidity and ecological restoration management are the main reasons for the positive reversals of carbon sinks. However, warming and drought shift the carbon sinks from increasing to decreasing in Chongqing, east of Guangxi and Guizhou. The findings of this study highlight the significant role of ecological restoration projects and reexamine the impact of climate change on carbon sequestration.

Dynamic assessment of restored ecosystem health based on pressure‐state‐response subsystem‐system model in a karst trough valley

AbstractLimited soil and water resources in a sloping karst trough valley have negatively affected the local population and ecosystem health. A deeper understanding of karst ecosystem health and its driving mechanism are important for ecosystem management and restoration. In recent decades, the karst trough valley has been exposed to multiple threats from various natural and anthropogenic factors. Assessment of which is essential to understand the state of the karst ecosystem and to develop a suitable, scientifically proven management strategy. Based on the pressure‐state‐response‐subsystem‐system (PSR‐SS) model, the restored ecosystem health of karst trough valley was assessed from 2000 to 2015 at the grid scale. The principal component analysis (PCA) method was adopted to explore the factors driving ecosystem health change. It is found that from the years of 2000 to 2015, there was an improvement in ecosystem health in karst trough valley ecosystem. Land use analysis maps indicate a slight decrease in woodland and grassland and increase in cropland and urban buildup, and the Land coverage increased from 84.87% to 87.64%. The area of karst rock desertification decreased by 75.3 km2 from 2000 to 2015. The AEH indices of 0.27 (2000), 0.45 (2005), 0.46 (2010) and 0.68 (2015), which indicate moderate warning, pre‐warning, early warning and generally healthy, respectively. The 17 selected driving factors were grouped into two broad categories by PCA, one is national policy, and the other one is natural condition and local activities. National policy was to be found the most important influence on ecosystem health. Our findings emphasize the key role of government in ecosystem health change, which would give directions to the sustainable development of karst trough valley areas.

Vegetation types and rainfall regimes impact on surface runoff and soil erosion over 10 years in karst hillslopes

Southwest China is one of the largest contiguous karst areas in the world. Due to the particularity of geological conditions, extreme rainfall events and unreasonable land use, this region is experiencing severe soil erosion. Therefore, the main purpose of this study is to evaluate the influences of vegetation type and rainfall regime on runoff and soil loss in southwest China. The recording of 143 rainfall events from 2006 to 2015 have been divided into 5 rainfall regimes by K-means clustering method. The vegetation type included soil and water conservation forest, grassland, cropland and economic fruit forest. Results showed that vegetation type and rainfall regime both had significant influences on runoff and soil loss. Among the four vegetation types, the cropland produced the largest runoff and soil loss, and the minimum runoff and soil loss were observed in grassland. The rainfall regime I with the shortest duration and highest rainfall intensity produced the largest runoff, accounting for 45% of the total runoff. The rainfall regime IV with shorter duration and higher rainfall intensity generated the greatest soil loss, occupying about 41% of the total soil loss. The general linear model indicated that the main factors affecting runoff were vegetation type, maximum 30-minute rainfall intensity (I30) and rainfall duration, while the soil loss is highly linked to vegetation type and I30. This study suggested that grassland is a good choice to control soil erosion when land use conversion is implemented. Furthermore, replacing soil and water conservation forest with economic fruit forest can not only effectively control soil erosion, but also increase the income of residents in karst regions. Due to the low soil formation rate in karst areas, the soil erosion risk is still high and great efforts should be paid to control soil erosion and rock desertification in this region.

