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Background: Nutrient limitation is a universal phenomenon in terrestrial ecosystems. Root and mycorrhizal are critical to plant nutrient absorption in nutrient-limited ecosystems. However, how they are modified by N and P limitations with advancing vegetation successions in karst forests remains poorly understood. The present study compared the diversity indices, composition, and co-occurrence network of arbuscular mycorrhizal fungi (AMF) between grassland, shrubland, shrub-tree forest, and tree forest in subtropical karst forests, as well as soil nutrients and fine root functional traits (e.g., specific root length (SRL), specific root area (SRA), diameter, biomass, and N and P contents). Results: The fine roots diameter, biomass, and N and P contents increased with advancing succession, whereas SRL and SRA decreased. Network complexity and Richness and Chao1 indices of AMF increased from grassland to shrub-tree forest but decreased in tree forest. The fine roots N and P contents were positively related to their diameter and biomass, soil nutrients, and AMF composition but were negatively correlated with SRL and SRA. Moreover, these two parameters increased with the increase of soil nutrients. The variations in fine roots N and P contents were mainly explained by soil nutrients and fine root functional traits in grassland and by the interactions of soil nutrients, fine root functional traits, and AMF in the other three stages. Additionally, the interactive explanation with AMF increased from shrubland to shrub-tree forest but decreased in tree forest. Conclusions: Our results indicated that mycorrhizal strategy might be the main nutrient acquisition strategy under N and P co-limitation. In contrast, the root strategy is the main one when an individual is subject to limitations in N or P in karst ecosystems. Root and mycorrhizal nutrient acquisition strategies are generally mutualistic, mycorrhizal strategy enhances plant nutrient acquisition under N and P co-limitation. [ABSTRACT FROM AUTHOR]

In urban industrial area, mining activity directly affects the dynamic of carbon, and consequently, the release of carbon dioxide (CO2) into the atmosphere. The main objective of this research is to study the impact of most important abiotic environmental factors on soil respiration in post-coalmine ecosystems. The moisture and temperature of the soil, along with CO2 outflow from the soil, were measured over three consecutive seasons, using 92 samples from coalmine heaps and 10 samples from deciduous forests in the same urban industrial region. Based on a survey of 396 species, a cluster analysis distinguished all deciduous and 22 forest plots grown on coalmine heaps from herbaceous plots from same coalmine heaps. The lowest soil respiration rate (0.62 mg CO2 per hour per square meter) was recorded in the herbaceous vegetation class on coalmine heaps, compared to (0.76 mg and 0.96 mg) from coalmine-heap forests and deciduous forests, respectively. Species richness and diversity positively affected soil respiration in heap herbaceous plots, though this effect was less pronounced in forests grown on coalmine heaps and in deciduous mixed forests. Unlike soil water content, soil temperature negatively correlated with soil respiration on coalmine heaps, diverging from the well-studied positive impact of soil temperature and respiration in deciduous mixed forests. Our spatial and temporal analyses emphasize that the water content of the substrate is the most significant abiotic element that affects the soil respiration on coalmine heaps positively during early vegetation succession. [ABSTRACT FROM AUTHOR]

Central European peatlands are critically endangered by climate change, eutrophication, disturbed water regime and inappropriate management. This leads to their degradation, which affects all components of these habitats including fungi, and significantly fungi participating in the carbon cycle such as saprotrophs, mycorrhizal symbionts and parasites. Nature conservation efforts focus mainly on macrofungi, especially ‘fungi important for nature conservation’ (FINC) which are rare or associated with endangered habitats. To find out whether standard environmental DNA (eDNA) sequencing methods can be used to monitor the effect of peatland degradation on FINC and fungal communities, we established pairs of plots in degraded and well-preserved parts of ten peatlands in the Třeboň Protected Landscape Area (Czech Republic). Peatland degradation was locally caused by a combination of different factors (water level and chemistry) followed by vegetation succession, whose effect on fungi was evaluated using multivariate analyses. A total of 28 FINC species were detected using macrofungal surveying, whereas 25 were found using eDNA of Sphagnum and peat (Illumina sequencing of ITS2). These two methods agreed on 13 predominantly abundant FINC species, most of which grew in both well-preserved and degraded plots. However, their sensitivity to the studied degradation could not be assessed due to the low abundance of most species. Fungal communities found on the basis of both methods (macrofungal survey, eDNA) were affected by water chemistry, whereas a significant effect of vegetation and locally expansive plants was demonstrated only in fungal communities found using macrofungal survey. Optimisation (e.g. specific primers) for local conditions leading to a better FINC capture must be carried out if eDNA is to be used in the practice of evaluating management effects on peatlands.

While the link between plant species diversity and biomass has been well‐studied, the impact of evolutionary diversity on community biomass across long timescales or ongoing change remains a subject of debate. We elucidated the association between evolutionary diversity and community aboveground biomass (AGB) using an ideal experimental system with over 150‐year history of natural vegetation regeneration. Higher phylogenetic diversity facilitated the sampling effect under the influence of environmental filtering, and caused an increase in AGB. Phylogenetic structure varied from aggregation to dispersion during the later period of vegetation recovery (70–150 years), which was correlated with increases in niche complementarity and increasing AGB. Woody plant evolutionary diversity was used as a key to predict the relationship between vegetation recovery and AGB, with a total explanatory power of ~84.7%. Mixed forests composed of evergreen conifers and deciduous broadleaf forests had higher carbon sequestration potential than that of pure forests, which is advantageous for increasing top‐stage AGB. This research expands our knowledge of the causes and effects of biodiversity and ecosystem function dynamics over time and space, which is important for accurately predicting future climate change effects. [ABSTRACT FROM AUTHOR]

Mediterranean landscapes were drastically affected by high levels of abandonment of agricultural and other land practices during the last century. These changes in land use can have significant effects on diversity patterns by altering disturbance and competition equilibria within plant communities at the landscape level. Particularly, such changes have been found to affect the patterns of phylogenetic diversity and structure by causing nonrandom losses of species through filtering effects and landscape homogenization. By investigating diversity patterns across a region submitted to high levels of land use changes, located in a (sub‐) mountainous area of northwestern Greece (northern Pindus), we aimed at understanding the patterns of phylogenetic diversity and structure in relation to land abandonment and the subsequent recovery of natural vegetation. We sampled 250 vegetation plots equally divided in grasslands and forests, distributed across the different classes of land use occurring in the general study area based on the period since the last change in land use. Standardized metrics of Faith's phylogenetic diversity, mean phylogenetic distance, and mean nearest taxon distance were used to investigate phylogenetic diversity patterns across communities and different land‐use regimes. A Principal Coordinates of Phylogenetic Structure analysis was employed to evaluate the variation in lineage composition among communities, and boosted regression trees were used to identify the relative influence of community differentiation (as captured by the classification of sampling plots in ecologically and floristically distinct vegetation communities), plant life strategies (competition, stress tolerance, and disturbance), and climatic, topographic, and soil variables on phylogenetic diversity metrics. Community differentiation was identified as the main driver of phylogenetic patterns. Additionally, phylogenetic diversity and structure were observed as having a statistically significantly negative correlation with disturbance, a statistically significantly positive correlation with stress tolerance, and a weaker positive correlation with competition. Phylogenetic clustering was observed for the early successional grassland communities submitted to stronger effects of disturbance, while phylogenetic randomness (or rarely overdispersion) was observed in forest communities submitted to stronger effects of competition. Finally, phylogenetic clustering of grassland communities was more evident shortly after land abandonment. [ABSTRACT FROM AUTHOR]

Soil metabolites are critical in regulating the dynamics of ecosystem structure and function, particularly in fragile karst ecosystems. Clarification of response of soil metabolism to vegetation succession in karst areas will contribute to the overall understanding and management of karst soils. Here, we investigated the metabolite characteristics of karst soils with different vegetation stages (grassland, brushwood, secondary forest and primary forest) based on untargeted metabolomics. We confirmed that the abundance and composition of soil metabolites altered with vegetation succession. Of the 403 metabolites we found, 157 had significantly varied expression levels across vegetation soils, including mainly lipids and lipid-like molecules, phenylpropanoids and polyketides, organic acids and derivatives. Certain soil metabolites, such as maltotetraose and bifurcose, were sensitive to vegetation succession, increasing significantly from grassland to brushwood and then decreasing dramatically in secondary and primary forests, making them possible indicators of karst vegetation succession. In addition, soil metabolic pathways, such as galactose metabolism and biosynthesis of unsaturated fatty acids, also changed with vegetation succession. This study characterized the soil metabolic profile in different vegetation stages during karst secondary succession, which would provide new insights for the management of karst soils. [ABSTRACT FROM AUTHOR]

