Search

Novel methods for sampling and characterizing biodiversity hold great promise for re-evaluating patterns of life across the planet. The sampling of airborne spores with a cyclone sampler, and the sequencing of their DNA, have been suggested as an efficient and well-calibrated tool for surveying fungal diversity across various environments. Here we present data originating from the Global Spore Sampling Project, comprising 2,768 samples collected during two years at 47 outdoor locations across the world. Each sample represents fungal DNA extracted from 24 m3 of air. We applied a conservative bioinformatics pipeline that filtered out sequences that did not show strong evidence of representing a fungal species. The pipeline yielded 27,954 species-level operational taxonomic units (OTUs). Each OTU is accompanied by a probabilistic taxonomic classification, validated through comparison with expert evaluations. To examine the potential of the data for ecological analyses, we partitioned the variation in species distributions into spatial and seasonal components, showing a strong effect of the annual mean temperature on community composition. [ABSTRACT FROM AUTHOR]

Climatic gradients such as latitude and elevation are considered primary drivers of global biogeography. Yet, alongside these macro‐gradients, the vertical space and structure generated by terrestrial plants form comparable climatic gradients but at a fraction of the distance. These vertical gradients provide a spectrum of ecological space for species to occur and coexist, increasing biodiversity. Furthermore, vertical gradients can serve as pathways for evolutionary adaptation of species traits, leading to a range of ecological specialisations.In this review, we explore the ecological evidence supporting the proposition that the vertical gradient serves as an engine driving the ecology and evolution of species and shaping larger biogeographical patterns in space and time akin to elevation and latitude. Focusing on vertebrate and invertebrate taxa, we synthesised how ecological patterns within the vertical dimension shape species composition, distribution and biotic interactions.We identify three key ecological mechanisms associated with species traits that facilitate persistence within the vertical environment and draw on empirical examples from the literature to explore these processes.Looking forward, we propose that the vertical dimension provides an excellent study template to explore timely ecological and evolutionary questions. We encourage future research to also consider how the vertical dimension will influence the resilience and response of animal taxa to global change. [ABSTRACT FROM AUTHOR]

Kraits (genus Bungarus) are a group of highly venomous elapid snakes found across tropical Asia. Although they are notorious for causing many, often deadly, envenomations throughout the continent, their taxonomy and species nomenclature is subject to regular revisions. The boundaries demarcating B. candidus, B. multicinctus, and B. wanghaotingi, in Southern China and Northern Myanmar are particularly obscure. Despite the extensively overlapping distributions for the three species, only B. multicinctus has been documented in Hong Kong. Following genetic analyses, we suggest that both B. multincinctus and B. wanghaotingi occur in Hong Kong. However, our morphological examinations are overall inconclusive in distinguishing the two species. With potential interspecific antivenin differences, the new identification of B. wanghaotingi in Hong Kong is of important medical interest. We recommend further ecological, taxonomic, and behavioural studies be conducted to properly distinguish B. multincinctus and B. wanghaotingi in the region. [ABSTRACT FROM AUTHOR]

A major research question concerning global pelagic biodiversity remains unanswered: when did the apparent tropical biodiversity depression (i.e., bimodality of latitudinal diversity gradient [LDG]) begin? The bimodal LDG may be a consequence of recent ocean warming or of deep-time evolutionary speciation and extinction processes. Using rich fossil datasets of planktonic foraminifers, we show here that a unimodal (or only weakly bimodal) diversity gradient, with a plateau in the tropics, occurred during the last ice age and has since then developed into a bimodal gradient through species distribution shifts driven by postglacial ocean warming. The bimodal LDG likely emerged before the Anthropocene and industrialization, and perhaps ~15,000 y ago, indicating a strong environmental control of tropical diversity even before the start of anthropogenic warming. However, our model projections suggest that future anthropogenic warming further diminishes tropical pelagic diversity to a level not seen in millions of years. [ABSTRACT FROM AUTHOR]

Aim: Thermal physiology is commonly used in mechanistic models to predict species distribution and project distribution change. Such thermal constraints for ants are often measured under laboratory conditions as critical thermal limits (CTmax and CTmin), but have also been observed in the field as foraging thermal limits (FTmin and FTmax). Here we compared distribution projections based on ant physiological and behavioural thermal limits with their realized distributions to assess the validity of using ecophysiological models to predict species ranges over large scales. Location: Global. Taxon: Ants. Methods: From published literature, we compiled a database of 148 lab‐measured critical thermal limits and 137 field‐observed foraging thermal limits for 20 ant genera distributed around the world. We projected their potential ranges using active hour thresholds by matching their thermal limits or preferred thermal breadth (incorporating thermal optima) with hourly surface temperature data. We then compared the projections against a comprehensive global database of ant distributions to assess the validity of physiologically and behaviourally based models. Results: We found that surface temperature plays a clear role in generic‐level ant biogeography. Projections based on foraging thermal limits were more conservative in constraining ranges to observed distributions, while projections based on critical thermal limits often overestimated ranges. Furthermore, thermal limit models can be improved by incorporating behaviourally derived thermal optima. Main conclusions: Our results suggest that temperature‐dependent activity niches and thermal optima better reveal species realized thermal niches than critical thermal limits, and hence can improve predictions of species distributions and future distribution changes under climate change. [ABSTRACT FROM AUTHOR]

