Influence des perturbations anthropiques historiques sur les patrons d'invasion de plantes et de vers de terre non-indigènes dans une forêt primaire tempérée (réserve naturelle Gault, Mont St-Hilaire)

De longs délais temporels peuvent exister entre les perturbations survenant à un site et les réponses des espèces de la communauté occupant ce site. Ces changements écosystémiques transitoires lents en comparaison d’une vie humaine peuvent être difficiles à détecter ou à comprendre sans la prise en compte du contexte temporel par l’utilisation de données historiques. C’est souvent le cas pour les processus d’invasion de plantes ou d’animaux non-indigènes dans les communautés forestières. Bien que les perturbations anthropiques soient reconnues pour faciliter les invasions dans ce type de communauté, des temps de latence importants peuvent tout de même survenir à chaque étape du processus. On peut donc penser que les patrons d’invasion d’un site représenteraient davantage les legs écologiques des perturbations plus anciennes que ceux des perturbations plus récentes. Ce mémoire vise à évaluer si l’on gagne à tenir compte de l’âge des perturbations pour expliquer les invasions biologiques établies dans les sites environnants. Pour vérifier cela, nous avons inventorié l’abondance et la composition des communautés de plantes et de vers de terre non-indigènes dans 85 parcelles dispersées dans l’ensemble de la Réserve Naturelle Gault. Suite à une reconstitution fouillée de l’historique des perturbations anthropiques, nous avons comparé le pouvoir explicatif des perturbations initiées avant 1910 avec celui des perturbations survenues après 1910. Nous avons aussi pris en compte les variables environnementales reconnues comme importantes. Les résultats suggèrent que dans les forêts de la Réserve Naturelle Gault, la présence et l’intensité des invasions de plantes et de vers de terre non-indigènes sont en premier lieu expliquées par la proximité aux perturbations anthropiques initiées il y a plus d’un siècle. Les conclusions de ce mémoire soulignent l’importance de l’utilisation d’une approche historique pour comprendre pleinement la durée des impacts écologiques des perturbations anthropiques quant à la facilitation des processus d’invasion biologique

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Publisher Copyright: © 2021, The Author(s).Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.Peer reviewe

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

Influence des perturbations anthropiques historiques sur les patrons d'invasion de plantes et de vers de terre non-indigènes dans une forêt primaire tempérée (réserve naturelle Gault, Mont St-Hilaire)

De longs délais temporels peuvent exister entre les perturbations survenant à un site et les réponses des espèces de la communauté occupant ce site. Ces changements écosystémiques transitoires lents en comparaison d’une vie humaine peuvent être difficiles à détecter ou à comprendre sans la prise en compte du contexte temporel par l’utilisation de données historiques. C’est souvent le cas pour les processus d’invasion de plantes ou d’animaux non-indigènes dans les communautés forestières. Bien que les perturbations anthropiques soient reconnues pour faciliter les invasions dans ce type de communauté, des temps de latence importants peuvent tout de même survenir à chaque étape du processus. On peut donc penser que les patrons d’invasion d’un site représenteraient davantage les legs écologiques des perturbations plus anciennes que ceux des perturbations plus récentes. Ce mémoire vise à évaluer si l’on gagne à tenir compte de l’âge des perturbations pour expliquer les invasions biologiques établies dans les sites environnants. Pour vérifier cela, nous avons inventorié l’abondance et la composition des communautés de plantes et de vers de terre non-indigènes dans 85 parcelles dispersées dans l’ensemble de la Réserve Naturelle Gault. Suite à une reconstitution fouillée de l’historique des perturbations anthropiques, nous avons comparé le pouvoir explicatif des perturbations initiées avant 1910 avec celui des perturbations survenues après 1910. Nous avons aussi pris en compte les variables environnementales reconnues comme importantes. Les résultats suggèrent que dans les forêts de la Réserve Naturelle Gault, la présence et l’intensité des invasions de plantes et de vers de terre non-indigènes sont en premier lieu expliquées par la proximité aux perturbations anthropiques initiées il y a plus d’un siècle. Les conclusions de ce mémoire soulignent l’importance de l’utilisation d’une approche historique pour comprendre pleinement la durée des impacts écologiques des perturbations anthropiques quant à la facilitation des processus d’invasion biologique

