Human‐induced globalization of insular herpetofaunas

Aim: The aim was to document the impact of the globalization of human activity on the biodiversity and biogeographical patterns of reptilian and amphibian faunas across islands worldwide. Location: Islands worldwide. Time period: From the 15th century to the present time. Major taxa studied: Reptiles and amphibians. Methods: We compiled lists of the reptilian and amphibian species that occurred on islands before the 15th century and of those that occur currently. For each species group, we calculated differences in species richness and in compositional similarities among islands, between the two periods. Regression models were used: (a) to associate the observed differences with spatial patterns of geographical, climatic, biotic and human factors; and (b) to quantify changes in the relative importance of non-human factors in explaining the spatial patterns of species richness and compositional similarity. Results: The richness of reptile and amphibian species increased consistently across islands worldwide. Hotspots of increase were detected in the Caribbean and the Indian Ocean. The composition of species assemblages was substantially homogenized; this was particularly true for amphibians within the Caribbean Sea and for reptiles within the Caribbean Sea and Indian Ocean and between the Indian and the Pacific Oceans. Our results showed that spatial patterns of change in species richness and compositional similarity are driven by human and natural factors. The driving role of mean annual temperature is particularly consistent, and current reptile richness and compositional similarity patterns for both species groups are increasingly being shaped by the global temperature gradient. Main conclusions: The globalization of human activity is eroding the regionalized character of insular herpetofaunas and leading to the emergence of global-scale gradients of taxonomic composition and species richness. Projections of increasing rates of biological invasions, extinctions and climate change suggest that these changes are likely to be aggravated even further in the coming decadesinfo:eu-repo/semantics/acceptedVersio

Calandra lark habitat selection: strong fragmentation effects in a grassland specialist

Conserving grassland birds in farmed landscapes requires the maintenance of favourable agricultural land uses over a range of spatial and temporal scales. Here we examined the field and landscape-scale habitat requirements of the calandra lark (Melanocorypha calandra), an obligate grassland bird often associated with open Mediterranean farmland. Breeding and wintering lark densities were assessed in 42 fallowfields in southern Portugal, and related to three sets of variables reflecting field, landscape and neighbourhood effects. Variation partitioning was used to isolate the unique and shared contributions of sets of variables to explained variation in lark distribution and abundance models. At the field scale, the presence of trees and shrubs showed the strongest negative effects on calandra lark. At the landscape scale therewere strong positive response of larks to the amount and patch size of open farmland habitats, and negative responses, albeit weaker, to drainage and road densities. Calandra lark distribution and abundance was also positively related to that of conspecifics in surrounding fields, particularly in spring. Results suggest that calandra larks are highly sensitive to habitat fragmentation, requiring fallow fields with no shrubs or trees, embedded in large expanses of open farmland. This supports the view that grassland bird conservation in Mediterranean agricultural landscapes may require a combination of land-use regulations and agri-environment schemes preventing ongoing shrub encroachment and afforestation of marginal farmland

Networks of global bird invasion altered by regional trade ban

Research Article - EcologyWildlife trade is a major pathway for introduction of invasive species worldwide. However, how exactly wildlife trade influences invasion risk, beyond the transportation of individuals to novel areas, remains unknown. We analyze the global trade network of wild-caught birds from 1995 to 2011 as reported by CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). We found that before the European Union ban on imports of wild-caught birds, declared in 2005, invasion risk was closely associated with numbers of imported birds, diversity of import sources, and degree of network centrality of importer countries. After the ban, fluxes of global bird trade declined sharply. However, new trade routes emerged, primarily toward the Nearctic, Afrotropical, and Indo-Malay regions. Although regional bans can curtail invasion risk globally, to be fully effective and prevent rerouting of trade flows, bans should be globalinfo:eu-repo/semantics/publishedVersio

Patterns and drivers of the global diversity of non‐native macrofungi

Aim: To uncover the biogeography of non-native macrofungal diversity worldwide, by analysing patterns and drivers of (1) regional variation in species richness, (2) compositional similarity between regional species assemblages and (3) the spatiotemporal trends of first records. Location: Global. Methods: We used a database providing 1608 distribution records of 554 non-native macrofungal species in 167 national and sub-national regions worldwide. Regression models accounting for regional levels of recording capacity were used to relate spatial variation of non-native macrofungal richness and of regional compositional similarities to variables representing geographical, socio-economic and biophysical characteristics of regions. Temporal trends of first records were assessed at the global and continental scales and for distinct ecofunctional groups. Results: Regions reporting higher diversity of non-native species occur mainly in Europe, the Americas and Oceania. Regression models showed that regions with greater gross domestic product per capita, areal extent and in the Southern Hemisphere have higher non-native species richness, while regions with similar mean temperatures and latitudinal position share higher compositional similarities. Numbers of first records of non-native macrofungi have grown quasi-exponentially between 1753 and 2018, reflecting not only improved recording capacities but also likely an increasing number of introductions.Main Conclusions: We find that many regions of the world already harbour a high diversity of non-native macrofungi, with economic, climatic and introduction pathwayrelated factors explaining a relevant portion of the geographical patterns formed by these taxa. Given that socio-economic activity has increased strongly in recent decades, the global anthropogenic redistribution of macrofungi is likely to intensify further in the near future.info:eu-repo/semantics/publishedVersio

Effects of changed grazing regimes and habitat fragmentation on Mediterranean grassland birds

