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Species distribution models (SDMs) are numerical tools that combine species occurrence (or abundance) data with environmental variables, to predict the species’ distribution spatially. SDMs are increasingly used for purposes of conservation planning and management of ecosystems. The model performance can be measured as the goodness-of-fit (GOF), which describes how well it fits (e.g., the discrepancy between the statistical model and the data observed). However, there is still a need for a deeper understanding of the ecological characteristics of the modelled species which can affect the accuracy of those models. Here, we compared the goodness-of-fit of SDMs, considering several ecological characteristics of 56 bird species: Most frequently used environment, body mass, home-range, species specialization index (SSI), diet specialization and detectability. All SDMs were performed on the same dataset, and the relative frequency of each species was also incorporated to account for occurrence heterogeneity. GOF of SDMs was not significantly correlated with species’ frequency, home-range, body mass, degree of detectability or level of diet specialization. Overall, the birds with more accurate SDMs (GOF) were species of grasslands and the GOF was positively associated with SSI, indicating that more habitat-specialized species are better predictable. Our findings suggest that is important to focus not only on statistical issues potentially related to model performance but also on ecological characteristics of single species because can improve the performance of modellistic procedures, increasing their predictive power.

Evaluations ecosystem health-based field studies can assist decision-makers in formulating more targeted conservation policies to better manage ecosystems and landscape. To analyze forest characteristics in the Zabarwan Mountain Range we used the Floristic Quality Assessment Index (FQAI) technique to evaluate the ecosystem health status of the vegetation. According to our findings, the forest area showed an FQAI rating of 61.41. The FQAI ranked 54 of the plant species growing in the forest region at 0, 30 species at 1–3, 51 species at 4–6, 30 species at 7–8, and 17 species at 9–10. Of the 54 alien species ranking 0, thirteen species were invasive, 36 were naturalized, and five were casual. Amoung the forest types, the Broadleaved forest harbored most alien species (35%) and the scrub forest the least (6%). Based on habitat-wise distribution, the largest (38%) species pool was observed in natural forest habitats, while human-modified habitat types harbord 51% of species. Roadsides exhibited the by far highest alien species number (45%) together with other anthropogenic habitats. The investigation of indicator species revealed a separation between the various ranking groups, as evidenced by high indicator values. Important alien indicator species ranking 0 were i.e., Aesculus indica, Ailanthus altissima, Celtis australis, Daucus carota, Poa bulbosa, Prunus armeniaca, Prunus cerasus, Quercus robur, and Salix alba, which showed a significant p-value for indicator species analysis. The findings of this study provide a method for measuring vegetation communities' responses to alien invasions and as a result can serve for developing management methods to preserve ecosystems, particularly in protected areas, from this biodiversity threat.

China’s freshwater ecosystems are gradually invaded by an increasing number of non-native fish species. However, to date, some controversy about the number of native and non-native freshwater fish species in wild habitats and very limited information on ecological or biological traits mediating fish introduction success at a national scale have prevented the proposal and implementation of targeted conservation and management strategies. To address these urgent issues, first we compiled an up-to-date inventory of 1,797 fish species (1,597, 84, and 116 native, exotic (originating from outside China), and translocated (originating from within China) species, respectively) along with 13 traits encompassing various ecological and life-history strategies for each species, which is the most comprehensive freshwater fish database in China as we know. Here, we found that non-native species mainly belonged to three orders (Perciformes, Siluriformes, and Cypriniformes) and three families (Cichlidae, Cyprinidae, and Salmonidae). Native species were significantly (P

The physical impact of bottom towed fishing gears does not only reduce the abundance and biomass of species, but also alter the overall species composition and, through this, the functioning of benthic communities. The vulnerability of a species is determined by its individual combination of morphological, behavioural and life history traits. In turn, ecosystem functions are most affected when those species identified as vulnerable, contribute disproportionately to that function. On the basis of this paradigm, trait-based indices of physical resistance (RI) and recovery potential (RPI) were developed and combined into an overall vulnerability index on a species level, the RRI or Resistance and Recovery Potential Index. The developed indices can be used to explore how resistance and recovery potential of benthic communities change over different levels of trawling. Furthermore, the RRI allows for dividing the benthic community into groups expressing different levels of vulnerability that can be linked to ecosystem functions to explore functional vulnerability to trawling. The RRI index futher opens up the possibility for scenario modelling by simulating the extinction or loss of vulnerable species and its effects on functions. This may be of particular interest in data poor case studies that lack trawling gradient data, or to explore the consequences of potential increases in fishing effort. The validity of the trait-based RRI index was tested by comparing individual species’ RRI scores to empirically observed responses over a trawling gradient. RRI score and observed responses (regression slopes) were significantly correlated providing support for the rationality of the approach. Moreover, further analysis of the data evidenced clear increases of resistance and resilience indices over the trawling gradient, demonstrating that communities lost vulnerable species with increasing trawling. When exploring the effects of trawling on the bioturbation, as a chosen ecosystem function, we found it to be disproportionately affected though the loss of vulnerable species. The proposed indices provide new insights into the link of species vulnerability and function. Such information is of vital interest to environmental managers focused on preserving ecosystem functions and services in the face of anthropogenic global change.