Mathieu Beauséjour : La révolte de l'imagination = The Revolt of the Imagination

"The Revolt of the Imagination is a bilingual monograph presented in the retrospective exhibition of the same name presented at the Regional museum of Rimouski for the 17th of June Septembre 2014 and at L'EXPRESSION, the exhibition centre of Saint-Hyacinthe from the 14th of February to the 19th of April 2015. For this exhibition, Andréanne Roy acted as curator." - Publisher's website

Global meta-analysis reveals no net change in local-scale plant biodiversity over time

Global biodiversity is in decline. This is of concern for aesthetic and ethical reasons, but possibly also for practical reasons, as suggested by experimental studies, mostly with plants, showing that biodiversity reductions in small study plots can lead to compromised ecosystem function. However, inferring that ecosystem functions will decline due to biodiversity loss in the real world rests on the untested assumption that such loss is actually occurring at these small scales in nature. Using a global database of 168 published studies and >16,000 nonexperimental, local-scale vegetation plots, we show that mean temporal change in species diversity over periods of 5–261 y is not different from zero, with increases at least as likely as declines over time. Sites influenced primarily by plant species’ invasions showed a tendency for declines in species richness, whereas sites undergoing postdisturbance succession showed increases in richness over time. Other distinctions among studies had little influence on temporal richness trends. Although maximizing diversity is likely important for maintaining ecosystem function in intensely managed systems such as restored grasslands or tree plantations, the clear lack of any general tendency for plant biodiversity to decline at small scales in nature directly contradicts the key assumption linking experimental results to ecosystem function as a motivation for biodiversity conservation in nature. How often real world changes in the diversity and composition of plant communities at the local scale cause ecosystem function to deteriorate, or actually to improve, remains unknown and is in critical need of further study