A New Approach to Spatial Landslide Susceptibility Prediction in Karst Mining Areas Based on Explainable Artificial Intelligence

Landslides are a common and costly geological hazard, with regular occurrences leading to significant damage and losses. To effectively manage land use and reduce the risk of landslides, it is crucial to conduct susceptibility assessments. To date, many machine-learning methods have been applied to the landslide susceptibility map (LSM). However, as a risk prediction, landslide susceptibility without good interpretability would be a risky approach to apply these methods to real life. This study aimed to assess the LSM in the region of Nayong in Guizhou, China, and conduct a comprehensive assessment and evaluation of landslide susceptibility maps utilizing an explainable artificial intelligence. This study incorporates remote sensing data, field surveys, geographic information system techniques, and interpretable machine-learning techniques to analyze the sensitivity to landslides and to contrast it with other conventional models. As an interpretable machine-learning method, generalized additive models with structured interactions (GAMI-net) could be used to understand how LSM models make decisions. The results showed that the GAMI-net model was valid and had an area under curve (AUC) value of 0.91 on the receiver operating characteristic (ROC) curve, which is better than the values of 0.85 and 0.81 for the random forest and SVM models, respectively. The coal mining, rock desertification, and rainfall greater than 1300 mm were more susceptible to landslides in the study area. Additionally, the pairwise interaction factors, such as rainfall and mining, lithology and rainfall, and rainfall and elevation, also increased the landslide susceptibility. The results showed that interpretable models could accurately predict landslide susceptibility and reveal the causes of landslide occurrence. The GAMI-net-based model exhibited good predictive capability and significantly increased model interpretability to inform landslide management and decision making, which suggests its great potential for application in LSM.

Spatial variations and the key driving factors of soil losses on dolomite slopes

We selected a typical dolomite slope and set up three micro-plots (projection length was 2 m, width was 1.2 m) on the upper, middle, and lower slopes to analyze the variations of soil losses and the key influencing factors during two hydrological years (2020-2021). The results showed that soil losses at different slope positions on dolomite slopes followed an order of semi-alfisol in lower slopes (386 g·m-2·a-1) > inceptisol in middle slopes (77 g·m-2·a-1) > entisol in upper slopes (48 g·m-2·a-1). Downward along the slope, the positive correlation gradually increased between soil losses and surface soil water content, as well as rainfall, while it gradually decreased with the maximum 30 min rainfall intensity. The meteorological factors affecting soil erosion on the upper, middle and lower slopes were the maximum 30 min rainfall intensity, precipitation, average rainfall intensity and surface soil water content, respectively. Soil erosion processes on upper slopes were mainly driven by raindrop splash erosion and infiltration-excess runoff, while that on lower slopes were mainly driven by saturation-excess runoff. The volume ratio of fine soil in the soil profile was the key factor of soil losses on dolomite slopes, with an explanation rate of 93.7%. The lower slope was the key site of soil erosion in the dolomite slopes. Subsequent rock desertification management should be based on the erosion mechanism of different slope positions, while control measures should be arranged according to local conditions.

Characteristics of Soil Moisture Variation in Agroforestry in Karst Region

The special above-ground and underground dual structure in the karst area makes the capacity of surface water storage in this area poor. In water-limited ecosystems, soil moisture is the key to the survival of plants. Influenced by rainfall and soil texture, soil moisture variation characteristics of different vegetation types are different in slope land. Many researchers use rainfall simulation experiments to study the influence of soil water movement processes under rainfall patterns, but there are few studies under natural conditions. In this paper, wood trees, peach trees, flue-cured tobacco, and grassland were planted at the buffer zone boundary of Shibing, a World Heritage site, along different elevations in the depression of the research site. Peach trees and flue-cured tobacco were the main cash crops in the area. The soil layers of 0–0.15 m, 0.15–0.30 m, 0.30–0.45 m, 0.45–0.60 m, and 0.60–0.75 m were taken as research objects. Rainfall and soil moisture were monitored every ten minutes to study the variation of soil moisture of vegetation types under different rainfall patterns. Through the analysis of soil physicochemical properties and vegetation types, it was found that soil moisture changes were different in different land types. In general, shallow soil moisture (0~0.30 m) was more active in the wet season (CV > 10%) but tended to be stable in the dry season. The rainy season rainfall had the greatest influence on soil moisture change. The response level of soil moisture to rainfall of all vegetation types was grassland > peach trees > flue-cured tobacco. These results can provide ecological and economic suggestions for karst areas with large population distribution in China, so as to reduce the impact of rock desertification on this area.

