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• Vegetation classification improve our knowledge and understanding of complex ecosystems. • Vegetation classification, description and mapping method for large areas (> 90 000 hectares). • The use of Sentinel-2 and topo-morphological data in conjunction with limited floristic surveys (new approach) resulted in an accurate classification, description and vegetation map of the Karoo National Park. • A total of 12 major plant communities and two sub-communities that are distinctly linked to various abiotic factors were identified, described and mapped for the Karoo National Park. The higher-lying rocky steep midslopes as well as the valley bottomland areas had the highest diversity and species richness. This study aimed at classifying, mapping and describing the plant communities of the Karoo National Park using floristic surveys in conjunction with Sentinel-2 and topo-morphological data. Karoo National Park, Western Cape, South Africa. The vegetation of the Karoo National Park was delineated into homogenous physiognomic-physiographic units using Sentinel-2 images. A total of 128 survey plots (100 m2 each) were surveyed within the different homogeneous units during the period 2016 to 2020. Within each survey plot, all rooted species were identified and their cover abundance estimated. Each plot was photographed and its geolocation recorded. The floristic data were captured using the Braun Blanquet Personal Computer suite and exported to the JUICE Software programme. A modified TWINSPAN classification was done to derive a first tabled synopsis of the plant communities. The different plant communities were subsequently classified and described according to their diagnostic and dominant species gleaned from the synoptic table. Species richness was determined by counting the number of different species per plant community while the Shannon–Wiener Index and Rich-Gini–Simpson Index of diversity (D) were used to derive indices of species diversity per plant community. 12 major communities and two sub-communities that are distinctly linked to various abiotic factors were identified, described and mapped. The higher-lying rocky steep midslopes as well as the valley bottomland areas had the highest diversity and species richness. This study proves the efficacy of using Sentinel-2 and topo-morphological data in classification, description and mapping vegetation of extensive natural areas. The vegetation map and classification of plant communities provide a baseline to inform management decisions. Taxonomic reference: SA-Plant Checklist-2019–2020, South African National Biodiversity Institute, 2020, Botanical Database of Southern Africa (BODATSA) (http://posa.sanbi.org/) [accessed January 2022]. [ABSTRACT FROM AUTHOR]

Swahili coastal forests, spanning the Kenyan and Tanzanian coastlines and the Zanzibar Archipelago, are integral to the biodiverse Eastern Arc and Coastal Forest region. These forest ecosystems face considerable anthropogenic threats. This study contributes to the available knowledge on the floral composition and plant community assemblages of Mnemba Island, a small sandy cay in the Zanzibar Archipelago, which helps to establish baseline data for conservation purposes. Two main coastal forest plant communities were identified: (1) the Casuarina cunninghamiana–Suriana maritima open to closed sandy dry coastal forest, and (2) the Eugenia capensis–Mimusops obtusifolia coastal forest. A total of 91 different plant species belonging to 54 plant families were identified for the island. Community 2, an indigenous forest, supports diverse bird breeding colonies and is a crucial habitat for the threatened Aders' duiker. Understory development is limited due to the historical Suni antelope overpopulation. Environmental factors like salt spray, allelochemicals, herbivore browsing, and climate fluctuations influence the vegetation abundance and composition. The study underscores differences in species diversity and composition between the planted Casuarina community and the natural atoll vegetation. The natural vegetation shows affinities with the Zanzibar–Inhambane edaphic coral-rag scrub forest and the transitional rainforest. Several species characteristic of Indian Ocean atolls were identified, providing insights into invasion ecology and conservation strategies. The study contributes conceptually to our understanding of vegetation dynamics in island ecosystems by highlighting the interplay between plant communities, environmental processes, and human activities. The fragile yet resilient nature of Mnemba's unique ecosystem is emphasised, offering insights for conservation management, long-term monitoring, and adaptive approaches tailored to island environments. [ABSTRACT FROM AUTHOR]

Secondary forests represent a significant proportion of global forest cover, with over 70% of forests in East Asia classified as regenerating. While succession has been studied extensively in temperate systems, trajectories of subtropical succession remain poorly characterized in highly disturbed, urban‐adjacent forests. Investigating the additive beta diversity components of turnover and nestedness may reveal community assembly mechanisms driving secondary succession. The present study investigates plant community assembly along a successional gradient from 7 to 70 years following the onset of succession in secondary subtropical forests in Hong Kong, China. Plant survey data for 28 plots were analysed, generating additive Simpsons turnover and nestedness beta diversity metrics. Dissimilarity matrices were generated and modelled as a function of environmental matrices including forest plant community age (years following onset of secondary succession), inter‐community distance (metres), and soil moisture saturation (%) across three elevational bands using generalized dissimilarity models. Nonmetric multidimensional scaling of plant communities was conducted with Bray–Curtis dissimilarity matrices. Inter‐community distance and successional age differentially influenced plant species turnover between lowland and Montane forest types. Models of nestedness found that plot age and soil moisture saturation were significant drivers of nestedness patterns in plant communities across elevational classes. Turnover represented a higher proportion of Sorensen beta diversity than nestedness, while ANOSIM found significant differentiation between plant communities at different successional stages. Turnover patterns suggest a deterministic model of community assembly, with strong patterns of species replacement between communities at fine spatial scales and successional stages, as well as clear compositional shifts between lowland and montane forest types. NMDS analysis and functional compositional assessments suggested a transition from early successional communities with a high proportion of shrub species, to later successional communities with a higher proportion of tree species, with an increase in species turnover with greater age dissimilarity. [ABSTRACT FROM AUTHOR]

Ungulate herbivory might induce different effects on the diversity and growth of trees and shrubs. The density, distribution, and the species of ungulates as well as plant communities' composition and other factors determine whether ungulate herbivory promotes or limits plants' diversity and growth. The impacts of ungulates on woody plants are commonly surveyed with exclosure-control approaches. In practice, such surveys frequently only cover short periods of time, addressing immediate management needs. Long-term surveys, documenting lasting effects of ungulate herbivory, are highly needed, but still rare. However, the general transferability of outcomes of long-term surveys might be limited due to different disturbing factors. This study addresses two basic aspects of long-term monitoring in mountainous forests, based on a unique 30-year data set: (1) Possible long-term effects of herbivores on forest vegetation (e.g., species/structural diversity of woody plants) and (2) potential differences between short-term and long-term surveys in terms of height growth patterns. In our study, diversity of woody plant species showed great variability with no significant impact of ungulate herbivory. The presence of ungulates had a significantly negative effect on the vertical structural diversity and growth of trees. Due to the slower growth on control plots, it took trees longer to reach a 160 cm height-threshold with their terminal shoots than on exclosure plots. Our long-term control-exclosure data set indicated that long-term survey data indeed might differ from growth patterns represented by short-term surveys. This can be induced by several factors, like site-specific growth patterns of trees, occurrences of natural abiotic disturbances that influence the functional life of exclosures, and others. [ABSTRACT FROM AUTHOR]

Forest fires play a pivotal role in influencing ecosystem evolution, exerting a profound impact on plant diversity and community stability. Understanding postfire recovery strategies holds significant scientific importance for the ecological succession and restoration of forest ecosystems. This study utilized Partial Least Squares Path Modeling (PLS-PM) to investigate dynamic relationships among plant species diversity, phylogenetic diversity, soil properties, and community stability during various recovery stages (5-year, 15-year, and 23-year) following wildfires on the northeastern margin of the Qinghai-Tibet Plateau. The findings revealed: (1) Over time, species richness significantly decreased (p< 0.05 or p< 0.01), while species diversity and dominance increased, resulting in uniform species distribution. Community stability progressively improved, with increased species compositional similarity. (2) Throughout succession, phylogenetic diversity (PD) significantly decreased (p< 0.01), accompanied by rising Mean Pairwise Distance (MPD) and Mean Nearest Taxon Distance (MNTD). Net Relatedness Index (NRI) shifted from positive to negative, indicating an increasing aggregation and dominance of plants with similar evolutionary traits in burned areas. Early succession witnessed simultaneous environmental filtering and competitive exclusion, shifting predominantly to competitive exclusion in later stages. (3) PLS-PM revealed that in the early recovery stage, soil properties mainly affected community stability, while species diversity metamorphosed into the primary factor in the mid-to-late stages. In summary, this study showed that plant diversity and phylogenetic variation were successful in revealing changes in community structure during the succession process. Soil characteristics functioned as selective barriers for plant communities during succession, and community stability underwent a multi-faceted and dynamic process. The soilplant dynamic feedback continuously enhanced soil conditions and community vegetation structure thereby augmenting stability. Post-fire vegetation gradually transitioned towards the original native state, demonstrating inherent ecological self-recovery capabilities in the absence of secondary disturbances. [ABSTRACT FROM AUTHOR]

The stability, diversity, and biomass of grassland plant communities directly impact the functionality and resilience of ecosystems, making them a focal point for ecological research. This three-year study (2021–2023) in the Habahe pastoral area of Xinjiang, China, aimed to investigate the long-term effects of grazing on grassland vegetation structure, community stability, species diversity, and productivity. The results indicate the following. (1) The Habahe pastoral area hosts a relatively rich plant species diversity, with 40 species distributed across 17 families and 37 genera, predominantly comprising perennial and annual herbs. (2) Grazing significantly affected grassland structure and function, resulting in a 4.35% decrease in plant community stability, a 40.74% decrease in species richness, a 21.55% decrease in species dominance, a 5.08% decrease in species diversity, a 46.79% decrease in aboveground biomass, a 61.86% decrease in coverage, and a 72.12% decrease in height. (3) Grazing alters the relationship between species diversity and community stability, shifting it from a positive correlation to a negative one (p < 0.01) or rendering it non-significant after grazing. (4) Grazing affects the correlation between aboveground biomass and both species diversity and community stability. While the positive correlation between aboveground biomass and species diversity persists, it is not statistically significant (p > 0.05) after grazing. Conversely, the correlation between aboveground biomass and community stability shifts from positive to negative (p < 0.01). These results emphasize the need for integrated management strategies that consider both grazing intensity and plant community composition to maintain the health of grassland ecosystems. [ABSTRACT FROM AUTHOR]