Central European peatlands are critically endangered by climate change, eutrophication, disturbed water regime and inappropriate management. This leads to their degradation, which affects all components of these habitats including fungi, and significantly fungi participating in the carbon cycle such as saprotrophs, mycorrhizal symbionts and parasites. Nature conservation efforts focus mainly on macrofungi, especially ‘fungi important for nature conservation’ (FINC) which are rare or associated with endangered habitats. To find out whether standard environmental DNA (eDNA) sequencing methods can be used to monitor the effect of peatland degradation on FINC and fungal communities, we established pairs of plots in degraded and wellpreserved parts of ten peatlands in the Třeboň Protected Landscape Area (Czech Republic). Peatland degradation was locally caused by a combination of different factors (water level and chemistry) followed by vegetation succession, whose effect on fungi was evaluated using multivariate analyses. A total of 28 FINC species were detected using macrofungal surveying, whereas 25 were found using eDNA of Sphagnum and peat (Illumina sequencing of ITS2). These two methods agreed on 13 predominantly abundant FINC species, most of which grew in both well-preserved and degraded plots. However, their sensitivity to the studied degradation could not be assessed due to the low abundance of most species. Fungal communities found on the basis of both methods (macrofungal survey, eDNA) were affected by water chemistry, whereas a significant effect of vegetation and locally expansive plants was demonstrated only in fungal communities found using macrofungal survey. Optimisation (e.g. specific primers) for local conditions leading to a better FINC capture must be carried out if eDNA is to be used in the practice of evaluating management effects on peatlands. [ABSTRACT FROM AUTHOR]

Background: The Minqin Oasis, which is located in Wuwei City, Gansu Province, China, faces a very serious land desertification problem, with about 94.5% of its total area desertified. Accordingly, it is crucial to implement ecological restoration policies such as cropland abandonment in this region. In abandoned croplands, abiotic factors such as soil properties may become more important than biotic factors in driving vegetation succession. However, the connections between soil properties and vegetation succession remain unclear. To fill this knowledge gap, this study investigated these connections to explore major factors that affected vegetation succession, which is meaningful to designing management measures to restore these degraded ecosystems. Methods: This study investigated seven 1–29-year-old abandoned croplands using the "space for time" method in Minqin Oasis. Vegetation succession was classified into different stages using a canonical correlation analysis (CCA) and two-way indicator species analysis (Twinspan). The link between soil properties and vegetation succession was analyzed using CCA. The primary factors shaping community patterns of vegetation succession were chosen by the "Forward selection" in CCA. The responses of dominant species to soil properties were analyzed using generalized additive models (GAMs). Results: Dominant species turnover occurred obviously after cropland abandonment. Vegetation succession can be classified into three stages (i.e., early, intermediate, and late successional stages) with markedly different community composition and diversity. The main drivers of vegetation succession among soil properties were soil salinity and saturated soil water content and they had led to different responses of the dominant species in early and late successional stages. During the development of vegetation succession, community composition became simpler, and species diversity decreased significantly, which was a type of regressive succession. Therefore, measures should be adopted to manage these degraded, abandoned croplands. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to explore the vertical distribution of soil nutrients in sand dunes of N. tangutorum nebkhas at different successional stages in the Ulanbuhe Desert, and to provide a scientific foundation for the stable growth of N. tangutorum shrubs in the region. [Methods]N. tangutorum nebkhas sand piles at different succession were selected stages as the research objects. Through preliminary vegetation investigation, based on the dead rate and coverage of the N. tangutorum shrub, it was divided into different succession stages, namely the development stage (dead rate 10％～30％, coverage 20％～40％), stable stage (dead rate＜10％, coverage 40％～60％), and decline stage (dead rate＞50％, coverage＜20％). Three relatively independent N. tangutorum nebkhas sand piles were selected for each succession stage. The vegetation characteristics and soil nutrients in the inter dune area and on windward and leeward slopes of sand piles were investigated and determined, respectively. [Results]As the succession of the N. tangutorum shrub progresses, the height, crown length, and width of the N. tangutorum first increased and then decreased. Among them, the crown length in the stable stage was significantly higher than that in other stages (p＜0. 05), increased by 45. 50％and 50. 01％compared to the developmental and declining stages, respectively (p＜0. 05). At the leeward slope, the soil nutrient content during the development stage shows a'descending ascending descending 'trend with the increase of soil depth, while the organic matter content during the stable and declining stages showed a decreasing trend, reaching the minimum value at 40-60 cm. At the windward slope, the content of soil organic matter and total nitrogen in 40-60 cm soil layer reached the maximum value in the decline stage with the development of the succession stage, but the content of total nitrogen in the development and decline stage reached the minimum value in 40-60 cm soil layer with the increase of the soil depth, which was 83. 33％and 80. 31％lower than that in 0-10 cm soil layer, respectively (p＜0. 05). The soil nutrients of the white thorn shrub sand pile at different slope positions reached their maximum values at 0-10 cm, but overall, the nutrient enrichment effect of the N. tangutorum nebkhas sand pile soil was not significant. [Conclusion]This research has shown that the soil nutrients in the N. tangutorum nebkhas sand pile are mainly concentrated on the surface of the sand pile. How to alleviate the activation of the N. tangutorum nebkhas sand pile and soil nutrient loss is an important guarantee for the stability of the N. tangutorum nebkhas sand pile in arid environments. [ABSTRACT FROM AUTHOR]

In urban industrial area, mining activity directly affects the dynamic of carbon, and consequently, the release of carbon dioxide (CO2) into the atmosphere. The main objective of this research is to study the impact of most important abiotic environmental factors on soil respiration in post-coalmine ecosystems. The moisture and temperature of the soil, along with CO2 outflow from the soil, were measured over three consecutive seasons, using 92 samples from coalmine heaps and 10 samples from deciduous forests in the same urban industrial region. Based on a survey of 396 species, a cluster analysis distinguished all deciduous and 22 forest plots grown on coalmine heaps from herbaceous plots from same coalmine heaps. The lowest soil respiration rate (0.62 mg CO2 per hour per square meter) was recorded in the herbaceous vegetation class on coalmine heaps, compared to (0.76 mg and 0.96 mg) from coalmine-heap forests and deciduous forests, respectively. Species richness and diversity positively affected soil respiration in heap herbaceous plots, though this effect was less pronounced in forests grown on coalmine heaps and in deciduous mixed forests. Unlike soil water content, soil temperature negatively correlated with soil respiration on coalmine heaps, diverging from the well-studied positive impact of soil temperature and respiration in deciduous mixed forests. Our spatial and temporal analyses emphasize that the water content of the substrate is the most significant abiotic element that affects the soil respiration on coalmine heaps positively during early vegetation succession.

China is currently the world’s largest carbon emitter and has pledged to achieve carbon neutrality by 2060, which requires significant reductions in emissions and the removal of carbon dioxide removal. Precise and efficient forestation has become a key strategy to increase carbon sequestration and mitigate the effects of climate change. In order to obtain a high-accuracy distribution area of potential forestation land, a variety of influencing factors on potential forestation land were selected in this study, including vegetation factors and environmental factors. Combining the two models “law of the minimum factors (LMF)” and “equal weight classification (EWC)” predicts the spatial distribution pattern of potential forestation land in China. And, we calculated the available forestation area in each province and predicted future forest coverage. The results showed that the potential forestation area using the LMF method reached approximately 5.65 × 105 km2, and the potential forestation area using the EMC method reached approximately 4.95 × 105 km2. Combining the two models, the final potential forestation area in China was approximately 6.29 × 105 km2, of which approximately 1.02 × 105 km2 was evaluated as a high-confidence area. If all potential forestation land obtained from the two models was successfully planted, China’s forest coverage rate would reach nearly 26 %. Two newly introduced vegetation factors, namely vegetation resilience and top vegetation succession, were considered in this study to make the prediction results of potential forestation distribution more accurate and reasonable. In addition, the results obtained in this study can provide certain assistance for the specific implementation of national forestation policies, and can provide a reference for promoting forestation actions and achieving the goal of carbon neutrality.

Phytoremediation is a sustainable way to clean contaminated urban soil, but selecting the right plants and designing communities is crucial. This study focuses on the vegetation in a disused steel plant in Chongqing, China, abandoned for nearly two decades. The goal is to reveal the plant community and succession patterns to inform the restoration of brownfield sites. This study combined the sample line and plot to investigate the vegetation and its growth environment in the Steel Plant. Information was recorded, including plant species, quantity, distribution, soil nutrients, humidity, and light. Cluster analysis categorized plant community types, and redundancy analysis examined the link between environmental conditions and plant types. The study found that: 1) There are 65 plant species (including 13 native trees) in the steel plant’s brownfield area, with Broussonetia papyrifera, Pteris vittata, and Debregeasia orientalis being the most abundant. The plants inside the plant were divided into seven groups based on species composition. 2) Soil moisture showed a significant positive correlation (Pearson index of 0.628) with plant survival, followed by a notable correlation with light intensity. 3) Environmental conditions partly influenced plant species composition and abundance variations. 4) 11 hyper-accumulating plant species were identified, focusing on three: the As hyper-accumulator Pteris vittata and the Cd hyper-accumulators Solanum nigrum and Debregeasia orientalis. The findings of this research will offer valuable insights for applying phytoremediation techniques in addressing contamination issues in brownfields within steel plants.