Species distribution models (SDM) are widely used as indicators of different aspects of geographical ranges for many purposes, from conservation to biogeographical and evolutionary analyses. However, these techniques are susceptible to various sources of uncertainty. Data coverage, species’ ecology, and the characteristics of their geographic distributions can affect SDM results, often generating critical errors in predicted distribution maps. We assess the influence of data quality, the characteristics of species distributions, and ecological traits on SDM performance. We predict the distributions of dung beetle species in Madrid region (central Spain) using six SDM techniques and validate them on an independent dataset. We relate variations in model performance with environmental completeness, data characteristics, and species traits through a partial least squares analysis. In this analysis, body size, nesting behaviour, marginality, rarity, data prevalence, Relative Occurrence Area (ROA), range size, niche breadth, and completeness are used as predictors of six assessment metrics (sensitivity, specificity, kappa, TSS, CCR, and AUC). Marginality and data prevalence were the variables that most influenced SDM performance, followed by range size, ROA, and niche breadth: species presenting higher marginality and data prevalence, and smaller ROA and niche breadth were associated with better models. Nesting behaviour, rarity, niche completeness, and body size had minor importance for SDM performance. Our results highlight the importance of taking species’ and data characteristics into account when modelling and comparing large groups of species using SDM. This implies that estimates of species richness and composition based on stacked SDMs can show high levels of error if they are constructed for groups of species with diverse ecological traits and types of geographic distributions. We suggest that the species holding characteristics that lead to poor SDM performance should not be included when constructing composite biodiversity variables. Further effort is needed to develop SDM methodologies and protocols that account for such source of uncertainty.

Highlights • We evaluated indicators for detecting climate change effects on marine vertebrates. • Included foraging, diet, mass, breeding timing & success, and population size. • Foraging trip time was the best metric for detecting climate effects of 106 metrics. • There was no single second best measure. • Our results can be used to design cost-effective large scale monitoring. Abstract Designing monitoring programs to detect impending climate change effects on marine vertebrates is challenging, as data sufficient for large-scale power analysis is severely limited, yet sensitivity and response time of potential indicator variables are key uncertainties. In the absence of such data, the experience of researchers can be used to inform decision making on monitoring design to detect impacts of climate change. We used expert elicitation to identify ecological traits of seabirds and marine mammals that have or were expected to respond to climate change. We analyzed the projected biological changes for five general categories of ecological traits that have been shown elsewhere to relate to climate signals: foraging and diet, body mass, breeding phenology, breeding success, and population size. Based on analysis of 106 traits in the five categories, 29 experts rated foraging- and diet-related traits to be the most responsive to climate change, although predictions for traits in this category were also the most variable across experts. Body mass related traits were projected to change almost as frequently, but with much lower variance. The timespan over which experts expected to see change also varied between trait categories. Foraging success was expected to respond most quickly. Considering sensitivity and response rate, we predict that the duration of foraging trips will be the best climate change indicator among the 106 traits. When combined with cost estimates, our results allow managers to choose ecological indicators that deliver information on system response in the most cost-effective manner. [ABSTRACT FROM AUTHOR]

Water scarcity is becoming one of the greatest challenges that human societies will face during this century. Monitoring water availability is expensive and technically challenging. In this regard, biological communities (e.g. aquatic insects) offer a cost-effective alternative, since they integrate temporal and spatial hydrological variability. Here we explore the potential of Chironomidae (Diptera), which have been usually neglected due to their complex taxonomy, as indicators of both local habitat condition and water scarcity. The study took place in 28 sites across seven dryland streams distributed within a 400 km 2 section of the Upper San Pedro River basin, southeastern Arizona. The selected streams covered a wide range of hydrological variability, which was continuously measured through the deployment of 15 electrical resistance (ER) sensors. Chironomidae taxa with no drought-resistance strategies were rarely found in streams that experienced frequent drying events (i.e. intermittent and ephemeral streams), suggesting that droughts have the potential to reduce species richness due to local extinctions of drought-intolerant taxa. Intermittent and ephemeral streams registered low canopy cover and a significantly higher abundance of scrapers (which mainly feed on algae) and shredders (feeding on poorly decomposed coarse organic material). This suggests that structural changes associated to drought (e.g. reduced canopy cover and decomposition rates) might lead to changes in the functional composition of the Chironomidae assemblages. We conclude that Chironomidae species can be used as indicators of hydrological variability and the impacts of drought on streams in the absence of flow gauges. [ABSTRACT FROM AUTHOR]

