Journal of Vegetation Science最新文献

{"title":"How does the taxonomic and functional structure of plant communities differ between riverine and palustrine swamps?","authors":"Philippe Janssen,&nbsp;Laurie Bisson-Gauthier,&nbsp;Eduardo González-Sargas,&nbsp;Audréanne Loiselle,&nbsp;Marcel Darveau,&nbsp;Bérenger Bourgeois,&nbsp;Monique Poulin","doi":"10.1111/jvs.13319","DOIUrl":"https://doi.org/10.1111/jvs.13319","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Questions</h3>\u0000 \u0000 <p>How does the type of swamp, that is, riverine vs palustrine, shape understorey and overstorey plant communities? Beyond swamp type, how do spatial, topographic, soil and landscape characteristics determine the taxonomic and functional structure of swamp communities?</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Location</h3>\u0000 \u0000 <p>Southern Québec, Canada.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We sampled riverine and palustrine swamp plant communities in two watersheds within two ecoregions with contrasting land use. At the site scale (<i>n</i> = 56), we analyzed differences between riverine and palustrine swamps in plant richness and cover, species composition, and mean and dispersion values for ecological and morphological traits. At the plot scale (<i>n</i> = 213), we assessed the relative influence of a set of environmental parameters on species richness and cover, as well as on trait values using mixed models and on species composition using redundancy analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Species composition and the mean value of traits varied significantly between the two types of swamps. While riverine swamps hosted more non-native species and were composed of more mesophilic species, shorter in height and with dominant resource acquisition strategies, palustrine swamps sheltered more non-vascular taxa and tall hygrophilous vascular species with more conservative resource strategies. The surrounding landscape and local microtopography within swamps had a significant effect on plant community structure. Species diversity and trait dispersion increased from agricultural-dominated to forest-dominated landscapes, and from homogeneous to heterogeneous substrates.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Habitats provided by riverine and palustrine swamps are complementary for wetland biodiversity. Our results underline the need to develop conservation plans to protect a wide variety of freshwater swamp types; for example, management actions that maintain or promote heterogeneous topographic forms at the site scale, and continuity of forest cover at the landscape scale.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 6","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patterns of local plant diversity and community saturation in deciduous forests in Europe","authors":"Jolina Paulssen,&nbsp;Jörg Brunet,&nbsp;Sara A. O. Cousins,&nbsp;Guillaume Decocq,&nbsp;Pieter De Frenne,&nbsp;Pallieter De Smedt,&nbsp;Per-Ola Hedwall,&nbsp;Jonathan Lenoir,&nbsp;Jaan Liira,&nbsp;Jessica Lindgren,&nbsp;Tobias Naaf,&nbsp;Taavi Paal,&nbsp;Alicia Valdés,&nbsp;Kris Verheyen,&nbsp;Monika Wulf,&nbsp;Martin Diekmann","doi":"10.1111/jvs.13318","DOIUrl":"https://doi.org/10.1111/jvs.13318","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Questions</h3>\u0000 \u0000 <p>How do local forest conditions and characteristics at the forest patch - scale and landscape - scale affect plot-scale plant diversity in Europe? Do these patterns vary between forest specialists and generalists? Do community saturation patterns differ between forests varying in their surrounding landscape type?</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Location</h3>\u0000 \u0000 <p>Deciduous forests sampled along a European gradient from southwest to northeast comprising eight regions in five countries (France, Belgium, Germany, Sweden, Estonia).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We examined the effects of local conditions assessed by means of Ellenberg indicator values (soil moisture, soil nitrogen, soil pH, light availability), patch-scale characteristics (patch-scale plant diversity, forest patch age, forest patch size) and a landscape-scale variable (representing low and high connectivity of forest patches) on plot-scale plant diversity, separately for forest specialist and generalist species. Additionally, we ran regression models to examine community saturation patterns.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found patterns of niche partitioning among forest specialists and generalists. Low light availability and medium soil moisture favored forest specialists, while generalists were mostly present at higher light availability and medium and high soil moisture. In general, we found the highest plot-scale diversity at medium soil pH. Patch-scale diversity showed a positive impact on plot-scale diversity and plots in the high-connectivity landscape had a higher diversity than plots in the low-connectivity landscape. Further, we observed a high degree of community saturation in both landscape types.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The positive impact of a high connectivity of forest patches on local plant diversity emphasizes the importance of small semi-natural habitats like tree lines, unused field margins and hedgerows to enhance the potential dispersal of forest plants across agricultural landscapes. Community saturation patterns revealed the increasing relevance of local conditions and processes for plot-scale diversity when patch-scale diversity increases.