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Selection within natural communities has mainly been studied along large abiotic gradients, while the selection of individuals within populations should occur locally in response to biotic filters. To better leverage the role of the latter, we considered the hierarchal nature of environmental selection for the multiple dimensions of the trait space across biological levels, that is, from the species to the community and the ecosystem levels. We replicated a natural species richness gradient where communities included from two to 16 species within four wetlands (bog, fen, meadow, and marsh) contrasting in plant productivity. We sampled functional traits from individuals in each community and used hierarchical distributional modeling in order to analyze the independent variation of the mean and dispersion of functional trait space at ecosystem, community, and species levels. The plant productivity gradient observed between wetlands led to species turnover and selection of traits related to leaf nutrient conservation/acquisition strategy. Within wetlands, plant species richness drove trait variation across both communities and species. Among communities, variation of species richness correlated with the selection of individuals according to their use of vertical space and leaf adaptations to light conditions. Within species, intraspecific light‐related trait variation in response to species richness was associated with stable population density for some species, while others reached low population density in more diverse communities. Within ecosystems, variation in biotic conditions selects individuals along functional dimensions that are independent of those selected across ecosystems. Within‐species variations of light‐related traits are related to demographic responses, linking biotic selection of individuals within communities to eco‐evolutionary dynamics of species. [ABSTRACT FROM AUTHOR]

Questions: Plant greening phenology is a key response trait that drives numerous ecosystem functions such as carbon storage and flowering. Plant communities with a diversity of phenology responses could show a longer greening season due to more complete occupation of the temporal window available for growth. However, it is unclear how species composition and richness affect the phenology of local plant communities. Location: This study was conducted in wetland landscapes of the St. Lawrence River in the province of Québec, Canada (46.07°N; 73.17°W). Methods: We used close‐range digital imagery to monitor the greening phenology and species richness of 20 herbaceous plant communities from 2013 to 2016. We quantified the number of greening phenology patterns observed each year within each plant community using singular value decomposition of close‐range image time series. Results: The number of plant species within plant communities was independent of the number of phenology patterns, or the length of the greening season. However, the number of phenology patterns correlated positively to the greening season length in all four years of monitoring. Conclusions: The relationship between the number of phenology patterns and the greening season length suggests a complementary use of the temporal window available for growth within plant communities. Species richness was a poor indicator of the diversity of phenology responses in wet meadow communities. The absence of a positive relationship between the number of plant species and the diversity of greening phenology patterns, or the length of the greening season, suggests that other descriptors of plant communities are of importance. Species richness is more often than not a weak predictor of the functioning of local plant communities in the wild. [ABSTRACT FROM AUTHOR]

Ecological communities are unique assemblages of species that coexist in consequence of multi-causal processes that have proven hard to generalize. One possible exception are processes that control the biomass packing of vegetation stands; the amount of aboveground standing biomass expressed per unit volume. In this paper, I investigated the empirical and geometric underpinnings of biomass packing in terrestrial plant communities. I support that biomass packing in nature peaks around 1 kg m-3 across contrasted contexts, ranging from grasslands to forest ecosystems. Using published experimental and long-term survey data, I show that expressing biomass per unit volume cancels the effects of air temperature, species richness and soil fertility on aboveground stocks, thus providing a general comparative measure of storage efficiency in plant communities. [ABSTRACT FROM AUTHOR]

• Wetland type, indicator choice and aggregation influence synergies and trade-offs among EFS. • Peatland and ash swamps had strong opposing patterns of EFS provisioning. • The three wetland types maximized biodiversity, but supported different taxonomic group. • Using a single indicator for biodiversity might lead to diverging conclusions. • Our results provide a benchmark for wetland conservation planning. Wetlands are the world's most important providers of ecosystem functions and services (EFS) and the most threatened ecosystems. Systematic conservation planning strategies are urgently needed to identify efficient strategies that optimize EFS provisioning in wetlands. Evaluating synergies and trade-offs among EFS indicators provides an ideal framework, as they highlight the challenges faced by conservationists. However, associations between indicators often vary across region, scale, and ecosystem type. In this study, we compared the provisioning of eight EFS of three types of wetlands to evaluate the influence of indicator choice and aggregation on synergies and trade–offs. We quantified 25 EFS indicators in 37 lake-edge wetlands consisting of 12 peatlands, 8 alder swamps, and 17 ash swamps. We analyzed the synergies and trade-offs among wetland types and among EFS indicators, as well as the general EFS provisioning patterns of each type using cosine similarities and multivariate analysis. We showed that wetland type strongly influences the strength and direction of associations, with peatlands and ash swamps showing opposing patterns. While some EFS categories are less sensitive to indicator choice and aggregation, others, such as biodiversity, show important trade-offs. Our results revealed that synergies and trade-offs are strongly influenced by indicator choice and that protecting a diversity of wetland types is necessary to support multiple EFS categories. [ABSTRACT FROM AUTHOR]