The disturbed forest system can be restored through successional processes, where changes in the diversity of plant species serves as key indicators of processes. Meanwhile plant water use efficiency and nitrogen dynamics are important factors influencing photosynthesis-water coupling and nutrient stress in plants, respectively, during forest recovery. Analyzing these factors is crucial for understanding forest recovery and promoting sustainable ecosystem development. In this study, traditional vegetation surveys and biodiversity indices, along with foliar stable carbon and nitrogen isotope analyses, as well as nitrogen content analyses, were conducted in a subtropical forest with various successional stages following human and natural disturbances in Sichuan province, China. These analyses were used to assess species diversity patterns, evaluate water use efficiency, and assess nitrogen dynamics in primary, secondary, and artificial forests. The results showed distinct stage-specific differences in succession among forest types. Primary forests exhibited the highest successional stage but were limited by water stress and high nitrogen competition, with the highest δ13C values (i.e., −29.0 ‰), lowest δ15N values (i.e., −3.6 ‰), and the lowest nitrogen contents (i.e., 3.6 %) on average. Artificial forests had the lowest species diversity due to species dominance and nitrogen competition, with the lowest δ13C values (i.e., −29.7 ‰), relatively low nitrogen contents (i.e., 4.0 %), and high δ15N values (i.e., −1.8 ‰). Secondary forests, with longer recovery periods, reached higher successional stage due to sufficient nitrogen and water, which is indicated by the highest δ15N values and nitrogen contents (i.e., −1.7 ‰ and 4.5 %), and the relatively low δ13C values (i.e., −29.4 ‰), leading to accelerated vegetation growth. This study highlights not only the importance of analyzing plant diversity, but also the material cycles, especially water use efficiency, and nitrogen dynamics, to understanding forest recovery. These findings can support effective conservation and sustainable development of subtropical forest ecosystems.

Background The Minqin Oasis, which is located in Wuwei City, Gansu Province, China, faces a very serious land desertification problem, with about 94.5% of its total area desertified. Accordingly, it is crucial to implement ecological restoration policies such as cropland abandonment in this region. In abandoned croplands, abiotic factors such as soil properties may become more important than biotic factors in driving vegetation succession. However, the connections between soil properties and vegetation succession remain unclear. To fill this knowledge gap, this study investigated these connections to explore major factors that affected vegetation succession, which is meaningful to designing management measures to restore these degraded ecosystems. Methods This study investigated seven 1–29-year-old abandoned croplands using the “space for time” method in Minqin Oasis. Vegetation succession was classified into different stages using a canonical correlation analysis (CCA) and two-way indicator species analysis (Twinspan). The link between soil properties and vegetation succession was analyzed using CCA. The primary factors shaping community patterns of vegetation succession were chosen by the “Forward selection” in CCA. The responses of dominant species to soil properties were analyzed using generalized additive models (GAMs). Results Dominant species turnover occurred obviously after cropland abandonment. Vegetation succession can be classified into three stages (i.e., early, intermediate, and late successional stages) with markedly different community composition and diversity. The main drivers of vegetation succession among soil properties were soil salinity and saturated soil water content and they had led to different responses of the dominant species in early and late successional stages. During the development of vegetation succession, community composition became simpler, and species diversity decreased significantly, which was a type of regressive succession. Therefore, measures should be adopted to manage these degraded, abandoned croplands.

Abstract Soil organic matter is closely linked to the quality of Agroecosystems and directly influences the agricultural production and the environmental conditions. Understanding of soil organic matter dynamics in agroforestry systems requires studies with a temporal focus, since the changes in its chemical composition tend to follow a gradual behavior. The aim of this study was to investigate the dynamics of changes in stocks and chemical composition of soil organic matter under agroforestry, using systems in different stages of vegetation succession. The soil sampling was carried out from trenches, and litter fractions were also sampled. The samples were collected from different layers of the soil profile under the following conditions: Control; agroforestry with 1 year; agroforestry with 3 years; agroforestry with 7 years and Forest in natural regeneration. The following attributes/parameters were determined/calculated: i) C and N contents and stocks and C/N ratio; ii) C and N proportions in soil granulometric fractions and iii) kinetics of organic matter accumulation in soil with the time of systems evolution. The results showed: i) The C/N ratio tended to increase in depth but did not show a clear variation between the systems evaluated; ii) the adoption of successive agroforestry practices has the potential to increase the C and N stocks in soil; iii) the soil organic matter accumulation occurs gradually during the systems evolution and is mainly related to the particulate fraction (> 0.053 mm).

Background: High-severity fires are serious anthropogenic threats to forests, as they can cause forest degradation on unrecoverable scales. Therefore, understanding the patterns and drivers of post-fire regeneration is essential to designing restoration proposals. Hypotheses: After a high-severity fire, we expected greater species richness and abundance of individuals in flat sites than in hillside sites since seeds, nutrients, and organic matter accumulate in flat landforms. Compared to some Pinus species, Quercus species are more drought-tolerant after a forest fire and, therefore, they are expected to dominate post-fire chronosequences. Study site: The study was conducted in the “La Primavera” Flora and Fauna Protection Area. Methods: We sampled vegetation and microenvironmental variables from 2021 to 2022 at 18 sites located on flat and hillside areas, at 3, 9, and ≥ 20 years since the last high-severity forest fires (TSF). Results: The richness of woody and herbaceous species was higher at 3 TSF and 9 TSF. The topographic condition did not significantly drive the richness and abundance of woody species, but richness and abundance of herbaceous species were significantly greater in flat sites. The oak tree Quercus resinosa Liebm. was the dominant species throughout the chronosequence. Conclusions: Quercus resinosa represents a foundational species for recovering forest structure and composition. Flat sites may act as regeneration nuclei, but hillside sites require greater restoration efforts.

Soil microbes are the primary drivers of the material cycling of the forest ecosystem, and understanding how microbial structure and composition change across succession assists in clarifying the mechanisms behind succession dynamics. However, the response of soil microbial communities and assembly processes to succession is poorly understood in subtropical forests. Thus, through the "space instead of time" and high throughput sequencing method, the dynamics of the soil bacterial and fungal communities and assembly process along the succession were studied, where five succession stages, including Abandoned lands (AL), Deciduous broad-leaved forests (DB), Coniferous forests (CF), Coniferous broad-leaved mixed forests (CB), and Evergreen broad-leaved forests (EB), were selected in a subtropical forest on the western slope of Wuyi Mountain, southern China. The results demonstrated that succession significantly decreased soil bacterial α-diversity but had little effect on fungal α-diversity. The composition of soil bacterial and fungal communities shifted along with the succession stages. LEfSe analysis showed the transition from initial succession microbial communities dominated by Firmicutes, Bacteroidota, Ascomycota, and Chytridiomycota to terminal succession communities dominated by Actinobacteriota and Basidiomycota. Distance-based redundancy analysis (db-RDA) revealed that soil total organic carbon (TOC) was the main factor explaining variability in the structure of soil bacterial communities, and multiple soil environmental factors such as the TOC, soil total nitrogen (TN), C:N ratio, and pH co-regulated the structure of fungi. The null models illustrated that deterministic processes were dominant in the soil bacterial communities, while the stochastic processes contributed significantly to the soil fungal communities during succession. Collectively, our results suggest that different patterns are displayed by the soil bacterial and fungal communities during the succession. These findings enhance our comprehension of the processes that drive the formation and maintenance of soil microbial diversity throughout forest succession. [ABSTRACT FROM AUTHOR]

The contradiction between humans and land is prominent in the karst area of Southwest China. Human destruction of vegetation eventually leads to serious water loss and soil erosion, resulting in a large number of rocky desertification. In order to control the expansion of rocky desertification, the Chinese government has carried out a series of projects, such as returning farmland to forest, natural forest protection and Yangtze River shelterbelt projects, which have caused corresponding changes in land use and vegetation cover. As one of the most important types of rocky desertification control in China, karst graben basins are usually characterized by drastic changes in basin-mountain topography, great climate contrast, severe soil flow/loss, poor vegetation site conditions, and the slow recovery of community ecosystem. Therefore, the study on the comprehensive control of rocky desertification at the karst graben basin became urgent. The ecological stoichiometry is a state-of-the-art science that analyzes the regional circulation patterns of biogeochemical elements from the perspective of element metrology, which provides a new insight to solve the problem of nutrient supply/demand and circulation in ecosystems. It has important application value in the study of soil nutrient circulation and balance mechanism, and is one of the hot spots in current ecological research. However, domestic studies on ecological stoichiometry mainly select desert steppe, Loess Plateau and Minjiang River estuary as research areas in recent years. There is a paucity of systematic studies on soil metrology characteristics in different stages of vegetation succession at karst graben basins, and the response of soil nutrients and ecological stoichiometry to different types of vegetation restoration is still unclear. In order to elucidate the content and stoichiometric ratios of C, N and P elements in the soils in different stages of vegetation succession at karst graben basins, Santang, located in Xiaojiang karst basin, Luxi county, Yunnan Province, was selected as a study area. This area is dominated by a subtropical monsoon climate, with the average annual temperature of 15.2 °C, the average annual sunshine of 2,122 h, and the average annual precipitation of 1,000 mm. The main tree species in the study area include Platycladus orientalis (L.) Franco, sticky alder, Yunnan pine, and so on. In January 2018, by the "space for time" approach, the soils from 5 different stages of vegetation succession (corn land, grassland, shrub land, planted forest and primary forest) were collected from different soil depths (0--10 cm and 10--20 cm) according to the sampling method of profile excavation. The soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) contents were determined by potassium dichromate oxidation with an external heating method, Kjeldahl method, and molybdenum antimony anti-colorimetric method. Excel 2019 software was used for data statistics. One-Way ANOVA, Duncan's new multiple range test method (LSD), Pearson correlation and Two-way ANOVA in SPSS 25.0 software were used to study the variance and correlations of soil ecological stoichiometric characteristics. The study results are expected to further reveal nutrient restriction and nutrient change patterns in the vegetation succession process, meanwhile, providing the scientific basis for vegetation restoration management and rational use of land resources in karst graben basins. There were significant differences in soil nutrient contents in different succession stages, mainly manifested in the 0--10 cm soil layer. SOC and TN contents showed an overall increasing trend with the increase of succession years, while TP content fluctuated and showed no obvious change pattern. Soil C and N contents differed significantly among soil layers. Specifically, SOC and TN contents in 0--10 cm soil layer were higher than those in 10--20 cm soil layer at each succession stage. Compared with C and N contents, soil P content did not differ significantly among soil layers at each succession stage, except for the content in the primary forest. In 0--10 cm soil layer, C/N, C/P and N/P showed significantly positive correlations with SOC content; C/P and N/P indicated significantly positive correlations with TN content; soil TP content was not significantly correlated with C/N, C/P and N/P. There was no significant correlation between soil physicochemical properties and soil stoichiometric ratio in the 10--20 cm soil layer. In the present study, the N/P ratios of 0--10 cm soil in different succession stages were between 2.71 and 5.93, and those of 10--20 cm soil were between 3.11 and 4.92. Essentially, all of the N/P ratios of soil at different depths were lower than 10, indicating that vegetation growth in the study area was more likely to be limited by N. However, given the fact that P content in karst soil is relatively low, vegetation growth should be first limited by P rather than N. Moreover, vegetation types and soil depths significantly affected SOC, TN and TP contents and their stoichiometric ratios in the study area. In summary, soil nutrient and stoichiometric ratios at karst graben basins change significantly with vegetation restoration chronosequence, and soil physicochemical properties have an important impact on soil stoichiometric ratios. These results are of great significance for further research on soil nutrient balance and limiting factors in karst graben basins. [ABSTRACT FROM AUTHOR]