Aims: Changes in precipitation patterns, such as the predicted increases in the frequency of climatic extremes, are likely to alter plant communities, but whether responses to drought or to wetter conditions respectively cause consistent, opposite responses is debated. Here, we assessed the response in biomass production and species diversity of water‐limited plant communities to the direction (increase or decrease) and magnitude (micro‐ and macro‐climatic effects) of changes in soil moisture. Location: We reciprocally translocated soils containing seed banks from two climates (semi‐arid and mediterranean) at a micro‐climatic (opposite slopes) and a macro‐climatic scale (between climates) in Chile. Results: Biomass production for the soils that were translocated from wetter to drier climates was unrelated to the available soil moisture. The lowest biomass was produced in the wettest climate on the wet slope. Biomass production increased after a translocation to the drier climate (representing the largest change in climate). Nonetheless, the highest overall biomass for the wet to dry translocation was produced on the mediterranean dry slope with intermediate soil moisture. However, on the same mediterranean dry slope, biomass was almost zero for soil translocated the other way round (from drier to wetter). Diversity after 24 months was unaffected by micro‐climatic change, but soils transplanted toward the drier climate yielded a plant community with increased diversity. Conclusion: Our results showed direction and magnitude of climate change but also the response factor that is studied matters to detect direction‐dependent responses; i.e., species richness had a linear and reversible response. However, the response of biomass depended on the origin of the transplanted material (soil and plant community), indicating history dependence (hysteresis). This emphasizes that responses to unidirectional climate manipulation experiments may not be able to capture the entire nature of the response of plant communities to climate change. [ABSTRACT FROM AUTHOR]

Premise: Theory predicts and empirical studies have shown that ecologically manipulated communities with high species diversity are resistant to invasion, but do these predictions and results hold true when applied to highly competitive invaders in natural communities? Few studies of diversity‐mediated invasion resistance have measured both invasion resistance and invader impact in the same study. Methods: We used a two‐year field experiment to test: (1) diversity‐mediated competitive resistance to patch expansion by the grass, Microstegium vimineum; and (2) the competitive effect of M. vimineum on resident plant diversity. We examined responses of M. vimineum to two native plant density‐reduction treatments that had opposite effects on species diversity: (1) reducing species richness via the removal of rare species; and (2) reducing dominance by reducing the density of the dominant resident species. We examined the effects of M. vimineum reduction by pre‐emergent herbicide on resident diversity in the second year of the study. Results: Neither rare species removal nor dominant species reduction significantly increased M. vimineum density (relative growth rate). The pre‐emergent herbicide dramatically reduced M. vimineum in year 2 of the study, but not most resident plants, which were perennials and indirectly benefited from the herbicide at a more productive site, presumably due to reduced competition from M. vimineum. Conclusions: Diversity‐mediated resistance did not effectively deter invasion by a highly competitive invader. In the case of M. vimineum and at more productive sites, it would appear that nearly complete removal of this invader is necessary to preserve plant species diversity. [ABSTRACT FROM AUTHOR]

Background: Grasslands provide fundamental ecosystem services that are supported by their plant diversity. However, the importance of plant taxonomic diversity for the diversity of other taxa in grasslands remains poorly understood. Here, we studied the associations between plant communities, soil chemistry and soil microbiome in a wooded meadow of Čertoryje (White Carpathians, Czech Republic), a European hotspot of plant species diversity. Results: High plant diversity was associated with treeless grassland areas with high primary productivity and high contents of soil nitrogen and organic carbon. In contrast, low plant diversity occurred in grasslands near solitary trees and forest edges. Fungal communities differed between low-diversity and high-diversity grasslands more strongly than bacterial communities, while the difference in arbuscular mycorrhizal fungi (AMF) depended on their location in soil versus plant roots. Compared to grasslands with low plant diversity, high-diversity plant communities had a higher diversity of fungi including soil AMF, a different fungal and soil AMF community composition and higher bacterial and soil AMF biomass. Root AMF composition differed only slightly between grasslands with low and high plant diversity. Trees dominated the belowground plant community in low-diversity grasslands, which influenced microbial diversity and composition. Conclusions: The determinants of microbiome abundance and composition in grasslands are complex. Soil chemistry mainly influenced bacterial communities, while plant community type mainly affected fungal (including AMF) communities. Further studies on the functional roles of microbial communities are needed to understand plant-soil-microbe interactions and their involvement in grassland ecosystem services. [ABSTRACT FROM AUTHOR]

Introduction: Although it is widely acknowledged that biodiversity maintains plant community assembly processes, exploring the patterns and drivers of beta-diversity (β-diversity; species variation among local plant communities) has received much less attention compared to alpha-diversity (α-diversity; species variation within a local plant community). Here, we aim to examine the patterns and spatial–environmental drivers of taxonomic and phylogenetic β-diversity, and their components such as species turnover and nestedness, in large-scale Leymus chinensis grassland communities. Methods: We collected plant community data from 166 sites across widely distributed L. chinensis communities in northern China, and then calculated the taxonomic and phylogenetic β-diversity indices (overall, turnover and nestedness) using a pairwise dissimilarity approach. To assess the effects and to explain the variation in the patterns of β-diversity, we collected data on geospatial, climate and soil conditions. We applied descriptive statistics, Mental correlations, and multiple linear regression models to assess the patterns and spatial–environmental drivers of β-diversity. Results: The β-turnover, as compared to β-nestedness, exhibited a predominant influence, constituting 92.6% of the taxonomic β-diversity and 80.4% of the phylogenetic β-diversity. Most of the spatial–environmental variables were significantly positively correlated with the overall taxonomic and phylogenetic β-diversity and β-turnover, but not with β-nestedness. Climatic factors such as MAP and MAT were the strongest predictors of both taxonomic and phylogenetic β-diversity and β-turnover. The variance partitioning analysis showed that the combined effects of spatial and environmental factors accounted for 19% and 16% of the variation in the taxonomic and phylogenetic β-diversity (overall), 17% and 12% of the variation in the β-turnover, and 7% and 1% of the variation in the β-nestedness, respectively, which were higher than independent effects of either spatial or environmental factors. Discussion: At larger spatial scales, the turnover component of β-diversity may be associated with the species complementarity effect, but dominant or functionally important species can vary among communities due to the species selection effect. By incorporating β-diversity into grassland management strategies, we can enhance the provision of vital ecosystem services that bolster human welfare, serving as a resilient barrier against the adverse effects of climate change at regional and global scales. [ABSTRACT FROM AUTHOR]

One challenge of landscape ecology involves understanding the effects of expanded anthropized areas and related land-use changes on species over time. Understanding how floristic composition is shaped in urban and rural environments is a prerequisite for undertaking the development and implementation of conservation strategies in urban areas. We aimed to investigate landscape composition over temporal scales and resultant effects on the functional diversity and species richness of plants in Cerrado fragments. We sampled 18 Cerrado fragments in urban and rural areas of Campo Grande, Mato Grosso do Sul. We compared Functional Diversity indices between urban and rural areas. We evaluated whether species richness and functional dispersion (FDis) are affected by the surrounding matrix at a 1-km radius in different years (1985, 2002, 2018). In total, 123 species were recorded in the fragments, and species richness ranged from 15 to 33 . Functional richness (FRic) was higher in urban fragments and lower in rural fragments. Land use had no effect on species richness, but functional dispersion was negatively affected by changes in the landscape across time, the loss of green areas from 1985 to 2002, and the expansion of urban areas from 2002 to 2018. Species richness is not a useful metric for understanding the temporal impacts of landscape changes on plants, since plant community dynamics demonstrate an increase in the dominance of species with greater similarity of traits. [ABSTRACT FROM AUTHOR]

Humid dunes slacks are a highly threatened habitat, listed as vulnerable in the EU habitat red list. Accelerated successional processes in dune systems have resulted in the loss and degradation of ideal conditions for specialist dune slack species, hence the need for conservation management. We investigated the restoration of a dune slack in North Wales, UK, where vegetation and soil removal to 10 cm depth was undertaken to reinstate nutrient‐poor, open and damp conditions. We assessed the outcomes of the management for dune slack communities over the 18 years since restoration. We also assessed the differences between restored and unrestored areas of dune slacks. The dunes were restored in the winter of 2004/2005, after which we conducted vegetation surveys in fixed quadrats for most years in the restored and adjacent, un‐restored dune slacks. Species diversity and plant community composition changes over time were assessed using Shannon's index, multivariate analysis and indicator species analysis. Comparisons between the restored and unrestored areas of the dune slacks were also made. Ellenberg indicator values (EIVs) were examined to identify potential environmental drivers of post management successional changes. After 18 years the restored dune slacks developed a species‐rich and diverse community. compared to the unrestored slacks. The establishment of species occurred rapidly in the first three years, followed by continued but slower increases in species richness and diversity. This is due to the addition of new species without losses of established species. EIVs show no significant difference over time suggesting the restored areas are still at an early stage of succession. Distinct stages of community change since restoration are characterised by different indicator species. Plants are likely to be largely recruited from an existing seed bank. Restoration by turf removal may be suitable for other low nutrient, species rich habitats dependent upon fluctuating groundwater levels. [ABSTRACT FROM AUTHOR]