Vocalizing animals are known to produce a wide range of species-specific spectral and temporal communication patterns. As a consequence, the acoustic heterogeneity of insect communities is expected to increase with the number of vocalizing species. Using a combination of simulation models and field surveys, we tested the hypotheses that (1) acoustic heterogeneity increases with the number of cricket and katydid species in ensiferan communities and (2) acoustic heterogeneity of naturally assembled ensiferan communities is higher than that of randomly assembled ones. The slope of the acoustic heterogeneity-species richness relationship in naturally assembled communities was positive but did not differ from that of randomly assembled communities, suggesting a rather weak competition for the acoustic space. Comparing the species richness-acoustic heterogeneity relationship of naturally and randomly assembled communities, our study provides a novel approach for understanding species assembly rules in animal groups that rely on acoustic communication. [ABSTRACT FROM AUTHOR]

According to two main and non-exclusive scenarios, plant diversity can influence the growing season of vegetation stands through: (i) functional complementarity among species and, (ii) functional selection of species from the regional pool. The objective of this study was to evaluate whether plant species richness prolongs the active photosynthetic period length (APPL) of freely assembled riparian herbaceous communities in agroecosystems of Eastern Canada. We selected a total of 44 herbaceous communities in riparian buffers of varying species richness but which were comparable in their soil characteristics and cumulative growing degree-days. Independent of abiotic factors, we observed a general positive relationship between species richness and the APPL of riparian herbaceous communities. In the first sampling year, the APPL of species-rich communities was, on average, 30 days longer than the APPL of species-poor communities. Species-rich communities were sheltering herbaceous species with delayed green offset dates in comparison to communities dominated by Phalaris arundinacea , a dominant species in these riparian buffers. This relationship was not observed in the second sampling year. We suggest that the presence of a significant and positive APPL–species richness relationship was related to exceptionally dry climatic conditions in the first sampling year. We estimated that, under certain conditions, restoring the species diversity of herbaceous riparian communities in intensively managed agroecosystems could account for a net carbon uptake gain of up to 900 kg C yr −1 ha −1 of riparian buffer. [ABSTRACT FROM AUTHOR]

1. Biomass measures are central to estimating secondary productivity and studying how resources are distributed within an ecosystem. Because directly measuring insect biomass is a lengthy process, many authors have resorted to empirical length-dry mass relationships. 2. The objective of this study was to evaluate the relative importance of latitude, climate and physical habitat (aquatic vs. terrestrial) in explaining the variability in length-dry mass relationships among insect populations. 3. A global meta-analysis of the body length-dry mass power coefficients of 457 insect samples was conducted using mixed-effects models. 4. The length-dry mass power coefficients of insects were positively related to the absolute latitude of the study site and to habitat type; with insects captured in aquatic habitats being characterised by higher allometric coefficients than terrestrial ones. Neither the annualised climatic variables (temperature and precipitation) nor the metamorphosis type of insect taxa had a significant effect on the allometric coefficients. 5. The findings may lead to a generalised body length-dry mass relationship for insects, accounting for both the phylogenetic relatedness and the environmental (biotic and abiotic) context of populations. [ABSTRACT FROM AUTHOR]

Decades of study have attempted to define a generalized environmentalheterogeneity- biodiversity (EH-BD) relationship, with the traditional MacArthurian nichebased hypothesis remaining as the dominant reference point; i.e., increasing heterogeneity promotes biodiversity by increasing resource opportunities. However, studies have frequently reported negative or nonsignificant relationships. In a vast majority of them, environmental heterogeneity was defined along a gradient of increasing randomness, toward complete disorder. A new conceptual framework could help to reconcile the array of observed relationships. Using an extensive literature review, we test a conceptual framework proposing that the direction of environmental-heterogeneity-biodiversity relationships is contingent on the level of human footprint to which an ecosystem is subjected (the anthropocline). The results reveal that highly modified and seminatural ecosystems are characterized by a dominance of positive and negative EH-BD relationships, respectively, whereas natural ecosystems show mixed responses. Out of this novel framework arises the revised perspective that natural ecosystems are typified, not by maximal or minimal, but by intermediate levels of environmental heterogeneity [ABSTRACT FROM AUTHOR]

