Search Results (25)

Global warming has exacerbated the impact of regional drought on vegetation ecosystems, especially in typical karst areas with fragile ecosystems that are more severely affected by drought. However, the response mechanisms of vegetation ecosystems in karst areas to drought stress are still uncertain. With drought stress in the summer of 2022, we examined the spatiotemporal patterns of drought in a World Heritage karst site, Guilin, China, and revealed the exacerbated drought impacts on vegetation ecosystems in karst areas with various vegetation indices. Firstly, we analyzed the spatiotemporal characteristics of drought from 2000 to 2022, utilizing the temperature vegetation dryness index (TVDI), highlighting the intra-annual variability of drought in 2022. Additionally, we compared the responses of different vegetation types to drought stress in karst and non-karst areas and explored the exacerbated impacts of drought stress on vegetation ecosystems within the same year with three vegetation indices, namely, the Normalized Difference Vegetation Index (NDVI), Leaf Area index (LAI), and Gross Primary Production (GPP) in karst areas. The results showed that drought started in July and persisted from August to November at moderate to severe levels (with severe drought in September), eventually easing in December. Karst areas exhibited severe drought (TVDI = 0.76), which more significantly impacted regional vegetation ecosystems than those in non-karst areas. Different vegetation types also experienced greater drought stress in karst areas compared to non-karst areas. The vegetation indices increased at the early- to mid-stages of drought (July to September) compared to those in the baseline year (2020–2021), mainly due to the increase in non-karst areas. However, vegetation indices decreased at the late drought stage (October to November), primarily due to the decrease in karst areas, indicating that the karst topography exacerbated the impact of drought on regional vegetation ecosystems. Since LAI and GPP exhibited similar changing patterns to TVDI, with GPP showing particularly strong alignment, they can be used to reveal the response mechanisms of ecosystems to drought stress in karst areas. We emphasize the importance of monitoring the responses of vegetation ecosystems to climate-induced droughts stress and enhancing their resilience to future climatic challenges, particularly in karst areas. Full article

Amid global desertification, this study investigates karst ecosystems; analyzing soil’s physiological and ecological properties within intricate fissure networks supporting plant root growth. This study investigates soil nutrients in three types of rocky fissure network habitats in Maolan, through field surveys and experimental measurements. Significant variability was found across habitats. The quantities of organic carbon, total nitrogen, available nitrogen, available phosphorus, and available potassium were highest in Type I soil, followed by Type III; and were lowest in Type II. Total phosphorus was highest in Type III, intermediate in Type I, and lowest in Type II; while total potassium content was highest in Type III, moderate in Type II, and lowest in Type I. Based on nutrient participation in C, N, P, and K cycles, Type I habitats had the highest levels, Type III had moderate levels, and Type II had the lowest levels; while potassium-related nutrients were highest in Type III. The nutrient ratios C/K, N/K, P/K, and N/P were highest in Type I, moderate in Type II, and lowest in Type III. C/N was highest in Type II, moderate in Type III, and lowest in Type I; while C/P was highest in Type II, moderate in Type I, and lowest in Type III. A comprehensive nutrient evaluation ranked Type I as the best, Type III as moderate, and Type II as the worst. Key factors such as average trace length, areal density, and integration significantly influence soil nutrients by impacting humus and soil storage, and the growth space for plant roots within rocky habitats. Additionally, the orientation of fissures primarily impacts nutrient cycling, while both the angles and lacunarity significantly affect the stoichiometric ratios of nutrients. Rocky habitat networks characterize soil quality. A comparison of existing studies reveals stoichiometric differences between karst and non-karst regions. Effective ecological restoration in karst areas requires targeted strategies that consider the specific attributes of different rocky habitats. This study enhances understanding of soil nutrients in karst forest ecosystems and proposes new approaches for soil’s ecological restoration and combating global desertification. Full article

