In the past 20 years, karst desertification control has produced remarkable results, and the South China karst has been a global hotspot for greening. However, in the new stage of karst ...desertification control, the functional lag of forest ecosystems and the insufficient supply capacity of ecosystem services are gradually becoming prominent. We not only lack systematic research on vulnerability and resilience, structure and stability, ecological assets and services, carrying capacity and ecological security, and service trade-offs/synergies and optimization in controlled ecosystems. There is still a lack of research on the ecological processes of newly constructed forests in improving ecosystem functions and services. Therefore, this reprint mainly focuses on the research improvement of forest ecosystem functions in karst desertification control. This includes the improvement mechanism of ecosystem structure, function, and services, the mechanism of ecosystem service tradeoff/synergy, and function optimization. An optimization model of ecosystem function and an improvement path for eco-product supply are introduced. The role of functional traits in the maintenance of ecological function and services is also established, and social–ecological responses to afforestation in karst desertification control are discussed.
Vegetation restoration has been widely used in karst rocky desertification (KRD) areas of southwestern China, but the response of microbial community to revegetation has not been well characterized. ...We investigated the diversity, structure, and co-occurrence patterns of bacterial communities in soils of five vegetation types (grassland, shrubbery, secondary forest, pure plantation and mixed plantation) in KRD area using high-throughput sequencing of the 16S rRNA gene. Bray-Curtis dissimilarity analysis revealed that 15 bacterial community samples were clustered into five groups that corresponded very well to the five vegetation types. Shannon diversity was positively correlated with pH and Ca
content but negatively correlated with organic carbon, total nitrogen, and soil moisture. Redundancy analysis indicated that soil pH, Ca
content, organic carbon, total nitrogen, and soil moisture jointly influenced bacterial community structure. Co-occurrence network analysis revealed non-random assembly patterns of bacterial composition in the soils.
, GR-WP33-30, and
were identified as keystone genera in co-occurrence network. These results indicate that diverse soil physicochemical properties and potential interactions among taxa during vegetation restoration may jointly affect the bacterial community structure in KRD regions.
•We proposed a framework to improve the monitoring of Karst rocky desertification.•Long-term trends show a fluctuating succession process and indicate low resilience of the system.•Intra-annual ...variations demonstrate the vulnerability of Karst rocky desertification regions.•Extreme climate events have long-lasting negative legacy effects.
Karst rocky desertification (KRD) is a typical ecological issue in southwestern China. Comprehensively revealing the KRD succession processes is crucial for implementing effective restoration efforts. In this study, we proposed a generalized framework to improve the monitoring of KRD at regional scale using high-frequency Landsat time series. The framework involved the development of the Karst Rocky Desertification Criterion Index (KRDCI) and multi-temporal scales trends analysis. We illustrated the use of this framework in Puding County southeast China, by (1) exploring the KRD succession processes at three time scales: General Trend (GT), Inter-annual Cumulative Trends (IACT), and Intra-annual Variability Trends (IAVT) from 2000 to 2021 and; (2) modeling and quantifying the driving factors. Results showed that: (1) KRDCI is a highly effective indicator, with overall accuracy and Kappa coefficients above 0.9; (2) The GT analysis showed a positive improving trend with 59.3 % areas improved and 40.7 % degraded, only 1.4 % areas were persistent significant degraded. Indeed, the IACT analysis illustrated that degraded areas decreased from 64.8 % to 45.7 % (2000–2003) and 50.7 % to 40.7 % (2013–2021), while increased from 45.7 % to 50.7 % during 2003–2013. In contrast, the IAVT analysis indicated that improved areas ranged from 22.9 % to 40.5 % and degraded areas ranged from 59.5 % to 77.1 % over 22 years. In particular, the persistent significant degraded areas remained at 25.0 % for almost all the years. (4) Random Forest demonstrated that environmental factors and land use change are both major influences, and extreme climate events have long-lasting legacy effects on KRD succession. These findings indicated that the vulnerability and low resilience of ecosystem in KRD regions still remained after the implementation of the restoration programs. Although our framework was specific to southeast China, we believed that it would be valuable to monitor and evaluate the effectiveness of restoration efforts in regions characterized by high landscape heterogeneity.
