Search

Distributions of plants are expected to change in response to climate change, but the relative probability of that change is often unknown. Curl-leaf mountain mahogany (Cercocarpus ledifolius), an important browse species used by ungulates as forage and cover across the western US, is thought to be moderately to highly vulnerable to climate change this century, and a reduction in curl-leaf mountain mahogany occurrence may negatively impact ungulates reliant upon it. A combination of probability density estimation and vector analysis was used to predict curl-leaf mountain mahogany distribution across the species range relative to climate space and how that relationship would affect curl-leaf mountain mahogany at a local scale. Locally, we used the curl-leaf mountain mahogany population at the Bighorn Canyon National Recreation Area (BICA) in Montana and Wyoming for comparison. We modeled the probability of curl-leaf mountain mahogany occurrence across its distribution using water balance data to spatially and temporally assess the vulnerability of a population at a local scale. Modeled probabilities of occurrence and vector analysis indicated the species to remain in some areas within BICA but will be vulnerable in others given the predicted changes in temperature and precipitation in BICA if historical trajectories continue. This information allows managers to direct limited resources to other management actions by using the best available science to inform decisions. Other curl-leaf mountain mahogany populations currently inhabiting wetter, drier sites may follow a similar trajectory as the effects of climate change manifest. The approach used serves as a model to assess the predicted trend for species-specific plant communities of concern that may be adversely affected by climate change. [ABSTRACT FROM AUTHOR]

Sustainable Urban Drainage Systems (SUDS) are ecosystems that are based on engineered soil and designed plant communities to manage stormwater on-site and to enhance infiltration, evapotranspiration, and cooling, thus reducing flooding and urban heat islands. In addition, SUDS may act as hotspots for biodiversity and could be more socially accepted if they work well and are multifunctional. However, we still lack a critical understanding of the techno-ecological basis to construct SUDS sustainably. Due to climate change and pollutants such as de-icing salts, SUDS are confronted with harmful environmental triggers that interfere with their sustainable development. Thus, the challenge is to combine stormwater treatment and urban drainage with principles of restoration ecology, while implementing expertise from soil science, microbiome research, and plant ecology. In this perspective paper, we will discuss the SUDS development and maintenance principle and the role of interdisciplinary research in reaching these goals. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to examine the community characteristics of grassland plants in the Habahe region of Altai Mountains, changes in plant diversity, aboveground biomass in relation to community stability, and to provide data support for the development of a rational grazing system in Habahe region. [Methods] From 2020 to 2022, 18 representative fixed sample plots were selected in the summer pasture of Habahe in Altai Mountains to do surveys to investigate the number of species in the sample plots, cover and height, etc., and to determine the aboveground biomass, β-diversity (Sφrensen β-diversity index and Jaccard β-diversity index), species diversity (Margalef richness index, Simpson dominance index, Shannon-Wiener diversity index and Alatalo evenness index) and M. Godron community stability. The relationship between community stability and plant diversity and its biomass before and after grazing was analyzed. [Results] (1) 30 species of grassland communities were distributed in the Habahe region of Altai Mountains, belonging to 14 families, with Asteraceae, Rosaceae and Gramineae in the majority. (2) The diversity index, cover, plant height and above-ground biomass of grasslands in the Habahe region showed a significant downward trend after grazing. (3) The stability of grassland communities in the Habahe region before grazing was positively correlated with the Margalef richness index, the Simpson dominance index, and the Shannon-Wiener index diversity index in a highly significant way (p＜0.01); and the stability of grassland communities in the Habahe region after grazing was positively correlated with the Simpson dominance index in a significant way (p＜0.05) . (4) The relationship between grassland community stability and aboveground biomass in the Habahe region before grazing showed a significant positive correlation (p＜0.05), and the relationship between grassland community stability and aboveground biomass in the Habahe region after grazing showed no correlation. [Conclusion] The relationship between grassland community stability and diversity and biomass changed significantly after grazing, and grazing had a greater impact on community stability and reduced the stability of the community to a certain extent, but the community was generally in a stable state. [ABSTRACT FROM AUTHOR]

Vineyards are highly intensive systems very often located in biodiversity hotspots at the global scale. These ecosystems are now facing major environmental, agronomical and economic issues that challenge their sustainability. Based on multiple evidence, I illustrate here how biodiversity and several nature-based solutions across scales, from manipulating within-field plant communities to landscape-scale diversification, can provide benefits related to key societal challenges that vineyard socio-ecosystems are facing. These findings support the idea that biodiversity and ecosystem services play a key role in the functioning of these landscapes and that nature-based solutions offer a sustainable pathway for the future of vineyard agroecosystems. This literature review also highlights several gaps of knowledge that define a research agenda for nature-based solutions to strengthen multifunctionality of vineyard landscapes. [ABSTRACT FROM AUTHOR]

Background: A growing body of evidence demonstrates that host-associated microbial communities of plant leaf surfaces (i.e. the phyllosphere) can influence host functional traits. However, it remains unclear whether host selection is a universal driver of phyllosphere community assembly. We targeted mānuka (Leptospermum scoparium) and three neighbouring non-mānuka plant species along an 1800-m transect in a New Zealand native bush to conduct a hypothesis-driven investigation of the relative influence of host species identity and stochastic dispersal on the composition of natural phyllosphere bacterial communities. Results: We detected significant correlations between host species identity and mānuka phyllosphere communities that are consistent with a dominant role of host selection in the assembly of the mānuka phyllosphere microbiome. In contrast, the phyllosphere community compositions of neighbouring, ecologically similar native plants were highly variable, suggesting that stochastic processes, such as dispersal, had a stronger influence on the phyllosphere microbiomes of those non-mānuka plants compared to the phyllosphere microbiome of mānuka. Furthermore, the distribution of phyllosphere taxa among plant species was congruent with a scenario in which microorganisms had dispersed from mānuka to non-mānuka phyllosphere microbiomes. Conclusions: We conclude that host selection of phyllosphere communities is not and should not be presumed to be a universal trait across plant species. The specificity of the mānuka phyllosphere microbiome suggests the presence of functionally significant bacteria that are under direct, possibly chemically mediated, selection by the host. Furthermore, we propose that phyllosphere microbiomes under strong host selection, such as that of mānuka, may act as a source of microorganisms for the phyllosphere microbiomes of neighbouring plants. 2ZqHFcd3Z-Di37dyajupxd Video Abstract [ABSTRACT FROM AUTHOR]

Understanding how land use affects temporal stability is crucial to preserve biodiversity and ecosystem functions. Yet, the mechanistic links between land-use intensity and stability-driving mechanisms remain unclear, with functional traits likely playing a key role. Using 13 years of data from 300 sites in Germany, we tested whether and how trait-based community features mediate the effect of land-use intensity on acknowledged stability drivers (compensatory dynamics, portfolio effect, and dominant species variability), within and across plant and arthropod communities. Trait-based plant features, especially the prevalence of acquisitive strategies along the leaf-economics spectrum, were the main land-use intensity mediators within and across taxonomic and trophic levels, consistently influencing dominant species variability. Functional diversity also mediated land-use intensity effects but played a lesser role. Our analysis discloses trait-based community features as key mediators of land-use effects on stability drivers, emphasizing the need to consider multi-trophic functional interactions to better understand complex ecosystem dynamics. [ABSTRACT FROM AUTHOR]

Studying the characteristics of soil moisture in afforestation area and its response to different grades of rainfall is helpful to quantitatively analyze the change law of soil moisture in afforestation area and provide theoretical basis for rational and efficient use of soil moisture. In this study, four artificial plant communities were selected, including Hedysarum scoparium community, Calligonum mongolicum community, H. scoparium- C. mongolicum community and C. mongolicum- H. scoparium community. The soil moisture content, soil moisture storage and their response characteristics to different grades of rainfall from June to October were compared and analyzed. The results showed that the SMC of H. scoparium- C. mongolicum community and C. mongolicum- H. scoparium community were lower than that of H. scoparium community and C. mongolicum community. The coefficient of variation of soil moisture content in C. mongolicum community was the largest, which was 22.7%, and the coefficient of variation of soil moisture content in H. scoparium-C. mongolicum community was the smallest, which was 19.4%. The recharge of rainfall to soil moisture storage of four artificial plant communities was different. The recharge of different grades of rainfall to soil moisture storage of C. mongolicum community and C. mongolicum-H. scoparium community was higher than that of H. scoparium community and H. scoparium-C. mongolicum community. In general, the utilization of soil moisture content in different soil layers by H. scoparium-C.mongolicum community is more balanced, and the soil moisture content in each soil layer is less affected by rainfall and has higher stability. Therefore, considering the configuration mode of H. scoparium- C. mongolicum community in the future aerial seeding afforestation process is conducive to the rational and efficient utilization of soil moisture in the afforestation area. [ABSTRACT FROM AUTHOR]