Seismic lines are the dominant anthropogenic disturbance in the boreal forest of the Canadian province of Alberta, fragmenting over 1900 km2 of peatland areas and accounting for more than 80% of all anthropogenic disturbance in this region. The goal of this study is to determine whether the wildland fires that burn across seismic lines in peatlands result in the regeneration of woody vegetation within the ecotonal areas adjacent to seismic lines. We use a combination of seismic line and vegetation structural characteristics derived from multi-spectral airborne lidar across a post-fire peatland chronosequence. We found an increasing encroachment of shrubs and trees into seismic lines after many years since a fire, especially in fens, relative to unburned peatlands. Fens typically had shorter woody vegetation regeneration (average = 3.3 m ± 0.9 m, standard deviation) adjacent to seismic lines compared to bogs (average = 3.8 m ± 1.0 m, standard deviation), despite enhanced shrubification closer to seismic lines. The incoming solar radiation and seismic line age since the establishment of seismic line(s) were the factors most strongly correlated with enhanced shrubification, suggesting that the increased light and time since a disturbance are driving these vegetation changes. Shrub encroachment closer to seismic lines tends to occur within fens, indicating that these may be more sensitive to drying conditions and vegetation regeneration after several years post-fire/post-seismic line disturbance. [ABSTRACT FROM AUTHOR]

The thinning vegetation and soil erosion problems left behind by extractive mining have caused serious environmental pollution, and vegetation restoration is one of the effective strategies to counter them. To study the effects of vegetation restoration on plant community species diversity, soil carbon, nitrogen and phosphorus, and the response of their plant community succession, four communities of different ages (1, 7, 10, 40) and one natural forest (>50 years) in the Kunyang phosphate mine were selected, and the analysis was carried out using the methods and protocols for plant community inventory. The species composition was recorded, and soil was collected from 0–60 cm in each community to determine the response of soil nutrients and plant diversity to the restoration process. The results show that the species richness of the community increases with the restoration year, the species composition at 40 years of restoration is similar to that of the natural forest, and the Shannon–Wiener diversity index in the tree layer at 40 years of restoration is greater than in the natural forest. Soil pH showed a decreasing trend with restoration year, and TP and AP increased with increasing time series. And the linear stepwise regression analysis showed that soil pH, soil organic carbon (SOC), total phosphorous (TP), available phosphorous (AP), and restoration year were the main factors of plant diversity. Compared to restoration of 10 years, TP and AP at the restoration of 40 years increased to 11.9–20.0 g∙kg−1 and 33.4–75.5 mg∙kg−1. The SOC of the community reached a maximum at 40 years of restoration, 1.5, 2.8, and 2.4 times higher at 0–20 cm, 20–40, and 40–60 cm, respectively, than at 1 year. The organic carbon fraction increased with the restoration year in an 'N' pattern, and mineral-associated organic carbon (MOC) and unstable organic carbon fraction decreased at 10 years and 40 years of restoration. The SOC of natural forests decreased, but stable organic carbon increased. The soil pH, SOC, and organic carbon fraction of the communities decreased with increasing soil depth, while TP and AP increased with increasing soil depth at the later period of restoration. In general, with extended restoration years, 40 years plant of restoration in phosphate mines can be expected to allow for plant community succession to climax community, and the key influence on plant diversity are the phosphorus and stable carbon fractions. These results are expected to facilitate the future basis for vegetation succession and restore systems during mining area restoration. [ABSTRACT FROM AUTHOR]

Large-scale afforestation is considered a natural way to address climate challenges (e.g., the greenhouse effect). However, there is a paucity of evidence linking plant diversity to soil carbon sequestration pathways during long-term natural restoration of temperate vegetation. In particular, the carbon sequestration mechanisms and functions of woody plants require further study. Therefore, we conducted a comparative study of plant diversity and soil carbon sequestration characteristics during 150 years of natural vegetation restoration in the temperate zone to provide a comprehensive assessment of the effects of long-term natural vegetation restoration processes on soil organic carbon stocks. The results suggested positive effects of woody plant diversity on carbon sequestration. In addition, fine root biomass and deadfall accumulation were significantly positively correlated with soil organic carbon stocks, and carbon was stored in large grain size aggregates (1-5 mm). Meanwhile, the diversity of Fabaceae and Rosaceae was observed to be important for soil organic carbon accumulation, and the carbon sequestration function of shrubs should not be neglected during vegetation restoration. Finally, we identified three plants that showed high potential for carbon sequestration: Lespedeza bicolor, Sophora davidii, and Cotoneaster multiflorus, which should be considered for inclusion in the construction of local artificial vegetation. Among them, L. bicolor is probably the best choice. [ABSTRACT FROM AUTHOR]

The Miyanaka Intake Dam fishway underwent improvements in 2012, and we established a new rock-ramp fishway called the Seseragi Fishway, cognizant of its utility as a passage and a habitat for bottom-dwelling and small fish with weak swimming ability. However, the fishway is occasionally submerged by floods, causing sediment accumulation that leads to changes in the vegetation composition. In addition, the arrival and inflow of seeds from upstream and the surrounding areas result in vegetation changes. In this study, the inside and outside of the rock-ramp fishway were divided into eight areas, and the vegetation succession after 2012 was determined. A correlation was observed between the results of fish catch surveys during the same period and the vegetation. Based on these results, we reported on the process of steadily operating the rock-ramp fishway while devising and improving specific management methods. Changes in vegetation, such as an increase in upright vegetation and a decrease in flow-obstructing vegetation, contributed to an increase in the population of bottom-dwellers, weak swimmers, and juvenile fish. The existence and management of appropriate vegetation are important for maintaining fishways inhabited by a variety of fish species. [ABSTRACT FROM AUTHOR]

Vegetation and fire archives of the late Holocene are essential for understanding the importance of natural and anthropogenic forcings on past and future vegetation successions as well as climate changes. Here we present a 1640-year record of vegetation and fire history of the Lake Haixihai catchment in northwestern Yunnan, southwest China. Pollen and charcoal analyses as well as XRF (X-ray fluorescence) analysis of lacustrine sediments from Lake Haixihai were employed to reveal its regional vegetation, forest fire, and soil erosion intensity changes over the last 1640 years. The results show their significant changes attributed to both climatic conditions and human activities: The lake catchment witnessed the densest forests (including pine and hemlock forests, and evergreen broadleaved forests) and the weakest soil erosion of the last 1640 years as well as relatively frequent forest fires at 380–880 AD, when vegetation succession, forest fire, and soil erosion were mainly driven by natural forcings, i.e., climatic conditions. A significant and abrupt drop in forest density, minor changes in abundance of forest components, and gradually strengthening soil erosion occurred at the transition from 880 to 1040 AD, when anthropogenic forcings such as the development of agriculture and systematic deforestation gradually became dominant ones driving vegetation succession and soil erosion. After this transition, forest density and soil erosion intensity never returned to the level before 880 AD, implying that the modern landscape in the lake catchment was already established approximately at as early as ca. 1040 AD. No significant changes in forest component and density as well as forest fire and soil erosion occurred until 1940 AD. The most frequent forest fires, the strongest soil erosion, and low forest density after 1940 AD might be attributed partially to climatic conditions and partially to extensive deforestation around 1960 AD. [ABSTRACT FROM AUTHOR]