Changing environment markedly shapes plant diversity and vegetation across all spatial scales. It leads to innumerable local, regional and sometimes global changes in plant communities. Here, we present eleven full-text research articles of the Special Issue "Plant communities in changing environment", which focuses on the evaluation of plant diversity and vegetation changes in different plant communities. We conclude that the results of all research studies show that plants, habitat and functional diversity are strongly conditioned in space and time by various factors, including climate, water regime, snow conditions, and human activities. These changes are also among most significant potential threats for plant diversity. [ABSTRACT FROM AUTHOR]

Rehabilitation strategies for degraded mine dumps have generally seen limited success due to different complications associated with mining biophysical disturbance. In this study, we tested a combination of two methods to expedite revegetation of kimberlite tailings at Letseng Diamond Mine (i.e., in the Afro‐alpine areas of Lesotho). We ran trials on different growth media located on fine and coarse kimberlite tailings (i.e. sites) mixed with different substrate combinations and topsoil and sowing a seed mix comprised of native plant species. Overall, as predicted, fine kimberlite tailings displayed significantly higher plant abundance than coarse kimberlite tailings, and sown seeds performed significantly better than spontaneous colonisation by emerging species. Kimberlite tailings mixed with topsoil (100 mm) showed significantly greater plant abundance, and similarly, when coarse kimberlite tailings were introduced to fine tailings. Physicochemical analyses of growth media components suggested that topsoil provided additional nutrients and that plants could readily access available nutrients in the fine kimberlite tailings. We noted a gradual significant increase in plant abundance over 5 years, enhanced by new plant species emerging from the topsoil seed bank or by natural seed dispersal. Although plant abundance differed significantly, both fine and coarse kimberlite tailings displayed high plant species diversity (H = 3.4 and D = 0.95 and H = 3.5 and D = 0.95, respectively). Out of 36 emerging plant species, 15 species spontaneously colonised both growth media. The significant variation in abundance among plant species between treatments was mostly attributed to dominant forb species, namely Chrysocoma ciliata, Glumicalyx montanus, Oxalis obliquifolia, Senecio inaequidens and Trifolium burchellianum. We have identified suitable growth media for plant community restoration on kimberlite tailings in the Drakensberg alpine area using a seed mix of native plant species in combination with natural seed dispersal from the surrounding pristine environment. We provide evidence for using two complementary approaches to optimise native plant community development during restoration in the Drakensberg alpine area. [ABSTRACT FROM AUTHOR]

Nature reserves play an important role in the protection of biological habitats and the maintenance of biodiversity, but the performance and mechanisms of desert steppe nature reserves in improving plant community productivity, biodiversity and soil nutrient content are still largely unknown. To investigate the conservation effects of desert steppe nature reserve management on plant productivity and biodiversity, we compared the plant biomass, diversity and soil nutrient content inside and outside the West Ordos National Nature Reserve through sample survey, biomass determination, diversity index calculation and soil nutrient content determination. We found the following: (1) The aboveground biomass and belowground biomass of plant communities in the nature reserve were significantly larger than those outside the reserve; and the aboveground biomass of plant communities in shrub–steppe was significantly larger than that of herb grassland in both the nature reserve and the outside of the reserve. (2) The Margalef richness index, Shannon–Wiener index and Simpson index were significantly greater in the reserve than outside the nature reserve. In the desert steppe, the establishment of the nature reserve increased the α-diversity of the plant community. (3) The soil organic carbon (SOC) and soil total nitrogen (STN) were greater in the nature reserve than outside the reserve, and for the 10–20 cm and 20–40 cm soil layers, the SOC and STN were significantly greater in the core protected zone of the reserve than outside the reserve. The reserve significantly increased the nutrient content of the deeper soil layers. (4) The aboveground biomass of the plant community had a significant positive linear relationship with the species richness index, the Shannon index, and the Simpson index. There was a positive correlation between the diversity of the plant community and the soil nutrients. In summary, the nature reserve improved local plant productivity, biodiversity and the soil nutrient content, and the soil nutrient content in deeper soil layers may be the driving factor for the increase in productivity and biodiversity, which deepens our understanding of the conservation effectiveness of the nature reserve and its mechanisms. [ABSTRACT FROM AUTHOR]

Simple Summary: The effects of invasive plants on species diversity and ecosystem stability differ owing to the different stages of invasion. Xanthium spinosum is an invasive weed that is widely distributed in Europe, Asia, and North America. Its adaptability and competitive advantage over native species have led to agricultural loss and biodiversity reduction, yet its impact on local plant communities under different degrees of invasion has not been reported. Therefore, in this study, we aimed to investigate the effects of different degrees of invasion by X. spinosum on the diversity, stability, and invasibility of local plant communities in Yining County, Xinjiang, China. We believe that our study makes a significant contribution to the literature because we found that as the degree of X. spinosum invasion increased, species diversity and community stability decreased, while community invasibility increased. Notably, a light degree of invasion was found to enhance the diversity and stability of local plant communities. Based on our findings, we recommend that X. spinosum be controlled and eradicated in the early stages of invasion to prevent further invasion and harm to indigenous species. Studying the effects of different degrees of exotic plant invasion on native plants' community structure and plant diversity is essential for evaluating the harm caused to ecosystems by plant invasion. In this study, we investigated the effects of Xanthium spinosum, a widespread invasive species, on plant community species diversity and community stability in the Ili River Valley area of Xinjiang, China, under three invasion levels (no invasion and low, moderate, and heavy invasion), and the competitive advantage index, invasion intensity, and contribution of plant community species diversity to community stability and invasibility were determined for the prickly fungus under different degrees of invasion. The results show that there were significant differences (p < 0.05) in the species diversity and community stability of plant communities caused by different degrees of invasion of X. spinosum. The species diversity and stability of plant communities were negatively correlated with the community invasibility, competitive advantage, and invasion intensity of X. spinosum (p < 0.05); therefore, the competitive advantage and invasion intensity of X. spinosum increase with the increase of its invasion degree. On the contrary, community species diversity and stability decreased with the increase of its invasion degree, ultimately leading to differences in community invasibility under different invasion degrees. The Shannon–Wiener and Simpson's indices were the greatest contributors to community stability and invasibility, respectively. Moderate and heavy levels of invasion by X. spinosum reduced the diversity and stability of local plant communities, increased the invasibility of communities, and substantially affected the structures of plant communities. Therefore, the continued invasion by X. spinosum will have an immeasurable impact on the fragile ecosystems and diversity of indigenous species in Xinjiang. We recommend that this invasive species be controlled and eradicated at the early stages of invasion to prevent further harm. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the characteristics and species diversity of semi-natural plant communities on Langqi Island, a coastal island in Fujian Province, China. Additionally, we explored the environmental factors that influenced species diversity and community distribution. The results revealed that the semi-natural plant communities on Langqi Island had rich plant species diversity, with variations in diversity among different plant formations. The soil total potassium and nitrogen contents significantly affect the species diversity of the semi-natural plant communities, whereas the soil pH, soil total nitrogen content, organic matter content, available potassium content, and elevation significantly affect the community distribution. This study can provide important reference information for the construction of semi-natural or artificial plant communities on islands. (1) Background: Islands are relatively independent and fragile ecosystems with unique habitats. Studying the relatively stable semi-natural plant communities on islands can enrich island vegetation data and provide an understanding of the factors affecting species diversity and distribution. (2) Methods: The semi-natural plant communities on Langqi Island (LI) in Fujian Province were sampled, and the redundancy method was used to analyze the correlation between species diversity, community distribution, and environmental factors. (3) Results: (i) There were 432 species of vascular plants, with 306 genera and 110 families; (ii) the semi-natural plant communities consisted of three vegetation types, 10 formations, and 10 clusters; (iii) the species diversity indices of the semi-natural plant communities presented a trend of gradually decreasing along the shrub, tree, and herb layers. Different formations varied in terms of the species diversity index; and (iv) the soil total potassium and nitrogen contents significantly affected the species diversity of the LI semi-natural plant communities, whereas the pH, soil TN content, organic matter content, AK content, and altitude significantly affected the community distribution. (4) Conclusions: Selecting appropriate tree species for mixed forests based on plant characteristics and regional conditions, together with regulating the soil nutrient content, can improve the species diversity of semi-natural plant communities. [ABSTRACT FROM AUTHOR]

Desertification reversal is globally significant for the sustainable development of land resources. However, the mechanisms of desertification reversal at the level of plant community are still unclear. We hypothesized that desertification reversal has clear effects on plant community composition, plant functional types (PFTs), and other vegetation characteristics, including plant diversity and biomass, and their changes in the early stages of reversal are more dramatic than in later stages. We investigated the vegetation of four to five different stages of desertification reversal at each of seven large study sites in southwestern Mu Us Sandy Land, China. The results show that the dominant species in very severe desertification areas were replaced by perennial grasses in potential desertification areas. The importance values of annual forbs and perennial sub-shrubs decreased dramatically (from 42.59 and 32.98 to 22.13 and 5.54, respectively), whereas those of perennial grasses and perennial forbs increased prominently (from 13.26 and 2.71 to 53.94 and 11.79, respectively) with the reversal of desertification. Desertification reversal increased the complexity of plant community composition by increasing plant species in each PFT, and C3 plants replaced C4 plants to become the dominant PFT with reversal. Plant species richness and species diversity rose overall, and aboveground plant biomass significantly (p < 0.05) increased with the reversal of desertification. Most vegetation characteristics changed more strikingly in the early stages of desertification reversal than in later stages. Our results indicate that the type and composition of the plant community were dramatically affected by desertification reversal. Anthropogenic measures are more applicable to being employed in early stages than in later stages, and Amaranthaceae C4 plants are suggested to be planted in mobile dunes for the acceleration of desertification reversal. This study is useful for designing strategies of land management and ecological restoration in arid and semiarid regions. [ABSTRACT FROM AUTHOR]

