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Specific mechanisms of precipitation change due to global climate variability on plant communities in coastal salt marsh ecosystems remain unknown. Hence, a field manipulative precipitation experiment was established in 2014 and 5 years of field surveys of vegetation from 2017 to 2021 to explore the effects of precipitation changes on plant community composition. The results showed that changes in plant community composition were driven by dominant species, and that the dominance of key species changed significantly with precipitation gradient and time, and that these changes ultimately altered plant community traits (i.e., community density, height, and species richness). Community height increased but community density decreased with more precipitation averaged five years. Furthermore, changes in precipitation altered dominant species composition and functional groups mainly by influencing soil salinity. Salinity stress caused by decreased precipitation shifted species composition from a dominance of taller perennials and grasses to dwarf annuals and forbs, while the species richness decreased. Conversely, soil desalination caused by increased precipitation increased species richness, especially increasing in the dominance of grasses and perennials. Specifically, Apocynaceae became dominance from rare while Amaranthaceae decreased in response to increased precipitation, but Poaceae was always in a position of dominance. Meanwhile, the dominance of grasses and perennials has the cumulative effect of years and their proportion increased under the increased 60% of ambient precipitation throughout the years. However, the annual forb Suaeda glauca was gradually losing its dominance or even becoming extinct over years. Our study highlights that the differences in plant salinity tolerance are key to the effects of precipitation changes on plant communities in coastal salt marsh. These findings aim to provide a theoretical basis for predicting vegetation dynamics and developing ecological management strategies to adapt to future precipitation changes.

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Anthropogenic climate change has increased the frequency of drought, wildfire, and invasions of non-native species. Although high-severity fires linked to drought can inhibit recovery of native vegetation in forested ecosystems, it remains unclear how drought impacts the recovery of other plant communities following wildfire. We leveraged an existing rainfall manipulation experiment to test the hypothesis that reduced precipitation, fuel load, and fire severity convert plant community composition from native shrubs to invasive grasses in a Southern California coastal sage scrub system. We measured community composition before and after the 2020 Silverado wildfire in plots with three rainfall treatments. Drought reduced fuel load and vegetation cover, which reduced fire severity. Native shrubs had greater prefire cover in added water plots compared to reduced water plots. Native cover was lower and invasive cover was higher in postfire reduced water plots compared to postfire added and ambient water plots. Our results demonstrate the importance of fuel load on fire severity and plant community composition on an ecosystem scale. Management should focus on reducing fire frequency and removing invasive species to maintain the resilience of coastal sage scrub communities facing drought. In these communities, controlled burns are not recommended as they promote invasive plants.

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Environmental circumstances shaping soil microbial communities have been studied extensively. However, due to disparate study designs, it has been difficult to resolve whether a globally consistent set of predictors exists, or context-dependency prevails. Here, we used a network of 18 grassland sites (11 of those containing regional plant productivity gradients) to examine (i) if similar abiotic or biotic factors predict both large-scale (across sites) and regional-scale (within sites) patterns in bacterial and fungal community composition, and (ii) if microbial community composition differs consistently at two levels of regional plant productivity (low vs. high). Our results revealed that bacteria were associated with particular soil properties (such as base saturation) and both bacteria and fungi were associated with plant community composition across sites and within the majority of sites. Moreover, a discernible microbial community signal emerged, clearly distinguishing high and low-productivity soils across different grasslands independent of their location in the world. Hence, regional productivity differences may be typified by characteristic soil microbial communities across the grassland biome. These results could encourage future research aiming to predict the general effects of global changes on soil microbial community composition in grasslands and to discriminate fertile from infertile systems using generally applicable microbial indicators.

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Understanding the long-term impact of projected climate change on tropical rainforests is critical given their central role in the Earth's system. Palaeoecological records can provide a valuable perspective on this problem. Here, we examine the effects of past climatic changes on the dominant forest type of Southeast Asia - lowland dipterocarp forest. We use a range of proxies extracted from a 1400-yr-old lacustrine sedimentary sequence from north-eastern Philippines to determine long-term vegetation responses of lowland dipterocarp forest, including its dominant tree group dipterocarps, to changes in precipitation, fire and nutrient availability over time. Our results show a positive relationship between dipterocarp pollen accumulation rates (PARs) and leaf wax hydrogen isotope values, which suggests a negative effect of drier conditions on dipterocarp abundance. Furthermore, we find a positive relationship between dipterocarp PARs and the proxy for phosphorus availability, which suggests phosphorus controls the productivity of these keystone trees on longer time scales. Other pollen taxa show widely varying relationships with the abiotic factors, demonstrating a high diversity of plant functional responses. Our findings provide novel insights into lowland dipterocarp forest responses to changing climatic conditions in the past and highlight potential impacts of future climate change on this globally important ecosystem.