Dry evergreen Afromontane forests are severely threatened due to the expansion of agriculture and overgrazing by livestock. The objective of this study was to investigate the composition of woody species, structure, regeneration status and plant communities in Seqela forest, as well as the relationship between plant community types and environmental variables. Systematic sampling was used to collect vegetation and environmental data from 52 (20 m x 20 m) (400 m2) plots. Density, Diameter at Breast Height (DBH), basal area, frequency, and importance value index (IVI) of woody species were computed to characterize the vegetation structure of the forest. Agglomerative hierarchical cluster analysis and Canonical Correspondence Analysis (CCA) with R software were used to identify plant communities and analyse the relationship between plant community types and environmental variables, respectively. A total of 68 woody plant species belonging to 63 genera and 44 families were identified. The Shannon diversity index and evenness values of the study area were 2.12 and 0.92, respectively. The total basal area and density of woody species were 27.4 m2 ha−1 and 1079.3 individual ha−1, respectively. The most frequent woody species in the Seqela forest included Albizia gummifera (51.92%), Croton macrostachyus (44.23%), Olinia rochetiana and Teclea nobilis (36.54%). Additionally, the most dominant species, as indicated by their importance value index (IVI), were Erythrina brucei (IVI = 11.24), Prunus africana (IVI=8.68), and Croton macrostachyus (IVI=7.38). Four plant community types were identified: Albizia gummifera - Ekebergia capensis, Prunus africana - Croton macrostachyus, Vachellia abyssinica - Dombeya torrida and Schefflera abyssinica - Teclea nobilis. The CCA results showed that the variation of species distribution and plant community formation were significantly (P < 0.05) related to altitude, organic matter, aspect, slope and soil available phosphorus. The regeneration status assessment of the forest revealed a good regeneration status, which was linked to diverse and abundant seed bank in the soil can ensure a continuous supply of seeds for regeneration; therefore, it is recommended to implement periodic soil seed bank assessments to monitor seed diversity and abundance and inform targeted conservation actions. [ABSTRACT FROM AUTHOR]

Summary: Plants rely on solar energy for growth through photosynthesis, yet excessive light intensity can induce physiological damage. Despite the considerable harm, inadequate attention has been directed toward understanding how plant‐associated microorganisms mitigate this stress, and the impact of high light intensity on plant microbial communities remains underexplored. Through this Viewpoint, we aim to highlight the potential of microbial communities to enhance plant resilience and understand how light stress can shape plant microbiome. A full understanding of these dynamics is essential to design strategies that take advantage of microbial assistance to plants under light stress and to effectively manage the impact of changing light conditions on plant–microbe interactions. [ABSTRACT FROM AUTHOR]

Owing to its topographic variations, Ethiopia is a biodiversity-rich country. However, the long-term degradation of resources has resulted in isolated forest patches largely around sacred places. Thus, this work was aimed to evaluate the plant community formation and structural dynamics of the Abraham Sacred Forest patch. Data were collected from 60 plots located on transect lines. Five subplots (4 m2), four at each corner and center, were set to collect juveniles' data. Individuals of each species and cover abundance were recorded, and adults' stem girth was measured. Hierarchical cluster analysis was used to identify plant communities. A Kruskal-Wallis followed by Tukey's honestly significant difference test was performed to check the statistical significance among the plant communities. Shannon-Wiener diversity index, equitability index, and non-parametric species richness estimators were used to quantify species diversity, evenness, and richness, respectively. Structural parameters and size class ratios were used to analyze the vegetation structure and regeneration status. Seventy wood species, distributed in 62 genera and 38 families, were recorded. Fabaceae was the most species-rich (10 species) family. Three plant communities were identified. A Kruskal-Wallis test indicated that the community types showed significant differences (P < 0.05) with respect to altitude and slope. The density and basal area of the forest were 4580.4 ha-1 and 35.18 m2ha-1 respectively. The inverted J-shaped pattern in DBH classes implies a good reproduction status. However, importance value index and regeneration status analyses revealed that certain species, like Astropanax abyssinicum (Hochst. ex. A. Rich) Seem, Myrica salicifolia Hochst. ex. A. Rich and Dombeya torrida (G.F.Gmel) Bamps, require conservation priority. [ABSTRACT FROM AUTHOR]

Herein, we report the presence of a plant paleocommunity, dominated by ferns of the family Osmundaceae, structurally preserved from the only known Mesozoic, fossiliferous geothermal deposits, from the La Matilde Formation (Middle-Upper Jurassic) in the Deseado Massif of Southern Patagonia, Argentina. A total of 13 siliceous chert blocks sampled in an area of approximately 250 m2, preserving a monotypic assemblage dominated by Osmundaceae embedded within its original swampy substrate, are documented. Additional Osmundaceae and fewer ferns and conifers are present in the stratigraphically continuous, adjacent chert levels. This association is comparable to those dominated by Osmundaceae in modern swampy settings, such as in high-altitude lagoons in the Paraná Forest in Northeastern Argentina. In addition, a diverse community of mutualistic, parasitic, and saprotrophic microorganisms associated with the ferns and conifers in the assemblage is present. These compositional, paleoenvironmental, and trophic characteristics of the Jurassic Osmundaceae suggest a possible case of ecological stasis, where Osmundaceae-dominated plant communities apparently persisted in swamps of comparable structures, functions, and physical characteristics for over 150 million years. This suggests that Osmundaceae formed similar communities in compatible settings in the Jurassic, becoming preserved in analogous configurations. [ABSTRACT FROM AUTHOR]

Background: Fungal communities around plant roots play crucial roles in maintaining plant health. Nonetheless, the responses of fungal communities to bacterial wilt disease remain poorly understood. Here, the structure and function of fungal communities across four consecutive compartments (bulk soil, rhizosphere, rhizoplane and root endosphere) were investigated under the influence of bacterial wilt disease. Results: The results showed that bacterial wilt disease caused different assembly patterns of fungal communities in the bulk soil, rhizosphere, rhizoplane and endosphere. Under the influence of bacterial wilt disease, a decreased fungal diversity was observed in the rhizoplane and endosphere, and completely different kinds of fungal genera were enriched in the four compartments. The complexity and stability of fungal networks were less affected, but the number of key fungal members in networks were significantly reduced in diseased samples. Functional predictions based on FUNGuild suggested that with the pathogen infection, saprotrophic fungi were increased in the bulk soil, but pathotrophic fungi (potential plant and animal pathogens) were increased in the rhizosphere, rhizoplane and endosphere. Conclusion: This work provides a deep insight into the effects of bacterial wilt disease on fungal communities along the soil-root continuum, and is helpful to identify plant-associated beneficial fungi to resist plant disease. Clinical trial number: Not applicable. [ABSTRACT FROM AUTHOR]

To characterize the naturalized population of burr medic (Medicago polymorpha L.), a valuable pasture legume, in subtropical Queensland, Australia, a collection of 1747 lines from 107 sites in 11 regions was grown, and 26 phenotypic and agronomic attributes were recorded. This data matrix was analyzed by cluster, principal co-ordinates, discriminant and correlation analyses to examine line relationships based on plant attributes and their association with site characteristics of climate and soil. Among the wide polymorphism of attributes across the collection zone, there were a number of notable phenotypic associations. One of these, with large green leaves, minimally dentate leaf margins, and light purple petioles, was widely distributed. Three others, one with a distinctive magenta leaf mark, dark purple petioles, and an upright habit; one with those same attributes but with a prostrate habit; and one with grey-green leaves, high frost resistance, and the ability to stay green and to produce high pod yields, were associated with climatic and soil characteristics in the north, east, and south of the collection zone, respectively. Days to flowering were longer in lines from saline soils at lower altitude, and plant vigor was greatest in lines from more fertile soils with higher rainfall. A wide variation in time to flower of lines at all collection sites contributes to the adaptation of M. polymorpha in subtropical Queensland and potentially to its persistence with future climate change. [ABSTRACT FROM AUTHOR]