Plant species diversity was studied in 20 sandy wadis of the northern Algerian Sahara (Ghardaïa region). Based on subjective sampling, 20 floristic surveys were carried out in the various sandy biotopes in February-April 2022. Through an ascending hierarchical analysis, we distinguished 3 phytoecological groups and assessed their functional, biogeographic, and abundance characteristics. The recorded plants represented 15 species (296 individuals) belonging to 15 genera of 10 botanical families. The most represented families were the Fabaceae, Anacardiaceae, Brassicaceae, and Poaceae. In terms of the real plant-life spectrum, hemicryptophytes (51.7% of individuals) dominated the sandy wadis, followed by chamaephytes (33.1%) and phanerophytes (15.2%). In the real dispersal spectrum, the barochores prevailed (60%). The real phytogeographic spectrum shows that the Saharan endemic element reached the highest share (32.7%). In terms of abundance, an analysis of the real spectrum revealed that very common species (52%) dominate in the Ghardaïa region, but some fairly rare plants were also found. Indeed, the sandy biotopes of the wadis of the Ghardaïa region are valuable habitats for the conservation of plant species in the northern Algerian Sahara. [ABSTRACT FROM AUTHOR]

Floral traits are assumed to be the main determinants of plant's pollinator spectrum, yet a majority of temperate plant species possess traits allowing to a certain degree of generalisation of their pollinator spectrum. The actual level of pollinator spectrum generalisation is likely to be the result of both plant floral traits and the diversity and abundance of plant species a plant co‐occurs with. We expect that plant species co‐occurring in highly diverse plant communities should host more generalised pollinator spectra.In the present study, we explore the degree to which the composition and generalisation of plant–pollinator spectra depend on the plant's niche width (measured as co‐occurrence with other plant species) and its local dominance (as measured by mean cover in the community). For this purpose, we compiled a database of >250 plant species pollinator spectra from the literature and coupled it with data on plant niche width and local dominance based on the Czech National Phytosociological Database.Species with wider niches had on average more generalised pollinator spectra, ranging from bumblebee‐dominated spectra to diptera‐ and/or nitidulid beetle‐dominated spectra, which was strongly related to plant phylogeny. Plants with bumblebee‐dominated spectra had neither wide niches nor niche specialists.The majority of plants had either muscid‐, hoverfly‐ or nitidulid‐dominated or completely generalised pollinator spectra. Among such plants, higher local dominance increased the proportion of opportune muscids in pollinator spectrum, while hoverflies showed the opposite pattern. Honeybees although rather infrequent in pollinator spectra also showed a strong preference for locally dominant plant species.Synthesis: The composition of a plant's pollinator spectrum is not independent of other aspects of the plant's life history, namely niche width and the ability to dominate the community. Wider plant species niches result in more generalised pollinator spectra, supporting our hypothesis that habitat generalists are less prone to specialisation on particular pollinator groups. Conversely, the ability to dominate local plant communities influenced pollinator spectra mainly through specific responses of individual pollinator groups. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Question: Livestock grazing affects plant communities in drylands worldwide. However, our current understanding of the Patagonian drylands has primarily been derived from comparing exclosures with grazing conditions or from single‐site grazing gradients. The pending question is: do impacts of grazing intensification on Patagonian plant communities change along aridity gradients? Location: Patagonia, Argentina. Methods: We surveyed vegetation cover of perennial species in paddocks with different sheep‐grazing pressure (ungrazed, lightly, moderately, and intensively grazed, based on long‐term stocking rates), in three plant communities located along a regional aridity gradient: a semi‐desert (arid), a shrub–grass steppe (semi‐arid), and a grass steppe (dry sub‐humid). In these communities, we analyzed the effects of grazing pressure on the total cover of vegetation, the cover of dominant plant life‐forms (grasses and shrubs), the plant species diversity, and the traits of dominant plant species. Results: Intensification of sheep grazing significantly decreased total vegetation cover in the semi‐desert, but not in the steppes. Although grazing decreased the cover of grasses (particularly of the highly preferred ones) in all communities, in the shrub–grass and grass steppes this reduction was offset by an increase in the cover and size of shrubs. Plant diversity was not consistently affected by grazing pressure in these communities. Traits of dominant plant species partially explained community responses to grazing intensification. Conclusions: Livestock grazing intensification reduces the forage quantity and quality of Patagonian plant communities, but the severity depends on plant community types. In semi‐deserts (the most arid), grasses were drastically affected, while in the steppes, the grazing effects on grasses were low and partially compensated by an increase in the cover and size of shrubs, which fulfill critical roles other than forage provision. It is fundamental that grazing pressure be adapted to forage resource availability for each community type to achieve sustainable management in the context of climate change. [ABSTRACT FROM AUTHOR]

The change grassland plant communities demonstrate with elevation has been one of the hot issues in ecological research, and there remain many unsolved problems. In order to further elucidate the rules of grassland plant community change with elevation, this study took the Burqin forest area as a research object, using field survey, redundancy analysis and grey correlation analysis to comprehensively assess the characteristics of change in grassland plant communities with elevation and the relationship of this evolution with environmental factors. The results showed that (1) the numbers of species, community biomass, community cover and community densities of grassland plant communities showed an "M" pattern with the increase in elevation. There were significant changes in the importance values and dominance of plants at different elevations; with increasing elevation, grassland plants became primarily dominated by cold-tolerant and well-adapted perennials. (2) The similarity coefficients of grassland plant communities at different elevations ranged from 0.06 to 0.62, i.e., from very dissimilar to moderately similar. (3) As the elevation increased, the Margalef species richness index, Shannon–Wiener diversity index, Simpson dominance index and Alatalo evenness index all showed an "M" pattern trend. (4) The degrees of correlation between temperature and precipitation and community biomass and species diversity were at a high level, and these were the most important environmental factors affecting the biomass and species diversity of grassland plant communities in the Burqin forest area. The results of this study can provide a theoretical basis for the rational utilization of grassland resources and for the sustainable development of grassland ecosystems in the Burqin forest area. [ABSTRACT FROM AUTHOR]

Understanding the relationship between nitrogen addition and the diversity and productivity of alpine grassland plant communities is important for the sustainable development of grassland ecosystems. However, it is unclear how nitrogen addition, growth stage, and interactions between these factors affect plant biomass and diversity when regulating soil and plant nutrient factors. This study researched the temporal variations in plant community diversity and biomass after nitrogen addition in an alpine grassland from 2020 to 2021. Furthermore, this study used structural equation modeling to determine the direct and indirect pathways of plant and soil factors regulating plant biomass and diversity. Results showed that (1) nitrogen addition had significant effects on aboveground biomass, belowground biomass, and total biomass, while growth stage only had significant effects on aboveground biomass. Nitrogen addition, growth stage, and their interaction significantly affected the Shannon–Wiener diversity, the Margalef species richness, and the Pielou evenness. (2) Redundancy analysis indicated that total aboveground phosphorus, aboveground ammonium nitrogen, soil total nitrogen, and soil available nitrogen were the most significant explanatory variables for plant biomass variation, while soil available nitrogen, total soil nitrogen, and total belowground nitrogen were the key predicting factors for plant community composition variation. (3) Structural equation modeling revealed that plant biomass and diversity changed with nitrogen addition and growth stage. Nitrogen addition directly increased aboveground, belowground, and total biomass and indirectly affected plant biomass through the effectiveness of aboveground ammonium nitrogen, total aboveground phosphorus, and total soil nitrogen. Plant diversity was directly affected by the growth stage and indirectly by nitrogen addition through soil nitrogen and root nitrogen, which further affected plant diversity and evenness indices. The decrease in plant community diversity and species richness caused by nitrogen addition and different growth stages indirectly and negatively affected aboveground plant biomass. Overall, the results of this study indicate that plant biomass and diversity in alpine grasslands are affected by exogenous nitrogen addition and growth stage. [ABSTRACT FROM AUTHOR]

Desert ecosystems possess an astonishing biodiversity and are rich in endangered species. This study investigated characteristics of species diversity and soil environmental factors in three major deserts of China's Alxa Plateau. The Alxa Desert included 183 plant species belonging to 109 genera and 35 families. The highest numbers of plant species belonged to the Compositae, Gramineae, and Chenopodiaceae families. The research area belongs to the semi-shrub and small semi-shrub deserts in temperate deserts. Species diversity was low, with the Shannon–Wiener index (H′) of shrub-herb = shrub > herb > tree. The Pielou evenness index (E) of shrub herb vegetation was the lowest, indicating more enriched species and fewer sparse species in the community, and that these types of vegetation had the characteristics of rich and obviously dominant species. Redundancy analysis (RDA) and correlations between the comprehensive plant community biodiversity index and soil factors indicated that soil-available phosphorus (NP), organic matter (SOM), and electrical conductivity (EC) had significant impacts on community species diversity. The herbaceous shrub community exhibited the highest H′, Simpson index (D), species richness index (S), soil moisture (SW), and soil nutrients. Planting Calligonum mongolicum, Ephedra membranacea, Artemisia annua, and Phragmites australis to form a typical desert shrub community for community diversity protection is recommended to effectively protect and restore desert ecosystems. [ABSTRACT FROM AUTHOR]