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How Tibetan red deer (Cervus elaphus wallichii) acclimates to high altitude environment during the withered grass period is one of the challenges in maintaining their nutrient intake. It is an important basis to study the nutritional ecology of wild large ungulates in alpine ecosystems by investigating the changes in plant communities with altitude during the withered grass period and how these changes affect the food composition of Tibetan red deer. In this study, we selected the Tibetan red deer in Sangri County, Shannan region of Tibet as the research subject. We carried out field surveys on the altitude, plant communities, and feeding traces of the Tibetan red deer in March of 2021 and 2022 during the withered grass period on the Tibetan Plateau. Detrended correspondence analysis and canonical correspondence analysis were used to study altitudinal variations in plant communities and the regularity of food composition. The results showed that during the period of withered grass, Tibetan red deer ate primarily Salix daltoniana, Rosa macrophylla var. glandulifera and Dasiphora parvifolia. S. daltoniana accounted for more than 50% of the food composition, as the main food resources for red deer in withered grass period. In the low altitude area (4100-4300 m), plant community included Caragana versicolor, R. macrophylla and Berberis temolaica, and Tibetan red deer mainly ate R. macrophylla, C. versicolor and Artemisia wellbyi. In higher altitude area (4300-4600 m), plant community consisted of Rhododendron nivale, Rhododendron fragariiflorum, and Sibiraea angustata, and Tibetan red deer mainly fed on S. daltoniana, Salix obscura, and Carex littledalei. At different altitudes, the dominant plant species were the main food of Tibetan red deer. It is suggested that the changes of plant community composition with altitude directly affected food composition of Tibetan red deer, indicating different food composition patterns with altitude gradients.

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Subtropical and tropical forests in Asia often comprise canopy dominant trees that form symbioses with ectomycorrhizal fungi, and species-rich understorey trees that form symbioses with arbuscular mycorrhizal fungi. We propose a virtuous phosphorus acquisition hypothesis to explain this distinct structure. The hypothesis is based on (i) seedlings being rapidly colonised by ectomycorrhizal fungi from established mycelial networks that generates positive feedback and resistance to pathogens, (ii) ectomycorrhizal fungi having evolved a suite of morphological, physiological, and molecular traits to enable them to capture phosphorus from a diversity of chemical forms, including organic forms, and (iii) allocation of photosynthate carbon from adult host plants to provide the energy needed to undertake these processes.

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Heavy grazing generally reduces grassland biomass, further decreasing its carbon sink. Grassland carbon sink is determined by both plant biomass and carbon sink per unit biomass (specific carbon sink). This specific carbon sink could reflect grassland adaptative response, because plants generally tend to adaptively enhance the functioning of their remaining biomass after grazing (i.e. higher leaf nitrogen content). Though we know well about the regulation of grassland biomass on carbon sink, little attention is paid to the role of specific carbon sink. Thus, we conducted a 14-year grazing experiment in a desert grassland. Ecosystem carbon fluxes, including net ecosystem CO2 exchange (NEE), gross ecosystem productivity (GEP) and ecosystem respiration (ER), were measured frequently during five consecutive growing seasons with contrasting precipitation events. We found that heavy grazing reduced NEE more in drier (-94.0 %) than wetter (-33.9 %) years. However, grazing did not reduce community biomass much more in drier (-70.4 %) than wetter years (-66.0 %). These meant a positive response of specific NEE (NEE per unit biomass) to grazing in wetter years. This positive response of specific NEE was mainly caused by a higher biomass ratio of other species versus perennial grasses with greater leaf nitrogen content and specific leaf area in wetter years. In addition, we also detected a shift of grazing effects on specific NEE from positive in wetter years to negative in drier years. Overall, this study is among the first to reveal the adaptive response of grassland specific carbon sink to experimental grazing in plant trait view. The stimulation response of specific carbon sink can partially compensate for the loss of grassland carbon storage under grazing. These new findings highlight the role of grassland adaptive response in decelerating climate warming.