The World Natural Heritage Sites (WNHSs), which have unique ecosystems, ecological landscapes, and biodiversity, are the common heritage of all of humanity. The evolutionary pathway of ecosystem services (ESs) in the Karst WNHS between the years 2000 and 2020 has been examined, and the trade-offs and synergies among the ESs have been quantified. This research serves as a point of reference for the rational utilization of natural resources and for the protection of the ecological environment within the Karst WNHS. This research aims to assess the following ESs in the Karst WNHS, for the period 2000–2020: water conservation (WC), soil conservation (SC), carbon sequestration (CS), and habitat quality (HQ). Additionally, the objective of this study is to examine the space–time evolution of these ESs. Spearman’s correlation coefficient and spatial auto-correlation analyses were utilized to ascertain the temporal and spatial trade-offs and synergies for each ES. The results of this study indicate the following: (1) Between the years 2000 and 2020, the inter-annual changes in HQ and CS at the Shibing and Libo-Huanjiang WNHS exhibited a relatively stable pattern, with a gradual increasing trend, and in contrast, the inter-annual changes in WC and SC exhibited greater fluctuations; (2) the distribution of ESs is closely linked to land use patterns, and woodland is the most critical land type of the ESs, contributing the most to each ES; (3) population density is negatively correlated with various ecosystem services, while GDP is positively correlated with each ecosystem service; and (4) the Karst WNHS in Southern China demonstrates a clear and significant synergistic relationship between WC and CS. This relationship is primarily characterised by a strong synergistic effect. The synergistic relationship between HQ and WC exhibited a weakening trend within both study areas. Furthermore, the SC demonstrated a spatial trade-off relation with HQ, CS, and WC. Full article

Clarifying the spatial and temporal evolution characteristics of the ecological environment quality of World Heritage Karst Sites (WHKSs) and its response to different rocky desertification grades at spatial scales is crucial for the monitoring and protection of WHKSs as well as the implementation of ecological and environmental policies in karst regions. The ecological evaluation model of Remote Sensing Ecological Index (RSEI) was used to evaluate the ecological environment of Libo–Huanjiang World Heritage Karst site and Shibing World Heritage Karst site, and then the spatial autocorrelation and geo-detection model was used to further analyze the ecological environment, and final spatial overlay of RSEI and rocky desertification by year to analyze the linkage relationship between RSEI and rocky desertification. The results showed that (1) in the three-phase ecological environmental quality evaluation of the two heritage sites, the RSEI in 2010, 2016, and 2022 reached 0.60, 0.67, and 0.64 for the Libo–Huanjiang heritage site, and RSEI in 2010, 2016, and 2022 for the Shibing heritage site reached 0.60, 0.74, and 0.70, respectively; (2) the RSEI of both heritage sites show a gradually increasing positive spatial correlation, and has significant spatial aggregation characteristics, with both heritage sites dominated by the high-high and low-low spatial aggregation categories; (3) both heritage sites have the highest degree of explanation of changes in ecological quality by the NDBSI factor, indicating that this factor plays a key role in changes in ecological quality at heritage sites; (4) the response of the RSEI mean value of Libo–Huanjiang in each grade of rocky desertification area is, from high to low, no rocky desertification, non-karst, potential rocky desertification, mild rocky desertification, moderate rocky desertification, intensive rocky desertification, and extreme intensity rocky desertification, and the response of the RSEI mean value of Shibing is, from high to low, non-karst, no rocky desertification, potential rocky desertification, mild rocky desertification, and moderate rocky desertification. The spatial superposition analysis of the RSEI index and rocky desertification index can quantitatively study the changing status of the ecological environment in different rocky desertification areas, and the results of the study can provide theoretical references for the environmental monitoring and the prevention and control of rocky desertification in the karst areas and WHKSs. Full article