基于生态监管的生态保护修复工程实施成效评估指标体系

PDF HTML阅读 XML下载 导出引用 引用提醒 基于生态监管的生态保护修复工程实施成效评估指标体系 DOI: 10.5846/stxb202201260248 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2020YFC1806305） Ecological supervision oriented evaluation indicator system for performance assessment of ecological protection and restoration project implementation Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:生态监管是保障生态保护修复工程有效实施的重要途径，生态保护修复监督评估是我国当前维护生态环境安全的迫切需求和生态监管开展的有力抓手。在对国内外已有生态保护修复成效评估相关理论方法进行分析的基础上，围绕生态保护修复工程实施目标，结合生态监管要求，统筹考虑"山水林田湖草生命共同体"理念、生态保护修复工程类型、指标可操作性和兼容性等因素，综合运用频度分析法、专家咨询法和层次分析法等方法，提出了生态保护修复工程实施成效评估指标体系，构建了包括生态环境成效和工程管理成效的指标体系。其中，生态环境成效指标由共性指标和个性指标组成，共性指标包括生态系统格局、生态系统功能、生态干扰等方面的具体指标，个性指标包括森林保护修复工程、草原保护修复工程、湿地保护修复工程、矿山修复工程、防沙治沙工程、石漠化治理工程、水土流失治理工程、地质灾害治理工程、流域综合治理工程等不同工程类型的具体指标。工程管理成效指标主要包括工程绩效、工程实施及公众满意等方面的具体指标。在对各项指标评估的基础上，通过综合评估计算对生态保护修复工程实施成效进行评估。基于生态系统格局指数、生态系统功能指数、生态干扰指数、工程管理成效指数及不同工程类型的个性指标指数，得到生态保护修复工程实施成效综合指数，在此基础上，对生态保护修复工程实施成效进行分级，包括不合格、一般、良好和优秀4个等级，反映生态保护修复工程实施成效状况。研究可为生态监管要求下的生态保护修复工程实施成效评估提供指导方法和重要参考。 Abstract:Surveillance, monitoring and management are important measures to maintain the ecological benefits from the ecological protection and restoration projects. Evaluation on these projects is needed to protect the eco-environmental safety and an effective measure for the ecological management. Based on the investigation on the domestic and abroad studies on the methodology, the indicator selection and the application, this study proposes an index system to evaluate the ecological effects of the ecological protection and restoration projects, focusing on the implementation goals of the ecological protection and restoration projects as well as ecological supervision objectives. Taking the concept of "a living community of mountains, waters, forests, farmlands, lakes, and grasslands", the types of ecological protection and restoration projects, the operability and compatibility of indicators, and other factors into comprehensive consideration, the index system that includes the ecological and environmental achievements as well as the project management performances is established using the methods of frequency analysis, expert consultation and analytic hierarchy process. Among them, the ecological and environmental achievements indicators are composed of common and individual indicators. Common indicators include specific indicators of ecosystem pattern, ecosystem function, and ecological interference. Individual indicators include specific indicators of different project types, such as forest protection and restoration projects, grassland protection and restoration projects, wetland protection and restoration projects, mine restoration projects, sand control projects, rock desertification management projects, soil erosion management projects, geological disaster management projects, and comprehensive watershed treatment projects. The indicators of project management performances mainly include specific indicators of project performance, project implementation, and public satisfaction. The values of assessment indicators focus on the change rates of their values to the background values, reflecting the relevant changes arising from the implementation of ecological protection and restoration projects. Based on the assessment of each indicator, the implementation performances of ecological protection and restoration projects is evaluated through comprehensive calculation. According to the ecosystem pattern index, ecosystem function index, ecological disturbance index, project management effectiveness index, and individual indexes of different project types, a comprehensive index of ecological protection and restoration project implementation performances is obtained. On this basis, the implementation performances of ecological protection and restoration projects is graded into four levels:unqualified, average, good, and excellent, indicating the status of implementation performances of ecological protection and restoration projects. This study can provide a guiding method and important reference for assessing the implementation performances of ecological protection and restoration projects in accordance with the ecological supervision requirements. 参考文献 相似文献 引证文献