Assessments of species diversity and richness are essential to understand present ecological and biodiversity conditions for effective conservation management strategies. Biodiversity indicators determine rangeland health and response to grazing, fire regimes and climate change. This research examined species richness, diversity and composition in a protected mountainous grassland. Two data sets, both collected from a 30 × 30 m plot, with similar species composition and cover were combined. One data set was collected using a 100‐step point survey and the other from a series of 16 plots. A single‐factor analysis of variance was used to test if the mean species richness and diversity of the sites differed across the study area. Species accumulation curves were used to determine the relationship between species richness and the number of sampling units per site. The results from fitting a species–area equation showed that the estimated maximum species richness was slightly greater than the observed species pool in all sites, meaning that the sampling units were not adequate (albeit by small margins) to capture all vascular plant species in the sites. Diversity metrics could, thus, be used to monitor species change within grassland plant communities. [ABSTRACT FROM AUTHOR]

Dramatic urbanization in the subtropical city of Hong Kong leads to enormous numbers of soil slopes. In addition to supporting infrastructure, soil slopes also allow revegetation work to enhance the ecological value of urban landscapes. However, groundcovers that exhibit much wider uses in slope revegetation, are often ignored. Our study mainly focused on the seasonal variation in groundcover on soil slopes and the association with slope performance and the degree of urbanization. The groundcovers in terms of plant cover, diversity and community composition on thirty-five soil slopes widespread in Hong Kong were examined. The groundcover abundance was then compared between wet and dry seasons and among districts with different degrees of urbanization. It was also correlated with various slope performances for any associations. The results showed considerably low plant cover (less than 50%) on soil slopes despite better performance in the wet season. The initially planted groundcovers have largely been replaced by a variety of naturally occurring plants, leading to a proliferation in species richness and plant diversity of revegetated slopes. Native ferns, including Blechnum orientale, Cyclosorus parasiticus and Dicranopteris pedata, dominated the landscape in both seasons. In addition, the plant diversity and community composition did not vary between seasons but indicated significant differences among urban and suburban districts. Regarding slope performance, slope angle imposed challenges to groundcover growth, as it showed a positive association with the plant community in the wet season but had a negative impact in the dry season. Slope openness and silt soil were found to have positive relationships with the groundcover community. Overall, although a more diverse groundcover community was observed, the poor formation of groundcovers on revegetated soil slopes indicated the need for improvement work to provide more sustainable urban landscapes. Highlights: • The seasonal variation in plant coverage, diversity and community composition of groundcovers on revegetated soil slopes in Hong Kong were assessed. • A generally low plant cover was found on soil slopes, with higher growth performance in the wet season. • Plant diversity and community composition of groundcovers did not vary between seasons but differed significantly among areas with different degrees of development. • Slope angle, canopy openness and soil texture were significantly associated with plant community composition. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Questions: Soil resource heterogeneity influences the outcome of plant–plant interactions and, consequently, species co‐existence and diversity patterns. The magnitude and direction of heterogeneity effects vary widely, and the processes underlying such variations are not fully understood. In this study, we explored how and under what resource conditions small‐scale heterogeneity modulates grassland plant diversity. Location: Oderhänge Mallnow, Potsdam, Brandenburg, Germany. Methods: We expanded the individual‐based plant community model (IBC‐grass) to incorporate dynamic below‐ground resource maps, simulating spatial heterogeneity of resource availability. Empirical centimeter‐scale data of soil C/N ratio were integrated into the model, accounting for both configurational and compositional heterogeneity. We then analyzed the interplay between small‐scale heterogeneity and resource availability on the interaction and co‐existence of plant species and overall diversity. Results: Our results showed significant differences between the low‐ and high‐resource scenarios, with both configurational and compositional heterogeneity having a positive effect on species richness and Simpson's diversity, but only under low‐resource conditions. As compositional heterogeneity in the fine‐scale C/N ratio increased, we observed a positive shift in Simpson's diversity and species richness, with the highest effects at the highest level of variability tested. We observed little to no effect in nutrient‐rich scenarios, and a shift to negative effects at the intermediate resource level. The study demonstrates that site‐specific resource levels underpin how fine‐scale heterogeneity influences plant diversity and species co‐existence, and partly explains the divergent effects recorded in different empirical studies. Conclusions: This study provides mechanistic insights into the complex relationship between resource heterogeneity and diversity patterns. It highlights the context‐dependent effects of small‐scale heterogeneity, which can be positive under low‐resource, neutral under high‐resource, and negative under intermediate‐resource conditions. These findings provide a foundation for future investigations into small‐scale heterogeneity–diversity relationships, contributing to a deeper understanding of the processes that promote species co‐existence in plant communities. [ABSTRACT FROM AUTHOR]

In order to reveal the influence of highway construction on the natural grassland and ecological system in Qinghai-Tibet Plateau, two representative construction points at a distance of 17 km which are ongoing construction area of S10 Zhuoni-Hezuo expressway in Gannan Tibetan autonomous prefecture of Gansu province were investigated. The sampling sites were 10 and 500 m away from the construction red line, and the sampling dates were June and September 2021. Line transect method was used to collect the samples, and species composition, coverage, height and biomass of plant community were calculated; the composition of plant community and species diversity were analyzed by SPSS software, and the least significant difference(LSD)method was used to test the significance of the above indexes, meanwhile the influences of highway construction on plant species, growth and diversity were discussed. The results show that there are 86 plant species presenting in investigation sites and the important values of Kobresia capillifolia, K. tibetica and Elymus nutans are higher; there are no significant difference between two investigation sites or between two distances(10 and 500 m away from the red line of highway construction)in the same location for most of the indices; only Shannon index and biomass of plant have significant difference(P<0.05)in a few sampling sites, suggesting that there is little difference of plant community composition in the investigation sites and the different distances away from the red line of highway construction. The vegetation height, average height, biomass and Menhinick index of plant in September are significantly higher(P<0.05)than those in June, indicating that the plants away from the red line of highway construction recover naturally and grow normally through their own adaptation, although the highway construction partially destroys and affects the surrounding natural environment. In general, under strict control of construction behavior, plant communities and growth in different distances away from the red line of highway construction have little change, and the damages to the ecosystem are relatively small. [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]

In a locale-scale mountainous forest, changes in slope aspect can cause microclimate heterogeneity, which can impact both soil environment and plant community, and influence the soil microbial communities as well. However, the relationship between the aboveground plant community and belowground soil microbial communities and the change in slope aspect is not well understood. A case study was carried out in a subalpine coniferous forest in western China to investigate the above- and belowground relationship of three slope aspects, the north-facing slope, the flat site and the south-facing slope. The plant community attributes were evaluated by the community survey, considering species diversity and the plant total basal area of trees and shrubs to represent the plant productivity. Soil bacteria were determined based on 16S rRNA gene and soil fungi on a nuclear ribosomal internal transcribed spacer (ITS) using high-throughput Illumina sequencing. The results showed that slope aspects significantly affect the aboveground plant productivity and diversity, and the community composition and structure of both aboveground plants and soil bacteria and soil fungi. Soil bacteria and soil fungi correlated differently with aboveground plant community changes in the slope aspects in terms of diversity and community composition and structure. A structural equation model (SEM) revealed that slope aspects caused by aboveground plant productivity changes correlated significantly with the soil fungal community composition and structure, while the soil bacterial community was rather weakly correlated with the plant community, and its changes in community composition and structure were mainly affected by the soil properties and soil fungal community. Further studies considering plant functional traits, soil microbial functional groups, and seasonal changes may reveal a deeper correlation between the aboveground plants and belowground soil microbials at the local scale in subalpine coniferous forests. [ABSTRACT FROM AUTHOR]

Higher plant species diversity decreases variability of plant community productivity. The stabilizing effect of plant diversity can result from species‐specific responses to environmental fluctuations and from shifts in competitive hierarchies. Evolutionary adaptation of species to surrounding plant diversity could further decrease productivity variability.We used a three‐year dataset from a crop diversity experiment with seven species to assess the effect of crop diversity and selection history on temporal variability of yield.We found contrasting patterns of temporal variability: Yield of species varied more in mixtures than in monocultures over years. However, at community‐level, we found lower yield variability in crop mixtures compared to monocultures, although only in combination with fertilizer application under Mediterranean climate. Furthermore, we found that a mixture selection history can increase yield productivity and decrease its variability, although only in monocultures. This suggests that the interspecific interactions among crops in mixtures act as an evolutionary selective force, promoting niche complementarity.Synthesis. Our results highlight the ecological and evolutionary role of plant interactions in crop mixtures, which can affect yield stability, while also reflecting on the importance of climate and resource availability in modifying the diversity‐stability relationship. [ABSTRACT FROM AUTHOR]