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The reduction of soil nutrient content is one of the major reasons caused grassland degradation in China. Nutrient addition is thus considered as an effective measure for the restoration of degraded grasslands. However, over-fertilization can lead to decrease in plant diversity. To clarify the appropriate amount of nutrient addition and the underlying mechanism that promotes grassland restoration, we set up a nitrogen and phosphorus co-addition experiment in a degraded typical steppe of Inner Mongolia, and examined the responses at community, functional group and species levels to nutrient addition. The results showed that nutrient addition enhanced biomass while did not reduce species richness at the community level. The biomass showed a saturation response with the increases of nutrient addition, which approached saturation under the 12.0 g N·m-2, 3.8 g P·m-2 treatment. Species richness increased significantly under the lower nutrient treatments (N <9.6 g·m-2, P < 3.0 g·m-2) compared with the control, while the two high nutrient treatments did not alter species richness. At the functional group level, biomass and abundance of perennial rhizome grasses increased significantly with the increases of nutrient addition levels. Biomass and density of annuals increased significantly under high nutrient addition levels. However, the abundance and biomass of perennial bunchgrasses and perennial forbs were rarely affected. At the species level, six target species responded differently to nutrient addition. Biomass of Leymus chinensis was significantly increased due to the increase of population density and individual biomass. Biomass of Stipa grandis, Agropyron cristatum and Cleistogenes squarrosa change little. Biomass of Potentilla acaulis and Carex korshinskyi were reduced due to the decreases in individual biomass and population density, respectively. As a measure of restoring degraded grassland, nutrient addition could significantly increase biomass and species diversity, decrease biomass of the degradation indicator species, and increase biomass of perennial rhizomes grasses.

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The effect of nitrogen and glyphosate on the plant community composition was investigated in a simulated field margin ecosystem. The plant community composition was inferred from pin-point cover data using a model-based ordination method that is suited for modelling pin-point cover data. The mean structure of the ordination model is analogous to a standard linear model, which enabled us to estimate the mean effects of nitrogen and glyphosate and their interaction in the two-dimensional ordination space. There were significant effects of both nitrogen and glyphosate on the plant community composition and overall species diversity. The effects of nitrogen and glyphosate on the plant community composition differed significantly. Furthermore, the estimated combined effects of nitrogen and glyphosate indicated that nitrogen and glyphosate enforced the effect of each other on the plant community composition by synergistic interactions. Addition of nitrogen and glyphosate was found to favor a plant community that was dominated by perennial grasses, and there was a tendency for glyphosate to select for plant communities in which annual plants were more frequent. The results suggest that using the notion of plant functional types and specific knowledge of the degree of glyphosate tolerance may be effective for predicting the effect of glyphosate on the community composition.

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PREMISE: Effective seed dispersal is essential to the success of plant species. Swida amomum (silky dogwood) has a seed-dispersal syndrome characteristic of autumn-ripening shrubs with fleshy fruits; attached fruits are ingested and defecated by birds, while fallen fruits are consumed by ground-foraging birds and mammals. METHODS: We documented that fallen fruits of this shrub were consumed by two aquatic turtle species (eastern painted turtle [Chrysemys picta] and red-eared slider [Trachemys scripta]) and that their seeds were defecated. We compared germination success (percentage of seeds germinated) of defecated seeds, seeds collected from a pond surface, and seeds removed from shrubs. RESULTS: While four seed species were identified in fecal samples, seeds of S. amomum were the most frequent (93%) among samples and the most numerous (106 seeds) in any sample. Average proportion of fecal seeds germinated (85.99%) exceeded that of seeds from the pond surface (82.76%) and from shrubs (60.24%), albeit the difference in germination success was insignificant. When analyzed using fecal samples from painted turtles only, the difference in germination success between fecal seeds and those collected from pond or shrub became significant. CONCLUSIONS: Our findings represent the first report of S. amomum seeds being dispersed by turtle gut passage and suggest aquatic turtles could be an important part of a secondary seed dispersal process influencing woody plant community composition in temperate wetland ecosystems.