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 6","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvs.13318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid declines in species diversity and occurrence of common plant species are related to nutrient availability and soil moisture in open habitats","authors":"Maxime Buron,&nbsp;Emmanuelle Porcher,&nbsp;Eric Fédoroff,&nbsp;Luc Berrod,&nbsp;Jeanne Vallet,&nbsp;Olivier Bardet,&nbsp;Gabrielle Martin,&nbsp;Nathalie Machon","doi":"10.1111/jvs.13316","DOIUrl":"https://doi.org/10.1111/jvs.13316","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>Environmental changes in Europe influence plant community composition, but the literature quantifying these changes often shows inconsistent trends, due mostly to heterogeneous survey methods. Here, we investigated temporal changes in plants over 12 years at the species and community level at a regional scale, using a standardized, plot-based monitoring scheme.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Location</h3>\u0000 \u0000 <p>Data originated from 1,389 permanent plots of a standardized monitoring scheme targeting plant communities. Plots were distributed in the Burgundy region (France), initially grouped into 175 (2 km × 2 km) grid cells containing eight 10-m² plots each, that were surveyed in at least 2 years between 2009 and 2020.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We characterized changes in vascular plants in 10-m² plots by examining the temporal changes in the probability of occurrence of common species, changes in species diversity using species richness, Shannon–Wiener and Pielou's indices and changes in abundance-weighted mean community ecological preferences using Ellenberg indicator values.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Across 198 common species, probability of occurrence in the region has shown a decline since 2009. This decline is associated with a general decrease by 13% of both species richness and the Shannon index between 2009 and 2020. This trend was stronger in annual crops and grasslands, whereas forest diversity remained relatively constant over time. Pielou's index diminished on average, except in natural forests. Mean community Ellenberg indicator values suggested slight changes in plant community composition, with an increasing preference for nutrient-poor soils and Atlantic conditions over time.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The observed biodiversity loss in the Burgundy region is consistent with a widespread shift in community composition in response to environmental change. Existing conservation measures do not seem to compensate for the average losses, indicating that these measures are still inadequate to protect plant communities. Our approach also emphasizes the speed at which plant communities are changing and thus the need for better monitoring of the European flora.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 6","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three decades of understorey vegetation change in Quercus-dominated forests as a result of increasing canopy mortality and global change symptoms","authors":"Janez Kermavnar,&nbsp;Lado Kutnar","doi":"10.1111/jvs.13317","DOIUrl":"https://doi.org/10.1111/jvs.13317","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Questions</h3>\u0000 \u0000 <p>The long-term response of understorey vegetation to increasing tree mortality has rarely been addressed in resurvey studies. For two <i>Quercus</i>-dominated forest types, we asked: (a) How did overstorey alterations, induced by canopy mortality, affect understorey diversity and composition? (b) Is there a signal of global change effects on understorey communities? (c) Are these assemblages experiencing a homogenization process?</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Location</h3>\u0000 \u0000 <p>Five sites in <i>Quercus robur</i> (QR) and four sites in <i>Q. petraea</i> (QP) forests, Slovenia.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We studied changes in vascular plants in the understorey layer from 1992/1993 to 2023 across 45 permanent 20 m × 20 m plots in QR and QP forests, respectively. Vegetation surveys were carried out following the standard Braun-Blanquet method. We compared original surveys with recent resurveys using multivariate analysis, ecological indicator values (EIV), plant traits and methods that quantify changes in individual species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Since the early 1990s, tree layer cover decreased from 95% to an average of 55% in QR, whereas it remained relatively high (77%) in QP plots. This resulted in denser understorey vegetation and a significant increase in plot-level species richness in QR forests, but a slight decrease in QP forests. The extensive loss of canopy cover and disturbance effects in QR forests caused significant changes in species composition. Species turnover in QR was driven by colonization of new disturbance-tolerant taxa characterized by ruderal traits, whereas the compositional shift in QP was to a greater extent due to species losses. We detected a process of vegetation thermophilization (increase in EIV-temperature), suggesting an effect of rapid climatic warming. Understorey communities are now more similar to each other than 30 years ago, indicating a decrease in beta-diversity (floristic homogenization).