Web-crawling approaches, that is, automated programs data mining the internet to obtain information about a particular process, have recently been proposed for monitoring early signs of ecosystem degradation or for establishing crop calendars. However, lack of a clear conceptual and methodological framework has prevented the development of such approaches within the field of conservation biology. Our objective was to illustrate how Google Trends, a freely accessible web-crawling engine, can be used to track changes in timing of biological processes, spatial distribution of invasive species, and level of public awareness about key conservation issues. Google Trends returns the number of internet searches that were made for a keyword in a given region of the world over a defined period. Using data retrieved online for 13 countries, we exemplify how Google Trends can be used to study the timing of biological processes, such as the seasonal recurrence of pollen release or mosquito outbreaks across a latitudinal gradient. We mapped the spatial extent of results from Google Trends for 5 invasive species in the United States and found geographic patterns in invasions that are consistent with their coarse-grained distribution at state levels. From 2004 through 2012, Google Trends showed that the level of public interest and awareness about conservation issues related to ecosystem services, biodiversity, and climate change increased, decreased, and followed both trends, respectively. Finally, to further the development of research approaches at the interface of conservation biology, collective knowledge, and environmental management, we developed an algorithm that allows the rapid retrieval of Google Trends data. [ABSTRACT FROM AUTHOR]

Abstract: Fall biological processes are driven by a combination of environmental factors, with cumulative effects over the length of the growing season, which are currently difficult to model. This study evaluated if leaf color change in fall (i.e., leaf yellowing) and brook trout spawning could be two biological processes that are synchronized at a regional scale and if leaf yellowing could be used to determine the peak of spawning activity of this species. To this end, we surveyed 551 brook trout redds and examined 193 digital images of forest trees in the Laurentides Wildlife Reserve (Québec, Canada) over the fall season. Results showed that leaf yellowing and brook trout spawning were synchronized, providing one of the first examples of temporal matching between freshwater and terrestrial biological processes at the regional scale. Considering the difficulty of monitoring the phenology of freshwater fish spawning at high spatial and temporal resolution, terrestrial integrators of environmental conditions, such as leaf color change, may prove to be promising predictors of spawning activity in the management of fish populations. [Copyright &y& Elsevier]

Protected areas cover over 12% of the terrestrial surface of Earth, and yet many fail to protect species and ecological processes as originally envisioned. Results of recent studies suggest that a critical reason for this failure is an increasing contrast between the protected lands and the surrounding matrix of often highly altered land cover. We measured the isolation of 114 protected areas distributed worldwide by comparing vegetation-cover heterogeneity inside protected areas with heterogeneity outside the protected areas. We quantified heterogeneity as the contagion of greenness on the basis of NDVI (normalized difference vegetation index) values, for which a higher value of contagion indicates less heterogeneous land cover. We then measured isolation as the difference between mean contagion inside the protected area and mean contagion in 3 buffer areas of increasing distance from the protected-area border. The isolation of protected areas was significantly positive in 110 of the 114 areas, indicating that vegetation cover was consistently more heterogeneous 10-20 km outside protected areas than inside their borders. Unlike previous researchers, we found that protected areas in which low levels of human activity are allowed were more isolated than areas in which high levels are allowed. Our method is a novel way to assess the isolation of protected areas in different environmental contexts and regions. [ABSTRACT FROM AUTHOR]

Two of the oldest observations in plant geography are the increase in plant diversity from the poles towards the tropics and the global geographic distribution of vegetation physiognomy (biomes). The objective of this paper is to use a process-based vegetation model to evaluate the relationship between modelled and observed global patterns of plant diversity and the geographic distribution of biomes. The global terrestrial biosphere. We implemented and tested a novel vegetation model aimed at identifying strategies that enable plants to grow and reproduce within particular climatic conditions across the globe. Our model simulates plant survival according to the fundamental ecophysiological processes of water uptake, photosynthesis, reproduction and phenology. We evaluated the survival of an ensemble of 10,000 plant growth strategies across the range of global climatic conditions. For the simulated regional plant assemblages we quantified functional richness, functional diversity and functional identity. A strong relationship was found (correlation coefficient of 0.75) between the modelled and the observed plant diversity. Our approach demonstrates that plant functional dissimilarity increases and then saturates with increasing plant diversity. Six of the major Earth biomes were reproduced by clustering grid cells according to their functional identity (mean functional traits of a regional plant assemblage). These biome clusters were in fair agreement with two other global vegetation schemes: a satellite image classification and a biogeography model (kappa statistics around 0.4). Our model reproduces the observed global patterns of plant diversity and vegetation physiognomy from the number and identity of simulated plant growth strategies. These plant growth strategies emerge from the first principles of climatic constraints and plant functional trade-offs. Our study makes important contributions to furthering the understanding of how climate affects patterns of plant diversity and vegetation physiognomy from a process-based rather than a phenomenological perspective. [ABSTRACT FROM AUTHOR]

