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Biocrusts determine soil stability and resiliency, with a special role played by oxygenic photoautotrophic microorganisms in these communities. We evaluated temporal and geographic trends in studies focused on these microorganisms in biocrusts. Two databases were surveyed to obtain scientific articles published from 1998 to 2020 containing the terms 'biocrusts,' 'algae,' and 'cyanobacteria.' Although interest in biocrusts has increased recently, their ecological importance is still little explored. The scientific articles that mentioned a species list of cyanobacteria and/or algae revealed a very heterogeneous geographic distribution of research. Biocrusts have not been explored in many regions and knowledge in the tropics, where these communities showed high species richness, is limited. Geographic gaps were detected and more detailed studies are needed, mainly where biocrust communities are threatened by anthropogenic impacts. Aiming to address these knowledge gaps, we assembled a taxonomic list of all algae and cyanobacteria found in these articles, including information on their occurrence and ecology. This review is an updated global taxonomic survey of biocrusts, which importantly reveals their high species richness of oxygenic photoautotrophic microorganisms. We believe this database will be useful to future research by providing valuable taxonomic and biogeographic information regarding algae and cyanobacteria in biocrusts.
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Cianobactérias , Microbiologia do Solo , Cianobactérias/classificação , Cianobactérias/genética , Biodiversidade , SoloRESUMO
Purpose of Review: Houseflies, Musca domestica L., are an important sanitary pest that affects human and domesticated animals. They are mechanical carriers of more than 100 human and animal diseases including protozoan, bacterial, helminthic, and viral infections. Recently, it was demonstrated that houseflies acquired, harbored, and transmitted SARS-CoV-2 (COVID-19) for up to 1 day post-exposure. The most widely used control strategy relays on the application of pyrethroid insecticides due to their effectiveness, low mammalian toxicity, low cost, and environmental safety. The main mechanism of action of pyrethroids is to exert their toxic effects through affecting the voltage-sensitive sodium channel (VSSC) modifying the transmission of the nerve impulse and leading to the death of the insects. Target site insensitivity of the VSSC is due to the presence of single nuclear polymorphisms (SNPs) named knockdown mutations (kdr). In this review, we synthetize recent data on the type and distribution of these mutations globally. Recent Findings: Housefly resistance is reported in several countries. Increased applications of pyrethroids to control housefly populations led to the emergence of multiple evolutionary origins of resistance determined by five amino acid substitutions or specific mutations in the VSSC: kdr (L1014F), kdr-his (L1014H), super-kdr (M918T + L1014F), type N (D600N + M918T + L1014F), and 1B (T929I + L1014F). According to the global map obtained, high levels of resistance to pyrethroids are associated with the L1014F mutation found mostly in North America, Europe, and Asia, while the super-kdr mutation was mostly found in the American continent. The level of protection conferred by these alleles against pyrethroids was generally kdr-his < kdr < Type N ≤ super-kdr ≤ 1B. The relative fitness of the alleles under laboratory conditions was susceptible â kdr-his > kdr > super-kdr suggesting that the fitness cost of an allele was relative to the presence of other alleles in a population and that the reversion of resistance in a free insecticide environment might be quite variable from one region to another. Summary: An adequate integrated pest management program should consider monitoring susceptibility to pyrethroids to detect early levels of resistance and predict the spread and evolution of resistant phenotypes and genotypes. From this review, the pyrethroid resistance status of housefly population was determined in very few countries and has evolved independently in different areas of the world affecting chemical control programs.
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The prediction of the potential distribution of invasive alien species is key for the control of their proliferation. This study developed ensemble niche models to explore the distribution patterns of Cecropia peltata and Ulex europaeus under baseline and future conditions, as well as the factors that regulate them. The models were based on occurrence records as well as climate, land-use and topography datasets. Climatic factors played a stronger role than land-use and topographical factors in their distribution patterns. Additionally, temperature seasonality and temperature annual range were the optimal predictor for the global distributions of C. peltata and U. europaeus, respectively. Under the baseline-RCP 8.5 scenario in 2070, significant increases in habitat suitability for C. peltata were generally detected in tropical regions, while for U. europaeus under the same condition, significant increases in habitat suitability were generally observed in west coast of South America and Europe, suggesting the impacts of climate changes on species distribution may be species specific. The contrast changes of suitable habitat areas for U. europaeus under the baseline-2.6 and 8.5 scenarios may suggest that the scenarios of climate changes may modify its distribution patterns and variations in suitable habitats. The double-edged effects of global warming on plant invasions may be a result of the scenario specific climate change and the species-specific responses to changes in climate. Our findings highlight the importance of climate change scenario specific and species-specific research on the impact of climate change on plant invasions.
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Mudança Climática , Espécies Introduzidas , Ecossistema , Europa (Continente) , América do SulRESUMO
Ericoid mycorrhiza is arguably the least investigated mycorrhizal type, particularly when related to the number of potential hosts and the ecosystems they inhabit. Little is known about the global distribution of ericoid mycorrhizal (ErM) fungi, and this holds true even for the prominent ErM mycobiont Rhizoscyphus ericae. Earlier studies suggested R. ericae might be low in abundance or absent in the roots of Southern Hemisphere's Ericaceae, and our previous investigations in two Argentine Patagonian forests supported this view. Here, we revisited the formerly investigated area, albeit at a higher altitude, and screened fungi inhabiting hair roots of Gaultheria caespitosa and Gaultheria pumila at a treeless alpine site using the same methods as previously. We obtained 234 isolates, most of them belonging to Ascomycota. In contrast to previous findings, however, among 37 detected operational taxonomic units (OTUs), OTU 1 (=R. ericae s. str.) comprised the highest number of isolates (87, â¼37 %). Most of the OTUs and isolates belonged to the Helotiales, and 82.5 % of isolates belonged to OTUs shared between both Gaultheria species. At the alpine site, ericoid mycorrhizal fungi dominated, followed by dark septate endophytes and aquatic hyphomycetes probably acting as root endophytes. Our results suggest that the distribution of R. ericae is influenced, among others, by factors related to altitude such as soil type and presence/absence and type of the neighboring vegetation. Our study is the first report on R. ericae colonizing Ericaceae roots in the Southern Hemisphere and extends the known range of this prominent ErM species to NW Patagonia.
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Ericaceae/microbiologia , Glomeromycota/isolamento & purificação , Micorrizas/fisiologia , Argentina , Glomeromycota/classificação , Glomeromycota/genética , Filogenia , Raízes de Plantas/microbiologiaRESUMO
The Americas are presently experiencing the most serious known outbreak of Zika virus (ZIKV). Here, we present a novel set of analyses using environmental characteristics, vector mosquito distributions, and socioeconomic risk factors to develop the first map to detail global ZIKV transmission risk in multiple dimensions based on ecological niche models. Our model predictions were tested against independent evaluation data sets, and all models had predictive ability significantly better than random expectations. The study addresses urgent knowledge gaps regarding (1) the potential geographic scope of the current ZIKV epidemic, (2) the global potential for spread of ZIKV, and (3) drivers of ZIKV transmission. Our analysis of potential drivers of ZIKV distributions globally identified areas vulnerable in terms of some drivers, but not for others. The results of these analyses can guide regional education and preparedness efforts, such that medical personnel will be better prepared for diagnosis of potential ZIKV cases as they appear.