Alpine ecosystems, highly sensitive to climate change, are experiencing shifts in species ranges and community structure. These changes are driven by a complex interplay of climatic and environmental factors, land use changes, geomorphological dynamics, and species interactions, which can often lead to contrasted and sometimes unexpected dynamics. Historical records provide a valuable opportunity to capture these complexities by revealing long‐term changes, opening a gateway to hypothesise about the key underlying processes. We investigated changes in the floristic composition of subalpine to nival vegetation communities by resurveying a period of 70 years. To understand vegetation patterns, we (i) resampled vegetation at plot level and remapped the area, (ii) analysed the role of driving climate, environmental, and land use factors on vegetation distribution and vascular plant species richness, and (iii) modelled plant‐plant interactions from community data. The results reveal that vegetation cover patterns were strongly influenced by local climate and soil properties. The species richness is also influenced by the livestock density and the flat morphology. It should be noted that climate change caused wetland habitats to become drier and accelerated secondary succession through upward migration and range‐infilling processes. Furthermore, a trend towards eutrophication was observed. The results suggested that certain plant communities, particularly those found in snowbeds, were more vulnerable to environmental changes that have occurred over the past 70 years. Synthesis: This study highlighted the complexity of vegetation dynamics. In addition to thermophilisation and aridification, changes in land use affect species composition, species richness, and vegetation cover. Substrate conditions also play an important role. [ABSTRACT FROM AUTHOR]

Topography has an important influence on plant–soil relationships. However, research on plant–soil relationships in alpine grassland at the slope aspect and slope position scales is currently inadequate. In this paper, based on the topographic and geomorphological characteristics of the study area, alpine grassland with typical slope aspect and slope position conditions was selected as the research object. Through field investigations and laboratory research to reveal how the characteristics of the alpine grassland plant community and soil factors respond to changes in topography. The results show: Slope aspect and slope position changes significantly affect alpine grassland plant communities and soil properties. In terms of the dominant species in plant communities, the sunny slopes were dominated by Poaceae and the shady slopes were dominated by Polygonaceae. Plant community characterization variables showed a decreasing trend from shady to sunny slopes and bottom to top. The soil factors showed significant differences among the six types of topography (p < 0.05), and the magnitude order in different slope aspects and positions was basically shady slope > sunny slope and bottom > middle and top. Correlation analysis showed that there were good correlations between soil organic carbon (SOC), soil water content (SWC), total nitrogen (TN), pH, and plant community characteristics in alpine grassland. In addition, redundancy analyses (RDA) indicated that the divergence in plant community characteristics was primarily driven by the change difference in SOC along topographic gradients. Our findings may provide a scientific basis for the restoration and utilization of alpine grassland vegetation and the evaluation of the ecological environment in this region. [ABSTRACT FROM AUTHOR]

Paleoenvironmental insights gleaned from geological history are profoundly important for the discovery and exploitation of mineral resources. In China's Bohai Bay Basin, the Kongdian Formation represents the principal oil-bearing stratum from the Eocene Epoch. However, a comprehensive understanding of its paleoenvironmental evolution and stratigraphic division has been hindered by the paucity of paleontological data. To address this gap, three sedimentary cores were meticulously collected from the southern extremity of the Liaoxi Uplift within the Bohai Bay. These cores underwent a thorough sporopollen-algae analysis to elucidate their stratigraphic division and to reconstruct the associated paleoenvironmental conditions. The analysis yielded the identification of three distinct sporopollen-algae assemblages of the regional Kongdian Formation: (1) The assemblage of Divisisporites longilaesuratus-Betulaepollenites-Tiliaepollenites microreticulatus is indicative of the lower submember of the Kongdian Formation Ek2; (2) The assemblage of Polypodiaceaesporites-Alnipollenites indicates the upper submember of the Ek2; (3) The assemblage of Pterisisporites undulatus-Taxodiaceaepollenites-Ephedripites corresponds to the Kongdian Formation Ek1. These assemblages reflect a significant evolutionary trajectory of the regional plant communities throughout the Kongdian Formation. Initially, there were evergreen arbor-shrub mixed forests, which transitioned to green algae-herb-evergreen broadleaved biota and finally evolved into evergreen conifer-shrub mixed forests. This botanical evolution mirrors shifts in the paleoclimate, which experienced a progression from conditions of high temperature and high humidity through a phase of warm, semi-humid environments to eventually high temperature and semi-arid conditions. [ABSTRACT FROM AUTHOR]

Aridity, edaphic variables and livestock grazing are major drivers of plant community composition across arid rangelands. Accumulated knowledge exists on the impact of each driver on community composition. Although previous studies have demonstrated changes in direct grazing impacts on ecosystem functions and community composition at different aridity levels, ranging from mesic to arid grasslands, whether a regional‐scale and continuous spatial pattern of plant compositional change along a gradient of aridity or edaphic variables is altered by grazing remains controversial. We compared the determinants and patterns of compositional changes with/without highly intensive grazing in the semi‐arid/arid regions of Mongolia. The compositional changes based on Bray–Curtis dissimilarity were investigated using generalized dissimilarity modeling, including geographic distance, aridity, soil pH and soil texture as independent variables. Aridity consistently had a significant impact on community composition, regardless of the region and presence/absence of grazing. However, a difference in response patterns was observed between the regions. The compositional change was steeper at the upper (drier) limit of aridity than at the lower limit in the arid region. This pattern indicates the vulnerability of plant communities to aridity shifts owing to future climate change, especially in the desert steppe of Mongolia, although the predictions of shifts in aridity are not accurate. In addition, regardless of the region, the effects of soil pH on the community composition were eliminated by the presence of grazing. Grazing may homogenize community composition by not reflecting the spatial heterogeneity of soil pH or nutrient availability via selective herbivory. Despite the potential indirect impacts of climate change on community composition via soil pH, the observations for only plant communities under intensive grazing might overlook regional biodiversity changes caused by global change drivers. [ABSTRACT FROM AUTHOR]

Climate change is causing marked shifts to historic environmental regimes, including increases in precipitation events (droughts and highly wet periods). Relative to droughts, the impacts of wet events have received less attention, despite heavy rainfall events increasing over the past century. Further, impacts of wet and dry events are often evaluated independently; yet, to persist and maintain their ecosystem functions, plant communities must be resilient to both precipitation events. This is particularly critical because while community properties can modulate the resilience (resistance, recovery, and invariability) of ecosystem functions to precipitation events, community properties can also respond to precipitation events. As a result, community responses to wet and dry years may impact the community's resilience to future events. Using two decades (2000–2020) of annual net primary productivity data from early successional grassland communities, we evaluated the plant community properties regulating primary productivity resistance and recovery to contrasting precipitation events and invariability (i.e. long‐term stability). We then explored how resilience‐modulating community properties responded to precipitation. We found that community properties—specifically, evenness, dominant species (Solidago altissima) relative abundance, and species richness—strongly regulate productivity resistance to drought and predict productivity invariability and tended to promote resistance to wet years. These community properties also responded to both wet and dry precipitation extremes and exhibited lagged responses that lasted into the next growing season. We infer that these connections between precipitation events, community properties, and resilience may lead to feedbacks impacting a plant community's resilience to subsequent precipitation events. Synthesis. By exploring the impacts of both drought and wet extremes, our work uncovers how precipitation events, which may not necessarily impact productivity directly, could still cryptically influence resilience via shifts in resilience‐promoting properties of the plant community. We conclude that these precipitation event‐driven community shifts may feedback to impact long‐term productivity resilience under climate change. [ABSTRACT FROM AUTHOR]

This study evaluates the growth, survival pressures, and community dynamics of Barringtonia racemosa (L.) Spreng. populations in Jiulong Mountain and Suixi County, Guangdong Province. Six distinct plant communities were identified, with human disturbances significantly disrupting natural succession processes. The population in Jiulong Mountain, particularly within the Talipariti tiliaceum-B. racemosa community (JLS-T), experienced higher survival pressures compared to Suixi County. Interspecific competition varied, with species like Derris trifoliata, T. tiliaceum, and invasives such as Ipomoea cairica and Mikania micrantha exerting substantial pressure on B. racemosa. Analysis of 234 B. racemosa individuals revealed significant correlations between diameter at breast height (DBH), plant height, and age structure distribution, with a linear relationship between DBH and height underscoring their relevance in understanding wood volume, biomass, and stand structure. Survival pressures were inversely related to DBH, indicating reduced competition as trees matured. Growth patterns exhibited an age-dependent plateau in height, potentially influenced by environmental and anthropogenic factors. Management strategies should prioritize the growth of individuals with DBH less than 5 cm (age classes I ~ II). These findings underscore the need for targeted conservation efforts to protect B. racemosa communities and sustain wetland ecosystems. [ABSTRACT FROM AUTHOR]