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Despite some common trends, vegetation responses were forest type-specific. Our study presents evidence of understorey vegetation changes triggered by increased canopy mortality (a strong local driver particularly in QR plots) and also points to the signal of global change symptoms (thermophilization, homogenization), which acted rather independently from the observed decline in tree layer cover.</","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 6","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvs.13317","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"You shall know a species by the company it keeps: Leveraging co-occurrence data to improve ecological prediction","authors":"Andrew Siefert,&nbsp;Daniel C. Laughlin,&nbsp;Francesco Maria Sabatini","doi":"10.1111/jvs.13314","DOIUrl":"https://doi.org/10.1111/jvs.13314","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Aim</h3>\u0000 \u0000 <p>Making predictions about species, including how they respond to environmental change, is a central challenge for ecologists. Because of the huge number of species, ecologists seek generalizations based on species’ traits and phylogenetic relationships, but the predictive power of trait-based and phylogenetic models is often low. Species co-occurrence patterns may contain additional information about species’ ecological attributes not captured by traits or phylogenies. We propose using a novel ordination technique to encode the information contained in species co-occurrence data in low-dimensional vectors that can be used to represent species in ecological prediction.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>We present an efficient method to derive species vectors from co-occurrence data using Global Vectors for Word Representation (GloVe), an unsupervised learning algorithm originally designed for language modelling. To demonstrate the method, we used GloVe to generate vectors for nearly 40,000 plant species using co-occurrence statistics derived from sPlotOpen, an open-access global vegetation plot database, and tested their ability to predict elevational range shifts in European montane plant species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Co-occurrence-based species vectors were weakly correlated with traits or phylogeny, indicating that they encode unique information about species. Models including co-occurrence-based vectors explained twice as much variation in species range shifts as models including only traits or phylogenetic information.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Given the widespread availability of species occurrence data, species vectors learned from co-occurrence patterns are a widely applicable and powerful tool for encoding ecological information about species, with many potential applications for describing and predicting the ecology of species, communities and ecosystems.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 6","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvs.13314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of biological and environmental filtering on the community assembly of two grasslands in southern Mexico","authors":"Emiliano Romero-Rodríguez,&nbsp;Carlos Martorell,&nbsp;Diego García-Meza","doi":"10.1111/jvs.13315","DOIUrl":"https://doi.org/10.1111/jvs.13315","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Questions</h3>\u0000 \u0000 <p>Community assembly is envisaged as filters that preclude some species in the regional pool from invading local communities. We tested whether the large floristic differences between adjacent calcicole and calcifuge grasslands are explained by either of five filters: environment (soil) or positive or negative interactions with plants and with soil biota.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Location</h3>\u0000 \u0000 <p>Southern Mexico.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We conducted a reciprocal-transplant experiment with 20 species that were introduced to both habitats under three conditions: intact local community, without plants, and in sterilized plots. Each of the five filters mentioned above predict unique patterns in the performance (survival and growth) of plants in the six treatments. Thus, we used multimodel inference to determine which filters (patterns) were consistent with the evidence.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We detected at least one filter operating on all but four species. Survival data showed frequent support for environmental filtering, with interactions (mostly positive) playing a secondary role; however negative interactions became as frequent as environmental filtering when growth was considered.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The large physicochemical differences between the soils of both grasslands explain the high frequency of environmental filtering. Soils differed in nutrient availability, but also had toxic concentrations of different elements. Survival was strongly influenced by early mortality, while size was measured at the end of the experiment. It is thus likely that the differences between analyses based on survival and size reflect an ontogenetic change from positive to negative interactions. Other plants frequently facilitate seedlings, but this interaction often turns competitive over time. Soil mutualists provide nutrients that seedlings cannot access, but antagonists build up in the rhizosphere as plants age. Unlike studies that infer filters from extant plants in communities or from successful invasions, our approach provides direct evidence on which filters cause species to be absent from communities.