Land abandonment is one of the main drivers of land use/land cover (LULC) change across Europe, which has already led to a significant loss of open habitats, threatening species hosted in them. We investigated LULC changes for a period of 70 years in a mountainous area of central Greece (Mt Agrafa) by mapping its land cover for the years 1945, 1996 and 2015, calculating transition matrices of land cover classes and performing intensity analysis at different levels. Subareas of the study area, with different population trends, were compared in regard to their LULC change trends. Possible drivers of LULC changes were explored by means of Random Forest modeling, and landscape metrics were calculated to assess their trends. Our results showed great changes in LULC class cover, significant shrinkage of open habitats, accelerated rates of change in the recent period and no differences in LULC change patterns in relation to different population trends. Variables expressing favorability of ecological conditions for forest establishment or probability of farmland abandonment were found as more important drivers of the spatiotemporal distribution of LULC classes, while landscape metrics revealed certain trends. Our main conclusion is that land abandonment and the subsequent vegetation succession are going through a semifinal stage, before their completeness and the almost absolute dominance of the forest, and repopulation of the countryside cannot unconditionally ensure any halting effect on the land abandonment process. [ABSTRACT FROM AUTHOR]

Vegetation plays an important role in the flow of material energy and nutrient cycle in the ecosystem. Karst vegetation is one of the main factors to maintain the stability of karst ecosystem function. At the same time, as a medium connecting soil, atmosphere and rock, plants not only present the characteristics of water balance in hydrologic and ecological processes, but also are an important link in regional vegetation restoration which is the basis of ecological construction and rocky desertification control in karst areas. In order to comprehensively understand the research progress, development trend and hot issues of karst vegetation restoration at home and abroad, literature related to this topic from 1985 to 2021 was retrieved from the Web of Science Core Collection Database (WoS) and China National Knowledge Infrastructure (CNKI) in this study. Based on high-frequency keyword analysis, keyword co-occurrence and cluster analysis, time evolution analysis of research subject, etc., the focuses and trends of karst vegetation restoration were analyzed. The results show that 319 and 351 related articles were collected respectively in WoS and CNKI databases from 1985 to 2021, and the number of articles published in 37 years experienced an increase with fluctuation. The publishing of these articles could be divided into three stages, the first stage (before 2005), an initiation stage of the research, in which the number of articles published was small; the second stage (2005-2015), a stage with a significant increase of literature due to great attention from domestic and foreign scholars to the ecological reconstruction of karst areas; the third stage (2015-2021), a rapid development stage, in which the number of international publications saw a continuous increase, while the domestic number showed a rise with fluctuation, and the growth rate of domestic research is significantly higher than that of international research. Rocky desertification, vegetation succession, soil nutrients and species diversity are high-frequency keywords in the literature, reflecting the common concerns of domestic and foreign research. Among them, vegetation succession law, soil nutrients and species diversity are the core issues in studies on karst rocky desertification areas. International studies on karst vegetation restoration pay more attention to ecosystem services and climate change, while domestic studies mainly focus on vegetation restoration in karst rocky desertification areas in the early stage, and pay more attention to the effects of vegetation restoration on soil properties and plant community composition in the later stage. In recent years, the diverse configuration of karst vegetation restoration technology and mode, for example, Huajiang Mode, Pingshang Mode, Huanjiang Mode, Pingguo Mode, etc. put forward through test, research and development, has become one of the research focuses. In addition, environmental benefits of vegetation restoration (moisture, nutrients, soil and water loss, etc.), soil seed banks, microbe and plant functional groups, vegetation restoration and forestry industry (understory economy and ecological industry), karst plant restoration and karst carbon sink, etc. have gradually become new hot issues in the research field of karst vegetation restoration. In the research of "vegetation restoration", the issues about industrial development such as fruit forest for ecological economy, governance and management modes for ecological economy, etc. have also been taken into account. In recent years, the restoration of karst vegetation (the control of rocky desertification) in China is closely related to the projects of poverty alleviation and elimination, for example, Huajiang Mode --the establishment of comprehensive management of industry for ecological environment in medium-intensity rocky desertification areas in karst plateau canyon, Pingshang Mode--the facilitation of vegetation restoration by planting honeysuckle in the rocky desertification control of Zhenfeng county, Huanjiang Mode characterized with ecological migration, and the Pingguo Mode characterized with the dragon fruit planting in Pingguo county. Due to the slow soil formation rate, thin soil layer and easy soil erosion, the karst area falls into a typical vulnerable ecosystem in the world, and the vegetation restoration in this area is very difficult. Therefore, the vegetation restoration mode is selected for the purpose of improving soil structure and coordinating the balance among soil water, fertilizer, air and heat. In order to promote the development of karst vegetation restoration research, it is suggested to strengthen domestic and international cooperation, and to set up some observation points in the field to observe and compare the dynamics of karst vegetation restoration in different regions for a long time. By comparing the spatio-temporal changes of large scale at home and abroad, the function and significance of vegetation restoration process on ecological restoration in karst areas can be analyzed through monitoring data. Through the restoration technology, model and evaluation method of karst vegetation system, the construction of karst ecosystem and the multi-scale pattern of vegetation diversity from the perspective of life community of mountain, forest, field, lake and grass and the perspective of rural industry can be further revealed. By comparing the research at home and abroad, some new ideas will be provided for ecological restoration in karst areas. [ABSTRACT FROM AUTHOR]

Natural solutions by which humans can overcome challenges have been severely hampered by biodiversity losses. It is essential to understand the key natural variables that influence changes in community diversity to maintain ecosystem function. The Ziwuling area has a natural recovery succession history of 150 years. Therefore, a survey was conducted to compare species composition characteristics across different vegetation recovery stages while also providing a phylogenetic and taxonomic response to the correlation between beta diversity and soil stoichiometry. The results showed that beta diversity and endemic plants had a similar single-peak temporal pattern. Soil organic carbon (SOC) accumulation was significantly positively correlated with total nitrogen (TN) and was also negatively correlated with total phosphorus (TP). Overall, soil TN, time since vegetation restoration (TVR in years), and W-SS (endemic woody plants at each stage) were able to explain 94.3% of the total variation in beta diversity. Temperate species such as Carex lanceolata, Lespedeza bicolor, and Sophora davidii are the basis for community construction. Community beta diversity patterns are the result of a mixture of ecological (e.g., climate patterns and soil nutrients) and evolutionary processes. This study combined plant resource needs with how they respond to natural recovery times in order to provide useful knowledge to protect biodiversity, the nutrient cycle, and the function of restoration ecology. [ABSTRACT FROM AUTHOR]

Glacier forelands are among the most rapidly changing landscapes on Earth. Stable ground is rare as geomorphic processes move sediments across large areas of glacier forelands for decades to centuries following glacier retreat. Yet, most ecological studies sample exclusively on stable terrain to fulfill chronosequence criteria, thus missing potential feedbacks between geomorphic disturbances and vegetation colonization. By influencing vegetation and soil development, such vegetation‐geomorphic disturbance feedbacks could be crucial to understand glacier foreland ecosystem development in a changing climate. We surveyed vegetation and environmental properties, including geomorphic disturbance intensities, in 105 plots located on both stable and unstable moraine terrain in two geomorphologically active glacier forelands in New Zealand and Switzerland. Our plot data showed that geomorphic disturbance intensities permanently changed from high/moderate to low/stable when vegetation reached cover values of around 40%. Around this cover value, species with response and effect traits adapted to geomorphic disturbances dominated. This suggests that such species can act as "biogeomorphic" ecosystem engineers that stabilize ground through positive feedback loops. Across floristic regions, biogeomorphic ecosystem engineer traits creating ground stabilization, such as mat growth and association with mycorrhiza, are remarkably similar. Nonmetric multidimensional scaling revealed a linked sequence of decreasing geomorphic disturbance intensities and changing species composition from pioneer to late successional species. We interpret this linked geomorphic disturbance‐vegetation succession sequence as "biogeomorphic succession," a common successional pathway in unstable river and coastal ecosystems across the world. Soil and vegetation development were related to this sequence and only advanced once biogeomorphic ecosystem engineer species covered 40%–45% of a plot, indicating a crucial role of biogeomorphic ecosystem engineer stabilization. Different topoclimatic conditions could explain variance in biogeomorphic succession timescales and ecosystem engineer root traits between the glacier forelands. As glacier foreland ground is widely unstable, we propose to consider glacier forelands as "biogeomorphic ecosystems" in which ecosystem structure and function are shaped by geomorphic disturbances and their feedbacks with adapted plant species, similar to rivers and coasts. [ABSTRACT FROM AUTHOR]