Strip seeding is a novel restoration practice of strategically planting in strips, resulting in alternating seeded and unseeded areas to target efforts and reduce costs while achieving ecological outcomes similar to conventional methods of seeding entire sites. However, there has been limited work testing the efficacy of this method, including how strip width and percent seeded area affect restoration outcomes. We evaluated four native grass strip seed treatments (33%, 50% narrow, 50% wide, and 66% of area seeded), an unseeded control, and a conventional 100% seeded control to investigate: (1) how plant communities in seeded and unseeded strips change over time; (2) how initial strip width affect native species biomass, invasive species biomass, and plant species diversity; and (3) cost‐effectiveness of strip seeding in terms of management costs and benefits accrued. Four years post‐seeding, seeded and unseeded strips exhibited unique plant communities; seeded strips were characterized by native perennial grasses while unseeded strips had a higher abundance of annual forbs (majority non‐native) and non‐native annual grasses. Plant communities were similar within strips across strip seeding treatments. Invasion resistance and productivity scaled with percent area initially seeded, but by year four all strip seed treatments (33–66%) provided similar benefits to conventional seeding (100%). Overall, this suggests strip seeding is a promising, cost‐effective method to restore targeted species and maintain native grassland communities. Further research is needed on long‐term effects, ecological and economic barriers and opportunities, and provisioning of a broad suite of ecosystem services across different environmental contexts and management practices. [ABSTRACT FROM AUTHOR]

This study investigated the effects of heavy metals on the species diversity of the Xinjian Dyke Wetland, an ecosystem where reclaimed farmlands are being transformed back into wetlands through the introduction of indigenous plants. The sources of soil heavy metals were analyzed, and correlation analyses were conducted to assess the relationships between heavy metal content and biodiversity indices. The results indicated that (1) the mean contents of Hg, Cd, Cu, Zn, As, Cr, and Pb were higher than the control values, with the content of Hg, Cd, Cu, and Zn exceeding the national standard; (2) the soil heavy metals mainly came from pesticides, chemical fertilizer, transportation, sewage irrigation, and the soil matrix; and (3) Hg and As were not significantly correlated with the diversity indices, but there was a highly positive correlation for Cu, Cr, and Pb, and a significant negative correlation for Zn and Cd. Collectively, our findings indicated that heavy metals have different effects on the plant species diversity inXinjian Dyke reconstruction area. The ecological restoration of wetlands from reclaimed farmlands should reasonably increase tolerant species and maximize the ecological niche differentiation of the species. Moreover, functionally redundant species should not be planted. [ABSTRACT FROM AUTHOR]

Questions: Rhododendron ponticum subsp. baeticum is an invasive shrub of growing concern in continental Europe, but little is known about its impact on native plant communities. Here we ask: do environmental conditions differ between forest stands invaded by it and uninvaded stands? Do these differences correlate with R. ponticum's cover? Are these differences associated with differences in taxonomic and functional diversity of vascular plant species of the herb layer? Can these vegetation changes be explained by the sorting of certain life‐history traits by R. ponticum‐induced environmental changes? Location: Several forests invaded by R. ponticum in the French Atlantic domain. Methods: We recorded vegetation composition and a number of environmental variables in 400‐m2 plots that were established in 64 paired forest stands (32 invaded vs 32 uninvaded). We compiled traits from existing databases. We computed several metrics of taxonomic and functional diversity. We compared environmental variables and diversity metrics between invaded and uninvaded stands. We used correlation and regression analyses to relate them with R. ponticum's cover. We ran RLQ and fourth‐corner analyses to explore the relationships between R. ponticum invasion, environmental variables, species traits, and vegetation composition. Results: Independent of its abundance, R. ponticum invasion was associated with lower light arrival at the forest floor and increased litter thickness. Concomitantly, species richness and diversity and trait diversity were reduced. The major driver of species assemblages was soil pH, which strongly interacted with the invasion gradient. R. ponticum did not sort species according to traits associated with shade tolerance and thick‐litter tolerance. However, tree and shrub saplings were more abundant in invaded than uninvaded stands, at the expense of graminoid and fern species. Conclusions: As R. ponticum becomes the dominant shrub, it exerts new selection forces on life‐history traits of extant species, mostly via reduced light availability, increased litter thickness, and physical competition, thereby reducing taxonomic and functional diversity of the herb layer, without impeding tree and shrub self‐regeneration, at least in the short term. [ABSTRACT FROM AUTHOR]

In the High Arctic, nutrients are the most limiting resources, so terrestrial vegetation is of low complexity and grows slowly. However, locally, large seabird colonies increase soil fertility by deposition of faeces, supporting the development of rich and fast-growing plant communities. Here, we assessed how seabird colonies affected ecological niche segregation of plants, across the fertilisation gradient. Study sites were located near five little auk colonies, distributed longitudinally across the Svalbard archipelago. We described vascular plant composition and identified 13 environmental variables, based on which, we calculated and tested the niche overlap (NO) between the 18 most frequent species. Based on the hierarchical classification of the NO matrix, we distinguished typical High Arctic Vegetation (HAV), and Bird-Cliff Vegetation (BCV). The BCV was characterised by higher average NO and soil δ15N compared to HAV. The highest NO values across the fertilisation gradient were found on the border between the distinguished communities and were positively correlated with species diversity. We suggest that in the High Arctic, seabirds-delivered nutrients lead to the development of separate plant communities through the mechanism of avoiding inter-species competition, while simultaneous high species diversity and NO are related to high facilitation between plants on the border between the communities. [ABSTRACT FROM AUTHOR]

Question: Interspecific competition and seed dispersal are key mechanisms that may influence plant community assembly, but their relative importance remains difficult to disentangle as they can be affected by abiotic conditions (environmental filtering). We experimentally studied the balance between these processes in a Molinia wet meadow plant community in which abiotic constraints are mostly represented by flooding, while agricultural practices such as mowing prevent the dominance of a few competitive species. We hypothesized that (H1) mowing, by decreasing competitive exclusion and (H2) seed addition, by increasing immigration, both enhance plant species diversity, and that (H3) small variations in flooding intensity become secondary to these processes in determining species assembly. Location: French National Nature Reserve "Etang de Cousseau", Nouvelle Aquitaine, France. Methods: In a three‐year experiment, we added seeds of 17 species characteristic of Molinia wet meadows and managed above‐ground competition through mowing. We measured spatial variations in soil moisture as an indicator of the flooding regime. We recorded species relative cover, species richness and evenness annually, and measured light availability, linked with canopy openness, twice. Results: From the beginning of the experiment, small‐scale variations in soil moisture mainly affected species richness, composition and evenness, and canopy openness. Mowing significantly increased light availability and evenness, and affected the relative cover of several species, but not species richness. The addition of seeds did not influence any of the variables monitored during the experiment. Conclusion: Our study helps to disentangle processes underlying community assembly in wet meadows. It demonstrates significant and rapid effects of mowing on canopy opening and on community assembly, while seed addition had only a slight effect, possibly explained by an insufficient decrease in competitive interactions through mowing or unmeasured processes. It also shows that abiotic heterogeneity remains a primary driver of community assembly, even on a small scale. Finally, our results suggest that the respective weight of the different filters (dispersion, environment, competition) is subject to interannual variability or environmental stochasticity. [ABSTRACT FROM AUTHOR]

The traditional grasslands that characterize the cultural landscapes of the Palaeartic mountain massifs represent biodiversity hotspots. Yet, they are currently threatened by the intensification of farming practices, notably excesses in fertilization and irrigation.We experimentally investigated the passive restoration of montane and subalpine hay meadows after 6 years of management intensification, with different levels of fertilization and irrigation, followed by 5 years of release of intensive management, that is, extensification. More specifically, relying on a full randomized block‐design replicated at 11 Swiss study sites constituted of extensively managed meadows, we exposed during 6 years (2010–2015) four 20 m diameter plots to three levels of intensification (low, medium and high inputs), while a fourth plot served as a control (no inputs). In the second phase of the experiment (2016–2020), all study meadows underwent farming extensification.We monitored total species richness and plant diversity (Simpson diversity), indicator plant species as well as the composition and variability of the plant communities based on Bray–Curtis dissimilarity distances.We found that total species richness decreased in the most intensified plots after 6 years of intensification, but all plots retrieved their baseline species richness after 5 years of re‐extensification. In addition, we found no difference between the years in plant diversity (Simpson diversity) among the treatments. Yet, intensification led to different plants communities' compositions in all three levels of intensification in 2015 compared to the extensive plots, and this structural difference remained after 5 years of re‐extensification.Synthesis and applications. Land‐use intensification induces a rapid impoverishment of the flora of mountain meadows. Our results demonstrate the potential of mountain hay meadows to passively restore plant species richness after re‐extensification; however, plants communities did not fully recover. We recommend maintaining fertilization inputs as low as possible and operating active restoration on grasslands formerly intensified. [ABSTRACT FROM AUTHOR]

To explore the influence of topographic factors on the diversity and spatial distribution of plant species around FAST(Five-hundred-meter Aperture Spherical radio Telescope), three typical plant communities(tree layer, shrub layer, vine layer)in the karst peak-cluster depression around FAST were selected as the study objects, and ANOVA and canonical correspondence analysis(CCA)were used to investigate the species diversity and spatial distribution of plant communities under different topographic factors(altitude, slope, aspect, and gradient). The results were as follows:(1)The α-diversity index of plant communities around FAST showed a trend of shrub layer > tree layer > vine layer, and the α-diversity index of plants in the tree layer and vine layer increased with the increase of altitude(P<0.05), while the topographic factor had no significant effect on the α-diversity of plants in shrub layer.(2)The spatial distribution of plant community species around FAST was most influenced by the altitude, followed by the slope(P<0.05).(3)The Jaccard similarity index above 70% was extremely dissimilar and moderately dissimilar at altitude and slope gradients. The Jaccard similarity index of the three plant communities tended to increase with the increase of altitude and then decrease along the increase of the slope around FAST. In summary, species differed in their habitat selection, and altitude and slope are key factors affecting the spatial distribution of plant communities in the karst depressions around FAST. Species diversity can better reflect the differences in plant communities in terms of species composition. Species diversity is not only influenced by topographic factors, but also related to biotic and abiotic factors, such as temperature, precipitation, human activities, and functional plant traits. Therefore, corresponding environmental factors need to be added in future studies to further investigate the intrinsic mechanisms of plant species diversity and species spatial distribution at the regional scale and to strengthen the ecological protection of the surrounding area, improve the forest composition, and provide a good natural environment around FAST and in the karst peak-cluster depression. [ABSTRACT FROM AUTHOR]