LiDAR-based digital terrain models (DTMs) represent an advance in the investigation of small-scale geomorphological features, including dolines of karst terrains. Important issues in doline morphometry are (i) which statistical distributions best model the size distribution of doline morphometric parameters and (ii) how to characterize the volume of dolines based on high-resolution DTMs. For backward compatibility, how previous datasets obtained predominantly from topographic maps relate to doline data derived from LiDAR is also examined. Our study area includes the karst plateaus of Aggtelek Karst and Slovak Karst national parks, whose caves are part of the UNESCO World Heritage. To characterize the study area, the relationships between doline parameters and topography were studied, as well as their geological characteristics. Our analysis revealed that the LiDAR-based doline density is 25% higher than the value calculated from topographic maps. Furthermore, LiDAR-based doline delineations are slightly larger and less rounded than in the case of topographic maps. The plateaus of the study area are characterized by low (5–10 km⁻²), moderate (10–30 km⁻²), and medium (30–35 km⁻²) doline densities. In terms of topography, the slope trend is decisive since the doline density is negligible in areas where the general slope is steeper than 12°. As for the lithology, 75% of the dolines can be linked to Wetterstein Limestone. The statistical distribution of the doline area can be well modeled by the lognormal distribution. To describe the DTM-based volume of dolines, a new parameter (k) is introduced to characterize their 3D shape: it is equal to the product of the area and the depth divided by the volume. This parameter indicates whether the idealized shape of the doline is closer to a cylinder, a bowl (calotte), a cone, or a funnel shape. The results show that most sinkholes in the study area have a transitional shape between a bowl (calotte) and a cone. Full article

The Lijiang River Basin is a humid, subtropical, karst landform in China and is listed as a World Heritage Site. However, with the rapid development of urbanization and tourism activities in recent years, it faces increasingly severe non-point source pollution. To understand the temporal and spatial variations in nitrogen and phosphorus pollution discharge and the changes in river water quality, the Jingui Small Basin, in the upper reaches of the Lijiang River, was chosen as a representative system. Changes in nitrogen and phosphorus concentrations were continuously monitored in the main river channel and the river water quality was evaluated using the comprehensive water quality identification index method. The results indicated that there were obvious seasonal changes in nitrogen and phosphorus discharge loads in the basin. Both nitrogen and phosphorus discharge loads were higher in the crop-growing season than in the non-growing season. No significant difference in nitrogen and phosphorus discharge load between different scales was found, and the scale was not the key factor affecting the nitrogen and phosphorus discharge load of Jingui River. As the river flowed from the initial water source to the outlet of the basin, water quality was characterized by the spatial pattern of the upper reaches > the middle reaches > the lower reaches. Except for the water quality at the outlet of the basin in November and December, which reached Class V, the comprehensive water quality of each sub-basin reached the target water quality of the water function zoning from May to December. The elucidation of the nitrogen and phosphorus pollution discharge patterns in the Jingui River and the changes in water quality provide a reference for the control and management of agricultural non-point source pollution in the Lijiang River Basin. Full article

Changes in the spatial pattern of land use are inextricably linked to the ecosystem environment, and the assessment of regional eco-environment quality can help provide sustainable and healthy development strategies for heritage management organizations. In this study, based on RS and GIS technologies, we quantitatively analyzed the characteristics of land use changes in the Shibing Karst World Natural Heritage site from 2000 to 2020, and introduced the regional eco-environment quality assessment index for quantitative factor analysis. The results show that: (1) The heritage site is mainly dominated by forest and shrub, with more aggregated cropland, and impervious surfaces in the buffer zone. The area of shrub has increased during the 20-year period, occupying 12.63% of the total transferred area. Cropland has been basically converted to forest, accounting for more than 60% of the total transferred area, followed by shrubs, which have been basically transferred to ecologically better land types. (2) By analyzing the attitude of motivation, forest, shrub, and water have positive values, while cropland, grassland, and impervious surfaces have negative values. Grassland has the largest absolute value of kinetic attitude, and the smallest is for water. The integrated dynamic attitude is basically maintained at 24%, showing a state of rapid and then stable land category conversion. (3) Over the past 20 years, the regional eco-environment quality index has been stable between 0.68 and 0.71, and shows a trend of rapid growth and stabilization, which is consistent with the comprehensive attitude. The conversion between cropland, forest, and shrubs is the main cause of ecological improvement and deterioration. Overall, the relevant conservation measures at the site and China’s corresponding responses to global climate change have led to a stabilization and increase in the regional ecological quality of the site. The management measures of the relevant authorities have begun to bear fruit, but further promotion of the sustainable development of the site is needed to provide a scientific model for the conservation of other karst heritage sites. Full article