Carbon (C), nitrogen (N), phosphorus (P) and potassium (K) are the main nutrient elements widely found in soil, litter and leaves, and their stoichiometric ratios are important indicators of ecosystem functions. However, there is little research on the effects that nutrient cycle and vegetation succession have on leaf, litter and soil nutrients and stoichiometric ratios, especially in the fragile karst areas. To reveal the nutrient cycling characteristics and ecosystem stability mechanism during vegetation succession, leaf, litter and soil samples were collected from the herbaceous community (HC), shrub community (SC), secondary forest community (SF) and primary forest community (PF) in a typical karst area at growth and senescence phases. The results showed that the nutrient contents and stoichiometric ratios of leaf, litter and soil in the main layers of each community were significantly different at the growth and senescence phase. The utilization efficiency of N in the leaves of the main layers of each succession community first decreased and then increased at different growth stages, and the utilization efficiency of P increased but the reabsorption rates of N and P showed a continuous decreasing trend. In addition, there was a significant allometric relationship between N and P contents in plant leaves during the growth phase. More importantly, the internal stability of N content in plant leaves was higher than the P content, suggesting that vegetation succession significantly affected leaf, litter and soil nutrient contents and their stoichiometric ratios in our study region. The strength of the relationship between them reflects the inheritance and co–variation of nutrient content to a certain extent, and the differences in the strategies that different species in the community use to adapt to the fragile karst environment. This study concludes that plants in the karst region mainly improve their P utilization efficiency to adapt to low phosphorus stress in soil and ensure the normal physiological and biochemical responses in the process of vegetation succession. [ABSTRACT FROM AUTHOR]

It is important to understand the response of vegetation dynamics and surface water budget to the changing climate. To investigate the effects of vegetation and climate change on evapotranspiration and runoff on a basin scale, the SSiB4T/TRIFFID (SSiB4/TRIFFID coupled with TOPMODEL) is used to perform long-term dynamic simulations of vegetation succession and the water balance under different climate scenarios for a subalpine basin. The results of all experiments show that fraction of vegetation changes from a dominance of C3 grasses to tundra shrubs and then gradually approaches equilibrium with a dominance of forests. Change to evapotranspiration is very sensitive to temperature changes but is not sensitive to precipitation changes when the temperature remains unchanged. Runoff is very sensitive to changes in both temperature and precipitation. In the increase of temperature, evapotranspiration of forests increases the most among the three vegetation types. From the control run to the [T+5, (1+40%)P] run (A temperature increase of 5 °C, an increase in precipitation of 40%), the role of forests in increasing runoff changes to a reduction in runoff.

This study investigated the changes in soil physical properties after the abandonment of haypastures dominated by Helictotrichon pubescens and subsequent colonization by successional grasses Brachypodium pinnatum and Calamagrostis epigejos. We also investigated if there are linear relationships among the soil physical properties in the studied soils, and the results of the soil chemical property analysis were used as an aid in the interpretation of these relationships. The studied soil was calcocambisol on limestone. Soil samples were collected in disturbed and undisturbed state, and the differences among them were analysed by Mann-Whitney U test, whereas the relationships between soil properties were analysed with simple linear regression models. Soil solid particle density was higher in the B horizons of successional grasslands (median=2.61 g/cm3) than in those of haypastures (median=2.54 g/cm3). The A horizons of haypastures were barely 2–3 cm deep, whereas under successional grasses their depth reached as much as 25 cm. At the same soil depth (10–12 cm), the soil colonized by successional grasses had higher total porosity (median=53.3%) and lower bulk density (median=1.18 g/cm3) than those of haypasture soil (medians of 45.1% and 1.41 g/cm3, respectively). Soil total porosity and water holding capacity were positively linearly associated (r2= 0.71, P

Changes in species composition and diversity-productivity relationships during vegetation succession are of great significance for the restoration of degraded grasslands. However, the human intervention of grassland restoration mostly considers the single ecological (diversity) or production (biomass) function of grasslands, and does not fully consider the relationships between the two to improve the restoration effects. In this study, three vegetation types (desert grassland, sandy grassland and temperate savanna) were considered to simulate the three stages of restoration of degraded temperate savanna (early, middle and late restoration). Changes in species composition, diversity, and diversity-productivity relationships during the temperate savanna restoration were explored through spatiotemporal substitution. The results showed that with the progress of succession, xerophytes decreased significantly, mesophytes and hygrophytes increased, C4 plants decreased gradually, and C3 plants increased. The change of species richness was the main reason for community differences in the process of community succession, and species replacement mainly occurred between communities in the early and middle stages of succession. Species richness increased significantly from early to late stage of restoration. Latitude was significantly negatively correlated with species diversity. In the process of vegetation restoration, the impact of species richness, Pielou’s evenness, and β-diversity on biomass gradually developed positively and continued to increase, while the Simpson index showed the opposite effect. This study provides references for the restoration of temperate savanna and emphasizes the ecological and productive functions of the grassland should be taken into account in the restoration strategy.

This research investigates the association between the succession and restoration of degraded land in the southeast of Iran with artificial Calligonum forests regarding vegetation changes, soil properties, carbon (C) and nitrogen (N) pools in vegetation and soil. Eight forestry sites were selected, aged 1, 4, 6, 9, 11, 16, 25, and 30 years. Observations indicated that vegetation percentage, density, frequency, richness, and diversity of species substantially increased (p < 0.01). The highest percentage of vegetation (80.30%), density (62.70 n ha−1), richness (14.15), and diversity (0.90) was observed in the 30-year site. At the end of the succession phase under study (the 25- and 30-year sites), the variation trend of vegetation was steady. As the age of the forests increased, the soil nutrient values increased significantly during succession (p < 0.01), even though acidity and electrical conductivity (EC) did not change significantly over time (p > 0.01). In the early stages of succession, the soil’s C and N pools (aerial biomass, root, and litter) did not increase significantly (p > 0.01). Over time, however, C and N pools of the soil and plants increased (the highest amounts were seen in the 30-year site). The results indicated a significant difference in the soil and vegetation properties in the forestry sites. In general, planting native species and the succession of vegetation can play an effective role in preserving the environment in degraded lands and increasing the C and N pools.

The Białowieża Primeval Forest is one of the most pristine forested and peatland areas in Europe, as recognized by its status as the World Biosphere Reserve. Palaeoecological analyzes offer the possibility of establishing a record of ecosystem change over time, and therefore setting reference conditions for their assessment, protection and restoration. To assess the impact of hydrological changes, fire and pollution (dust, metals from smelting) on peatland and forest ecosystems, we carried out high-resolution, multi-proxy palaeoecological investigations of two peat cores (50 cm long) from nearby locations at a peatland located in the protected area (nature reserve) of the Białowieża Forest (CE Poland). Our study revealed that: i) between about 1780 and 1920 CE high fire activity likely caused by humans led to a partly decline in dwarf shrubs at the sampling sites; ii) between about 1910 and 1930 CE distinctive changes in local and regional plant succession took place that can be considered as a sign of disturbance in the peatland ecosystems; iii) during the last three decades we recorded a recent decrease of trace metals and pollen indicating a decrease in human activity. These changes are synchronous with a decrease of industrial activity and curbing of emission through legislation as well as the ongoing depopulation of villages in E Poland that started in 1990.Our data suggest that even well-preserved peatlands, located in protected areas might be far from their pristine state, predominantly due to disturbance effects from the past still lingering on. Nevertheless, the studied area remains one of the best-preserved forest ecosystems in Europe, despite the negative impact of human activity (deforestation, fires, hunting) over the past few centuries.

Dissolved organic matter (DOM) is the most active component in the soil environment. Understanding the chemical diversity of DOM and the interaction of the physicochemical properties of the soil are key to managing peatland under succession. In this study, we aimed to understand the effects of peatland succession on soil DOM. We collected soil samples (topsoil: 0–10 cm, subsoil: 10–20 cm) from peatland during different stages of peatland succession in mid–high latitude northern regions, determined the changes in quantity and quality of DOM using fluorescence spectroscopy and parallel factor analysis. We found that peatland succession altered the effectiveness of soil nutrients and water content. During the succession, the content of humus-like substances in the DOM of the topsoil increased and the content of protein-like material decreased, whereas the content of substances in the subsoil remained stable. pH was the key factor affecting the change in the composition of the DOM in the topsoil during peatland succession. The variation of DOM in the subsoil may be related to the vegetation composition. The results suggest that fluorescent DOM components respond significantly to changes in peatland succession, and DOM properties are driven by soil pH and vegetation composition during peatland succession. In conclusion, our results reveal the optical changes and factors that influence DOM in peatlands under succession. This suggests that DOM can be modified by simultaneous changes of the physicochemical properties in the soil and the vegetation cover.