The Nature Conservancy

Global biodiversity is in decline. This is of concern for aesthetic and ethical reasons, but possibly also for practical reasons, as suggested by experimental studies, mostly with plants, showing that biodiversity reductions in small study plots can lead to compromised ecosystem function. However, inferring that ecosystem functions will decline due to biodiversity loss in the real world rests on the untested assumption that such loss is actually occurring at these small scales in nature. Using a global database of 168 published studies and >16,000 nonexperimental, local-scale vegetation plots, we show that mean temporal change in species diversity over periods of 5-261 y is not different from zero, with increases at least as likely as declines over time. Sites influenced primarily by plant species' invasions showed a tendency for declines in species richness, whereas sites undergoing postdisturbance succession showed increases in richness over time. Other distinctions among studies had little influence on temporal richness trends. Although maximizing diversity is likely important for maintaining ecosystem function in intensely managed systems such as restored grasslands or tree plantations, the clear lack of any general tendency for plant biodiversity to decline at small scales in nature directly contradicts the key assumption linking experimental results to ecosystem function as a motivation for biodiversity conservation in nature. How often real world changes in the diversity and composition of plant communities at the local scale cause ecosystem function to deteriorate, or actually to improve, remains unknown and is in critical need of further study. spatial scale | permanent plots | ecosystem services A huge number of experiments has investigated the effects of species diversity (typically the number of species) on ecosystem function in small study plots (≤400 m 2 ), with a general consensus emerging that processes such as primary productivity and nutrient uptake increase as a function of the number of species in a community (1-6). These experiments thus appear to provide a powerful motivation for biodiversity conservation, given that ecosystem functions underpin many ecosystem services from which people benefit, such as forage production and carbon sequestration (1). However, the link between diversityfunction experiments and the widespread argument that ecosystem function should motivate biodiversity conservation (7-11) hinges on the untested assumption that global biodiversity declines apply to the small scale (2). Experimental studies typically focus on small spatial scales not only for practical reasons, but also because organisms, plants in particular, typically interact over short distances (12), and so it is at the small scale that biodiversity is most likely to have an important impact on the functioning of ecosystems (13)(14)(15). Habitat loss, invasive species, and overexploitation, among other factors, have accelerated global species' extinction well beyond the background rate (16-18), and it is tempting to assume that a global decline in biodiversity is necessarily accompanied by declines at smaller spatial scales. However, this is not a logical inevitability because, unlike other key variables involved in global environmental change, biodiversity at large scales (often termed gamma diversity) is not an additive function of biodiversity at smaller scales (alpha diversity). If global temperature or atmospheric CO 2 concentrations, for example, are increasing at the global scale, the net change over time within local areas must, on average, be positive. However, because local species losses may be accompanied by immigration of species from elsewhere, decreases in biodiversity at the global scale do not necessarily result in any biodiversity change at smaller scales (16, 19, Results and Discussion We conducted a systematic global meta-analysis of plant species diversity change over time in >16,000 plots (median plot area = 44 m 2 ) from all major vegetation types ECOLOGY temporal changes in plant species richness was centered on zero ( We used the interpretations of the authors of the original papers to classify papers according to possible drivers of vegetation change. Recognizing the considerable uncertainty in such interpretations using observational data, we use these categories to explore the possibility of explaining some of the variation among studies, rather than to conduct strong tests of particular hypotheses. Consistent with intuition, marked increases in species richness over time were found in studies in which authors attributed vegetation change to succession following major disturbances such as fire, severe storms, or logging (Postfire and Postdisturbance in Temporal change in species richness was also independent of plot area, temporal duration, and the latitude and longitude of a given study It is important to note that our results do not pertain to species losses caused by human activities at the global scale, for which there is broad scientific consensus and which have justifiably prompted conservation actions based on the ethical, cultural, and instrumental values that people place on different species (16)(17)(18) Our species richness database represents >8,500 cumulative years of change (318 data sets × 27.4-y average time span), covering much of the globe and most of the 20th and early 21st centuries, a period both preceded and characterized by intense human impacts on the earth. Nonetheless, we clearly have an overrepresentation of studies in Europe and North America. Interestingly, the studies from outside Europe and North America show, if anything, a slight tendency toward increasing local-scale species richness When sufficiently profound ecosystem transformations occur, such as converting a forest to a suburban garden or replacing a prairie with a cornfield, we assume that any effect of a change in the number of species on ecosystem function will be negligible compared with the effects of other changes: soil perturbation, a wholesale change in the composition of species, the management regime itself, etc. (6). For example, 100-m 2 plots in European forests in our database contain 14-28 plant species (six studies), whereas a typical domestic garden of the same area in the United Kindom contains almost 100 species (29). Likewise, a monoculture of corn contains far fewer plant species than the prairie it replaced. We argue that such increases (forest-to-garden) or decreases (prairie-to-corn) in species richness per se are effectively irrelevant to understanding changes in ecosystem functions, such as productivity or nutrient cycling, brought about by ecosystem transformation. However, species losses or gains from a forest, grassland, or other ecosystem that otherwise remains untransformed may well have an impact on ecosystem function. As such, the approach in many vegetation resurvey studies of not resurveying areas now occupied by human developments (e.g., forests now covered with residential homes and gardens) If plant biodiversity is not generally declining at local spatial scales, what are the real world implications of small-scale biodiversity manipulation experiments? In some settings, such as forest management or grassland restoration, such experiments closely mimic realistic scenarios (4, 6, Finally, although plant species diversity shows no net directional change at the local scale, individual sites show tremendous variation in the direction and magnitude of biodiversity trends Tundra (7) Savanna/Shrubland ECOLOGY Methods We searched the literature for papers reporting temporal change in the species richness or diversity of plant communities using the following search criteria in SCOPUS on 11 July 2012: [TITLE-ABS-KEY("plant community" OR "plant communities" OR vegetation OR forest* OR grassland* OR wetland* OR desert* OR savanna* OR tundra* OR steppe* OR shrubland* OR prairie* OR taiga OR rainforest* OR woodland* OR mangrove*) AND TITLE-ABS-KEY (biodiversity OR diversity OR richness OR evenness OR composition) AND ALL (resurvey* OR resample* OR revisit* OR "temporal change")]. This search returned 5,247 papers, the titles of which were scanned to eliminate obviously irrelevant papers, resulting in a list of 627 candidate papers. Candidate papers were individually examined for data meeting the following criteria: (i) species richness, diversity, or change in richness/diversity, were reported for two or more points in time spanning at least 5 y; (ii) plots were either permanently marked or semipermanent, the latter indicating that resurveyed plots were located in approximately the same places as originally surveyed plots; (iii) plots were ≤5 ha for surveys of trees or ≤1 ha for all other surveys (the vast majority of plots in the analysis were ≤1,000 m 2 ); and (iv) plots were nonexperimental, in that any human influence was not implemented as part of the study itself; for experimental studies (e.g., nutrient addition, burning), data were recorded for control plots only (see further justification in SI Methods). We searched the reference lists of the initial 627 papers for additional papers potentially with appropriate data, resulting in a second list of 380 papers, which were examined in the same way. We carefully searched for redundancy (i.e., multiple papers reporting data for the same plots), and in such cases retained the paper with the largest sample size and/or the longest duration. Data meeting our criteria were found in 148 papers, comprising 168 studies and 346 data sets (see SI Methods for details and SI Text and Dataset S1 for the raw data). For all data sets, we recorded the number of plots, plot area, plot type (permanent or semipermanent), the first and last years of surveys, country, approximate latitude and longitude, habitat type (forest, grassland, shrubland, savanna/shrubland, wetland, desert, tundra, anthropogenic (e.g., urban), primary succession (postvolcano), many habitats), and the life form(s) surveyed (forb, graminoid, bryophyte, tree, shrub, woody, all). The "all" category for life forms (235/346 data sets) indicated that all plants were recorded, although there was often ambiguity about inclusion of, for example, bryophytes, which might be absent entirely, or tree seedlings in forest understory plots. Mean species richness values were summed across different groups of species in the same plots (e.g., forbs and graminoids, natives and exotics) when such data were presented separately in the original papers. In cases for which the authors of a paper identified a primary driver of temporal vegetation change (262/346 data sets), we used the classification shown in Species richness data were available for 155 studies comprising 318 data sets. For each data set, a raw effect size (ES) was calculated as the log ratio of mean species richness in the last (Y2) and first (Y1) years of surveys (most data sets included only two time points). ES quantifies proportional change between two groups (35), which is appropriate for quantification of temporal change using the initial state as a control and the end state as a treatment (36). The raw log ratio was standardized to a common decadal time scale (35), by dividing by the time interval (t, in decades) between Y1 and Y2: ES = t −1 log(SR Y2 /SR Y1 ). The decadal scale effect size was used in all analyses except to test for the relationship between effect size and study duration. Note that the core result in our paper is insensitive to the decadescale standardization. ES's were analyzed in two ways: (i) presented in the main text, a Bayesian analysis of a multilevel model, in which the nonindependence of multiple data sets within papers is considered explicitly, and in which variation in ES can be related to predictor variables (covariates); and (ii) in the SI Methods, a traditional fixed-effect meta-analysis with each study weighted by the square root of sample size. The same analyses were conducted with ES calculated using diversity or evenness indices except for the evaluation of predictor variables, which was omitted due to small sample size. All analyses were conducted in R version 2.15.2 and OpenBUGS via the R2OpenBUGS package. Additional details are provided in SI Methods. ACKNOWLEDGMENTS. We thank J. Chase, D. Sax, and two anonymous reviewers for input on an earlier draft of the paper. M.V.,

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Data collated from data provided by original data collectors or from data provided within published articles. The MetaData.csv provides information on each of the original data sources, including bibliographic information about the original article and information on how many sites were sampled. The SiteData.csv gives site-level variables, such as geographic coordinates, the environmental parameters as well as site-level community metrics (species richness, total abundance and total biomass). The SppOccData.csv provides the observation level data - the occurrence, abundance and/or biomass of individual species/morpho-species/life-stage at a particular site. Not every data source contained such observation level data. Metadata information about the variables in each file are provided in the files MetaData_info.csv, SiteData_info.csv and SppOccData_info.csv, respectively. All files provided use the character encoding UTF-8, and missing values are represented by "NA"

Global distribution of earthworm diversity

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, and biomass. We found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms. However, high species dissimilarity across tropical locations may cause diversity across the entirety of the tropics to be higher than elsewhere. Climate variables were found to be more important in shaping earthworm communities than soil properties or habitat cover. These findings suggest that climate change may have serious implications for earthworm communities and for the functions they provide