Research and Design of Ecological Restoration Machinery for Rock Desertification--Multifunctional Mountain Seeder

A grassland carbon sink is a grassland planting activity with special requirements to implement carbon sink measurement and monitoring of the growth process of forage grasses on the land where the baseline has been determined, with the main purpose of increasing carbon sink. The development of grassland carbon sink is extremely beneficial to achieve the two important deployments of carbon peaking and carbon neutrality. Grasslands with one-fourth area in the south are limited by the rugged topography of the karst landscape and thin soil layer, and the efficiency of pasture planting is low. For the above problems, our team proposes a design around mountain pasture cultivation to reduce carbon emissions and apply it to increase carbon sinks in grasslands of stone desertification areas. The design can provide a concrete solution for restoring the ecological environment and enhancing the carbon sink capacity of grassland in stone desertification areas, and also provide a technical guarantee for local herders to increase their income and productivity. This work has the advantages of high market potential, low cost, composite multi-functional automatic operation, and high planting efficiency with a small size, which has good promotion value. It effectively reduces carbon emissions while improving vegetation cover and establishes a new model of combining green restoration and agricultural production in mountainous areas.

Reconstructing spatial pattern of historical cropland in karst areas of Guizhou, Southwest China

Karst regions are exceptionally responsive to global change with their harsh natural environment, fragile ecology, and acute human-land conflicts. The reconstruction of cropland spatial pattern in karst areas during the historical period is typical for studying human-land relations in karst areas and has important practical significance for climate study. The ecological environment changes at regional and global scales, primarily to provide essential data and a theoretical basis for studying the inverse evolution of rock desertification in karst areas. Guizhou province, a typical karst area, was selected as the research area in 1820. Based on the correction of historical population data and cropland data, a reconstruction model of cropland spatial pattern in karst areas during the historical period was constructed by selecting factors such as elevation, slope, soil types, organic matter content, climatic productivity potential, distance to river and distance from settlements to reconstruct the spatial pattern distribution of cropland in 1820 of Guizhou. The results show that the data on cropland recorded in Guizhou during the Qing dynasty is too low, mainly due to Yin-Ni and the policy of Tu-Di-Mian-Ke. In 1820, the total area of revised cropland in Guizhou was 1,851,792 hm2, with the highest proportion of 14.32% in Dading Fu and the lowest in Songtao Ting at 1.6%. Only 30% of the grid in Guizhou has a cropland distribution. It is mainly concentrated in the central part of Qianzhong District (Anshun and Guiyang Fu), the southern part of Qianbei District (Pingyue Fu and southern Zunyi Fu), the western part of Qiandongnan District, the central and eastern parts of the Qiandongbei District. The overall average reclamation rate of land in Guizhou is 10.93%, the highest reclamation intensity in Qianzhong District, with 8.5% of grids ≥ 50%, and the smallest in Qianxinan District, with only 1.65% of grids ≥ 50%. The analysis is validated by comparing the reconstruction model and the reconstruction results. It can be seen that the reconstruction model and research results of this paper can more objectively reflect the distribution of cropland in karst areas during the historical period, and the reconstruction model is suitable for karst areas with low productivity levels.