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Land use change obviously changes the plant community composition and soil properties of grasslands and thus affects multiple functions and services of grassland ecosystems. However, the response mechanisms of soil microorganisms, key drivers of the nutrient cycle and other soil functions during changes in grassland use type and associated vegetation are not well understood. In this study, Illumina high-throughput sequencing was used to analyze the changes in the soil microbial community structure of four grassland use types: exclosure (EL), mowed land (ML), grazed land (GL), and farmland (FL) in the Songnen Plain of Northeast China. The results showed that the FL and EL had significantly higher soil total nitrogen (TN) and lower soil electrical conductivity (EC) and pH than GL and ML. In contrast, the GL and ML had higher soil bulk density (BD) and organic matter, respectively, than the other land use types. In addition, the values of the Shannon diversity and Pielou's evenness indexes were highest in the EL of all the land use types. Based on the high-throughput sequencing results, we observed high levels of α diversity in the FL for both bacteria and fungi. A structural equation model (SEM) revealed that pH and EC had a direct and positive effect on the bacterial community structure and composition. In addition, plant taxonomic diversity (according to the Shannon diversity and Pielou's evenness indexes) indirectly affected the bacterial community composition via soil pH and EC. Notably, fungal composition was directly and positively correlated with soil nutrients and the value of Pielou's evenness index changed with land use type. In conclusion, soil properties and/or plant diversity might drive the changes in the soil microbial community structure and composition in different grassland use types.

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Climate changes and anthropogenic nutrient enrichment widely threaten plant diversity and ecosystem functions. Understanding the mechanisms governing plant species turnover across nutrient gradients is crucial to developing successful management and restoration strategies. We tested whether and how soil microbes, particularly arbuscular mycorrhizal fungi (AMF), could mediate plant community response to a 15 years long-term N (0, 4, 8, and 16 g N m-2  year-1 ) and P (0 and 8 g N m-2  year-1 ) enrichment in a grassland system. We found N and P enrichment resulted in plant community diversity decrease and composition change, in which perennial C4  graminoids were dramatically reduced while annuals and perennial forbs increased. Metabarcoding analysis of soil fungal community showed that N and P changed fungal diversity and composition, of which only a cluster of AMF identified by the co-occurrence networks analysis was highly sensitive to P treatments and was negatively correlated with shifts in percentage cover of perennial C4  graminoids. Moreover, by estimating the mycorrhizal responsiveness (MR) of 41 plant species in the field experiment from 264 independent tests, we found that the community weighted mean MR of the plant community was substantially reduced with nutrient enrichment and was positively correlated with C4  graminoids percentage cover. Both analyses of covariance and structural equation modeling indicated that the shift in MR rather than AMF composition change was the primary predictor of the decline in perennial C4  graminoids, suggesting that the energy cost invested by C4 plants on those sensitive AMF might drive the inferior competitive abilities compared with other groups. Our results suggest that shifts in the competitive ability of mycorrhizal responsive plants can drive plant community change to anthropogenic eutrophication, suggesting a functional benefit of mycorrhizal mutualism in ecological restoration following climatic or anthropogenic degradation of soil communities.

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Nonnative European earthworms are invading hardwood forests of the Chippewa National Forest, MN. While effects on plant communities at the leading edge of invasion have been studied, little is known about longer-term effects of invasive earthworms. We applied a model using historic O-horizon soil thickness and a chronosequence approach to classify 41 hardwood sites in the Chippewa National Forest as "long-term wormed" (wormed >2 decades), "short-term wormed" or "unwormed/lightly wormed." Graminoids, especially Carex pensylvanica, had the greatest mean percent cover in sites that had been wormed for over two decades. The families with the greatest negative change in mean percent cover after over two decades of earthworm invasion were Asteraceae, Violaceae, and Sapindaceae (specifically Acer species). Across all diversity metrics measured, long-term wormed sites had the lowest understory plant species diversity, short-term wormed sites had intermediate diversity, and unwormed/lightly wormed sites exhibited the highest diversity. Long-term wormed sites had the lowest mean species richness across all sample scales (1-1024 m2). The greatest within-group compositional dissimilarity occurred at sites that had been wormed for over two decades, suggesting that sites that had been wormed for over two decades have not reached a compositionally similar end-state "wormed" community type. Our study suggests that understory diversity will decrease as hardwood forest stands become wormed over time. While our results support other findings that exotic earthworm invasion is associated with lower understory plant diversity in hardwood forests, our study was the first to use space-for-time substitution to document the effects after multiple decades of earthworm invasion.