Abstract: The development of ecological indicators for actively monitoring an ecosystem at a high resolution in scale, space and time is a challenge of primary interest. In this context, measures of structural complexity derived from close-range repeat photography may form a part of the solution. Moreover, recent mathematical tools, such as recurrence plots and recurrence quantification analysis (RP-RQA), are becoming accessible for characterizing the multivariate dynamics of natural systems given short, stochastic and non-stationary series. In this study, a total of 9360 grey-level digital images were recorded on a weekly basis across 72 sites in an old-growth forest ecosystem and analyzed for structural complexity. Structural complexity was assessed using an information theoretic measure (mean information gain). The effect of the scene scale on the observed dynamics was verified across a gradient of forest descriptors and light habitats. Multiscale dynamics responded nonlinearly to changes in scene scale, whereas seasonal trends in structural complexity showed a range of deterministic and stochastic behaviours. The determinism of multiscale time-series was related to sapling density, tree cover, and tree species richness. The sensitivity and flexibility of the RP-RQA approach applied to proxy measures of structural complexity in digital images forms an efficient methodology which might be used for actively monitoring forest ecosystems. This field study is one of the first to demonstrate that old-growth forest ecosystems behave like complex systems exhibiting nonlinear vegetation structure and dynamics across scales. [Copyright &y& Elsevier]

Abstract: Conducting field samples for monitoring ecological dynamics across multiple spatiotemporal scales is a difficult task using standard protocols. One alternative is to measure a restricted set of variables which can serve as an ecological orientor (EO) for quantifying habitat change. The objective of this article is to derive from digital images a measure of structural complexity that may serve as a proximate EO for monitoring forest dynamics in space and time. The mean information gain (MIG) index was used as a measure of structural complexity in photographs taken directly in the field over the entire growing season. At a small scene extent, the complexity of light intensity variations in digital images was positively related to species richness. At larger scene extents, forest understorey and overstorey layers showed predictable ecological signatures in structural complexity. In general, intensity and chroma were the two color space components which yielded the greatest sensitivity to habitat change through time. Within the framework of a standardized photographic protocol, it seems therefore reasonable to consider MIG as a suitable EO for monitoring forest dynamics in both space and time. Our results support the idea that it is possible on one hand to adopt a more holistic view of ecological processes to gain, on the other hand, spatial and temporal degrees of freedom for testing multiple scale hypotheses in the field. [Copyright &y& Elsevier]

We used data from 17 populations of lacustrine brook trout (Salvelinus fontinalis) of the Canadian Shield, southern Quebec, to test whether early maturity (in males and females) and high reproductive effort (in females) are associated with increased (i) fish exploitation (sportfishing) and (ii) interspecific competition through their effects on growth and survival. The age at maturity of males and females was inversely related to the intensity of both fishing and interspecific competition. Fishing and interspecific competition affect the age at maturity through their effect on adult survival but not on growth, supporting predictions of life history models based on survival. In contrast, we did not find consistent effects of interspecific competition and fishing on the gonadosomatic index of females, which was directly related to survival (in all populations) and to the age at maturity (in exploited populations). These latter results are contrary to the predictions of life history models under the assumption that survival is directly related to growth rate. Our results suggest that reproductive effort and age at maturity are not dependent on growth when survival is independent of growth, as is the case in exploited and sympatric populations experiencing low adult survival but high growth. [ABSTRACT FROM AUTHOR]