Biological indicator methods represent one of the most effective and widely used strategies for understanding the influences of environmental degradation on biodiversity in various landscapes. Researchers and land managers generally assume that the present distributions of biological indicator species are influenced by the current environment. However, recent studies have suggested the importance of past environments to species distributions (i.e., a time lag between changes in species distribution and habitat alterations). Therefore, it is necessary to understand the effects of past environments on the distributions of indicator species. We conducted a survey on the Tokachi Plain in Hokkaido, Japan. We targeted two taxa that have been widely used as indicator species (carabid beetles and bats) and investigated whether past landscape environments influenced their present distributions. We showed that past landscape environments (5 decades prior to the present) influenced the distributions of some ecological trait groups in each taxon (large body size for carabid beetles and a 25 kHz peak echolocation frequency for bats) and that these effects varied among groups. Our results suggest the need to consider the dynamics of land-use changes and the effects of past environments on the distributions of indicator taxa, otherwise we may misunderstand the effects of environmental degradation on biodiversity. [ABSTRACT FROM AUTHOR]

• We provide the first global meta-analysis of bird functional diversity and human disturbances. • Bird functional diversity responded negatively to disturbances. • Isolation, logging and urbanization had negative effects on functional diversity. • Disturbances could jeopardize birds' functions, possibly threatening ecosystem resilience. Anthropogenic disturbances represent the main threat to biodiversity around the globe, yet effects are not restricted to species loss. Assessing the functional diversity, which measures the range and value of ecological traits of organisms, can provide a more direct link between biodiversity and ecosystem functioning. Therefore, as species' responses to disturbances depend on their ecological traits, ecosystem functions are likely to be also imperiled by human perturbations. Although the literature on the effects of disturbances on functional diversity has been increasing, results are highly varied. Here, we provided the first comprehensive global meta -analysis on the effects of human disturbances on functional diversity of birds. We also performed subgroup analyses by region, habitat specialization, functional trait, functional diversity index and disturbance type. Our results indicate a consistent negative effect of disturbances on bird functional diversity, regardless of the variability caused by the different predictor variables considered. Specifically, we revealed that studies that were conducted in the tropics, focused on feeding traits and calculated functional diversity and richness indices presented negative responses to disturbances. Additionally, the functional diversity of birds, regardless of habitat specialization, was also negatively affected by anthropogenic disturbances. Lastly, habitat isolation, logging and urbanization exhibited a consistent negative effect on the functional diversity of birds, whereas agriculture, habitat loss and multiple disturbances had no detectable influence. These results indicate that anthropogenic disturbances can be detrimental to birds, possibly jeopardizing their ecological functions and threatening ecosystem resilience. We therefore suggest that conservation efforts should particularly focus on reducing or mitigating the effects of these three disturbances to at least diminish their effects on avian functional diversity. Additionally, we highlight the need for novel studies to simultaneously investigate the direct relationship between disturbance, functional diversity and especially ecosystem function, through the employment of multiple complementary indices, in order to effectively assist conservation decisions. [ABSTRACT FROM AUTHOR]

• Macroinvertebrate multimetric assessment of ecological health was conducted. • 38 rivers in KwaZulu-Natal (KZN) Province, South Africa were assessed. • 9 of the selected metrics had strong correlations with environmental variables. • Increasing chemical deterioration along longitudinal gradients of rivers was found. • Macroinvertebrate community metrics could detect pollution and habitat degradation. This study examined the effectiveness of macroinvertebrate community-based multimetrics to assess the ecological health of 38 rivers in KwaZulu-Natal (KZN) Province, South Africa. The study area comprised of headwater to lowland rivers determined by their hydro-morphology. Of the 40 tested metrics, only 11 core metrics were finally selected because of their ability to distinguish between reference and impaired sites, correlation strength with environmental variables and their reliability. Nine out of the selected metrics had strong correlations with environmental variables and these were total number of taxa, total number of Diptera taxa, total number of Plecoptera individuals, percentage of Ephemeroptera Plecoptera and Trichoptera taxa, percentage of Odonata taxa, total number of Trichoptera individuals, total number of Gastropoda individuals, total number of Oligochaeta individuals and total number of Coleoptera individuals. This study showed increasing chemical deterioration along longitudinal gradients of the rivers in KZN. We found that macroinvertebrate community metrics could detect nutrient pollution, organic pollution and physical habitat degradation in the rivers of KZN. We recommend more studies and validation of macroinvertebrate community-based metrics in the assessment of rivers in KZN, because they are relatively cheap and easy to use. The use of macroinvertebrate community metrics could be an effective alternative assessment method in the case of the lowland rivers where the lack of quality data often has negative impacts on the use of the biotic indices (South African Scoring System (SASS), Average Score Per Taxon (ASPT) and Macroinvertebrate Response Assessment Index (MIRAI)). [ABSTRACT FROM AUTHOR]