Plant species diversity patterns and vegetation structure are influenced by climatic and other environmental factors. We hypothesized that a combination of edaphic and topographic factors affect not only plant community patterns, vegetation structure and heterogeneity but also the indicator species in the dry temperate zone of the Liakot forests, Hindu Raj series of Hindu Kush Mountains, Pakistan. Quadrat along the elevation gradient were used for vegetation sampling. Soil samples were collected from each quadrat and analyzed by using standard protocols. All the collected data were analyzed using Cluster Analysis, Indicator Species Analyses and Data attribute plots via Canonical Correspondance Analyses. Cluster Analysis using Sorensen distance measurements grouped the plant species into three communities based on microclimatic indicators. These communities were: (1) Celtis caucasica-Lonicera hispida-Pennisetum orientale, (2) Juglans regia-Rubus idaeus-Tragopogon gracilis, and (3) Abies pindrow-Parrotiopsis jacquemontiana-Agrostis gigantea. Elevation, aspect, organic matter, electrical conductivity and potassium were the strong ecological factors responsible for different communities' formation and their associated indicators in the region. Techniques and criteria used in the current study for communities formation and their respective indicator identification could be used further for management and conservation of the Liakot forest of the Hindu Raj series of Hindu Kush Mountains and other adjacent ecosystems of the northern Pakistan. Findings of the study can also be utilized in the reforestation drives. [ABSTRACT FROM AUTHOR]

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Over 40 years ago, Kempton (Biometrics, 35, 1979, 307) reported significant modification to plant community structure following a long‐term fertilization experiment. Many researchers have investigated this phenomenon in the years since. Collectively, these studies have shown consistent shifts in rank abundance relationships among species in communities following fertilization. The previous studies indicated that fertilization affects community structure through several critical processes, including trait‐based functional response, reordering of species in rank abundance diagram (RAD), and niche dimensionality, although some questions have remained. How does the species reordering driven by the plant responses cause characteristic trends in temporal changes of RAD? Why are those trends ubiquitous in various systems? To answer those questions, we theoretically investigated the effects of fertilization on community structure based on a colonization model (or Levins model) with competition–fecundity trade‐offs, which can result in the coexistence of multiple species under competition. The model represents characteristic RAD, which can be an adequate tool to study community composition. Our theoretical model comprehensively represents observed trends in rank abundance relationships following long‐term fertilization and suggests that competitive interactions among species are a critical factor in structuring species diversity in plant communities. [ABSTRACT FROM AUTHOR]

Purpose: Nitrogen enrichment is known to have a substantial impact on arbuscular mycorrhizal fungal (AMF) community in plant roots. However, the influence of elevated nitrogen on the phylogenetic structure of AMF across fine spatial scales, as well as the mechanisms behind such alterations, remained poorly understood. Methods: We collected 256 root samples of 16 common plant species belonging to 8 families along a nitrogen addition gradient (0, 5, 10 and 15 g N m− 2 year− 1) and then calculated the AMF phylogenetic diversity and dispersion across fine spatial scales using the next-generation sequencing. Results: Nitrogen addition and host identity significantly affected the phylogenetic alpha dispersion (plot-level phylogenetic dispersion), 'within-treatment' phylogenetic beta dispersion (phylogenetic dispersion among replicate plots within each treatment) and phylogenetic gamma dispersion (treatment-level phylogenetic dispersion), which were caused by the decrease in the relative abundance of a dominant genus (Glomus) and the increase of several non-dominant genera. Furthermore, nitrogen addition affected phylogenetic alpha dispersion mainly by influencing soil properties. In addition to the direct effect on 'within-treatment' phylogenetic beta dispersion, nitrogen addition and plot distance also significantly increased the dissimilarity of plant community and soil environments, thereby resulting in an increase in phylogenetic beta dispersion ultimately. Conclusion: The deterministic environmental filtering (host identity and soil environment) and short-distance dispersal limitation played critical roles in AMF community assembly under nitrogen fertilization conditions. Insightfully, this study provides a mechanistic understanding of the response of AMF community to nitrogen addition across fine spatial scales. [ABSTRACT FROM AUTHOR]

Riparian zones are among the most biologically diverse ecosystems in the Intermountain West, USA, and provide valuable ecosystem services, including high rates of biotic productivity, nutrient processing, and carbon storage. Thus, their sustainability is a high priority for land managers. Large ungulates affect composition and structure of riparian/stream ecosystems through herbivory and physical effects, via trailing and trampling. Bison (Bison bison) in Yellowstone National Park (YNP) have been characterized as "ecosystem engineers" because of their demonstrated effects on phenology, aboveground productivity of grasses, and woody vegetation structure. Bison have greatly increased in numbers during the last two decades and spend large periods of time in the broad open floodplains of the Northern Range of the Park, where they are hypothesized to have multiple effects on plant species composition and diversity. We sampled indicators of bison use as well as riparian vegetation composition, diversity, and structure along eight headwater streams within YNP's Northern Range. Total fecal density ranged from 333 to 1833 fecal chips and/or piles/ha, stubble heights ranged from 7 to 49 cm, and streambank disturbance ranged from 9% to 62%. High levels of bison use were positively correlated with exotic species dominance and negatively correlated with species richness, native species diversity, willow (Salix spp.) cover, and wetland species dominance. At three sites, the intensity of bison use exceeded recommended utilization thresholds to avoid degradation of streams and riparian zones on public lands. The influences of large herbivores, principally bison, on vegetation composition and structure suggest the cumulative effects of the current densities on the Northern Range are contributing to biotic impoverishment, representing the loss of ecosystem services that are provided by native riparian plant communities. In addition, contemporary levels of bison use may be exacerbating climate change effects as observed through ungulate‐related shifts in composition toward plant assemblages adapted to warmer and drier conditions. However, the resilience of native riparian vegetation suggests that sites currently heavily utilized by bison would have the potential for recovery with a reduction in pressure by this herbivore. [ABSTRACT FROM AUTHOR]

Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology, especially in vulnerable ecosystems such as tropical mountains. These studies are more relevant in global warming scenarios that induce the upward displacement of plant species towards reduced habitats and hostile environments in tropical mountains. This study aimed to analyze how altitude affects taxonomic and phylogenetic diversity in plant communities of tropical mountains. Thus, we tested if (i) increased altitude works as an environmental filtering promoting decreased species richness, decreased phylogenetic diversity, and increased phylogenetic clustering in these tropical mountains; and if (ii) plant communities of high altitude in tropical mountains are also result of recent diversification with plant species recently split shortening phylogenetic distances between closest related species. We tested effects of altitude on species richness and phylogenetic metrics using linear mixed-effects models. Mount Haleakala presented 114 species, Mount Kilimanjaro presented 231 species and Mount Purace presented 280 species. We found an environmental filtering effect with increasing altitude causing phylogenetic clustering, decreased phylogenetic diversity and decreased species richness. The decreasing phylogenetic distances between closest relatives are congruent with neo-endemics, suggesting recent plant diversification in high altitudes of tropical mountains, possibly driven by geographic isolation and environmental heterogeneity. Consequences of global warming should be monitored in tropical mountains focusing on distribution shifts. [ABSTRACT FROM AUTHOR]

Associational resistance (AR) is a positive interaction in which a plant suffers less herbivore damage due to its association with a protective plant. Here, we evaluated whether plants with extra-floral nectaries (EFNs) can share indirect defenses with neighboring plants. We sampled 45 individuals of an EFN-bearing liana (Smilax polyantha) and recorded whether their support species had EFNs. In S. polyantha, we measured foliar herbivory and flower and fruit production. We examined the ant species composition and visitation of S. polyantha and whether they changed according to the supporting plant type (with or without EFNs). We experimentally determined whether S. polyantha supplemented with artificial nectaries could share indirect defenses with defenseless neighboring plants. Support plants with EFNs indirectly benefited S. polyantha by sharing mutualistic ant species. Smilax polyantha supported by plants with EFNs had a more specific ant species composition, a higher number of visiting ants and ant species richness, and exhibited nearly 3 times less foliar herbivory. However, we did not observe differences in fruit production between the two groups of S. polyantha. Finally, we observed that S. polyantha with artificial nectaries increased ant visitation on neighboring plants 2.5 times. We provide evidence that interspecific neighbors with EFNs can experience reciprocal benefits by sharing indirect defenses. Such local effects might escalate and affect the structure of plant communities. [ABSTRACT FROM AUTHOR]