Conservation biologists can use several criteria, such as species richness and incidence of range-restricted species, to prioritize allocation of conservation efforts and identify sites of high ecological value. Recently, ecological uniqueness has been proposed as an effective criterion because it allows the identification of species assemblages that are complementary and irreplaceable. This study aims to determine whether the ecological uniqueness of plant communities is an adequate criterion for assessing the conservation value of ecosystems. We used two large datasets of lake-edge wetlands located in southern Québec (Canada) to achieve this objective. We computed the local contribution to beta diversity (LCBD) as a measure of uniqueness and evaluated its relationship to more common conservation criteria (richness, rarity and specialization of species, as well as site area and connectivity) using Pearson correlations and independent effects. Uniqueness decreased with increasing plant species richness, suggesting a conservation trade-off, whereas it increased with the percentage of rare and disturbance-sensitive specialist species. Highly unique sites were mostly of high conservation value, although the overall integrity of the landscape affected the quality of sites singled out as unique. The species composition of unique sites should be examined closely to determine their conservation value and other criteria should be used in conjunction with uniqueness to identify which set of sites to protect in a given landscape. • We identified lake-edge wetlands with unique plant assemblages in two study regions. • Landscape integrity affects success of uniqueness for targeting high quality sites. • Uniqueness is congruent with the incidence of rare and disturbance-sensitive species. • There is a trade-off between protecting unique sites and species-rich sites. [ABSTRACT FROM AUTHOR]

Freshwater fishes exhibit a wide range of auditory adaptations and capabilities, which are assumed to help them navigate their environment, avoid predators, and find potential mates. Yet, we know very little about how freshwater environments sound to fish, or how fish with different auditory adaptations respond to different soundscapes. We first compiled data on fish hearing acuity and adaptations and provided a portrait of how anthropogenic sounds compare to natural sounds in different freshwater soundscapes. We then conducted a sound‐enrichment field experiment at Lake Saint Pierre, a large fluvial lake in Canada, to evaluate the effect of motorboat sound exposure on the fish community by looking at the extent to which changes in species abundances were linked to auditory adaptations. Data compilation showed that the hearing acuity of most species overlaps with a wide range of ambient and anthropogenic underwater sounds while the field experiment showed that species with more specialized auditory structures were captured less often in sound‐enriched traps, indicating avoidance behavior. Our findings highlight the importance of considering species' sensorial adaptations when evaluating the community‐scale effects of anthropogenic sounds on the fish community, especially at low levels of anthropogenic activity. [ABSTRACT FROM AUTHOR]

Canopy structure is an important driver of the energy budget of grassland ecosystem and is, at the same time, altered by plant diversity. Diverse plant communities typically have taller and more densely packed canopies than less diverse communities. With this, they absorb more radiation, have a higher transpiring leaf surface and are better coupled to the atmosphere which leads to cooler canopy surfaces. However, whether plant diversity generally translates into a cooling potential remains unclear and lacks empirical evidence. Here, we assessed how functional identity, functional diversity and species richness of grassland communities in the Jena Experiment predict the mean and variation of plant surface temperature mediated via effects of canopy structure.Using terrestrial laser scanning, we estimated canopy structure describing metrics of vertical structure (mean height, LAI), the distribution (evenness) and the highest allocation (centre of gravity) of biomass along height strata. As metrics of horizontal structure, we considered community stand gaps, canopy surface variation and emergent flowers. We measured surface temperature with a thermal camera. We used SEM models to predict biodiversity effects on the surface temperature during two seasonal peaks of biomass.Before the first cut in May, herb‐dominated communities directly promoted lower leaf surface temperatures. However, communities with lower centre of gravity (mostly herb dominated) also increased canopy surface temperatures compared with grass‐dominated communities with higher biomass stored in the top canopy. Grass‐dominated communities showed a smaller variation of surface temperatures, which was also positively affected by species richness via an increase in mean height. In August, mean surface temperature decreased with increasing community CC and LAI. The variation of surface temperature was greater in herb‐dominated than in grass‐dominated communities and increased with plant species richness (direct effects).Synthesis. The mean and variation of canopy surface temperature were driven by differences in functional group composition (herbs‐ vs. grass dominance) and to a lesser extent by plant diversity. These effects were partly mediated the metrics of canopy structure but also by direct effects unrelated to the structural metrics considered. [ABSTRACT FROM AUTHOR]