Summary Affecting biodiversity, plants with larger genome sizes (GS) may be restricted in nutrient‐poor conditions. This pattern has been attributed to their greater cellular nitrogen (N) and phosphorus (P) investments and hypothesized nutrient–investment tradeoffs between cell synthesis and physiological attributes associated with growth. However, the influence of GS on cell size and functioning may also contribute to GS‐dependent growth responses to nutrients. To test whether and how GS is associated with cellular nutrient, stomata, and/or physiological attributes, we examined > 500 forbs and grasses from seven grassland sites conducting a long‐term N and P fertilization experiment. Larger GS plants had increased cellular nutrient contents and larger, but fewer stomata than smaller GS plants. Larger GS grasses (but not forbs) also had lower photosynthetic rates and water‐use efficiencies. However, nutrients had no direct effect on GS‐dependent physiological attributes and GS‐dependent physiological changes likely arise from how GS influences cells. At the driest sites, large GS grasses displayed high water‐use efficiency mostly because transpiration was reduced relative to photosynthesis in these conditions. We suggest that climatic conditions and GS‐associated cell traits that modify physiological responses, rather than resource–investment tradeoffs, largely explain GS‐dependent growth responses to nutrients (especially for grasses). [ABSTRACT FROM AUTHOR]

Background: The changes of microbial community on tobacco leaves are affected by several factors during fermentation. However, the relative contribution of different factors in determining microbial community is not clear. This study investigated the effects of fermentation time (fermentation for 0, 3, 6, 9 and 12 months), leaf position (middle and top tobacco leaves) and fermentation site (Longyan and Xiamen warehouses) on bacterial community of tobacco leaves using 16 S rDNA sequencing. Results: The results demonstrated that fermentation time had a much stronger impact on bacterial diversity, composition, co-occurrence network and functional profiles than leaf position and fermentation site. With the fermentation progressed, the difference of bacterial community between middle and top tobacco leaves was gradually reduced or even disappeared. The bacterial community diversity and network complexity at three, six and nine months of fermentation were significantly lower than those at fermentation initiation. Specific bacterial genera with desired functions were recruited at different fermentation stages, such as Terribacillus, Pantoea and Franconibacter at three or six months of fermentation and Pseudomonas at nine months of fermentation. The recruited microorganisms would form biofilms on tobacco leaves and compete for polysaccharide or protein substances to accelerate the degradation of tobacco macromolecular substances. Conclusions: In conclusion, fermentation time was an important factor in determining the composition and function of microbial community on tobacco leaves during the fermentation process. [ABSTRACT FROM AUTHOR]

Recently, attention has been shifting toward the perspective of the existence of plants and microbes as a functioning ecological unit. However, studies highlighting the impacts of the microbial community on plant health are still limited. In this study, fungal community (mycobiome) of leaf, root, and soil of symptomatic leaf-spot diseased (SS) oil palm were compared against asymptomatic (AS) trees using ITS2 rRNA gene metabarcoding. A total of 3,435,417 high-quality sequences were obtained from 29 samples investigated. Out of the 14 phyla identified, Ascomycota and Basidiomycota were the most dominant accounting for 94.2 and 4.7% of the total counts in AS, and 75 and 21.2% in SS, respectively. Neopestalotiopsis is the most abundant genus for AS representing 8.0% of the identified amplicons compared to 2.0% in SS while Peniophora is the most abundant with 8.6% of the identified amplicons for SS compared to 0.1% in AS. The biomarker discovery algorithm LEfSe revealed different taxa signatures for the sample categories, particularly soil samples from asymptomatic trees, which were the most enriched. Network analysis revealed high modularity across all groups, except in root samples. Additionally, a large proportion of the identified keystone species consisted of rare taxa, suggesting potential role in ecosystem functions. Surprisingly both AS and SS leaf samples shared taxa previously associated with oil palm leaf spot disease. The significant abundance of Trichoderma asperellum in the asymptomatic root samples could be further explored as a potential biocontrol agent against oil palm disease. [ABSTRACT FROM AUTHOR]

Precipitation distribution during the growing season and interannual precipitation variation may have significant impacts on grassland ecosystem productivity at the site level. To explore the effect of the distribution of precipitation on plant communities in the Inner Mongolian desert steppe dominated by Stipa breviflora, we analyzed monthly precipitation patterns during the growing season (May–October) over the past 60 years (1961–2020) and identified four major precipitation distribution patterns. These included the concentrated precipitation during July (TΛ7), August (TΛ8), and during the early and late growth stages. However, with precipitation being scarce during the boom (TM), the distribution resembled a normal distribution (T∩). Field experiments simulating the four distributions were conducted from May to October 2021. The results showed that the effects of the distribution of precipitation on plant species, diversity, and abundance were not significant; only the Pielou evenness showed a significant effect after July. The total above-ground net primary productivity (ANPP) of TΛ7 was 55.4% higher than those of the other three patterns, whereas the differences among the other three precipitation distributions were not significant. The annual forb Neopallasia pectinate was the primary contributor to the increased ANPP of TΛ7. These results suggest that the S. breviflora desert steppe achieved maximum productivity when the precipitation reached 41.6% of the annual average during July and satisfied the basic plant growth requirements during other months. This study emphasizes the implementation of management measures (irrigation or artificial precipitation) for maximizing forage yield and forecasting the plant composition in desert steppes. [ABSTRACT FROM AUTHOR]

The assessment of fire effects in Aleppo pine forests is crucial for guiding the recovery of burnt areas. This study presents a methodology using UAV-LiDAR data to quantify malleability and elasticity in four burnt areas (1970, 1995, 2008 and 2015) through the statistical analysis of different metrics related to height structure and diversity (Height mean, 99th percentile and Coefficient of Variation), coverage, relative shape and distribution strata (Canopy Cover, Canopy Relief Ratio and Strata Percent Coverage), and canopy complexity (Profile Area and Profile Area Change). In general terms, malleability decreases over time in forest ecosystems that have been affected by wildfires, whereas elasticity is higher than what has been determined in previous studies. However, a particular specificity has been detected from the 1995 fire, so we can assume that there are other situational factors that may be affecting ecosystem resilience. LiDAR metrics and uni-temporal sampling between burnt sectors and control aids are used to understand community resilience and to identify the different recovery stages in P. halepensis forests. [ABSTRACT FROM AUTHOR]

Mycorrhizal associations drive plant community diversity and ecosystem functions. Arbuscular mycorrhiza (AM) and ectomycorrhiza (EcM) are two widespread mycorrhizal types and are thought to differentially affect plant diversity and productivity by nutrient acquisition and plant–soil feedback. However, it remains unclear how the mixture of two mycorrhizal types influences tree diversity, forest biomass, and their relationship at large spatial scales. Here, we explored these issues using data from 1247 plots (600 m2 for each) across China's natural forests located mostly in temperate and subtropical regions. Both AM‐dominated and EcM‐dominated forests show relatively lower tree species richness and stand biomass, whereas forests with the mixture of mycorrhizal strategies sustain more tree species and higher biomass. Interestingly, the positive effect of tree diversity on biomass is stronger in forests with low (≤50%) than high AM tree proportion (>50%), reflecting a shift from the complementarity effect to functional redundancy with increasing AM trees. Our findings suggest that mycorrhizal dominance influences tree diversity and richness–biomass relationship in forest ecosystems. [ABSTRACT FROM AUTHOR]