Building ecological networks (ENs) is an important means to guarantee regional ecological security and achieve sustainable urban development. Development of ENs usually occurs at the county- or urban-area-scale, and there is a lack of linkage between ENs at different levels. Based on the systematic analysis of local environmental characteristics and ecological mechanisms of action in karst areas, the ENs at the county and urban areas levels are combined to build an ecological security pattern (ESP) for Shilin Yi Autonomous County (SYAC), a World Natural Heritage site. The results show that there are 18 Ecological resources in SYAC, with a total area of 326.512 km² and 29 ecological corridors. In the northern part of the county, an absence of ecological resources and corridors occurred due to the fragmentation of landscape patches and poor ecological service functionality. In this study, three new ecological resources and seven corridors were added in the northern part of the county according to the patch area and landscape connectivity index (PALCI) to balance the layout of ecological resources and corridors in SYAC and improve regional habitat quality. In addition, a total of eight cultural and natural resources were identified in the urban areas of SYAC, and ten cultural and natural landscape corridors were identified. By overlaying the ENs of the county and the urban areas, we identified 3.977 km² of Material Exchange Conversion Zone, 12.6593 km² of Priority Restoration Zone, and ten Ecological Stepping Stones. This work helps to establish the interface between the upper and lower levels of the network, and correct for deficiencies of conflicting ecological processes at different levels, and integrate existing green-space system planning research about karst terrains. Full article

Natural World Heritage properties provide humanity with a rich and diverse range of ecological products, and the realization of their economic value is related to heritage protection and the improvement of community residents’ well-being. In this study, the equivalent factor method was used to calculate the ecological product value (EPV), and the fishnet tool in ArcGIS was used for spatial zoning. The main land use type of the study area is forest land, accounting for over 82% of the total area. The conversion of land use types is weak in the property and strong in the buffer zone. The EPV of the study area was about USD 172.41 million, showing a downward trend before World Heritage inscription but an upward trend after the inscription, with forests as the main contributor. The spatial distribution of the ecosystem service value of the study area has obvious hierarchical characteristics. World Heritage inscription is beneficial for maintaining the stability of land use and for the improvement of the EPV of the property. The high- and low-EPV areas, respectively, are related to the distribution of forests and agricultural land. The dominant models of EPV in the study area are ecological forestry economy, water economy, and ecological agricultural economy. Full article

Sustaining karst landscape areas in World Heritage Sites under increasing human pressures and climate change is an emerging challenge. Growing evidence has highlighted the transition from traditional government-oriented regulation to the collaborative governance of different stakeholders in governing karst landscape resources. However, the complexity and dynamics of karst landscape policy and stakeholder networks are poorly understood. This study combined a legislative analysis, network analysis, and public survey to explore effective methods of karst landscape conservation in the Guilin World Heritage Site, China. The policy analysis showed that various national laws and local regulations have been enacted in China, but these regulations often focused on individual aspects of karst–human interactions. The network analysis indicated the complexity and relationship of networks in karst World Heritage Site governance at the national, provincial, and municipal scales. The majority of questionnaire respondents (65–89%) reported a medium and high level of karst landscape governance effectiveness. The insights in the present study may be valuable for other karst World Heritage Sites facing complex challenges, especially in developing countries. Full article

The conservation and sustainable tourism development of natural World Heritage has been one of the most challenging topics worldwide. One topic based on the identification of sites’ outstanding universal value is gradually forming a trend. Aesthetic value as a criteria for WH is an important driving force for the tourism development of most natural World Heritage sites and plays a vital role in the sustainable tourism development of heritage sites. However, due to the subjective consciousness involved in the assessment of aesthetic value, it is difficult to quantify. This means that the content of the protection of the aesthetic value of heritage sites is too general, and the exhibition of aesthetic value is inadequate, posing a threat to the sustainable development of heritage sites. This study selected the Libo Karst Heritage Site as the research area, identified and extracted the carriers and characteristics of the aesthetic value of the Karst heritage site through the combination of online text big data, landscape beauty evaluation, and ArcGIS spatial analysis, and analyzed the content and objectives of aesthetic value protection, clarified the scope of the conversation and tourism exhibits, and, finally, puts forward a conservation and sustainable tourism development strategy based on aesthetic value identification. This study was carried out using interdisciplinary technologies and methods, which provide a valuable reference for the construction of a quantitative evaluation system for the aesthetic value of natural World Heritage sites and the protection of outstanding universal value. This study contributes to filling the research gap regarding the comprehensive evaluation of the aesthetic value and protection and tourism development based on the outstanding aesthetic value identification of natural World Heritage sites. The strategy of cooperation between protection and sustainable tourism development based on prominent universal value recognition can be applied to other forms of conservation and development in other World Heritage sites with similar problems. Full article