Sounds are more easily transmitted underwater than through air and many freshwater fish species can hear them, particularly over the low frequencies. Recent studies on freshwater fish evidenced that hearing sensitivities can be limited by the level of ambient noise, a phenomenon also known as acoustic masking. However, it is still unclear whether variations in ambient noises, such as those produced by human activities, may alter fish trophic interactions.The general objective of this study was to propose and evaluate a theoretical framework explicitly linking fish attack rates to species hearing sensitivities and ambient noise levels in freshwater ecosystems. The proposed model shows that the feeding activity of fish at an intermediate position in the food web is conditional on the probability of being acoustically detected by their predators, or of encountering an acoustically distressed resource.Model simulations and preliminary field results suggest that yellow perch (Perca flavescens) could feed more actively in the presence of augmented ambient noise levels. Yellow perch captures per unit effort were higher by a factor of 2.7 in noisy versus quiet days. We argue that fish exposed to intermediate levels of noise could maximise the probability of detecting food patches while minimising their predation risk.Acoustic monitoring programmes for freshwater ecosystems require a fundamental knowledge of underwater noise levels, species hearing sensitivities and features affecting sound propagation. The approach proposed in this paper is seminal in linking the above descriptors in a coherent mathematical framework to understand the effect of underwater sounds on trophic interactions. Such framework is needed to make testable predictions and generalise to other taxa and ecological contexts. [ABSTRACT FROM AUTHOR]

The potential use of herbarium specimens to detect herbivory trends is enormous but largely untapped. The objective of this study was to reconstruct the long-term herbivory pressure on the Eurasian invasive plant, purple loosestrife (Lythrum salicaria), by evaluating leaf damage over 1323 specimens from southern Québec (Canada). The hypothesis tested is that that the prevalence of herbivory damage on purple loosestrife is low during the invasion phase and increases throughout the saturation phase. Historical trends suggest a gradual increase in hole feeding and margin feeding damage from 1883 to around 1940, followed by a period of relative stability. The percentage of specimens with window feeding damage did not begin to increase until the end of the twentieth century, from 3% (2-6%) in 1990 to 45% (14-81%) in 2015. Temporal changes in the frequency of window feeding damage support the hypothesis of an increasing herbivory pressure by recently introduced insects. This study shows that leaf damage made by insects introduced for the biocontrol of purple loosestrife, such as coleopterans of the Neogalerucella genus, can be assessed from voucher specimens. Herbaria are a rich source in information that can be used to answer questions related to plant-insect interactions in the context of biological invasions and biodiversity changes. [ABSTRACT FROM AUTHOR]

The potential use of herbarium specimens to detect herbivory trends is enormous but largely untapped. The objective of this study was to reconstruct the long-term herbivory pressure on the Eurasian invasive plant, purple loosestrife (Lythrum salicaria), by evaluating leaf damage over 1323 specimens from southern Québec (Canada). The hypothesis tested is that that the prevalence of herbivory damage on purple loosestrife is low during the invasion phase and increases throughout the saturation phase. Historical trends suggest a gradual increase in hole feeding and margin feeding damage from 1883 to around 1940, followed by a period of relative stability. The percentage of specimens with window feeding damage did not begin to increase until the end of the twentieth century, from 3% (2-6%) in 1990 to 45% (14-81%) in 2015. Temporal changes in the frequency of window feeding damage support the hypothesis of an increasing herbivory pressure by recently introduced insects. This study shows that leaf damage made by insects introduced for the biocontrol of purple loosestrife, such as coleopterans of the Neogalerucella genus, can be assessed from voucher specimens. Herbaria are a rich source in information that can be used to answer questions related to plant-insect interactions in the context of biological invasions and biodiversity changes. [ABSTRACT FROM AUTHOR]

The use of analytical techniques to delineate biogeographical regions is becoming increasingly popular. One recent example, Heikinheimo et al. ( Journal of Biogeography, 2007, 34, 1053–1064 ), applied the k-means clustering algorithm to define the biogeography of the European land mammal fauna. However, they used the Euclidean distance measure to cluster grid cells described by species-occurrence data, which is inappropriate. The Euclidian distance yields misleading results when applied to species-occurrence data because of the double-zero problem and the species-abundance paradox. We repeat their analysis using the Hellinger distance, a measure appropriate for species-occurrence data and which has been shown to outperform other such measures. Our results differ substantially from those presented by Heikinheimo et al. We argue that the rigorous application of appropriate statistical techniques is of crucial concern within conservation biogeography. [ABSTRACT FROM AUTHOR]

The authors focuses on the textural-discontinuity hypothesis (TDH) proposed by C.S. Holling to explain clumped body-mass distributions observed in mammals and birds. They explain that TDH states that the size of animals inhabiting a landscape should be dictated by the discontinuous structure of the landscape. They mention that model landscapes that use characteristic scales of resource distribution were found to host more co-existing species, which may help explain discontinuous body-mass distributions. They comment on a paper by J. Fischer and others that they claim did not assess landscape texture quantitatively. They mention that discontinuous habitat structure within landscapes can be difficult to measure, and that Fischer's study design allows researchers to simplify that task.

