Viruses are abundant, ubiquitous members of soil communities that kill microbial cells, but how they respond to perturbation of soil ecosystems is essentially unknown. Here, we investigate ...lineage-specific virus-host dynamics in grassland soil following “wet-up”, when resident microbes are both resuscitated and lysed after a prolonged dry period. Quantitative isotope tracing, time-resolved metagenomics and viromic analyses indicate that dry soil holds a diverse but low biomass reservoir of virions, of which only a subset thrives following wet-up. Viral richness decreases by 50% within 24 h post wet-up, while viral biomass increases four-fold within one week. Though recent hypotheses suggest lysogeny predominates in soil, our evidence indicates that viruses in lytic cycles dominate the response to wet-up. We estimate that viruses drive a measurable and continuous rate of cell lysis, with up to 46% of microbial death driven by viral lysis one week following wet-up. Thus, viruses contribute to turnover of soil microbial biomass and the widely reported CO2 efflux following wet-up of seasonally dry soils.
Biogeographical transition zones are areas of overlap, replacement or partial segregation between different biotas, which are sets of taxa sharing similar geographical distributions as a result of a ...common evolutionary history and ecological affinities. Transition zones occur in a few particular areas of the world where historically contingent processes have allowed different biotic elements to coexist and interact. Evolutionary or historical biogeographers have traditionally characterized transition zones by the overlap of different biotic elements. More recently, authors applying track analyses have detected transition zones by the presence of nodes or by conflicting results in cladistic biogeographic analyses. Ecological biogeographers have taken a different approach, usually applying quantitative methods, for example, species turnover indices to analyse the strength and breadth of biogeographic transition zones. Some authors consider transition zones to represent outstanding areas for analysing the principles shaping biotic assembly, whereas others have dismissed them, sometimes as artificial. Biogeographical transition zones are particularly interesting for a truly integrative biogeography, being natural laboratories where the interaction of historical and ecological processes can be analysed fruitfully, and are especially appropriate for an integrative approach, epistemologically grounded in integrative pluralism. A coherent conceptual framework to analyse transition zones, however, is still lacking.
Abstract Ecological strategies identified by plant functional traits are valuable descriptors for understanding species, populations, communities, and ecosystems in response to environmental ...conditions. Ecological strategies, in conjunction with the functional structure of plant communities, serve as crucial tools for investigating complex relationships among the environment, vegetation, and ecosystem functions. However, it remains unclear whether the functional structure (specifically, community‐weighted mean CWM traits) accurately reflects the optimal ecological strategies in forest communities. Here, we gathered seven functional traits for each species from four distinct forest vegetation types across four climatic zones, including leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf phosphorus concentration (LPC), leaf nitrogen concentration (LNC), wood density (WD) and maximum plant height (H). We based on CSR (Competitors, Stress‐tolerators, Ruderals) theory and “StrateFy” ordination method utilizing LA, LDMC and SLA to position them within CSR triangle and categorize them into four ecological strategy groups: Competitive, Stress‐tolerant, Intermediate, and Ruderal ecological strategy groups (C‐group, S‐group, Int‐group, and R‐group). We then determined the proportion of species in each group. Subsequently, we calculated the CWM trait values for the remaining four functional traits: WD (CWM‐WD), LPC (CWM‐LPC), LNC (CWM‐LNC) and H (CWM‐H). Non‐metric multidimensional scaling and hierarchical partitioning revealed that CWM‐WD, CWM‐LPC, CWM‐LNC and CWM‐H significantly influenced the ecological strategies of forest communities. The synergistic interaction of CWM‐WD and CWM‐LPC had the most significant impact on ecological strategies within forest communities. Notably, CWM‐WD emerged as the most crucial single CWM trait for explaining variation in ecological strategies within forest communities. In conclusion, our study demonstrates that CWM traits effectively reflect optimal CSR ecological strategies in forest communities across different climatic zones, with CWM‐WD serving as a preferred indicator. This can improve our critical insights into key ecological processes in forest communities using trait‐based approach.
Abstract Past climate changes have had large impacts on modern ecological patterns. Understanding if legacies are distinguishable in the climatic niches of extant and locally extinct taxa can provide ...insight into the importance of climate in extinction events. To better understand mid‐ to late‐Cenozoic New Zealand plant extinctions, which are often attributed to Cenozoic climate cooling, we identify 13 con‐familial extinct and extant New Zealand genus pairs, which have modern distributions in Australia. Using climatic niches derived from current geographic distributions in Australia, we compared (i) total niche breadth, (ii) niche overlap, and (iii) individual climate parameters, to investigate potential climate drivers of intrafamilial extinction and persistence patterns in New Zealand. A majority of New Zealand extinct genera (9 out of 13 pairs) do not indicate climate niche legacies consistent with susceptibility to extinction from changing climates, while the remaining four extinct/extant pairs show slight climatic niche legacies. Three extinct genera have warmer niches than their extant counterpart, which is consistent with extinction reflecting intolerance of cooling Cenozoic climates. The other genus pair with a climatic niche legacy has an extinct genus that is distinguished by a niche with smaller precipitation seasonality than its extant counterpart, suggesting that climate metrics other than temperature may also be important extinction drivers in some taxa. Our results show that the mechanisms of Cenozoic extinctions of New Zealand genera are likely more complex than taxa reaching environmental tolerances due to cooling climates. Comparisons of current climatic niches between extant and extinct sister taxa can provide useful insights into large‐scale, long‐term climatic legacies but more analyses, including trait and phylogeographic patterns, would lead to additional insights into alternative pathways of extinction.