Soil organic carbon (SOC) is an important component of soil ecosystems, and soils are a hotbed of microorganisms playing critical roles in soil functions and ecosystem services. Understanding the ...interaction between SOC and soil microbial community is of paramount significance in predicting the C fate in soils following vegetation restoration. In this study, high-throughput sequencing of 16S rRNA and ITS genes combined with 13C NMR spectroscopy analysis were applied to characterize SOC chemical compounds and elucidate associated soil microbial community. Our results indicated that the contents of SOC, total nitrogen, total phosphorus, microbial biomass carbon and biomass nitrogen, dissolved organic carbon, available potassium, exchangeable calcium and soil moisture increased significantly (P < 0.05) along with the vegetation restoration processes from corn land, grassland, shrub land, to secondary and primary forests. Moreover, the Alkyl C and O-alkyl C abundance increased with vegetation recovery, but no significant differences of Alkyl C were observed in different successional stages. In contrast, the relative abundance of Methoxyl C showed an opposite trend. The dominate phyla Proteobacteria, Acidobacteria, Actinobacteria, Ascomycota and Basidiomycota were strongly related to SOC. And, SOC was found to be the determining factor shaping soil bacterial and fungal communities in vegetation restoration processes. The complexity of soil bacteria and fungi interactions along the vegetation restoration chronosequence increased. Determinism was the major assembly mechanism of bacterial community while stochasticity dominated the assembly of fungal community. Bryobacter, Haliangium, and MND1 were identified as keystone genera in co-occurrence network. Besides, the dominant functional groups across all vegetation restoration processes were mainly involved in soil C and N cycles and linked to the enhanced recalcitrant SOC storage. Our results provide invaluable reference to advance the understanding of microbe response to vegetation restoration processes and highlight the impact of microbes on recalcitrant SOC storage.
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•Vegetation restoration in karst rocky desertification area enhanced soil organic carbon storage.•Vegetation restoration facilitated the complexity of soil bacterial and fungal networks.•Soil Bryobacter, Haliangium and MND1 play key roles in vegetation restoration processes.•Dominant functional groups involved in C and N cycling shift with vegetation restoration process.•Recalcitrant soil organic carbon storage linked to dominant microbial functional groups.
Karst rocky desertification is a severe irreversible ecosystem failure. The karst ecosystem is so fragile that it is vulnerable to environmental changes, degrading into rocky desertification. Prior ...studies revealed the potential connections between the soil bacterial community, the edaphic properties and the aboveground vegetation cover in the karst ecosystem. However, how these three elements affect each other and work together in propelling in the karst rocky desertification progress largely remains unexplored. To answer this question, we monitored the bacterial community variations in soils sampled from multiple sites at a successional karst rocky desertification region by sequencing the 16S rRNA V3-V4 regions. Overall, we detected 34 bacterial phyla in the karst soils, of which Proteobacteria, Actinobacteria, and Acidobacteria are the most abundant. Network analysis of the bacterial community- vegetation-edaphic property-vegetation interactions identified 6 bacterial herds that had significant correlation with soil Ca2+ and available phosphorus change during vegetation degradation. Further functional simulation of these bacterial herds unveiled the change of Ca2+ and available phosphorus might disturb the soil carbon and nitrogen metabolism, and thus weakened soil quality. In summary, we hypothesized a calcium-driven bacterial response mechanism in the karst rocky desertification progress.
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•The karst rocky desertification progress accompanies with the change of edaphic properties and soil microbial community structure.•The change of Ca2+ and available phosphorus in karst soils is strongly associated with six bacterial herds.•The Ca2+ and available phosphorus have close impact on the metabolism of soil carbon and nitrogen via interfering the soil bacterial community structure.