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 6","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The need for a strict delimitation of early tree life stages in vegetation ecology","authors":"Ricard Arasa-Gisbert,&nbsp;Víctor Arroyo-Rodríguez,&nbsp;Martín de Jesús Cervantes-López,&nbsp;Jorge A. Meave","doi":"10.1111/jvs.13313","DOIUrl":"https://doi.org/10.1111/jvs.13313","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Aim</h3>\u0000 \u0000 <p>For practical and theoretical purposes, ecological studies commonly classify trees into five major life-cycle stages: seed, seedling, sapling, juvenile and adult. Whereas the seed and adult stages are usually accurately delimited across studies, there are discrepancies and ambiguity in the categorization of seedlings, saplings and juveniles, which can significantly affect the conclusions of community ecology studies. Here we propose a standardized set of criteria intended for community-level research for delimiting these three stages based on biological and ecological rationales.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We assessed the relevance of such standardization by conducting a meta-analysis of the effects of two human-caused disturbances (defaunation and logging) on each early tree life stage and examining differences in effect sizes and confidence intervals among: (1) studies that match our delimitation criteria, (2) studies that do not match these criteria, and (3) all studies grouped together regardless of the criteria they used.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found stronger effects with narrower confidence intervals when considering only the studies that matched our standardized delimitation criteria. In fact, the proportion of significant effects was between 1.7 (defaunation) and 5.4 (logging) times higher in studies matching our delimitation criteria than in studies that do not match them, probably because confidence intervals were 2.3–3.1 times smaller in the former group than in the latter. For logging studies, the direction of the effects changed in 30%–50% of the cases when comparing the results from all data and studies not matching our criteria with the results of the studies matching our criteria, always from non-significant to significant effects.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These findings underscore the need for an ecologically meaningful categorization of early tree life stages based on standardized measures to increase the confidence, accuracy, reproducibility and generalization in plant biology and community ecological research. Synthesis efforts will particularly benefit from this standardized protocol.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 5","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation in CSR plant strategies along soil and climate gradients: A comparison between rocky outcrops and nearby rangelands","authors":"Fahime Rafiee,&nbsp;Hamid Ejtehadi,&nbsp;Mohammad Farzam,&nbsp;Maryam Behroozian","doi":"10.1111/jvs.13311","DOIUrl":"https://doi.org/10.1111/jvs.13311","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Question</h3>\u0000 \u0000 <p>Rocky outcrops in mountains represent unique ecosystems characterized by a series of stress-inducing features on living organisms. Despite numerous studies focusing on plant diversity and species community composition in these ecosystems, less attention has been given to understanding plant strategies in response to their challenging environment. This is essential, especially considering the existence of numerous endemic species facing climate change and human disturbances.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Location</h3>\u0000 \u0000 <p>The study was conducted in six sites located in rocky outcrops and their nearby rangelands across a rainfall gradient (160–910 mm) and under different soil fertility levels in northern Iran.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used competitor, stress tolerator and ruderal (CSR) strategies as functional groups to examine the responses of plant communities to environmental variation. The composition of plant species and functional traits were evaluated in ninety 1-m² plots. The influence of 10 soil and 5 bioclimatic factors on CSR plant strategies was examined along the rainfall gradient.