Abstract: Phenotypic plasticity, a process by which individuals modify their morphology, physiology, or behaviour in response to environmental changes, can be seen as the first step in adaptive evolution. Phenotypic plasticity is adaptive if two conditions are met: (1) the phenotype is associated with an environment (plastic response) and (2) the phenotype–environment association increases individual fitness (adaptive response). Using a reciprocal transplant experiment, we tested the hypothesis that functional morphological responses are correlated with growth at two organizational levels (between and within ecotypes) in brook charr. Four‐month‐old individuals from four littoral and four pelagic families raised in the laboratory were transferred into eight littoral (3 m × 4 m × 1.5 m depth) and eight pelagic (3 m × 4 m × 6 m depth) lake enclosures for a period of 12 weeks. Fin length (the main discriminant trait of the littoral and pelagic ecotypes) was less plastic than body shape. Growth was higher in the pelagic than in the littoral habitat, but offspring from littoral and pelagic parental origins did not experience higher growth in their respective habitats (comparison between ecotypes). The body shape of most individuals transplanted to their reciprocal environment shifted toward the form expected in that environment. This plastic response in body shape was functionally correlated with growth within ecotypes, but only in the littoral habitat. Furthermore, the within‐ecotype variance of both morphological traits and growth were higher in the littoral than in the pelagic habitat. Small phenotypic differences could have direct consequences on fitness in the less favourable habitat, inducing higher inter‐individual variance in growth and stronger phenotype–growth associations. We suggest that phenotypic accommodation and cryptic genetic variation, two mechanisms previously proposed as mechanisms involved in distinct situations, could be simultaneously involved to hasten the process of adaptive evolution in an unfavourable environment. A plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

The alteration of environmental conditions has two major outcomes on the demographics of living organisms: population decline of the common species and extinction of the rarest ones. Halting the decline of abundant species as well as the erosion of biodiversity require solutions that may be mismatched, despite being rooted in similar causes. In this study, we demonstrate how rank abundance distribution (RAD) models are mathematical representations of a dominance-diversity dilemma. Across 4,375 animal communities from a range of taxonomic groups, we found that a reversed RAD model correctly predicts species richness, based solely on the relative dominance of the most abundant species in a community and the total number of individuals. Overall, predictions from this RAD model explained 69% of the variance in species richness, compared to 20% explained by simply regressing species richness on the relative dominance of the most abundant species. Using the reversed RAD model, we illustrate how species richness is co-limited by the total abundance of a community and the relative dominance of the most common species. Our results highlight an intrinsic trade-off between species richness and dominance that is present in the structure of RAD models and real-world animal community data. This dominance-diversity dilemma suggests that withdrawing individuals from abundant populations might contribute to the conservation of species richness. However, we posit that the positive effect of harvesting on biodiversity is often offset by exploitation practices with negative collateral consequences, such as habitat destruction or species bycatches. [ABSTRACT FROM AUTHOR]

Over the past century farming activity has intensified worldwide, characterized by an increasing dependence on external inputs and on land conversion. Although the intensification of agriculture has increased productivity, the sustainability of agroecosystems has also been compromised. The objective of this study is to build multivariate relationships between farm structural characteristics and farm performance to highlight the relative costs and benefits of four main farming systems in Central Italy: organic, conventional, mixed and non-mixed farms. Results show that the relationship between cropping diversity and agroecological sustainability is associated to a mixed versus non-mixed farm management dichotomy, not to organic or conventional farming practices. The presence of livestock appears to have played an important role as an economic lever for diversifying the farm cropping system. [Copyright &y& Elsevier]

Additional risks arise from potential species misidentification generated by data producers, experts assessing digital data, or by automated species identification software (Jari'c et al. 2020). Digital data can also provide information on distributions, spread dynamic, life history, and impacts of invasive non-native species within the framework of iEcology (Jari'c et al. 2020). This could greatly increase the volume of available information on invasive non-native species, especially once web crawlers are used more commonly to automatically scrape the web, identify and validate species' mentions, and flag range expansions. Invasion culturomics and iEcology represent promising options to track and study invasions as well as societal attitudes and interactions with invasive non-native species. [Extracted from the article]