Many organisms exhibit changes in phenotypic traits as a response to seasonal environmental variation. We investigated the role of habitat in generating seasonal polyphenism in different populations of the light bush brown butterfly Bicyclus dorothea (Cramer, 1779) (Lepidoptera: Nymphalidae) in Cameroon. Butterflies were caught during the wet and dry seasons across four localities representing two distinct habitats, namely forest and ecotone (forest–savanna transition zone) over a 2-yr period (2015–2016). We found distinct variation in the wing pattern characteristics of butterflies in response to seasonality and habitat. Specifically we observed that: 1) all wing characters are not seasonally plastic in B. dorothea ; 2) populations from ecotone tend to be more variable, with individuals exhibiting wings with large spots during the wet season and very reduced spots in the dry season while in forest populations, individuals exhibit wings with large spots during the wet season, but in the dry season, spots are not as greatly reduced as their ecotone counterparts; 3) this polyphenism in B. dorothea alternated consistently during the wet and dry seasons over the 2 yr of sampling. Bicyclus species have become a textbook example of seasonal polyphenism while this study extends this model system to the unique forest–ecotone gradient of Central Africa and demonstrates the complexity of seasonal forms in different habitats. [ABSTRACT FROM AUTHOR]

Morphological traits can determine the ecological niches and performance of ectotherms and structure their distributions along environmental gradients. The thermal melanism hypothesis and Bergmann’s rule describe patterns of body colour luminance and body size along environmental gradients shaped by thermal influences on morphology. However, these patterns have rarely been investigated at the interspecific level for subtropical and tropical mountain environments. In this study, we sampled butterfly assemblages along elevations across three subtropical and tropical locations in China and examined how environmental factors affected body colour luminance and body size. We additionally reconstructed phylogenetic relationships among the sampled butterfly species and investigated morphology– elevation relationships within an evolutionary framework. Butterfly assemblages were consistently darker and larger at higher elevations across three replicate locations. Furthermore, based on a phylogenetic comparative analysis, we found that body colour luminance and body size of butterfly assemblages responded to elevation through both long-term processes and more recent environmental influences. Our findings support the thermal melanism hypothesis and Bergmann’s rule from diverse subtropical and tropical butterfly assemblages, indicating elevation may structure the distributions of tropical species through morphology. The thermal functions of morphology should therefore be considered when investigating species distribution patterns and responses to environmental changes. [ABSTRACT FROM AUTHOR]

Bicyclus dorothea dorothea (Cramer, 1779) is a widely distributed butterfly inhabiting much of the northern part of the tropical African rainforest. The biology of the species has not been well studied despite it being relatively common throughout its distribution. In this study, we report on the life history of B. d. dorothea following three years of research on the species in Cameroon. We describe the life cycle of the species and report on key life history aspects such as distribution, habitat, reproduction, and host plant relationships. [ABSTRACT FROM AUTHOR]

Distribution shifts are a common response in butterflies to a warming climate. Hong Kong has documented records of several new butterfly species in recent decades, comprising a high proportion of tropical species, some of which have successfully established. In this study, we examined possible drivers for the establishment of Euripus nyctelius Doubleday (Lepidoptera: Nymphalidae) by studying its thermal physiology and modeling current climate and future distributions projected by species distribution modeling (SDM). We found that E. nyctelius adults have a significantly higher critical thermal minimum than its local temperate relative, Hestina assimilis Linnaeus (Lepidoptera: Nymphalidae), suggesting a possible physiological constraint that may have been lifted with recent warming. SDMs provide further evidence that a shifting climate envelope may have improved the climate suitability for E. nyctelius in Hong Kong and South China—however, we cannot rule out the role of other drivers potentially influencing or driving range expansion, habitat change in particular. Conclusive attribution of warming-driven impacts for most tropical species is difficult or not possible due to a lack of historical or long-term data. Tropical insects will require a significant advancement in efforts to monitor species and populations across countries if we are to conclusively document climate-driven shifts in species distributions and manage the consequences of such species redistribution. Nevertheless, the warming climate and subsequent increased climatic suitability for tropical species in poleward areas, as shown here, is likely to result in future species redistribution events in subtropical and temperate ecosystems. [ABSTRACT FROM AUTHOR]

With increasing pressure from wildlife trade, conservation efforts must balance deficiencies in distribution data for species (the Wallacean shortfall) with the risk of increasing accessibility of locality for collectors. The Golden Kaiser-I-Hind (Teinopalpus aureus Mell) is an iconic butterfly restricted to Southeast Asia, popular in trade markets but lacking in ecological and conservation information. We compiled occurrence records and used them to assess multiple threats of T. aureus distribution-wide and at the national level. Results of species distribution models suggest that suitable habitats of T. aureus are montane forests in mid to high elevations in Southern China, Laos and Vietnam. However, habitat networks for the species are poorly connected, with some portions of its distribution experiencing intensive deforestation and threatened by climate change. The trade assessment results showed specimens of T. aureus were available for sale with high prices, indicating potential pressure from trade markets. We also found different conservation statuses and efforts to protect T. aureus across countries; the species is under strict protection in China, moderate protection in Vietnam and has no protection in Laos. Both recorded locations and projected distribution in the three countries were poorly covered by protected areas. These results together demonstrate the importance of distribution data in conservation management of threatened species while highlighting trade-offs inherent in not making location information widely available when trade pressure is present. Finally, we strongly encourage cross-border cooperation in sharing ecological information for consistent conservation management of species under multiple threats from habitat loss, climate change and illegal wildlife trade. [ABSTRACT FROM AUTHOR]