Rocky desertification is a process of soil erosion and vegetation destruction. On the surface, the landscape of rocky desertification is similar to that of desertification, which has a negative ...impact on the social and economic development of Southwest China. To clarify the influence of soil properties on plant diversity in rocky desertification areas, three grades of rocky desertification in Southwest Hunan Province were selected: light rocky desertification (LRD), moderate rocky desertification (MRD) and intense rocky desertification (IRD). Soil pH, soil organic carbon (SOC), N, P, K, Ca, Mg were measured, and the species compositions of herbs and shrubs were investigated. The effects of soil properties on plant diversity were studied by using redundancy analysis (RDA). The results showed that except soil pH and Ca, which increased with rocky desertification grade, the soil component contents were MRD > LRD > IRD. The species richness of shrubs was higher than that of herbs, and the difference was significant in MRD. The diversity of herbs first decreased and then increased, and the distribution became increasingly uniform. By contrast, shrub diversity exhibited an opposing distribution trend. RDA analysis showed that the soil nutrient content differed significantly among the rocky desertification grades. Among the nutrients analysed, N, P and K were the main factors affecting species composition in the rocky desertification areas, and their distribution characteristics partly explained the uneven distributions of herbs and shrubs.
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•Except for pH and Ca, the order of content of soil components was moderate > light > intense rocky desertification.•The species richness of shrubs in rocky desertification is higher than that of herbs.•The diversity of herbs and shrubs in rocky desertification showed opposite trends.•Soil properties affect plant diversity.
Rocky desertification, which is relatively less well known than desertification, refers to the processes and human activities that transform a karst area covered by vegetation and soil into a rocky ...landscape. It has occurred in various countries and regions, including the European Mediterranean and Dinaric Karst regions of the Balkan Peninsula, Southwest China on a large scale, and alarmingly, even in tropical rainforests such as Haiti and Barbados, and has had tremendous negative impacts to the environment and social and economic conditions at local and regional scales. The goal of this paper is to provide a thorough review of the impacts, causes, and restoration measures of rocky desertification based on decades of studies in the southwest karst area of China and reviews of studies in Europe and other parts of the world. The low soil formation rate and high permeability of carbonate rocks create a fragile and vulnerable environment that is susceptible to deforestation and soil erosion. Other natural processes related to hydrology and ecology could exacerbate rocky desertification. However, disturbances from a wide variety of human activities are ultimately responsible for rocky desertification wherever it has occurred. This review shows that reforestation can be successful in Southwest China and even in the Dinaric Karst region when the land, people, water, and other resources are managed cohesively. However, new challenges may arise as more frequent droughts and extreme floods induced by global climate change and variability may slow the recovery process or even expand rocky desertification. This review is intended to bring attention to this challenging issue and provide information needed to advance research and engineering practices to combat rocky desertification and to aid in sustainable development.
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•Chongqing karst was divided into two parts of pure-karst and semi-karst.•The driving factors on KRD and SE exhibit significant spatial heterogeneity.•SE exhibited a fluctuating ...downward trend after 2000 in Chongqing.•KRD degree showed a deterioration trend followed by an improvement after 2000.•The treatment effectiveness of ecological restoration is less significant in semi-karst.
The karst area is a prototypical ecologically fragile region, characterized by severe soil erosion and rocky desertification, which hinders sustainable development in these areas. To ensure effective and informed management, it is crucial to comprehensively analyze the long-term series of soil erosion and rocky desertification in terms of their changing characteristics and underlying driving factors. In this study, the Sen slope estimation and Mann-Kendall test were used to carefully examine the changes within the karst region of Chongqing, China, during the period of 2000–2020. Our findings revealed a deterioration followed by an improvement in the degree of rocky desertification in the study area. However, soil erosion exhibited a fluctuating downward trend due to the effective control measures implemented to address both rocky desertification and soil erosion. The driving factors behind these mentioned changes were studied using the Geographical Weighted Regression and Geodetector. Our results highlighted those natural, anthropogenic, and comprehensive factors all influenced the changes during the study period. Notably, each driving factor exhibited significant spatial heterogeneity. The combination of surface exposure rate and vegetation coverage emerged as the primary driver of rocky desertification evolution, while the combination of rainfall and vegetation coverage played a pivotal role in soil erosion evolution. Considering the geological characteristics of karst areas, our study revealed that the degree of rocky desertification and soil erosion in semi-karst areas was comparatively lower than that observed in pure-karst areas. However, in nearly 20 years of ecological restoration, the effectiveness of improvements in semi-karst areas is not as significant as in pure-karst areas. Therefore, more attention should be given to these areas in the future. The implications of this study are valuable for developing comprehensive strategies to combat rocky desertification and soil erosion customized to local conditions.
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