Changes in soil chemistry after invasion by bracken (Pteridium aquilinum) have been studied in heathlands, but comparable studies in meadows are lacking. We investigated if bracken invasion into P-deficient meadows alters the soil nutrient-resource pool, as well as the mechanisms behind it linked to soil processes and bracken nutrition. Furthermore, we investigated how community composition responds to differences in soil chemistry before and after the invasion. Soil and plant material sampling, along with vegetation survey, were performed during bracken peak biomass. Data analyses included analysis of variance and canonical correspondence analysis (CCA). Bracken invasion increased soil P availability, soil organic C concentration, as well as C:N, C:S and N:S ratios, while decreasing Fe and Co concentrations. Bracken pinnae were rich in P, and its rhizomes were rich in K, whereas N:P of pinnae and rhizomes was low. CCA showed contrasting abundance patterns of frequent meadow species related to P and K availability. Holcus lanatus exhibited competitive advantage under extremely low P availability. Increase in P availability under bracken may have occurred through promoting the leaching of Fe and Al. By increasing P availability for its growth and increasing N limitation for other species, bracken can gain a competitive advantage from the soil resource-niche perspective. Its ability to increase soil P availability, along with the physiological mechanisms behind its high P acquisition efficiency, seem to differentiate bracken from other species of competitive ecological strategy, which are mainly confined to nutrient-rich environments. This enabled bracken to invade P-deficient meadows. [ABSTRACT FROM AUTHOR]

To provide information that can support natural vegetation restoration in karst areas, we investigated the change rules of soil microbial communities during vegetation succession from bare rock to arboreal forest using high-throughput sequencing. The results showed that vegetation succession did not cause significant changes in alpha diversity of soil microbial communities. The main bacterial phyla were Proteobacteria, Actinobacteria, and Acidobacteria during vegetation succession. There was a shift from Ascomycota to Basidiomycota during succession, and the relative abundance of Basidiomycota in arboreal rhizosphere soil was the highest; this promoted mycorrhizal formation with the trees and mineral nutrient absorption by the host. Most of the symbiotic networks between soil microorganisms showed cooperative relationships. We propose that the dominant microbes contributed to the biological weathering of limestone and soil evolution under vascular plants. Furthermore, the findings of this study can help improve soil properties by providing insight into how to adjust microbial composition.

Abstract The Permian Taiyuan and Shanxi formations exposed in Shandong Province, eastern North China, contain abundant spores and pollen. In this study, a total of 42 genera and 146 species of spores and pollen from these Permian formations, native to northern China, are identified and related to the three epochs of the Permian Period (Cisuralian, Guadalupian, and Lopingian Epochs) as two assemblages: Assemblage I — the Laevigatosporites–Granulatisporites assemblage, inferred as the Cisuralian (~ 298.9–272.9 Ma); and, Assemblage II — the Gulisporites–Sinulatisporites assemblage, inferred as the Guadalupian (~ 272.9–259.1 Ma). Assemblage I represents growing ferns, whereas Assemblage II represents gymnosperms. The assemblage division and analysis indicated that the palaeoclimate of the study area during Early-Middle Permian time was dominated by warm and humid conditions, and later in the Middle Permian changed into moderately dry conditions.

Abstract Background Shifting cultivation (locally known as “jhum”) is a major driver of deforestation and loss of ecosystem services in rainforests. For developing any effective conservation of biodiversity and carbon service program, an in-depth understanding to the recovery of vegetation and carbon after abandonment of jhum is essential. We estimated species richness, abundance and composition of trees, shrubs and herbs, carbon distribution in aboveground and belowground components along a chronosequence of jhum fallow in northeast India, and elucidated the factors affecting the recovery processes of jhum fallows. Methods Species composition and other plant community attributes, carbon storage in different pools were studied in 5 jhum fallows (< 5, 5–10, 11–15, 16–20, 21–25 years old) and an old-growth forest. The data were subjected to linear mixed effect modeling using R-package “nlme” for identifying the important factors contributing to the recovery of vegetation and carbon. Results Species composition varied significantly (P < 0.05) between jhum fallows and old-growth forest. Tree density varied from 28 stems ha−1 in 5 years old jhum fallow to 163 stems ha−1 in old-growth forest. Both biomass carbon in all components and soil organic carbon were significantly (P = 0.01) lower in jhum fallows than in the old-growth forest except living non-woody biomass component. The recovery of aboveground biomass carbon was faster during early successive years than the mid-successive jhum fallows. Total ecosystem carbon and soil organic carbon stock in the oldest jhum fallow was 33% and 62% of those in the old-growth forest, respectively. The fallow age was found to be the most important explanatory factor in the recovery process of vegetation and carbon stock in re-growing fallows. Conclusion The shifting cultivation fallows gradually recovered both vegetation and carbon and are potential repository sites for biodiversity conservation, which may take much longer time to reach up to old-growth forest in northeast India.

There is growing awareness of the need for regenerative practices in the fight against biodiversity loss and climate change. Yet, we lack a mechanistic understanding of how microbial community composition and functioning are likely to change alongside transition from high-density tillage to large-scale vegetation restoration. Here, we investigated the functional dynamics of microbial communities following a complete vegetation successional chronosequence in a subtropical zone, Southwestern China, using shotgun metagenomics approaches. The contents of total soil phosphorus (P), available P, litter P, and microbial biomass P decreased significantly during vegetation succession, indicating that P is the most critical limiting nutrient. The abundance of genes related to P-uptake and transport, inorganic P-solubilization, organic P-mineralization, and P-starvation response regulation significantly increased with successional time, indicating an increased microbial "mining" for P under P limitation. Multi-analysis demonstrated microbial P limitation strongly inhibits carbon (C) catabolism potential, resulting in a significant decrease in carbohydrate-active enzyme family gene abundances. Nevertheless, over successional time, microorganisms increased investment in genes involved in degradation-resistant compounds (lignin and its aromatic compounds) to acquire P resources in the litter. Our study provides functional gene-level insights into how P limitation during vegetation succession in subtropical regions inhibits soil microbial C metabolic processes, thereby advancing our understanding of belowground C cycling and microbial metabolic feedback during forest restoration., Competing Interests: The authors declare no competing interests., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Society for Microbial Ecology.)

Abstract A mixed‐species bird flock is a social assemblage where two or more bird species are moving together while foraging and might benefit from increased foraging efficiency and antipredator vigilance. A “mega‐flock,” which includes flocking species from different vegetation strata, often exhibits high species diversity. Mechanisms for the formation of mega‐flocks have not yet been explored. In this study, we evaluated the influence of vegetation structure and bird species diversity in driving the occurrence of mega‐flocks. We investigated the composition of mixed‐species flocks, local bird communities, and vegetation structure in five vegetation types of two high‐elevation sites in central Taiwan. Mega‐flocks occurred more frequently in pine woodland than later successional stages of coniferous forests. However, species richness/diversity of local bird communities increased along successional stages. Therefore, vegetation variables exhibit more influence on the occurrence of mega‐flocks than local bird communities. Besides foliage height diversity, understory coverage also showed positive effects on flock size of mixed‐species flocks. Our results indicated that pine woodlands with more evenly distributed vegetation layers could facilitate the interactions of canopy and understory flocks and increase the formation of mega‐flocks and thus the complexity of mixed‐species flocks.

A mixed‐species bird flock is a social assemblage where two or more bird species are moving together while foraging and might benefit from increased foraging efficiency and antipredator vigilance. A "mega‐flock," which includes flocking species from different vegetation strata, often exhibits high species diversity. Mechanisms for the formation of mega‐flocks have not yet been explored. In this study, we evaluated the influence of vegetation structure and bird species diversity in driving the occurrence of mega‐flocks. We investigated the composition of mixed‐species flocks, local bird communities, and vegetation structure in five vegetation types of two high‐elevation sites in central Taiwan. Mega‐flocks occurred more frequently in pine woodland than later successional stages of coniferous forests. However, species richness/diversity of local bird communities increased along successional stages. Therefore, vegetation variables exhibit more influence on the occurrence of mega‐flocks than local bird communities. Besides foliage height diversity, understory coverage also showed positive effects on flock size of mixed‐species flocks. Our results indicated that pine woodlands with more evenly distributed vegetation layers could facilitate the interactions of canopy and understory flocks and increase the formation of mega‐flocks and thus the complexity of mixed‐species flocks. [ABSTRACT FROM AUTHOR]

To provide information that can support natural vegetation restoration in karst areas, we investigated the change rules of soil microbial communities during vegetation succession from bare rock to arboreal forest using high-throughput sequencing. The results showed that vegetation succession did not cause significant changes in alpha diversity of soil microbial communities. The main bacterial phyla were Proteobacteria, Actinobacteria, and Acidobacteria during vegetation succession. There was a shift from Ascomycota to Basidiomycota during succession, and the relative abundance of Basidiomycota in arboreal rhizosphere soil was the highest; this promoted mycorrhizal formation with the trees and mineral nutrient absorption by the host. Most of the symbiotic networks between soil microorganisms showed cooperative relationships. We propose that the dominant microbes contributed to the biological weathering of limestone and soil evolution under vascular plants. Furthermore, the findings of this study can help improve soil properties by providing insight into how to adjust microbial composition. [ABSTRACT FROM AUTHOR]

The response of coastal wetlands to future sea-level rise remains uncertain. Palaeoecological data are essential to constrain the still conflicting ecological models. However, obtaining detailed palaeo-coastal stratigraphic records before Holocene is often difficult due to repeated Quaternary marine transgression-regressions. Here we utilize pollen data from a deep-sea sedimentary archive in northern South China Sea to explore the historical behavior of coastal wetlands at a large river estuary over the last 140-kyr. A recurrent wetland (Cyperaceae)-pioneer species (Selaginella)-zonal forest (Pinus) succession throughout the last glacial-interglacial cycle implies a coastal salt marsh origin of the Cyperaceae pollen. Comparing with global sea-level reconstructions, the increases in Cyperaceae pollen abundance, and hence the expansions of coastal salt marsh, were found to be closely linked with rapid large-scale sea-level rises. This finding indicates a resilience of coastal wetlands to future sea-level rise, and highlights the probable importance of conventionally ignored horizontal adaptability in long-term survival of coastal wetlands. Overall, marine pollen records provide an opportunity to supplement existing palaeoecological observations of coastal wetlands during the Quaternary.