Monitoring and analysis of abandoned cropland in the Karst Plateau of eastern Yunnan, China based on Landsat time series images

The Karst Plateau in eastern Yunnan, China (KPEYC) is densely populated. In this area, rocks are widely exposed, and soil erosion and rock desertification are serious issues. Furthermore, the conflict between humans and land is prominent. It is important to monitor abandoned croplands to ensure regional food security, preserve the ecological environment, and promote sustainable regional development. Regarding the lack of historical data and inaccurate identification of abandoned cropland, this study proposed a monitoring method for abandoned croplands based on Landsat time series remote sensing images. First, a decision tree was used to generate constant samples from 2000 to 2020. Thereafter, land use in KPEYC was classified year-by-year based on the random forest method and abandoned cropland pixels were identified based on land use data. Finally, the spatial and temporal characteristics of abandoned cropland in the KPEYC were analysed. Based on the results, the overall accuracy of the method was 0.75. Cropland abandonment in the eastern Yunnan Karst Plateau displayed a rapid growth trend and a slow decrease during the study period, with a significant growth rate from 2001 to 2010. The abandoned cropland was mainly concentrated in southwestern Zhaotong City, the entire territory of Qujing City, and northwestern Wenshan Prefecture, among which Fuyuan County, Luoping County, and Huize County repeatedly experienced more serious cropland abandonment. In addition to social factors, topography had a greater influence on cropland abandonment in the KPEYC, and the greater the slope or altitude, the more severe the cropland abandonment.

Plant Functional Trait Responses to Dolomite and Limestone Karst Forests in Southwest China

Southwest China is distributed with the largest area of limestone and dolomite karst landscapes in the world, and its ecological environment is very fragile; the problem of rock desertification is particularly prominent. Karst lithological differences make habitats and soil heterogeneity more complex, and vegetation has developed certain morphological and physiological structural characteristics to adapt to these special environments, which will most likely lead to differentiation in vegetation functional characteristics, such as seed size, wood density, life type and flowering time, thus affecting the number and growth of seedlings and young trees and the future succession potential of forest stands in karst-vegetation restoration. Therefore, it is important to understand the differences in species composition and the functional characteristics of dolomite and limestone karst forests. Over a 2-year period, we investigated a total of 3170 individuals from 123 species and analyzed the relationship between the species compositions and the functional characteristics of two karst-forest areas with different lithology (i.e., limestone and dolomite karst). It was found that the average number of species with medium-diameter seeds and medium wood density in dolomite plots was obviously greater than the average number of species in limestone plots, but this reached no significant difference. However, with the gradual restoration of each forest, the height and carbon sequestration capacity of the trees began to diverge, with the relative abundance of species with tall trees and high wood density being significantly higher in limestone plots than in dolomite plots. The species richness of evergreen trees was significantly higher in the limestone plots than in the dolomite plots. There was no significant difference in the relative species richness of flowering plants in the two karst-forest areas during spring–summer and winter–spring seasons; however, the species richness of flowering plants in the limestone karst forests was significantly higher than that of flowering plants in the dolomite karst forests during summer and autumn seasons. These significant traits were very closely related to the species richness of the understory plants. Further insight into the temporal aspects of karst-forest succession is needed to grasp how functional traits affect the restorations of different lithological karst forests to their primary states.

Concentrated Stream Data Processing for Vegetation Coverage Monitoring and Recommendation against Rock Desertification

The vegetation covering regions is confined due to deforestation, mining industries, and environmental factors. The intensified deforestation and industrial development processes impact the vegetation coverage and fail to meet the food demands. Therefore, accurate monitoring of such regions aids in preventing adversary processes and their plant extinction. The monitoring process requires accurate data collection and analysis to identify the root cause that can be due to human/climatic/environmental changes. This article introduces a concentrated stream data processing method (CSDPM) assisted by an extreme learning paradigm. The different causes are analyzed using the extracted features in different learning perceptron layers. In this learning, the accumulated data is analyzed for similar features and trained for the consecutive or lagging input data streams. The monitoring process concluded with the learning output by classifying the plant extinction reason. Therefore, the identified reason is addressed through official policies with new recommendations or alternate vegetation improvements. More specifically, the data concentrated towards deforestation are the fundamental data required for feature matching. The features are initially trained from the existing datasets and previously acquired data from the converted landscapes. This proposed method is analyzed using the metrics analysis rate, analysis time, recommendation rate, and complexity.

