Maoyin Sheng

Plant diversity, including species and functional diversity, plays key roles in driving ecosystem material cycling and energy flow, and maintains ecosystem stability and service functions through dynamic interactions during succession. However, their relationship remains poorly understood in the context of ecosystem degradation succession. In a representative karst rocky desertification (KRD) area in southwestern China, we investigated plant species diversity and functional diversity across KRD succession using a space‐for‐time substitution approach, aiming to examine how plant species diversity relates to functional diversity and how both change during ecosystem succession. 127 plant taxa belonging to 47 families and 96 genera were recorded in the KRD vegetation survey. Results showed that KRD ecosystems generally exhibited low plant species diversity. The mean values of the Margalef, Shannon‐Wiener, Simpson and Pielou indices were not more than 2.5, 2.0, 0.85, and 0.9, respectively. Shannon‐Wiener, Simpson, and Pielou indices varied considerably across different KRD stages. The mean values of plant functional diversity indices (richness, evenness, divergence, disperence, and Rao's quadratic entropy) were no more than 18, 1.7, 1.6, 12, and 11, respectively. As KRD succession, these five plant functional diversity indices all underwent significant changes. Significant correlations between plant species and functional diversity were consistently observed across all KRD stages, and the underlying driving mechanisms of their coupling relationship were revealed. The synergistic evolution of plant functional traits and soil factors during KRD succession was quantified. This study revealed a dynamic shift from synergy to trade‐off between plant species diversity and functional diversity in the KRD process. These findings are of great significance for understanding the evolutionary mechanisms of biodiversity during terrestrial ecosystem succession and providing applicable strategies for KRD vegetation restoration.

Soil microorganisms play a critical regulatory role in various ecosystem functions, making them essential for maintaining ecosystem stability. Plant functional diversity influences soil physicochemical properties and shapes the structure and function of soil microbial communities. However, the response patterns of soil microorganisms to karst rocky desertification (KRD) succession remain poorly understood, particularly the relationship between microbial community dynamics and aboveground plant functional diversity. Here, the present study focuses on four typical succession KRD stages in a representative karst area of southwest China. By analyzing the diversity and community composition of soil microorganisms (bacteria and fungi), measuring soil physicochemical properties, and assessing aboveground plant functional diversity, the study aims to clarify the response patterns of soil microbial communities to KRD and their relationships with plant functional diversity in the KRD ecosystem of southwest China. The following main results and conclusions were obtained: (1) The composition of soil microbial communities and diversity varied significantly across different rocky desertification degrees. Functional diversity of aboveground plants also exhibited significant differences across varying rocky desertification degrees. (2) Both taxonomic composition and diversity indices of soil microorganisms (bacteria and fungi) showed significant ( p < 0.05) or highly significant ( p < 0.01) correlations with soil physicochemical properties and plant functional diversity across the four rocky desertification degrees. (3) During the karst rocky desertification succession, soil bacterial diversity was directly influenced by plant functional diversity and soil physicochemical properties. While, soil fungal diversity exhibited direct regulation by soil physicochemical properties and indirect effects from plant functional diversity mediated through soil properties. During the rocky desertification succession process, there are very complex interactions present among plants, soils, and microorganisms. Elucidating these relationships is of great significance for vegetation restoration and rocky desertification control in karst regions.

Phytolith-occluded organic carbon (PhytOC) is an important mechanism of long-term stable carbon sinks in terrestrial ecosystems. Farmland abandonment is a widespread land use change in the process of urbanization and industrialization and is still ongoing. Farmland abandonment can significantly affect soil carbon cycling. To elucidate the effects of farmland abandonment on soil PhytOC accumulation, in the present study, corn fields abandoned for 0 to 30 years ago in the mountainous areas of southern China were selected as the research objects. The change trends, influencing factors, and driving mechanisms of soil PhytOC accumulation during the abandonment process were studied. The following results were obtained: (1) The range of PhytOC content and storage of the 0–15 cm soil profile for both active and abandoned corn fields was 0.39–1.49 g·kg− 1 and 0.27–0.83 t·hm− 2, respectively. (2) There was a notable enhancement in soil PhytOC accumulation as the duration of abandonment lengthened. In particular, after 30 years of abandonment, soil PhytOC accumulation rose significantly. (3) Abandonment noticeably altered the contents and ratios of soil nutrients of C, N, P and Si, along with key soil enzyme activities such as urease, sucrase, alkaline phosphatase, and catalase. (4) In the context of corn field abandonment, increase in soil PhytOC was primarily attributed to modifications in PhytOC inputs due to variations in surface vegetation cover. The impact of soil environment alterations resulting from abandonment on PhytOC decomposition was less pronounced. These findings are instrumental for accurately assessing the carbon sequestration potential of farmland abandonment and for developing regional carbon management strategies based on such practices.

Karst rocky desertification (KRD) has become the most serious ecological environmental problem in South China. Since 2008, the Chinese government has implemented a special project for KRD control. Because there are large populations in KRD areas of South China who need to survive, KRD control must not only pay attention to the ecological effects of vegetation restoration but also take into account the economic benefits and industrial effects of the local populations' survival needs. Agro‐forestry integrated management can produce remarkable economic effects in vegetation restorations and can play an important role in KRD control. In this review, firstly, the KRD hazards and control in South China were reviewed. The features and advantages of agro‐forestry integrated management were concluded. Then, based on a typical case in South China, the model establishment and practice of agro‐forestry integrated management for KRD control were introduced. The case results showed that agro‐forestry integrated management achieved remarkable ecological and economic benefits in KRD control. Finally, the existing challenges and their optimization strategies of the agro‐forestry integrated management for KRD control were provided. This review provides important clues for scientific KRD control and is of great significance for the sustainable development of the karst region in South China.

Karst rocky desertification (KRD) is a serious ecological and environmental issue, hindering the sustainable socio-economic development of the karst area. To scientifically control this issue, lots of studies on KRD vegetation restoration have been conducted in the past few decades. In the present study, a systematic review of the research progress and future trends in KRD vegetation restoration was conducted. The results showed the following: (1) Studies on KRD vegetation restoration began in the 1990s and could be divided into the four following stages: germination (1993–2002), initial development (2003–2010), steady growth (2011–2016), and rapid growth (2017–2023); (2) research hot topics included theoretical implications, vegetation restoration strategies and technologies, ecological responses to the KRD vegetation restoration, and the coupling of vegetation restoration with landscape resource enhancement; (3) the research frontiers were as follows: the classification and restoration effectiveness of KRD vegetation types, the impacts of KRD vegetation restoration on soil microorganisms and soil erosion, the influences of ecological engineering and land use on KRD vegetation restoration, and the relationships between KRD vegetation restorations and karst ecosystem structural functions. Finally, research prospects were proposed from the research methods, perspectives, content, and shortcomings. This study provided valuable references for in-depth research in the field of KRD vegetation restoration.