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our results showed changes in CSR strategies from stress-tolerant species (S) in rocky outcrops toward intermediate strategies (S/CSR) in rangelands. Soil organic carbon, electrical conductivity and sand were consistently correlated with shifts from S towards C and R strategies in rangelands. Silt and sodium (Na) affected the presence of S strategies in outcrops. The stressful conditions induced by a fine soil texture and Na in outcrops were particularly effective in establishing the dominance of the S strategy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We identified patterns of shifts in CSR plant strategies that align with changes in environmental gradients. Although stress-tolerant species (S) were the dominant strategy in most cases, this shifted towards intermediate strategies (SR and CSR) under more benign environmental conditions. In outcrops, these changes were primarily aligned with soil parameters, whereas in rangelands, both soil and climate variables were correlative. However, these correlations varied between soil and climate factors, as well as between outcrop and rangeland landscapes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 5","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142451153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding post-fire vegetation recovery in southern California ecosystems with the aid of pre-fire observations from long-term monitoring","authors":"Xinyu Li,&nbsp;Sarah Kimball,&nbsp;Priscilla Ta,&nbsp;Katharina T. Schmidt,&nbsp;Diane R. Campbell","doi":"10.1111/jvs.13308","DOIUrl":"https://doi.org/10.1111/jvs.13308","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>Post-fire vegetation recovery is often determined by the similarity of post-burn with unburned sites because of a lack of in situ information on pre-fire communities. The inclusion of pre-fire data can help account for pre-existing differences and explore recovery also in terms of return to pre-fire conditions. We used long-term monitoring data in coastal sage scrub and grasslands to: (a) examine vegetation cover recovery of different functional groups; and (b) determine whether vegetation composition in burned areas has recovered in 4 years after fire with burned to unburned and pre- to post-fire comparisons.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Location</h3>\u0000 \u0000 <p>Orange County, California, USA.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We analyzed long-term vegetation monitoring (2007–2021) data from 39 grassland and 58 coastal sage scrub transects in southern California, including observations before and after the 2017 Canyon 2 fire. Linear mixed-effect models were used to determine whether forb, grass, and shrub covers differed between burned and unburned sites while considering the effects of year and repeated monitoring. We used canonical analysis of principal coordinates to analyze vegetation composition based on burn status and time of sampling.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Whereas vegetation cover in grassland recovered quickly, native vegetation cover in burned coastal sage scrub remained lowered 4 years after fire, though forb and non-native grass cover were higher in some post-fire years. Community composition in burned coastal sage scrub was still in recovery 4 years after fire when compared with unburned or pre-fire composition. Although burned and unburned grassland differed after fire in dominant grass species, inclusion of pre-fire data showed that this was a pre-existing difference.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Coastal sage scrub had not recovered pre-fire vegetation cover and composition by 4 years after fire, whereas grassland cover rebounded quickly, albeit with shifts in composition over time; patterns that were detected only by having pre- and post-fire data from long-term monitoring efforts.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 5","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvs.13308","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative evaluation of internal cluster validation indices using binary data sets","authors":"Naghmeh Pakgohar,&nbsp;Attila Lengyel,&nbsp;Zoltán Botta-Dukát","doi":"10.1111/jvs.13310","DOIUrl":"https://doi.org/10.1111/jvs.13310","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>Different clustering methods often classify the same data set differently. Selecting the “best” clustering solution from alternatives is possible with cluster validation indices. Because of the large variety of cluster validation indices (CVIs), choosing the most suitable index concerning the data set and clustering algorithms is challenging. We aim to assess different internal clustering validation indices.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Artificial binary data sets with equal- and unequal-sized well-separated a priori clusters were simulated and three levels of noise were then added. Twenty replications of each of the six types of data sets (two group sizes × three levels of noise) were created and analyzed by three clustering algorithms with Jaccard dissimilarity. Twenty-seven clustering validation indices are evaluated including both geometric and non-geometric indices.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Although, in theory, all CVIs could differentiate between good and wrong classifications, only a few perform as expected with noisy data. Tau and silhouette widths proved to be the best geometric CVIs both for equal and unequal cluster sizes. Among non-geometric indices, crispness and OptimClass performed best.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>We recommend using these best-performing CVIs. We suggest plotting the CVI value against the number of clusters because the lack of a sharp peak means that the position of the maximum is uncertain.</p>\u0000 </section>\u0000 </div>","PeriodicalId":49965,"journal":{"name":"Journal of Vegetation Science","volume":"35 5","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvs.13310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}