Information Extraction and Prediction of Rocky Desertification Based on Remote Sensing Data

Rock desertification has become the third most serious ecological problem in western China after desertification and soil erosion. It is also the primary environmental problem to be solved in the karst region of southwest China. Karst landscapes in China are mainly distributed in southwest China, and the area centered on the Guizhou plateau is the center of karst landscape development in southern China. It has a fragile ecological environment, and natural factors and human activities have influenced the development of stone desertification in the karst areas to different degrees. In this paper, Dafang County, Guizhou Province, was selected as the study area to analyze the effect of the decision tree and multiple linear regression model on stone desertification and to analyze the evolution characteristics of stone desertification in Dafang County from 2005 to 2020. The FLUS model was applied to predict and validate the stone desertification information. The results show that the overall accuracy of multiple linear regression extraction of stone desertification is 70%, and the Kappa coefficient is 0.69; the overall accuracy of decision tree extraction of stone desertification is 60%, and the Kappa coefficient is 0.521. The multiple linear regression stone desertification extraction model is more accurate than the traditional decision tree classification. The overlay analysis of stone desertification and slope, elevation, slope direction and vegetation cover showed that stone desertification was more distributed between 1300–1900 m in elevation; stone desertification decreased gradually with the increase in slope; each grade of stone desertification was mainly distributed in the range of 5 to 25° in slope, which might be related to human activities. The FLUS model was used to predict the accuracy of 2015 data in the region and project the changes in stone desertification area in 2035 under a conventional scenario and an ecological protection scenario in the region to provide a new reference for predicting stone desertification.

Driving factors of the variation of ecosystem service and the trade-off and synergistic relationships in typical karst basin

Since 2011, the Chinese government has been implementing a series of comprehensive rock desertification control projects. Concurrently, the relevant ecosystem service functions have been changing. However, few studies have quantitatively evaluated the variation of each ecosystem service function and its driving factors; moreover, the trade-off and synergistic relationships must be further explored. Therefore, the present study used a Soil and Water Assessment Tool (SWAT) model to stimulate three ecosystem service functions of the surface/underground runoff and surface sediment yield of Dabang River (a typical karst basin in Southwest China); the driving factors of ecosystem service variation were examined using geographic detectors; and a Spearman correlation analysis was performed to explore the trade-off and synergy between ecosystem services. This study revealed the following results: (1) The determination coefficient (R2) and Nash efficiency coefficient (NS) are>0.5 during the calibration and validation periods; therefore, they meet the model evaluation requirements, verifying the applicability of the SWAT model for ecological service function evaluation in karst areas. (2) Surface/underground runoff decreased by approximately 64% and 66.53% and surface sediment yield decreased by 25.89% in the study area from 2010 to 2018. (3) The geographic detector results revealed significantly higher explanatory power for two-factor detection than for single-factor detection for the variation of ecosystem services. Changes in various ecosystem services are closely related to rainfall reduction, land use changes, and the succession of rocky desertification. (4) Trade-off relationships exist between surface and underground runoff and between underground runoff and surface sediment yield; a synergistic relationship exists between surface runoff and surface sediment yield. The results provide a theoretical reference for the control of rocky desertification/soil erosion as well as for ecological protection and restoration work in karst areas of Southwest China.