Tree plantations are considered as a solution to reduce the impacts of climate change and can enhance biodiversity. Consequently, many tree planting schemes around the world have been started to achieve these dual objectives. However, many of these tree plantations are being implemented without proper design or post‐plantation management, often overlooking potential long‐term effects on biodiversity. Therefore, it is essential to identify which aspects of tree plantations can negatively impact biodiversity. Such knowledge is vital to design new plantations and manage existing ones, such that they do not pose threats or additional costs to the conservation of natural ecosystems. To this end, we conducted an observational study in the Mediterranean heathland habitat of the southwestern Iberian Peninsula. This treeless habitat, locally known as herriza, has been planted with pine trees until the onset of the 21st century. This historical tree plantation presents a unique natural experiment to assess the long‐term effect of tree cover, measured as canopy openness, on several community properties of plant, pollinators and their network of interactions. Our results reveal a strong positive relationship between canopy openness and floristic diversity and abundance. This means that, as we increase tree cover, plant diversity is reduced. We found this has consequences for pollinator diversity and plant–pollinator networks, the latter exhibiting declines in stability. Furthermore, we reveal the importance of woody blooming plants in comparison to non‐woody ones which, despite their greater importance for pollinators, they are the most impacted. These findings underscore the importance of tree cover for severely affecting multiple properties of plant–pollinator networks at different levels of organization. Overall, this knowledge indicates that high tree cover in plantations conducted 50 years ago is incompatible with maintaining and conserving plant–pollinator networks in natural treeless habitats, at least in the herriza. Actions that want to avoid negative long‐term effects of tree plantations on plant–pollinator communities should consider existing biodiversity before planting and refrain from achieving high tree cover values. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Climate and geological diversity have been proven to make an important contribution to biodiversity. Volcanic ecosystems often have a long geological history and diverse bedrock, thus shaping a variety of habitats. Understanding the relative importance and role of the contemporary climate and geological bedrock environment in volcanic biodiversity still needs further exploration. To address this knowledge gap, we investigated the patterns of plant diversity and phylogenetic structure at the community level in Qiniangshan Mountain, while also exploring the relationship between biodiversity and regional environmental factors (e.g., climate and bedrock types). In the Qiniangshan Mountain plant communities, species richness is higher at mid-to-high elevations. Montane communities exhibit higher species richness compared to coastal communities. There are significant differences in species richness among plant communities on different bedrock, with the highest species richness found on pyroclastic lava. Bedrock, along with climate factors related to energy and precipitation, collectively influence the patterns of species richness in plant communities. The Net Relatedness Index (NRI) of plant communities is influenced by climate factors and aspects, while the Nearest Taxon Index (NTI) is affected by both bedrock and climate factors. The Phylogenetic Diversity Index (PDI) is primarily related to climate factors. Climate and bedrock collectively influence the patterns of species richness and phylogenetic structure within Qiniangshan Mountain's plant communities. These findings highlight the profound impact of both climate and bedrock on montane vegetation and community biodiversity. [ABSTRACT FROM AUTHOR]

The emergence of β‐diversity of plant‐associated fungi across diverse coexisting host plant species in natural habitats is intricately linked to specific community assembly processes. Despite this, the relative contributions of various assembly processes to the observed β‐diversity patterns, as well as the influence of plant traits on these contributions, are still poorly understood. Here, we investigated the leaf/root‐associated fungal communities across nine coexisting dominant herbaceous perennials in a temperate grassland that had undergone a 17‐year mowing treatment. We elucidated the β‐diversity components and community assembly processes of these fungal communities. Furthermore, we explored relationships between leaf/root functional trait variations and fungal community assemblies. We tested the following hypotheses: (1) both species turnover and nestedness are important components of the fungal β‐diversity, with selection predominating in the fungal community assemblies; (2) mowing enhances the contributions of nestedness/selection; (3) plant trait variations significantly affect the fungal community assembly processes. Unexpectedly, our findings demonstrated a predominance of leaf/root fungal species turnover among coexisting plant hosts, contrasting with nestedness. Moreover, dispersal limitation emerged as the primary factor shaping fungal community assemblies, rather than selection processes. Although mowing significantly inhibited plant growth, its effects on the overall patterns of fungal assemblages were limited. We further observed that higher degrees of plant trait variations were primarily linked to stronger dispersal limitation, with a relatively weaker influence on heterogeneous selection. Additionally, the impact of plant traits on the selection process of root‐associated fungi was more pronounced compared to that of leaf‐associated fungi. Synthesis. Our study reveals that the β‐diversity of fungi associated with coexisting plants in natural grasslands is primarily attributed to fungal species replacement rather than gain‐and‐loss dynamics among these plants. Concurrently, this observed pattern is largely governed by dispersal limitation as opposed to selection. We propose that the primary mechanism through which plant hosts and their traits influence the structures of associated fungal communities is by limiting fungal dispersal, while niche differentiation among fungal taxa plays a secondary role. These findings offer a mechanistic insight into the assemblies of plant mycobiomes and further elucidate the plant‐mycobiome relationships within complex plant communities. [ABSTRACT FROM AUTHOR]

Summary Many plant species experience a prolonged subterranean phase during which they rely entirely on mycorrhizal fungi for carbon. While this mycoheterotrophic strategy spans liverworts, lycophytes, and ferns, most empirical research has centered on angiosperms. This study explores the fungal associations of Sceptridium (Ophioglossaceae), an early‐diverging fern with mycoheterotrophic gametophytes. We analyzed germination patterns and fungal associations in Sceptridium gametophytes, comparing them to the distribution and mycorrhizal partners of photosynthetic sporophytes. High‐throughput sequencing data reveal that mycoheterotrophic gametophytes consistently associate with a single Entrophospora fungus in the order Entrophosporales (Glomeromycotina), while photosynthetic sporophytes primarily partner with fungi from Glomeraceae (Glomerales, Glomeromycotina). Consequently, gametophytes exhibit spatial clustering without association with adult plants. This is the first documentation of an association between Entrophosporaceae (and the order Entrophosporales) and mycoheterotrophic plants. The drastic shifts in Sceptridium mycorrhizal communities across life stages likely reflect changing physiological needs during development. Further research is essential to determine whether the association with Entrophosporaceae is widespread among mycoheterotrophic species and to elucidate the functional and physiological mechanisms underlying these mycorrhizal shifts. [ABSTRACT FROM AUTHOR]

Environmental changes, such as climate warming and higher herbivory pressure, are altering the carbon balance of Arctic ecosystems; yet, how these drivers modify the carbon balance among different habitats remains uncertain. This hampers our ability to predict changes in the carbon sink strength of tundra ecosystems. We investigated how spring goose grubbing and summer warming—two key environmental‐change drivers in the Arctic—alter CO2 fluxes in three tundra habitats varying in soil moisture and plant‐community composition. In a full‐factorial experiment in high‐Arctic Svalbard, we simulated grubbing and warming over two years and determined summer net ecosystem exchange (NEE) alongside its components: gross ecosystem productivity (GEP) and ecosystem respiration (ER). After two years, we found net CO2 uptake to be suppressed by both drivers depending on habitat. CO2 uptake was reduced by warming in mesic habitats, by warming and grubbing in moist habitats, and by grubbing in wet habitats. In mesic habitats, warming stimulated ER (+75%) more than GEP (+30%), leading to a 7.5‐fold increase in their CO2 source strength. In moist habitats, grubbing decreased GEP and ER by ~55%, while warming increased them by ~35%, with no changes in summer‐long NEE. Nevertheless, grubbing offset peak summer CO2 uptake and warming led to a twofold increase in late summer CO2 source strength. In wet habitats, grubbing reduced GEP (−40%) more than ER (−30%), weakening their CO2 sink strength by 70%. One‐year CO2‐flux responses were similar to two‐year responses, and the effect of simulated grubbing was consistent with that of natural grubbing. CO2‐flux rates were positively related to aboveground net primary productivity and temperature. Net ecosystem CO2 uptake started occurring above ~70% soil moisture content, primarily due to a decline in ER. Herein, we reveal that key environmental‐change drivers—goose grubbing by decreasing GEP more than ER and warming by enhancing ER more than GEP—consistently suppress net tundra CO2 uptake, although their relative strength differs among habitats. By identifying how and where grubbing and higher temperatures alter CO2 fluxes across the heterogeneous Arctic landscape, our results have implications for predicting the tundra carbon balance under increasing numbers of geese in a warmer Arctic. [ABSTRACT FROM AUTHOR]