Grazing is the basic way of grassland utilization, and reasonable grazing is an important way to maintain the health of the grassland ecosystem. However, the traditional grazing time in warming seasons is negative for sustainable desert steppe ecosystem. Determining reasonable grassland grazing methods is to remain a critical issue for the ecological conservation and rational utilization of desert steppe. Therefore, our objectives were to explore the effects of warming seasonal rotation grazing on the species diversity and functional diversity of grassland plants and to reveal controlling factors of plant community diversity. The warm‐season rotational grazing modes included traditional time of grazing (FG), delayed start of grazing (YG), early end of grazing (TG), delayed start early end of grazing (YT), and enclosed steppe (CK). The results showed that the important value of Agropyron mongolicum of the gramineae and Lespedeza potaninii of the leguminosae in YG increased by 12.10%–120.66% and 23.57%–34.25% than other treatments (CK, FG, TG, and YT), respectively. Therefore, the YG treatment has more advantages on the IV of A. mongolicum of the gramineae and L. potaninii of the leguminosae. Warming seasonal rotational grazing (FG, YG, TG, and YT) significantly increased the important value of Leymus secalinus by 51.43%–79.64% compared with CK (p <.05). Compared with CK, FG and YG promoted the growth of gramineae and appropriately reduced the proportion of forbs. There was no significant difference in the Shannon–Wiener index between grazing treatments and CK, while the Shannon–Wiener index in YT increased by 21.43% and 15.71% compared with FG and YG (p <.05). The functional richness index in FG and YG significantly decreased by 19.05%–23.81% compared with CK and TG (p <.05). The results of the redundancy analysis showed that the diversity of plant communities was mainly affected by soil‐available nitrogen. These observations indicated that delayed start of grazing can improve the diversity of plant communities by increasing the important value of dominant plants in the community and promoting the growth of gramineous and leguminous plants, thereby optimizing the composition of community structure. Our findings can provide a theoretical basis for formulating a reasonable and scientific grazing period in desert steppe. [ABSTRACT FROM AUTHOR]

Karst landforms are mainly special landscapes formed by carbonate dissolution. They are characterized by calcium abundance, lack of soil resources, and insufficient water resources. The growth and development of vegetation in the karst area is restricted by the bedrock. It is very important to understand the synergistic interaction between vegetation metabolism and geochemistry of carbonate rocks in karst areas to maintain the stability of structure and function of the karst ecosystem. The mechanism and law of interaction between vegetation and rock geochemical background in karst areas from two aspects is expounded in this paper: vegetation community promotes weathering of carbonate rocks and geochemical background restricts vegetation. Through summarizing: ( 1 ) Plants promote the weathering and dissolution of carbonate rocks through physicochemical and biological actions, such as secreting carbonic anhydrase organic matter, improving the water retention performance of rock surface through boring by organisms and accelerating the disintegration of broken rocks through root splitting, thus forming a unique karst geochemical background of drought, high calcium, shallow soil layer and lack of nutrients in the soil layer. (2) With the long-term interaction between plants and the karst environment, plants adapt to environmental stress by adjusting their own structures and physiological functions, and even their unique plant succession rules. The plants that survived eventually evolved into unique karst plants that were drought-resistant, adaptable to high-calcium environments, and able to cope with nutrient deficiencies. Due to the solubility of carbonate rocks, the hydrologic system forms a two-layer spatial structure of surface and underground, which makes it difficult to utilize groundwater resources. As a result, the available water resources of local plants are limited, and are prone to drought stress. The drought resistance of plants adapts to the drought or water shortage environment mainly through physiological and biochemical processes, morphological structure and water use. In the morphological structure of the plant, through the stomatal regulation and the xeric structural characteristics of the leaves, the transpiration water loss of the plant is minimized. Some karst plants can cope with drought stress through physiological and biochemical processes, which can reduce the damage caused by drought stress by increasing the activities of antioxidant enzymes and accumulating osmoregulatory substances through phytochemicals. Karst plants improve water use efficiency and reduce transpiration through different water use methods in the dry season. For example, some plants absorb deep soil, deep bedrock water or groundwater water through developed deep roots, and some plants even use fog water. The adaptability of plants to high calcium is realized through physiological structure and process. In a high calcium environment, karst plants can limit the excess calcium transfer upward by forming calcified roots and keeping the calcium content in plants in a relatively stable state through the regulation of calcium oxalate crystal cells and leaves. Plants can also control the intracellular calcium ion concentration by regulating the calcium pool in vivo and controlling the absorption and transport of calcium. Organic acids and mycorrhiza secreted by roots can help vegetation obtain nutrients in the soil to cope with nutrient deficiency in the soil. The organic acid content secreted by the roots of karst plants is usually higher than that of non - karst plants, and the increase of organic acid content can help plants to absorb trace elements. Arbuscular mycorrhizal fungi (AM) and ectomycorrhizal fungi (ECM) help plants adapt to nutrient deficiency by absorbing mineral nutrients from the soil. (3) The vegetation succession in the karst area is similar to the general stage of vegetation succession in normal landforms, but the vegetation succession in the karst area has the particularity of self - generation. The vegetation succession from the middle to the top of the mountain takes a longer time. Vegetation succession changed physical and chemical properties and soil quality. In the process of succession, soil bulk density gradually decreases, and porosity gradually increases over time. At the same time, soil nutrients accumulate with the positive succession of vegetation. During the positive succession process of karst vegetation, the soil water and fertilizer retention capacity is enhanced, the stability is increased, and the survival probability of species and the species diversity are also increased. The special rock geochemical background in the karst area leads to the obvious changes in the spatial distribution of soil resources. High soil heterogeneity promotes the formation of plant community species diversity. For example, the tropical karst area in Xishuangbanna, Yunnan Province covers an area of 3600km 2, accounting for 19% of the land area. The forest survey results in the karst area show that there are 153 families, 640 genera and 1394 species of vascular plants, accounting for 77. 7% of the total floristic families, 56. 1% of the genera and 37. 9% of the species, respectively. The karst plant community is the result of the long interaction between the plant and the environment, the continuous adaptation to the environment and the growth and reproduction. The karstification of plants, the adaptation mechanism of plants under the typical karst soil environment such as drought, high calcium stress and lack of nutrient elements, as well as the succession characteristics of karst vegetation shown in the adaptation process and the biodiversity of vegetation are a whole interaction. The site growth of vegetation promotes the weathering of carbonate rocks and the formation of soil, creating conditions for their own growth. Meanwhile, soil area and soil thickness are positively correlated with plant diversity. The succession of vegetation changes the physical and chemical properties of soil and improves the quality of soil, and the karstification of carbonate rocks promotes the growth of vegetation. The adaptive mechanism of vegetation affects the distribution and growth of plants and promotes the succession process of plant communities and the formation of plant diversity. Due to the spatial heterogeneity of the karst environment and the diversity of plant habitats, plant diversity in karst areas is manifested as few genera, few species and endemic species. However, the internal relationship between plant diversity and the stability of the community ecosystem, as well as the comparative characteristics with non-karst areas still need to be further studied and explored. [ABSTRACT FROM AUTHOR]

Studies on the impacts of fertilization on plant production and species diversity are crucial for better maintaining the stability of grassland ecosystems and restoring degraded grasslands. Using a controlled fertilization experimental platform in a temperate Leymus chinensis meadow steppe ecosystem, the effects of different levels of nitrogen (N) and phosphorus (P) addition on plant community structure, biomass allocation, diversity, and the correlation relationship were explored. The major results were as follows: (1) The structural composition of the plant community changed after different levels of N and P addition; the dominance ratio and biomass of Poaceae plants increased gradually with increasing N and P addition levels. (2) The addition of N and P increased the height, density and coverage of the plant community, the biomass of the dominant L. chinensis and plant community and the total productivity of grassland, and reduced the root–shoot ratio of grassland biomass. For example, plant community biomass, gramineous plant biomass and grassland total productivity increased by 84.46–204.08%, 162.64–424.20%, and 38.12–46.44%, respectively, after N and P addition. (3) The community richness, diversity, and evenness indices decreased overall and showed binomial regression after N and P addition; the functional group of Poaceae plants was highly significantly negatively correlated with species diversity indices and was highly significantly positively correlated with the aboveground biomass of L. chinensis and community; Leguminosae plants and Ranunculaceae plants were highly significantly positively correlated with Margalef and Patrick richness indices; Ranunculaceae plants were highly significantly and negatively correlated with L. chinensis biomass, community biomass, and Poaceae plants. Moderate fertilization not only improved the plant community structure and productivity but was also beneficial for maintaining the grassland species diversity and stability. [ABSTRACT FROM AUTHOR]

Community stability is a fundamental factor sustaining ecosystem functioning and is affected by species richness and species evenness. The Arctic is warming more rapidly than other biomes, and cryptogam plant species (specifically lichens and bryophytes in this study) are major contributors to tundra biodiversity and productivity. However, to our knowledge, the impacts of warming on cryptogam community stability and the underlying mechanisms have not been investigated. We conducted a 13‐year summer warming experiment in mesic birch hummock tundra vegetation near Daring Lake in the continental interior of low Arctic Canada and recorded patterns of cryptogam species abundance in several different growing seasons. Warming decreased the stability of total community abundance, had no effects on species richness, but increased species evenness and species synchrony. Structural equation model analyses indicated that higher species richness was the principal factor associated with the stronger community abundance stability in the control plots and that this effect was driven primarily by a negative correlation with species synchrony. By contrast, higher species evenness was the principal factor associated with the weakened community abundance stability in the warming plots, and this effect was driven primarily by a positive correlation with species synchrony. Our study suggests that climate warming could reduce cryptogam plant community stability in low Arctic tundra and, therefore, decrease important ecosystem services, including carbon storage and food availability to caribou in northern regions. [ABSTRACT FROM AUTHOR]