In Iberian cereal-steppes, decoupling of payments from current production levels through the Single Farm Payment raised concerns regarding the potential for land abandonment and replacement of sheep by cattle, with eventual negative consequences for declining grassland birds. This study addressed this issue by analysing the responses of five grassland bird species of conservation concern to spatial land use gradients, which are expected to reflect changes potentially associated with the CAP reform. Our results show that both habitat fragmentation and grazing regimes were major drivers of breeding bird densities, though responses to these factors were species-specific. Thekla larks were most abundant in landscapes with small grassland patches and high edge density, whereas calandra larks were abundant only in large expanses of continuous open farmland habitat. Little bustard and short-toed lark densities declined in highly fragmented landscapes, but they appeared to tolerate or even benefit from low to moderate levels of open habitat fragmentation. Corn buntings were little affected by landscape patterns. At the field scale, little bustard and corn bunting densities were highest in fields grazed by cattle, whereas short-toed larks were mostly associated with sheep pastures. Short-toed larks and Thekla larks were most abundant in old fallow fields where cattle was largely absent, whereas corn buntings showed the inverse pattern. These results confirm the view that the same agricultural policies may be favourable for some species of conservation concern but detrimental to others, and so they cannot be assumed to bring uniform conservation benefits

Favourable areas for co-occurrence of parapatric species: niche conservatism and niche divergence in Iberian tree frogs and midwife toads

Aim Predicting species responses to global change is one of the most pressing issues in conservation biogeography. A key part of the problem is understanding how organisms have reacted to climatic changes in the past. Here we use species distribution modelling to infer the effects of climate changes since the Last Interglacial (LIG, about 130,000 ybp) on patterns of genetic structure and diversity in the Western Spadefoot toad (Pelobates cultripes) in combination with spatially-explicit phylogeographic analyses. Location Iberian Peninsula and mainland France. Methods 524 individuals from 54 populations across the species range were sampled to document patterns of genetic diversity and infer their evolutionary history based on data from mtDNA and fourteen polymorphic microsatellites. Generalized linear models based on distribution data were used to infer climatic favourability for the species in the present and in paleoclimatic simulations for the LIG, the Mid Holocene and the last glacial maximum (LGM). Results Estimates of genetic diversity show a decreasing trend from south to north, suggesting persistence of high historical population sizes in the southern Iberian Peninsula. Species distribution models show differences in climatic favourability through time, with significant correlations between historically stable favourable areas and current patterns of genetic diversity. These results are corroborated by Bayesian Skyline Plots and continuous diffusion phylogeographic analyses. Main conclusions The results indicate the presence of southern refugia, with moderate recent expansions at the northern end of the species’ range. Toads at the northern range margin exhibit the lowest genetic diversity and occupy areas of high past climate variability, classified as marginal in terms of favourability, rendering these populations most vulnerable to climate-mediated changes in the long term

A database of the global distribution of alien macrofungi

Human activities are allowing the ever-increasing dispersal of taxa to beyond their native ranges. Understanding the patterns and implications of these distributional changes requires comprehensive information on the geography of introduced species. Current knowledge about the alien distribution of macrofungi is limited taxonomically and temporally, which severely hinders the study of human-mediated distribution changes for this taxonomic group.info:eu-repo/semantics/publishedVersio

Distance to edges, edge contrast and landscape fragmentation: interactions affecting farmland birds arounf forest plantations

Afforestation often causes direct habitat losses for farmland birds of conservation concern, but it is uncertain whether negative effects also extend significantly into adjacent open land. Information is thus required on how these species react to wooded edges, and how their responses are affected by edge and landscape characteristics. These issues were examined in Mediterranean arable farmland, using bird counts at 0, 100, 200, 300 and >300 m from oak, pine and eucalyptus edges, embedded in landscapes with variable amounts and spatial configurations of forest plantations. Bird diversity declined away from edges, including that of woodland, farmland and ground-nesting birds. Positive edge responses were also found for overall and woodland bird abundances, and for five of the nine most widespread and abundant species (Galerida larks, stonechat, linnet, goldfinch and corn bunting). Strong negative edge effects were only recorded for steppe birds, with reduced abundances near edges of calandra larks and short-toed larks, but not of little bustards and tawny pipits. Edge contrast affected the magnitude of edge effects, with a tendency for stronger responses to old and tall eucalyptus plantations (hard edges) than to young and short oak plantations (soft edges). There were also species-specific interactions between edge and fragmentation effects, with positive edge responses tending to be strongest in less fragmented landscapes, whereas steppe birds tended to increase faster away from edges and to reach the highest species richness and abundances in large arable patches. Results suggest that forest plantations may increase overall bird diversity and abundance in adjacent farmland, at the expenses of steppe birds of conservation concern

Potential for invasion of traded birds under climate and land‐cover change

Humans have moved species away from their native ranges since the Neolithic, but globalization accelerated the rate at which species are being moved. We fitted more than half million distribution models for 610 traded bird species on the CITES list to examine the separate and joint effects of global climate and land-cover change on their potential end-of-century distributions. We found that climate-induced suitability for modelled invasive species increases with latitude, because traded birds are mainly of tropical origin and much of the temperate region is ‘tropicalizing.’ Conversely, the tropics are becoming more arid, thus limiting the potential from cross-continental invasion by tropical species. This trend is compounded by forest loss around the tropics since most traded birds are forest dwellers. In contrast, net gains in forest area across the temperate region could compound climate change effects and increase the potential for colonization of low-latitude birds. Climate change has always led to regional redistributions of species, but the combination of human transportation, climate, and land-cover changes will likely accelerate the redistribution of species globally, increasing chances of alien species successfully invading non-native lands. Such process of biodiversity homogenization can lead to emergence of non-analogue communities with unknown environmental and socioeconomic consequences.info:eu-repo/semantics/publishedVersio