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Introduction: Human concerns about fossil fuel depletion, energy security and environmental degradation have driven the rapid development of solar photovoltaic (PV) power generation. Most of the photovoltaic power generation plants are concentrated in desert, grassland and arable land, which means the change of land use type. However, there is still a gap in the research of the PV panel layout on grassland plant species diversity and ecological function. Methods: In this study, Illumina high-throughput sequencing technology was used to investigate the effects of PV panel arrangement on grassland plant species diversity and soil microbial diversity. In view of the differences in the microclimate at different sites of the PV panels, quadrates were arranged in front edge (FE), beneath the center of each panel (BP), back edge (BE), the uncovered interspace adjacent to each panel (IS) and the undisturbed grassland around the PV panels (Control), respectively. Results: PV panels (especially FE) significantly increased the total aboveground productivity (total AGB) and plant species diversity in grasslands. FE increased precipitation accumulation and plant species diversity directly and indirectly changed the diversity of soil bacterial and fungal communities. PV panels decreased the relative abundance of Actinobacteriota, while increased the relative abundance of Proteobacteria, Acidobacteriota, and Methylomirabilota. EC, Margalef' s richness and total AGB were the main factors affecting the composition of bacterial communities, while alkaline hydrolysis nitrogen (AN) and available phosphorus (AP) were the main factors affecting the composition of fungal communities. Discussion: In conclusion, the arrangement of PV panels increased the plant species diversity and soil microorganisms in grassland. This study provides important information for further understanding the impact of PV panels on grassland ecosystem function and is of great significance for maintaining grassland ecosystem function.

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While the effect of drought on plant communities and their associated ecosystem functions is well studied, little research has considered how responses are modified by soil depth and depth heterogeneity. We conducted a mesocosm study comprising shallow and deep soils, and variable and uniform soil depths, and two levels of plant community composition, and exposed them to a simulated drought to test for interactive effects of these treatments on the resilience of carbon dioxide fluxes, plant functional traits, and soil chemical properties. We tested the hypotheses that: (a) shallow and variable depth soils lead to increased resistance and resilience of ecosystem functions to drought due to more exploitative plant trait strategies; (b) plant communities associated with intensively managed high fertility soils, will have more exploitative root traits than extensively managed, lower fertility plant communities. These traits will be associated with higher resistance and resilience to drought and may interact with soil depth and depth heterogeneity to amplify the effects on ecosystem functions. Our results showed that while there were strong soil depth/heterogeneity effects on plant-driven carbon fluxes, it did not affect resistance or resilience to drought, and there were no treatment effects on plant-available carbon or nitrogen. We did observe a significant increase in exploitative root traits in shallow and variable soils relative to deep and uniform, which may have resulted in a compensation effect which led to the similar drought responses. Plant community compositions representative of intensive management were more drought resilient than more diverse "extensive" communities irrespective of soil depth or soil depth heterogeneity. In intensively managed plant communities, root traits were more representative of exploitative strategies. Taken together, our results suggest that reorganization of root traits in response to soil depth could buffer drought effects on ecosystem functions.

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Increased nitrogen (N) deposition threatens global biodiversity, but its effects in arid urban ecosystems are not well studied. In addition to altered N availability, urban environments also experience increases in other pollutants, decreased population connectivity, and altered biotic interactions, which can further impact biodiversity. In deserts, annual plant communities make up most of the plant diversity, support wildlife, and contribute to nutrient cycling and ecosystem processes. Functional tradeoffs allowing coexistence of a diversity of annual plant species are well established, but maintenance of diversity in urban conditions and with increased availability of limiting nutrients has not been explored. We conducted a 13-year N and phosphorus (P) addition experiment in Sonoran Desert preserves in and around Phoenix, AZ, to test how nutrient availability interacts with growing season precipitation, urban location, and microhabitat to affect winter annual plant diversity. Using structural equation modeling and generalized linear mixed modeling, we found that annual plant taxonomic diversity was significantly reduced in N-enriched and urban plots. Water availability in both current and previous growing seasons impacted annual plant diversity, with significant interaction effects showing increased diversity in wetter years and greater responsiveness of the community to water following a wet year. However, there were no significant interactions between N enrichment and water availability, urban location, or microhabitat. Lowered diversity in urban preserves may be partly attributable to increased urban N deposition. Changes in biodiversity of showy species like annual wildflowers in urban preserves can have important implications for connections between urban residents and nature, and reduced diversity and community restructuring with N enrichment represents a challenge for future preservation of aridland biodiversity.