Hydromorphological descriptors such as substrate type, water depth, and velocity are commonly used to describe fish habitat, but few studies have focused on how underwater sounds affect habitat use by freshwater fish. We evaluated the influence of the underwater soundscape and other habitat descriptors on the spatial distribution of brook trout (Salvelinus fontinalis) in a small stream in eastern Canada. Habitat measurements were made at high spatial resolution (2.5 m intervals). High acoustical heterogeneity of stream habitats (40–150 dB re 1 μPa) was related to differences in water velocity and depth as expected from theory. Brook trout densities were positively related to broadband sound pressure levels (SPL), irrespective of water velocity and depth, but in interaction with habitat type. The positive relationship between brook trout densities and SPL could be related to the high auditory threshold of salmonid fishes. Alternatively, brook trout may use the underwater soundscape to select favourable feeding habitats. Underwater sounds integrate the many environmental dimensions of a stream and may be used by fish as cues for habitat selection. [ABSTRACT FROM AUTHOR]

Intensive management of urban lawns is globally widespread, predominantly for aesthetic reasons. However, a growing body of knowledge demonstrates negative ecological and environmental effects of this practice.We present a meta‐analysis of North American and European studies from 2004 to 2019, which incorporates three previously unpublished datasets from eastern Canada, to investigate how mowing intensity impacts the ecology of urban lawns.The meta‐analysis provides aggregated evidence that invertebrate and plant diversity is lower in urban lawns under increased mowing intensity. This decline is independent of the level of contrast between mowing 'treatment' and 'control' (e.g. height or frequency of mowing), which differed considerably between studies. Intensive mowing also increases the occurrence of pest species (e.g. herbivorous beetle larvae and allergenic plants), though studies in this group were limited to northern environments. Changes in ecosystem‐level variables (soil temperature, soil moisture deficit and carbon deficit) were less evident and suggest changes in abiotic processes may take longer to become apparent.An economic case study of the mowing costs in Trois‐Rivières, Canada, suggests that cost savings of 36% may be possible with a modest reduction of mowing frequency.Synthesis and Applications. Increasing urban biodiversity and reducing greenhouse gas emissions are strong motivators for reducing lawn management intensity. We also suggest that the benefits of reducing pest species while saving lawn management costs may provide additional social and economic incentives for decision makers to review urban greenspace management practices. [ABSTRACT FROM AUTHOR]

Anthropogenic noise has been shown to alter the transmission environment and distort acoustic signals, prompting vocalizing species to use compensatory mechanisms. Through a meta-analysis we investigated the relative importance of biological and contextual factors predisposing species to shift their singing/calling frequencies in response to anthropogenic noise. We gathered data from 36 studies, synthesizing information on more than 160 experiments and 60 bird and anuran species. To estimate the breadth of frequency shift, we calculated a standardized effect size using Hedges' g. We fitted a multilevel linear mixed-effect model on g as the dependent variable weighted by its inverse variance, with typical frequency, body mass, experimental condition, and noise source type as independent terms. Our results reveal broader shifts in smaller bird species when compared with bigger species, an effect that was emphasized in the low-frequency component of the song spectrum. Birds increased their dominant frequencies when confronted to anthropogenic noise, whereas anurans were less prone to such shifts. Human-altered acoustic environments can be considered a novel selective force impelling change to the communication patterns of many vocalizing species. [ABSTRACT FROM AUTHOR]

Deterministic niche-based processes have been proposed to explain species relative abundance within communities but lead to different predictions: habitat filtering ( HF) predicts dominant species to exhibit similar traits while niche differentiation ( ND) requires that species have dissimilar traits to coexist., Using a multiple trait-based approach, we evaluated the relative roles of HF and ND in determining species abundances in productive grasslands. Four dimensions of the functional niche of 12 co-occurring grass species were identified using 28 plant functional traits. Using this description of the species niche, we investigated patterns of functional similarity and dissimilarity and linked them to abundance in randomly assembled six-species communities subjected to fertilization/disturbance treatments., Our results suggest that HF and ND jointly determined species abundance by acting on contrasting niche dimensions. The effect of HF decreased relative to ND with increasing disturbance and decreasing fertilization. Dominant species exhibited similar traits in communities whereas dissimilarity favored the coexistence of rare species with dominants by decreasing inter-specific competition. This stabilizing effect on diversity was suggested by a negative relationship between species over-yielding and relative abundance., We discuss the importance of considering independent dimensions of functional niche to better understand species abundance and coexistence within communities. [ABSTRACT FROM AUTHOR]