The intricate interplay between endophytic microorganisms and plants in the upkeep of biodiversity, the stability of communities, and the operation of ecosystems needs to be more adequately extensive. Although root-associated microbial communities of plants have been revealed for the last decade, the understanding of bacterial and fungal communities associated with the roots of medicinal plants remains elusive. To highlight the importance of Panax ginseng Meyer (PG) in our research, we investigated the root endophytic bacterial and fungal communities of Panax ginseng Meyer (PG), alongside Aralia cordata (AC), Angelica gigas (AG), and Peucedanum japonicum (PJ), utilizing amplicon-based community profiling and advanced bioinformatic methodologies. The study aimed to investigate the root-endophytic microbiota of ginseng and three other medicinal plants and identify similarities in microbiome composition across different plant species and families. Results revealed that root-endophytic bacterial and fungal communities were influenced by plant species and phylogenetic differences at the family level. Differential abundance tests and random forest models showed microbial features within the same plant family. PG had a distinctive microbial profile with significant B1653_o_Enterobacterales and F8_o_Helotiales. PG had a core microbiome, B10_Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, and a more evenly distributed microbial network compared to AG, PJ, and AC. Our research reveals the intricate endophytic microbial communities within the roots of medicinal plants, pinpointing specific taxa that may be pivotal to their medicinal qualities and overall plant health. These insights carry notable implications for future studies, particularly those focused on the endophytes of PG and their secondary metabolites, as they deepen our understanding of plant-microbe interactions and their role in enhancing the plants' therapeutic potential. [ABSTRACT FROM AUTHOR]

For most terrestrial plants, regeneration depends on the ability of seeds to germinate in the most favourable climatic conditions. Understanding seed germination phenology is thus crucial for predicting plant responses to environmental changes. However, a substantial gap persists regarding how microclimatic conditions influence germination in seasonal ecosystems. Here, we investigate the germination phenology of alpine plants in snow‐related microclimates as a tool for predicting the resilience of plant communities to climate change. We conducted a continuous seasonal experiment with fresh seeds to investigate germination phenology in 54 co‐occurring species from temperate and Mediterranean alpine communities. Using long‐term field microclimatic data series, we precisely mimicked two contrasting microclimatic regimes in growth chambers: (1) windy exposed edges with a snow‐free period in winter and warmer temperatures in summer (‘fellfield’) and (2) sheltered areas with lengthy snow cover and cooler temperatures (‘snowbed’). We validated the laboratory results with field sowing experiments to provide a complete picture of germination phenology. The analysis of phenology traits demonstrated that both communities displayed similar responses to microclimatic variation. Small microclimatic differences of 2–3°C a week, accumulated across a whole year in the laboratory, resulted in a quantifiable germination phenology delay in snowbed regime, with an average of 60 and 45 days for temperate and Mediterranean alpine respectively. The results from climatic chambers under realistic microclimatic regimes were consistent with the germination phenology registered from field experiments. We also observed macroclimatic effects manifested as reduced dormancy and increased autumn germination in Mediterranean alpine species. Synthesis. This study combines novel laboratory and field experimentation to tackle the understudied topic of germination phenology in habitats with sharp microclimatic gradients. Specifically, our findings suggest a predictable phenological shift in the germination of alpine plants along microclimatic gradients. In warmer conditions with reduced snow cover, alpine species are expected to advance germination 52 days on average, with potential disrupting effects on cold‐adapted species with strict germination requirements. This highlights the role of germination phenology to determine plant‐environmental relationships in mid‐latitude ecosystems, with strong impact on plant establishment and extinction risks under local microclimatic gradients. [ABSTRACT FROM AUTHOR]

Summary The plant community has a strong track record of RNA sequencing technology deployment, which combined with the recent advent of spatial platforms (e.g. 10× genomics) has resulted in an explosion of single‐cell and nuclei datasets that can be positioned in an in situ context within tissues (e.g. a cell atlas). In the genomics era, application of proteomics technologies in the plant sciences has always trailed behind that of RNA sequencing technologies, largely due in part to upfront cost, ease‐of‐use, and access to expertise. Conversely, the use of early analytical tools for characterizing small molecules (metabolites) from plant systems predates nucleic acid sequencing and proteomics analysis, as the search for plant‐based natural products has played a significant role in improving human health throughout history. As the plant sciences field now aims to fully define cell states, cell‐specific regulatory networks, metabolic asymmetry and phenotypes, the measurement of proteins and metabolites at the single‐cell level will be paramount. As a result of these efforts, the plant community will unlock exciting opportunities to accelerate discovery and drive toward meaningful translational outcomes. [ABSTRACT FROM AUTHOR]

Existing studies of root/shoot ratios (R/S) in the field show large differences among environments, from high values in unproductive environments to low values in productive environments. However, virtually, all such studies are community‐wide, that is compare biomasses of roots and shoots summed over all coexisting species. Therefore, we do not know to what extent this is due to innate interspecific differences in the R/S ratios or to plastic response to nutrient limitations. This is due to methodological difficulties in assigning roots into species, which preclude the contribution of species‐specific differences to the community‐wide R/S ratio. These limitations can be overcome by DNA analyses. We used qPCR to determine species‐specific R/S ratios in a montane grassland and compared these values to R/S ratios from a two‐season long single‐species pot experiment. To translate the qPCR data to root biomass units, we extracted DNA from the experimental plants to perform calibration for each species and to take into account potential change during the ontogeny of root systems. We used these calibration relationships to recalculate gene copies estimated in a set of field samples to species‐specific root biomass values. All species except one showed fairly high correlation between above‐ground biomass (determined by weighing) and below‐ground biomass (determined by qPCR) across all studied plots in the field. Root/shoot ratios determined from the field were for most species slightly lower than the aggregate values of the whole community determined by weighing both roots and above‐ground biomass. They showed significant correlation with the R/S ratios from the pot experiment, indicating innate differences among species that persist across two very different sets of conditions (multispecies community in the field, single species culture in pots). The field R/S ratios based on qPCR root estimation are informative on the true field patterns. This is supported by their correlation with the pot‐derived values. While the values seem to be slightly underestimated, they are well in the reasonable range of values. This opens a new field of study, namely examination how R/S ratios in the field respond to changed nutrient availability and diversity and species composition of neighbouring species. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Assessment of the plant's ability to take up mercury (Hg) from polluted soil was affected by location, plant family, and species in two former cinnabar mining areas in the Czech Republic. At each location, seven sampling points were marked out in the vicinity of former shafts and dumpsites connected to the mining activity, where representative soil samples and dicotyledonous plants were collected. The individual locations were characterized by specific plant communities, where, in most cases, different plant species were found within one family at both locations. The total Hg content in the soil, as well as gaseous elemental mercury (GEMsoil-air), confirmed elevated levels of this element in the mining-affected environment, with high variability of the data. The low Hg accumulation ability of plants, especially the low root–shoot translocation in most of the plant species, indicated the predominant occurrence of excluders. Among the families, the results showed the exceptional position of the Fabaceae family regarding soil Hg pollution, as the highest Hg content in both shoots and roots was determined for Onobrychis viciifolia. Therefore, the behavior of Fabaceae plants in polluted soil, the mechanisms of their tolerance to high Hg content, and their Hg accumulation ability deserve further research. [ABSTRACT FROM AUTHOR]

Serpentine ecosystems are characterised by multiple environmental stressors: high levels of trace metals such as nickel (Ni), low availability of macronutrients and low water retention. These harsh environmental conditions exert a strong selective force on the vegetation, but their effect on community assembly processes and the functional trait composition remains unknown.In 26 plots on four serpentine sites on Lesbos Island (Greece), we measured six leaf functional traits related to resource acquisition and stress resistance on the 20 most abundant plant species. We quantified the proportion of variance explained by inter‐ and intraspecific trait differences and tested if individual species showed changes in trait values explained by soil Ni content. We investigated the adaptive value and the community level changes for each trait along the natural soil Ni gradient using a mixed model approach and functional diversity analyses. We tested the role of the abundant serpentine endemic and Ni‐hyperaccumulating species Odontarrhena lesbiaca in driving these patterns.Intraspecific variation explained by soil Ni content is smaller than 4%, and most of the variance is explained by interspecific differences in trait values. Most species do not show significant changes in trait values in response to soil Ni. At the community level, low specific leaf areas, small and thick leaves are selected on high Ni soils. Functional diversity analyses suggest a shift towards a stress tolerance syndrome (thick and small leaves with low SLA values) and an increase in functional diversity on Ni‐rich soils. However, these patterns are driven by the increasing abundance of O. lesbiaca.The endemic Ni hyperaccumulator has a stress tolerance strategy with small thick leaves and low SLA, while the community of broadly distributed species show an increase in trait values related to dominance and fast growth.Synthesis. Intraspecific variation in leaf trait responds little to soil metal toxicity. Endemic species harbour unique trait values compared to species with broad distribution which should justify their conservation as a priority. [ABSTRACT FROM AUTHOR]