Role of the preferential flow at rock–soil interface in the water leaking process in near-surface fissures filled with soils in the karst rock desertification area

Soil preferential flow infiltrating rapidly through the rock–soil interface is an important hydrological process in karst rocky desertification area. However, how does the water leakage in the near-surface fissures, especially those filled with soil, proceed? The role of preferential flow at rock–soil interface of those fissures on water leakage process still puzzles us. The goal of this study was to reveal the role of soil preferential flow at the rock–soil interface in the process of water leaking of near-surface fissures. Five typical types of near-surface fissures were selected in an area experiencing severe rocky desertification in Guizhou Province, China. Dye tracer testing was applied, combined with digital image processing techniques. The results indicated that the rock–soil interface flow on both sides of the fissures is the most important preferential flow form in the fissures in karst area. The dyed area ratio of preferential flow varied from 0.12 to 0.48 in the rock + soil profiles, from 0.06 to 0.37 in the soil profiles, and between 0.02 and 0.16 in the rock–soil interface. The rock–soil interface is the smallest in terms of both their variation range of dyed area ratio and preferential flow patterns compared with soil and rock–soil profiles. The soil preferential flow in near-surface fissures mainly occurs in the soil depth range of 0–20 cm. The preferential flow path is mainly affected by the rock–soil interface on both sides and can pass through the clay layer with poor permeability. However, the soil depth of the dyed part was more than 50 cm. The soil preferential flow at the rock–soil interface is the main form of rapid downward leakage of water in near-surface fissures in the karst rocky desertification area, which can flow to the bottom of clay layer with poor permeability.

Dynamics of landscape ecological quality based on benefit evaluation coupled with the rocky desertification control in South China Karst

Human uncontrolled land use is the main cause of ecosystem degradation and increased rock desertification in karst areas of Southern China. Landscape ecological quality assessment (LEQA) based on land use plays a significant role in promoting sustainable ecological restoration in karst rocky desertification areas. This paper selects the karst plateau canyon rocky desertification comprehensive control demonstration area in South China as the research object to accurately quantify the impact of ecological management on landscape ecological quality changes (LEQ). Based on the characteristics of the karst ecological environment, the basic theory of spatial heterogeneity and landscape pattern is applied to evaluate the ecological quality of the study area at three levels: landscape stability, landscape disturbance degree, and ecological restoration and reconstruction ability. The results showed that the comprehensive score of regional ecological quality increased from 0.539 to 0.662 from 2015-2020. However, the ecological quality level of unused land and mining areas was still poor, and unsound production activities such as ore mining were the main hindrances to improvements in landscape ecological quality. Areas of better ecological quality were mainly distributed to the north and south of the study area. Treatment measures such as returning farmland to forest and agroforestry effectively improved the ecological environment quality of these areas, but the ecological benefits brought by the treatment in different areas varied significantly. The current analysis results show that the land use-based landscape ecological quality evaluation method is applicable in karst areas with special ecological environments. This work provides a new quantitative research method for the unique ecological environment in karst areas; it can accurately identify trends in ecological environment quality changes and provide a basis for sustainable ecological restoration.

Research Progress on Water–Fertilizer Coupling and Crop Quality Improvement and Its Implication for the Karst Rock Desertification Control

An important problem currently faced by karst rocky desertification management is the degradation of vegetation fruits, which encourages the search for a solution for the sustainable growth of vegetation. Water and fertilizer are key factors affecting crop quality (the formation of soluble solids, protein, amino acids, soluble sugar content, etc.). A comprehensive review of research related to water–fertilizer coupling and crop quality improvement may be beneficial for rocky desertification control. This study analyzed 427 related papers, and the results showed that: (1) the number of published papers showed an “S” curve growth trend over time, indicating that research in the field of water–fertilizer coupling has entered a mature stage after rapid growth, yet it is still in the initial stage in karst areas; (2) the research was mainly theoretical, but also included technology research and development, model construction, demonstration and extension, and monitoring and evaluation; (3) except for research related to greenhouse facilities, the research areas are mainly located in arid and semi-arid regions. The study further revealed (4) the frontier theory of water–fertilizer coupling and crop quality research. Finally, it was found that the theoretical and technical studies related to water–fertilizer coupling and crop quality improvement in karst areas are insufficient. Whether the existing theories and techniques are applicable to karst areas needs further verification. In addition to the areas of selecting germplasm with high water/fertilizer utilization efficiency and tolerance to rocky desertification, further improvement in the dynamic model of water–fertilizer coupling and the construction of a more applicable water–fertilizer coupling model could also be future research hotspots.