To study the soil genetic diversity of bacteria and fungi in different vegetation successions (grassland, shrubbery, primary forest and secondary forest) from the karst area, the Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) technology was applied. The results showed that: (1) the diversity of bacterial communities and the fungal communities in karst area were higher than non karst area in each vegetation succession. Compared with the survey from bacterial (the Shannon index was 2.97 in primary forest, 2.91 in secondary forest, 3.18 in shrubbery, 3.14 in grassland and 2.68 in non karst), fungal diversity between karst areas (the Shannon index was 3.56 in primary forest, 3.78 in secondary forest, 3.73 in shrubbery and 3.70 in grassland) and non karst areas (the Shannon index was 3.08) was more evident, which may be related to the alterations of the composition of plant community and the source of carbon in soil with the vegetation succession of karst ecosystem; (2) The comparation of bacterial diversity index and the richness comprehensively evaluated as follows: shrubbery > grassland > primary forest > nsecondary forest. The diversity index and the richness of fungal communities was as follows: secondary forest > shrubbery > grassland > primary forest. The results suggest that the fungal communities have been greatly changed via vegetation successions, but the diversity index and the richness of the bacterial communities have not been seriously affected. The results provide scientific basis for understanding karst surface ecosystem, which contributes to the future aim of protecting the karst from desertification.

This study investigated the changes in soil physical properties after the abandonment of haypastures dominated by Helictotrichon pubescens and subsequent colonization by successional grasses Brachypodium pinnatum and Calamagrostis epigejos. We also investigated if there are linear relationships among the soil physical properties in the studied soils, and the results of the soil chemical property analysis were used as an aid in the interpretation of these relationships. The studied soil was calcocambisol on limestone. Soil samples were collected in disturbed and undisturbed state, and the differences among them were analysed by Mann-Whitney U test, whereas the relationships between soil properties were analysed with simple linear regression models. Soil solid particle density was higher in the B horizons of successional grasslands (median=2.61 g/cm3) than in those of haypastures (median=2.54 g/cm3). The A horizons of haypastures were barely 2-3 cm deep, whereas under successional grasses their depth reached as much as 25 cm. At the same soil depth (10-12 cm), the soil colonized by successional grasses had higher total porosity (median=53.3%) and lower bulk density (median=1.18 g/cm3) than those of haypasture soil (medians of 45.1% and 1.41 g/cm3, respectively). Soil total porosity and water holding capacity were positively linearly associated (r2= 0.71, P<0.0001), but they were both negatively associated with bulk density (r2=0.98 and r2=0.67, respectively, P<0.0001), which was due to strong control of humus over the soil physical properties. We showed that the prevailing grassland type should not be ignored when studying physical properties of a specific soil type. [ABSTRACT FROM AUTHOR]

Soil cover is a prevailing method used at mine sites to ensure the safety of hazardous materials and restore ecological functions when the base materials are unfavorable for plant growth. The former open-pit Ningyo-toge Mine was backfilled with overburden and neutralized smelting residues and covered with soil in 1987. After 36 years, the vegetation remained dominated by the perennial herb Miscanthus sinensis , and woody plant establishment did not progress successfully. This study investigated the factors that inhibited woody plant establishment at the site. The soil profile survey revealed that the soil cover formed Bg horizons (pseudogley soil) with cloudy mottling, representative of poorly drained soil. In the Bg horizon, woody plant roots of Pinus densiflora and Weigela hortensis exhibited growth inhibition. Elemental analysis revealed that in the Bg horizon the roots of P. densiflora and W. hortensis accumulated high Fe concentrations exceeding 10,000 mg/kg DW at critical levels. Our results suggested that woody plant roots in the Bg horizon may have suffered from chronic oxygen deficiency accompanied by excessive Fe stress in the soil cover. Topsoil water content (<50 mm) and microtopographic features were not critical factors disrupting woody plant establishment because some individuals were growing in areas with high soil water content, exceeding 60%. Considering that woody plant roots were developed primarily in the shallow A horizon, A horizon formation by M. sinensis is a key step in initiating woody plant establishment by improving the soil structure and physiochemical characteristics of the soil cover, such as carbon content, exchangeable nutrients, and air-filled porosity. For successful mine pollution control and vegetation recovery, implementing an appropriate topsoil system, such as native forest soil, loosely graded and minor infiltration layer above the overburden would be necessary. [Display omitted] • Woody plant establishment was inhibited on soil-covered mine site for 36 years. • Pseudogley soil (Bg horizon) formation inhibited woody plant root growth. • Oxygen deficiency and Fe dissolution may have caused root growth inhibition. • A horizon formation by M. sinensis is key for initiating woody plants establishment. • Proper soil cover system would be necessary for successful forest recovery. [ABSTRACT FROM AUTHOR]

Identification of typical vegetation succession types and their important influencing factors is an important prerequisite to implement differential vegetation and soil management after land abandonment on the Loess Plateau, China. However, there is no reported study specifically on the identification of vegetation types and their important factors as well as the thresholds of the important factors for classification of the vegetation types, based on the medium- to long-term succession of natural vegetation after cropland abandonment. We collected vegetation and soil data on the natural vegetation with the longest 60-year-old forest communities that developed after cropland abandonment and analyzed the data using two-way indicator species analysis, detrended correspondence analysis, direct canonical correspondence analysis and classification tree model. The vegetation communities were classified into five distinct vegetation types, including Artemisia scoparia, Lespedeza davurica and Stipa bungeana, Artemisia giraldii pamp, Sophora viciifolia, Quercus liaotungensis and Biota orientalis. The years after cropland abandonment and soil C/N were further identified as important factors determining the types of vegetation. Likewise, it was observed that most of the investigated soil nutrient variables and soil texture-related variables improved with the vegetation succession while soil water in the surface layers showed a decreasing trend. These findings may provide an ecological basis for site-specific management of vegetation types after cropland abandonment in the medium-long term on the Loess Plateau. Our results encourage further exploration of vegetation succession and their important factors based on longer periods of vegetation succession after cropland abandonment under more soil and climatic conditions on the mountainous areas as the Loess Plateau.

Unmanned Aerial Vehicles (UAV) greatly extended our possibilities to acquire high resolution remote sensing data for assessing the spatial distribution of species composition and vegetation characteristics. Yet, current pixel‐ or texture‐based mapping approaches do not fully exploit the information content provided by the high spatial resolution. Here, to fully harness this spatial detail, we apply deep learning techniques, that is, Convolutional Neural Networks (CNNs), on regular tiles of UAV‐orthoimagery (here 2–5 m) to identify the cover of target plant species and plant communities. The approach was tested with UAV‐based orthomosaics and photogrammetric 3D information in three case studies, that is, (1) mapping tree species cover in primary forests, (2) mapping plant invasions by woody species into forests and open land and (3) mapping vegetation succession in a glacier foreland. All three case studies resulted in high predictive accuracies. The accuracy increased with increasing tile size (2–5 m) reflecting the increased spatial context captured by a tile. The inclusion of 3D information derived from the photogrammetric workflow did not significantly improve the models. We conclude that CNN are powerful in harnessing high resolution data acquired from UAV to map vegetation patterns. The study was based on low cost red, green, blue (RGB) sensors making the method accessible to a wide range of users. Combining UAV and CNN will provide tremendous opportunities for ecological applications. [ABSTRACT FROM AUTHOR]

Small patches of rainforest are numerous in subtropical Queensland. Their expansion into adjacent eucalypt forests is limited by fires and other factors. This study was completed in 1980 within a compact site of 200 ha in conserved forest at Mt Nebo, Queensland. It describes the separate contributions of many natural site factors to the stability of the boundaries between these forest types. The survey area included areas of eucalypt forest with a grassy understorey and adjoining ecotonal areas. These, in turn, merged into patches of old-growth complex notophyll vine forest (CNVF). Three separate datasets were recorded from 160 plots, clustered around 32 grid points: (i) canopy species; (ii) woody species in the understorey stratum; and (iii) site characteristics, as indicators of the potential for localised progression from eucalypt to CNVF at canopy level. CSIRO Division of Computing Research in Brisbane processed the data, using methods developed to define initial stages of recovery from clearing inside old-growth CNVF at nearby Mt Glorious. Apart from recent fires, the long-term expansion of CNVF across an ecological gradient at Mt Nebo was limited at various stages by factors such as the orientation, aspect and shape of slopes, soil derivation, the type and thickness of litter cover, soil moisture levels, and the presence and persistence of the exotic shrub lantana (Lantana camara). The compact survey area was free of some confounding influences seen in broader regional studies (e.g. variations in elevation, soil derivation, temperature and rainfall, and incomplete records of fire, grazing and clearing). In this study the ranges of separate sets of observations of canopy and understorey trees, and natural site characteristics within each plot, were unusually broad, allowing definition of how natural site factors combine to allow, and limit, succession from eucalypt forest to mature subtropical CNVF in the absence of fire. [ABSTRACT FROM AUTHOR]