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Heavy metal pollution is widespread, and has an increasing trend in some countries and regions. It can be easily accumulated in plants, leading to plant species loss and affecting plant community composition. Artificial restoration can conserve plant diversity in contaminated soils and accelerate the recovery of polluted ecosystems. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can increase the resistance of plants to adversity and promote the growth of plants in heavy metal polluted soils. In order to examine the effect of N and P nutrition on the conservation of plant community, we conducted a comparison experiment in greenhouse using soil with low N and P concentration, and set five treatments: C (soil with no heavy metals and fertilizer addition), H (soil with heavy metals addition but with no fertilizer), HN (soil with heavy metals and N addition), HP treatment(soil with heavy metals and P addition), HNP treatment (soil with heavy metals, N and P addition). Our results showed that heavy metal pollution reduced plant species by 300%, and significantly decreased plant diversity (P < 0.05). N addition increased the richness of plant species and increased the dominance of Euphorbia peplus, but had no significant effect on plant diversity and community structure, while reduced the evenness of plant species. P addition of HP and HNP treatments restored plant species richness and increased plant diversity under heavy metal pollution. The plant community structures of these two treatments were more similar to that of group C. Compared with N addition, P addition had a better performance to restoring the species composition and relative dominance of plant communities. Our results provided a guidance for the restoration of plant communities and the conservation of plant species in low N and P concentration soils with the context of heavy metal pollution.

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Heather (Calluna vulgaris) and broom (Cytisus scoparius), originally from Europe, are the main invasive plants on New Zealand's North Island Central Plateau, where they threaten native flora and fauna. Given the strong link between arthropod communities and plants, we explored the impact of these invasive weeds on the diversity and composition of associated arthropod assemblages in this area. The arthropods in heather-invaded areas, broom-invaded areas, and areas dominated by the native species manuka (Leptospermum scoparium) and Dracohyllum (Dracophyllum subulatum) were collected and identified to order. During summer and autumn, arthropods were collected using beating trays, flight intercept traps and pitfall traps. Diversity indices (Richness, Shannon's index and Simpson's index) were calculated at the order level, and permutational multivariate analysis (PERMANOVA) was used to explore differences in order-level community composition. Our results show a significant variation in community composition for all trapping methods in both seasons, whereas invasive plants did not profoundly impact arthropod order richness. The presence of broom increased arthropod abundance, while heather was linked to a reduction. Under all possible plant pairings between heather, broom, manuka, and Dracophylum, the impact of neighbouring plant identity on arthropod community composition was further explored for the samples collected using beating trays. The results suggest that during plant invasion, arthropod communities are affected by neighbouring plant identity and that impacts vary between arthropod sampling methods and seasons.

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Predicting how shifts in plant phenology affect species dominance remains challenging, because plant phenology and species dominance have been largely investigated independently. Moreover, most phenological research has primarily focused on phenological firsts (leaf-out and first flower dates), leading to a lack of representation of phenological lasts (leaf senescence and last flower) and full phenological periods (growing season length and flower duration). Here, we simultaneously investigated the effects of experimental warming on different phenological events of various species and species dominance in an alpine meadow on the Tibetan Plateau. Warming significantly advanced phenological firsts for most species but had variable effects on phenological lasts. As a result, warming tended to extend species' full phenological periods, although this trend was not significant for all species. Experimental warming reduced community evenness and differentially impacted species dominance. Shifts in full phenological periods, rather than a single shift in phenological firsts or phenological lasts, were associated with changes in species dominance. Species with lengthened full phenological periods under warming increased their dominance. Our results advance the understanding of how altered species-specific phenophases relate to changes in community structure in response to climate change.

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Nitrogen (N) deposition is a major threat to biodiversity in many habitats. The recent introduction of cleaner technologies in Switzerland has led to a reduction in the emissions of nitrogen oxides, with a consequent decrease in N deposition. We examined different drivers of plant community change, that is, N deposition, climate warming, and land-use change, in Swiss mountain hay meadows, using data from the Swiss biodiversity monitoring program. We compared indicator values of species that disappeared from or colonized a site (species turnover) with the indicator values of randomly chosen species from the same site. While oligotrophic plant species were more likely to colonize, compared to random expectation, we found only weak shifts in plant community composition. In particular, the average nutrient value of plant communities remained stable over time (2003-2017). We found the largest deviations from random expectation in the nutrient values of colonizing species, suggesting that N deposition or other factors that change the nutrient content of soils were important drivers of the species composition change over the last 15 years in Swiss mountain hay meadows. In addition, we observed an overall replacement of species with lower indicator values for temperature with species with higher values. Apparently, the community effects of the replacement of eutrophic species with oligotrophic species was outweighed by climate warming. Our results add to the increasing evidence that plant communities in changing environments may be relatively stable regarding average species richness or average indicator values, but that this apparent stability is often accompanied by a marked turnover of species.