Besides environmental sorting, other processes like biotic interactions and dispersal limitation are vital for the assembly of plant communities in high mountains and their re‐assembly under changing climatic conditions. Nevertheless, studies that compare the impact of these factors on plant community assembly above the tree line are largely lacking so far.We analysed occurrence changes in vascular plant communities of 492 permanent 1‐m2 plots in the alpine‐nival ecotone of Mt. Schrankogel, Austrian Alps by comparing resurvey data from 2014 with data from the initial survey in 1994. We combined these data with species inventories from 899 additional plots sampled in 2021 and 2022 across a larger landscape above the tree line covering an elevational range of 1700 m, which we used for fine‐scale habitat suitability modelling. We assessed the relative effects of projected habitat suitability, propagule pressure from surrounding populations and biomass density of neighbours on 1532 colonization and 372 extirpation events of 31 species observed on the permanent plots.We found that all three factors are significantly related to both colonisations and extirpations, with habitat suitability having the strongest, propagule pressure a slightly weaker, and vegetation density the weakest effect. Colonisations can be better explained by the three process proxies than extirpations.Our results indicate a crucial role of dispersal limitation besides the predominant effect of environmental filtering on the (re‐)assembly of the alpine‐nival plant community, while competitive/facilitative effects between plants tend to play a minor role. The strong imprint of nearby source plant populations on colonization/extirpation events suggests that recent plant migrations predominantly occur in small steps. This implies that while the topographically complex alpine terrain offers climatic microrefugia for plants, it may also pose potential barriers, hindering species from following their suitable climatic niches upwards.Synthesis: Besides filtering by environmental conditions dispersal limitation had a strong effect on the observed changes in a local alpine plant community over two decades. Limited dispersal capacities of plant species may counteract the ability of isolated cold areas to effectively shelter high alpine plants from the effects of climate warming. [ABSTRACT FROM AUTHOR]

Summary: Redistribution of precipitation across seasons is a widespread phenomenon affecting dryland ecosystems globally. However, the impacts of shifting seasonal precipitation patterns on carbon (C) cycling and sequestration in dryland ecosystems remain poorly understood.In this study, we conducted a 10‐yr (2013–2022) field manipulative experiment that altered the timing of growing‐season precipitation peaks in a semi‐arid grassland.We found that the delayed precipitation peak suppressed plant growth and thus reduced gross ecosystem productivity, ecosystem respiration, and net ecosystem productivity due to middle growing‐season water stress. Surprisingly, shifting more precipitation to the early growing season can advance plant development, increase the dominance of drought‐tolerant forbs, and thus compensate for the negative impacts of middle growing‐season water stress on ecosystem C cycling, leading to a neutral change in grassland C sink.Our findings indicate that greater precipitation and plant development in spring could act as a crucial mechanism, maintaining plant growth and stabilizing ecosystem C sink. This underscores the urgent need to incorporate precipitation seasonality into Earth system models, which is crucial for improving projections of terrestrial C cycling and sequestration under future climate change scenarios. [ABSTRACT FROM AUTHOR]

Livestock grazing represents the largest land use globally and causes impacts that vary according to intensity, evolutionary history and local environmental conditions. In the Dry Chaco, many grasslands were altered, modifying the cover of the species that make up the grasslands, which was significantly reduced in recent years due to inadequate livestock management. The aim of this study was to determine the possible effect of grazing on the herbaceous plant community, for which we estimated and compared the species richness, plant cover of palatable species, species composition and aboveground net primary productivity (ANPP) of grasslands with different intensities of livestock use in Copo National Park. We selected two natural grasslands with different grazing pressures (high and low grazing pressure) and two sites per grassland on five different dates (two dry seasons and three wet seasons). The results showed that there were no statistical differences of the grazing pressures evaluated in the richness and species composition or in the ANPP. However, there were statistically significant differences (P=0.0009) in the cover of palatable species, which was higher in low-pressure grasslands. These changes are associated with an increase in the cover of annual, woody, toxic or unpalatable species in the high-pressure grassland, altering the plant community without changing richness or species composition. On the other hand, ANPP was not significantly affected by different pressures, possibly due to the higher cover of aibe (Elionurus muticus), which is not consumed by cattle in advanced phenological stages. Therefore, the lack of changes in richness, composition and ANPP suggests compatibility between livestock grazing and conservation of the protected area, although monitoring of the cover of palatable species in grasslands under high pressure from livestock use is recommended to avoid degradation. [ABSTRACT FROM AUTHOR]

Premise: Plants can limit the leaf tissue consumed by insect herbivores through chemical, structural, and nutritional leaf defenses or by escaping in space and time. Escaping is related to the phenological patterns of plants, which in turn respond to climatic factors. This study evaluated leaf production in a coastal plant community in southern Brazil to test the following hypotheses: (1) Leaves are continuously produced in this ecosystem, and (2) synchrony acts as an escape strategy from herbivory. Methods: We evaluated leaf production patterns of 20 herbaceous, shrub, and tree species for 2 years using the Fournier index then measured leaf consumption in the second year. The Rayleigh test was used to verify the synchrony of phenological events. Correlations between leaf production and climatic factors and between leaf production synchrony and herbivory were analyzed. Results: New leaves were continuously produced at the plant community scale, but herbaceous and shrub species showed a phenological pattern distinct from that of tree species. Trees had peaks of synchrony in leaf production that were positively correlated with amount of leaf tissue consumed, refuting the hypothesis that synchrony acts as an escape strategy. Conclusions: The phenological and herbivory patterns in this plant community may be due to the supply of resources in the soil and the composition of the insect community. [ABSTRACT FROM AUTHOR]

Microbes regulate many dimensions of plant performance with multiscale implications for plant fitness, competition, coexistence, and ecosystem functioning. Yet, this fascinating and diverse arena of study has been limited to a few thematic areas, ecosystems, and regions. In particular, despite growing evidence that microbes may be critical players in the dynamics of plant communities in tropical and subtropical ecosystems, these regions remain poorly represented in studies of plant–microbe interactions. Such geographical gaps limit our ability to draw general inferences to comprehend how microbial effects on plant community dynamics may vary with context and, by extension, respond to global environmental change. In this special section of the American Journal of Botany, we bring together a diverse set of research on plant–microbe interactions from tropical and subtropical ecosystems. These papers explore intraspecific variation of soil microbial communities, the context dependency of host‐specific assembly of microbial communities on plants, and the new and exciting frontier of the microbiome of epiphytic plants. We hope that this compilation will fuel deeper forays into the many dimensions of plant–microbe interactions in megadiverse tropical and subtropical forests. [ABSTRACT FROM AUTHOR]

Premise: In the Amazon basin, seasonally flooded (SF) forests offer varying water constraints, providing an excellent way to investigate the role of habitat selection on microbial communities within plants. However, variations in the microbial community among host plants cannot solely be attributed to environmental factors, and how plant traits contribute to microbial assemblages remains an open question. Methods: We described leaf‐ and root‐associated microbial communities using ITS2 and 16 S high‐throughput sequencing and investigated the stochastic‐deterministic balance shaping these community assemblies using two null models. Plant ecophysiological functioning was evaluated by focusing on 10 leaf and root traits in 72 seedlings, belonging to seven tropical SF tree species in French Guiana. We then analyzed how root and leaf traits drove the assembly of endophytic communities. Results: While both stochastic and deterministic processes governed the endophyte assembly in the leaves and roots, stochasticity prevailed. Discrepancies were found between fungi and bacteria, highlighting that these microorganisms have distinct ecological strategies within plants. Traits, especially leaf traits, host species and spatial predictors better explained diversity than composition, but they were modest predictors overall. Conclusions: This study widens our knowledge about tree species in SF forests, a habitat sensitive to climate change, through the combined analyses of their associated microbial communities with functional traits. We emphasize the need to investigate other plant traits to better disentangle the drivers of the relationship between seedlings and their associated microbiomes, ultimately enhancing their adaptive capacities to climate change. [ABSTRACT FROM AUTHOR]