Abstract An ongoing challenge in evolutionary and ecological research focuses on testing biogeographic hypotheses for the understanding of both species' distributional patterns and of the factors ...influencing range limits. In this study, we described the climatic niches of Neotropical humid montane forest birds through the analysis of factors driving their evolution at inter‐ and intraspecific levels; and tested for differences among allopatric lineages within Aulacorhynchus, Chlorospingus, Cardellina, and Eupherusa . We employed ecological niche models (ENMs) along with an ordination approach with kernel smoothing to perform niche overlap analyses and test hypotheses of niche equivalence/similarity among lineages. In addition, we described the potential distributions of each lineage during the Late Pleistocene climate fluctuations, identifying historical range expansions, connectivity, and stability. Overall, we observed differences in environmental variables influencing climatic requirements and distributional patterns for our selected species. We detected the highest values of niche overlap mainly between Eupherusa and some Chlorospingus lineages. At both interspecific and intraspecific levels, sister lineages showed non‐identical environmental niches. Our results offer weak support to a moist forest model, in which populations followed the expansion and contraction cycles of montane forests, leading to a lack of niche conservatism among lineages (they tend to occupy not identical climatic environments) throughout Mesoamerica. Therefore, historical climatic conditions may act as ecological barriers determining the distributional ranges of these species.
Tetrapods (four-limbed vertebrates) invaded the land more than 370 million years ago and began to diversify into a spectacular range of morphologies and life modes, rapidly achieving a global ...distribution. However, due to the inherent temporal and spatial bias of the fossil record, global patterns of tetrapod diversity and biogeography during critical intervals of the group's evolution remain unresolved. This thesis focuses on examining the patterns and drivers of tetrapod diversity during two of these key intervals. Firstly, advanced statistical, phylogenetic, and modelling approaches were used to examine the impact of major environmental change on the first tetrapods to emerge onto land during the late Palaeozoic (358-272 million years ago). Next, these approaches were combined with palaeoclimatic reconstructions to examine the influence of climate on tetrapod diversity during the early Mesozoic (237-174 million years ago), when modern vertebrate groups, including the dinosaurs, were originating. Together, the results provide a comprehensive assessment of the impact of sampling biases on estimates of past diversity, as well as providing greater insights into the role of environmental and climate change on tetrapod diversity and biogeography.
A new species of Ceratina Oliveira, Favízia Freitas de; Silva, Lívia Raquel de Sousa; Zanella, Fernando César Vieira ...
ZooKeys,
12/2020
3
Journal Article
Recenzirano
A new species of the small carpenter bee, genus Ceratina (Ceratinula) Moure, from the Cerrado Biome in midwestern Brazil is described and illustrated. Ceratina (Ceratinula) fioreseana Oliveira, sp. ...nov. is easily distinguished from its congeners by the size of the facial maculations and the honey-yellow color of the legs and antennal scape, which distinguish it especially from Ceratina (Ceratinula) manni Cockerell, 1912, the most similar species in terms of facial maculation patterns. The geographic records of C. manni , here interpreted as endemic to the semiarid Caatinga region in northeastern Brazil, are presented, with new records for the Brazilian states of Piauí, Ceará and Bahia. A morphological description of both species is provided, including a comparison with the type specimen of C. manni from the state of Paraíba (Guarabira, formerly named Independencia). An identification key is provided for the described species of Ceratina (Ceratinula) recorded for Brazil according to Moure's Catalogue of Neotropical Bees.
Island biogeography theory posits that species richness increases with island size and decreases with isolation. This logic underpins much conservation policy and regulation, with preference given to ...conserving large, highly connected areas, and relative ambivalence shown toward protecting small, isolated habitat patches. We undertook a global synthesis of the relationship between the conservation value of habitat patches and their size and isolation, based on 31 systematic conservation planning studies across four continents. We found that small, isolated patches are inordinately important for biodiversity conservation. Our results provide a powerful argument for redressing the neglect of small, isolated habitat patches, for urgently prioritizing their restoration, and for avoiding simplistic application of island biogeography theory in conservation decisions.
Aim To develop and implement a method for phylogenetic biogeography that is both event based and geographically explicit, that is, that uses the geographical ranges observed in the terminals instead ...of 'predefined areas.' Methods The method, GEM (Geographically explicit Event Model), attributes vicariance, sympatry (range copying), point sympatry (subset sympatry) or founder events, to the internal nodes of the tree. The cost of a reconstruction is calculated as the event cost plus the amount of range changes along a branch, and the best reconstruction is the combination of the event and range assignments that minimize the cost. Results The approach was implemented in a computer program, EVS, using a geographical data model (a raster) in which range changes were measured by pixel counts. The program can be used in real-sized datasets, using an heuristic to find reasonable solutions in short times. Main conclusion GEM provides a method for direct analysis of joint data on phylogeny and explicit distribution ranges, and proposes both the ancestral ranges and the biogeographical events connected with cladogenesis.
Understanding what drives the geographic variation of species richness across the globe is a fundamental goal of ecology and biogeography. Environmental variables have been considered as drivers of ...global diversity patterns but there is no consensus among ecologists on what environmental variables are primary drivers of the geographic variation of species richness. Here, I examine the relationship of woody plant species richness at a regional scale in China with sixteen environmental variables representing energy availability, water availability, energy-water balance, seasonality, and habitat heterogeneity. I found that temperature seasonality is the best predictor of woody species richness in China. Other important environmental variables include annual precipitation, mean temperature of the coldest month, and potential evapotranspiration. The best model explains 85% of the variation in woody plant species richness at the regional scale in China.
PDF