The behavioral intention of tourists to protect the environment is a popular topic in tourism geography research. Understanding the mechanisms that influence the post-tour behavioral intentions of heritage site visitors can effectively promote the generation of positive behavioral intentions for the sustainable development of heritage sites. Starting from the “cognitive–emotional–behavioral” path of attitude theory, we introduced environmental knowledge awareness (EKA), geomorphological value perception (GVP), place attachment (PA) and behavioral intention (BI) variables to construct a model of the influence mechanism of tourists’ behavioral intentions towards conservation in heritage sites; we test this model on the Libo World Natural Heritage Site, a karst in southern China, as an example. The results show the following: (1) environmental knowledge awareness (EKA) is the basis of place attachment (PA) and behavioral intention (BI), and place attachment (PA) plays an influential mediating role. (2) Geomorphological value perception (GVP) has a positive effect on behavioral intention. (3) The “GEPB” conceptual model fits the “cognitive–emotional response–behavioral intention” chain of tourists in natural world heritage sites and passes the empirical test; (4) The direct positive effect of place attachment on behavioral intention is significant as an essential emotional factor that promotes behavioral intention. This study provides an empirical foundation for the synergistic development of conservation and tourism in World Heritage Karst Sites. It also discusses theoretical and managerial implications based on the findings and provides directions for future research. Full article

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. Full article

The evaluation and monitoring of the ecological environment quality of heritage sites can help provide sustainable and healthy development strategies for heritage management organizations. In this study, an ecological evaluation model based on the remote sensing ecological index (RSEI) was used to measure the ecological environment of the Shibing Karst World Heritage Site and its buffer zone and the Moran index and geographic probe model were combined to quantify the ecological environment. The results show that, (1) from 2013 to 2020, the ecological environment quality of the heritage site and buffer zone was moderate to high and the mean RSEI values in the three periods studied were 0.720, 0.723 and 0.742, showing an overall upward and improving trend; (2) ecological environment quality grades of moderate and good accounted for more than 70% of the area, the distribution pattern of ecological environment quality is significantly better at the heritage site than in the buffer zone and the southwest is better than the northeast; (3) the Moran index increased from 0.600 in 2013 to 0.661 in 2020, residing in the first and third quadrants, respectively, with significantly spatial aggregation; and (4) greenness and humidity were shown to play a positive feedback role on the ecological environment quality and the spatial influence ability of humidity and dryness was greater. Overall, the RSEI is an effective method of evaluating and monitoring the ecological environment quality of heritage sites, the ecological environment quality of the Karst heritage site in Shibing is in a steady state of improvement and the relevant departments of heritage conservation need to further coordinate the relationship between conservation and development to promote the sustainable development of the heritage site and provide effective solutions for the monitoring of other Karst World Heritage sites. Full article

In the face of increasing development pressure, how to fulfill the obligations under the World Cultural and Natural Heritage Convention and maintain the integrity of the Natural World Heritage Site (NWHS) is a major problem to be solved at present. Agroforestry (AF) development in the buffer zone maintains the integrity of NWHS and promotes sustainable ecological and economic development in the buffer zone. Still, few studies on the knowledge system of integrity protection of NWHS and AF development in the buffer zone research have been conducted. To fill this gap, this study conducts a systematic literature review based on 128 related articles retrieved from the Web of Science (WoS) database and the China National Knowledge Infrastructure (CNKI) database. Firstly, quantitative studies were conducted to analyze the annual numbers, content and study regions of the published literature. Secondly, the main research progress and achievements of integrity protection of WNHS and AF development in the buffer zone are classified and summarized. On this basis, this paper proposed key scientific issues that remain to be addressed in future, as well as exploring the implications for the World Heritage (WH) karst. This study is a scientific reference for the balanced development of NWHS integrity protection and AF in the buffer zone. Full article