Effects of Landscape Type Change on Spatial and Temporal Evolution of Ecological Assets in a Karst Plateau-Mountain Area.

The rocky desertification control project in karst areas exacerbates the transfer of landscape types, changes the ecosystem structure and function, and has a significant impact on ecological assets. How to analyze the relationship between landscape type shifts and the spatial and temporal evolution of ecological assets is one of the key questions that need to be addressed to achieve the goal of overall improvement in ecosystem quality and sustainable regional economic development. This study takes Qixingguan District, Bijie City, Guizhou Province—a typical karst plateau mountainous area—as the research object, and analyzes the spatial and temporal evolution characteristics of landscape type shifts and ecological assets triggered by rock desertification management from 1995–2018, based on the equivalence factor method, combined with the contribution rate, spatial autocorrelation, and sensitivity research methods. The results showed that arable land, grassland, and woodland were the main landscape types in the study area. The value of ecological assets showed a trend of increasing and then decreasing, with an overall increase of 87.70 × 106 yuan. The distribution pattern of ecological asset value from southwest to northeast is “high–low–high”. There is a significant positive correlation in the spatial distribution of the overall ecological assets, with similar aggregation between neighboring units. The expansion of forest land was the main factor for the rapid increase of assets from 1995 to 2010, with a contribution of 98.12%; the conversion of arable land and grassland to construction land was the main factor for the decrease of assets from 2010 to 2018, with a percentage of 81.06%, where the value of each type of service was mainly composed of five items, such as soil formation and conservation, biodiversity conservation and gas regulation, water conservation, and climate regulation. This study shows that spatial and temporal evolution assessment of ecological assets is an important manifestation of the effectiveness of rocky desertification control, which can provide decision support to resource managers and users for regional ecological environment construction.

Identifying Ecological Security Patterns Based on Ecosystem Services Is a Significative Practice for Sustainable Development in Southwest China

Southwest China, which is rich in biodiversity and a wide range of ecosystem services (ESs), is a strong support for local human wellbeing. This area is also one of the key components of the ecological security shelter (ESS) for national ecological security and biodiversity conservation. Due to the combination of man-made and natural factors, Southwest China has suffered serious ecological degradation that directly threatens ecological security which refers to the health status of ecosystems and ESs functions. Mapping ESs-based ecological security patterns (ESPs) is essential for designing conservation strategies that suitably combine regional environment conservation with sustainable utilization. We used the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs Tool) model to identify ecological conservation priority areas which integrated ecological sensitivity (soil erosion sensitivity, rock desertification sensitivity, landslide sensitivity, debris flow sensitivity, and freezing-thawing erosion sensitivity), ecological risk (drought risk, natural disaster risk, and socio-economic risk), and ecological conservation importance (soil conservation, water conservation, and biodiversity conservation importance). In this research, we summarized a new designing framework of ESs-based ESPs. We divided the study area into two zones and four belts including: (A) the alpine steppe and wetland zone, (B) Hengduan Mountain zone, (C) northern shelter belt (Daba-Micang Mountain), (D) central shelter belt (Wumeng-Wuling Mountain), (E) southern shelter belt (southern border of China), and (F) southwestern shelter belt (eastern Himalayas Mountain). Identifying distributions of the ESs-based ESPs has practical significance to improve local human wellbeing and to maintain sustainable development of natural-social ecosystems in Southwest China. Furthermore, ESs-based ESPs are necessary for local administrations to create rationalizing plans on balancing conservation and utilization of natural resources, so that policy-makers can put into place targeted prevention and control measures to limit the development of excessive consumption of natural resources and ecological damages, which is worth promoting.