Premise: Soil microbes can influence patterns of diversity in plant communities via plant–soil feedbacks. Intraspecific plant–soil feedbacks occur when plant genotype leads to variations in soil microbial composition, resulting in differences in the performance of seedlings growing near their maternal plants versus seedlings growing near nonmaternal conspecific plants. How consistently such intraspecific plant–soil feedbacks occur in natural plant communities is unclear, especially in variable field conditions. Methods: In an in situ experiment with four native tree species on Barro Colorado Island (BCI), Panama, seedlings of each species were transplanted beneath their maternal tree or another conspecific tree in the BCI forest. Mortality and growth were assessed at the end of the wet season (~4 months post‐transplant) and at the end of the experiment (~7 months post‐transplant). Results: Differences in seedling performance among field treatments were inconsistent among species and eroded over time. Effects of field environment were detected at the end of the wet season in two of the four species: Virola surinamensis seedlings had higher survival beneath their maternal tree than other conspecific trees, while seedling survival of Ormosia macrocalyx was higher under other conspecific trees. However, these differences were gone by the end of the experiment. Conclusions: Our results suggest that intraspecific plant–soil feedbacks may not be consistent in the field for tropical tree species and may have a limited role in determining seedling performance in tropical tree communities. Future studies are needed to elucidate the environmental and genetic factors that determine the incidence and direction of intraspecific plant–soil feedbacks in plant communities. [ABSTRACT FROM AUTHOR]

Aim: Ecological theory suggests that dispersal limitation and selection by climatic factors influence bacterial community assembly at a continental scale, yet the conditions governing the relative importance of each process remains unclear. The carnivorous pitcher plant Sarracenia purpurea provides a model aquatic microecosystem to assess bacterial communities across the host plant's north–south range in North America. This study determined the relative influences of dispersal limitation and environmental selection on the assembly of bacterial communities inhabiting S. purpurea pitchers at the continental scale. Location: Eastern United States and Canada. Time Period: 2016. Major Taxa Studied: Bacteria inhabiting S. purpurea pitchers. Methods: Pitcher morphology, fluid, inquilines and prey were measured, and pitcher fluid underwent DNA sequencing for bacterial community analysis. Null modelling of β‐diversity provided estimates for the contributions of selection and dispersal limitation to community assembly, complemented by an examination of spatial clustering of individuals. Phylogenetic and ecological associations of co‐occurrence network module bacteria was determined by assessing the phylogenetic diversity and habitat preferences of member taxa. Results: Dispersal limitation was evident from between‐site variation and spatial aggregation of individual bacterial taxa in the S. purpurea pitcher system. Selection pressure was weak across the geographic range, yet network module analysis indicated environmental selection within subgroups. A group of aquatic bacteria held traits under selection in warmer, wetter climates, and midge abundance was associated with selection for traits held by a group of saprotrophs. Processes that increased pitcher fluid volume weakened selection in one module, possibly by supporting greater bacterial dispersal. Conclusion: Dispersal limitation governed bacterial community assembly in S. purpurea pitchers at a continental scale (74% of between‐site comparisons) and was significantly greater than selection across the range. Network modules showed evidence for selection, demonstrating that multiple processes acted concurrently in bacterial community assembly at the continental scale. [ABSTRACT FROM AUTHOR]

Mountains have been recognized as biodiversity hotspots and possess strong elevational gradients. Whether these gradients exhibit similar characteristics in the multidimensional diversity patterns across different mountain ranges is a subject of inquiry. Exploring the elevational patterns of the diversity and phylogenetic information of plant species in the different subtropical mountains is necessary. Here, we compiled the elevational patterns of plant diversity occurring in the eight subtropical mountains of China and focused on the assessment of the patterns and determinants of the multi‐dimensional diversity and phylogenetic structure in different mountains. We also detected the elevational patterns and their relationship between different groups. The results indicate two main patterns of multi‐dimensional diversity: monotonic decrease and hump‐shaped, along with the area effect on the species diversity. There is a strong positive link between the non‐native and native species of species richness, and significant differences in phylogenetic structure's elevational distribution. We did not find the same rule in the mountains that the plant species in the lowlands indicate phylogenetic overdispersion, and the species in the higher elevation regions indicate phylogenetic clustering. We found that the plants' diversity peak is related to the mountains size, and this result showed that we should pay more attention to the conservation of plant communities in the higher elevation regions for the higher mountains. This study suggested that we should take different protective measures for the subtropical mountains: the lowland regions should be paid more attention in Mt. Lushan (LS), Mt. Guanshan (GS), Mt. Huanggang (HG), and Mt. Fanjing (FJ), and the middle‐altitude regions should be of concern for other mountains. This study helps to better understand the elevational gradients of species diversity on different scales and provides supporting scientific basis for biodiversity conservation in the subtropical mountain regions. [ABSTRACT FROM AUTHOR]

Symbiotic associations play a role in plant ecology and evolution, but the outcome of the interaction depends on the life‐history traits of the partners and the environmental context. Although symbiosis with vertically transmitted microorganisms should result in mutualism, it is not clear how the transmission process aligns with the outcome of the context‐dependent symbiosis.For 3 years, we sampled individuals of an annual plant species that forms symbiosis with a vertically transmitted fungal endophyte, in paired stands of two contrasting vegetation communities (humid mesophytic meadows [HMM]: productive/low stress, and humid prairies [HP]: less productive/high stress). We estimated the prevalence of symbiosis at the population level, and the fitness of the plant, the symbiotic status and vertical transmission efficiency at the individual level.Over 3 years, the prevalence of symbiosis was ≈100% in HMM and ≈75% in HP. Plant fitness was very low and high in years with precipitation below and above the yearly mean, respectively. The higher fitness of endophyte‐symbiotic plants was evident in the HMM and high precipitation years. Vertical transmission of endophytes was higher in HMM (≈96%) compared to HP (≈93%) and was not related to plant fitness. Despite transmission inefficiencies in HP, changes in prevalence within the growing season (from seeds to the final plant stand) suggest a fitness advantage for symbiotic plants.Vertical transmission is expected to promote mutualism as it aligns partners' fitness. Although symbiotic plants showed higher fitness and the probability of transmission failures was higher among low‐fitness plants, the variation in transmission efficiency between plants and vegetation communities was not related to the fitness of the individual host. Our study provides evidence that context‐dependent vertical transmission efficiency and endophyte‐mediated fitness advantages interact complexly to determine the prevalence of symbiosis in populations that occur in contrasting vegetation communities. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

In order to investigate the characteristics and driving factors of keystone species change in vegetation communities, we conducted a network analysis to analyze the complexity of grassland plant communities and keystone species. We conducted a study with six plots of degraded grassland, intact grassland, and various ages of artificial grassland. We systematically analyzed the characteristics of vegetation community and soil physical–chemical properties under different treatments. Our findings revealed that the 5-year-old artificial grassland exhibited lower biodiversity, as indicated by a Shannon–Weiner index of 1.70 and a Pielou's evenness index of 0.72. In comparison to the degraded grassland, soil organic carbon and nitrate nitrogen levels in the 5-year-old artificial grassland increased by 22% and 13%, respectively, while soil density decreased by 9%. However, despite the relatively stable plant community in the 21-year-old artificial grassland, it had not fully recovered to the level of natural grassland due to the complexity of the plant community and the shift in keystone species. Therefore, it is crucial to consider the impact of soil bulk density and nutrient levels on the complexity of the plant community when restoring degraded alpine meadows through the establishment of artificial grassland. [ABSTRACT FROM AUTHOR]

To describe the characteristics and dynamics of the Picea jezoensis (PJ) community, a survey of 48 forest plots containing PJ trees was conducted in Northeast China. Methods of community grouping, analysis of variance, and linear regression, and indicators of relative basal area (RBA, reflecting the dominance degree of species in the community) and temporary stability (TS, reflecting the stability of forest plant community), were employed. The objectives were to describe the dominant species composition and environment of the PJ community and to quantify the changes in PJ's dominance status. Communities with PJ trees were divided into four groups: PJ as the first dominant species; PJ as the second dominant species; PJ being co-dominant but ranked third or lower; and PJ as a non-dominant species. Among them, the PJ community (i.e., where PJ is the first dominant species) occupied sites at the highest elevation with a mean value of 1408 m, on gentle slopes ≤ 10°, where the tree species occurring with PJ mainly included Betula costata and Abies nephrolepis. A linear relationship was found between the TS and RBA. The threshold for PJ shifting between being the first and second dominant species in the community was RBA = 0.387. This study provides a scientific basis for judging the attributes and status of PJ community and the protection and restoration of PJ forests. These findings also provide comparable information for ecological research and conservation of PJ forests in other areas. [ABSTRACT FROM AUTHOR]