Biodiversity is facing unprecedented threats from climate change and anthropogenic pressures, with potential losses of species across both terrestrial and marine ecosystems. This study examines the impacts of climate change on medicinal plants in the Brazilian Cerrado, a threatened biodiversity hotspot. We projected future distributions of medicinal plants under three climate scenarios, employing eight atmosphere−ocean circulation models, using species distribution models (SDMs). Our analysis reveals alarming trends: medicinal plant species may lose 50–64
Lotic ecosystems are structured by factors operating at multiple spatial scales. We investigated how local and regional environmental variables influence the composition, richness, and abundance of Ephemeroptera, Plecoptera and Trichoptera (EPT) assemblages in streams of the Tocantins-Araguaia basin in the Cerrado (Brazilian savanna) biome, Goias, Brazil. We sampled aquatic insects and environmental variables in 19 streams. We employed multiple regression analyses to evaluate the impact of spatial and environmental factors on taxonomic richness and abundance. We applied multiscale multivariate codependence analysis (MMCA) to examine the environmental and spatial effects on assemblage composition. Our results revealed that taxonomic richness increased with the percentage of agriculture in the watershed at finer scales, reflecting colonisation by tolerant taxa. Total abundance, in turn, responded to local factors (conductivity and temperature) and watershed areas. The assemblage composition of EPT was primarily structured by broad-scale spatial gradients (similar to 192 and similar to 128 km), associated with altitude and pH, respectively. These findings demonstrate that spatial processes (limited dispersal) act together with specific environmental filters to shape assemblages. We conclude that conservation strategies for aquatic biodiversity in the Cerrado must adopt a multiscale perspective that considers both local factors and watershed integrity.
The extinction threshold hypothesis proposes a minimum of 30% habitat in a landscape to prevent isolation from affecting populations to local extinction. In this study, we tested scenarios of habitat loss in the landscape to evaluate whether the 30% habitat threshold is a good predictor of functional connectivity for 14 terrestrial herpetofauna species in eastern Brazilian Amazon landscapes. We evaluated functional connectivity across various habitat loss scenarios, utilizing species distribution models and landscape connectivity indices. We were able to demonstrate that below 32% habitat, overall regional connectivity in Southeastern Amazonia erodes, disturbing the ability of species to track environments within their climatic limits. However, species inhabiting montane savannahs in the region did not respond well to this 30% threshold and required the presence of sufficient areas to assess a possible decline. We also discovered that, when evaluated together, small patches in the landscape contributed to the integral connectivity of the study area and may demonstrate their importance as links between larger patches. Our results provide critical insights into the conservation needs of forest and montane savannah species, highlighting that while forest species adhere closely to a habitat threshold, montane savannah species require a different approach for conservation.
Spatial synchrony, defined as the temporal correlation between population fluctuations across different locations, is crucial for understanding the dynamics of ecological communities, especially aquatic ecosystems. Although well studied in temperate systems, the influence of taxonomic resolution on the detection of spatial synchrony remains poorly explored in tropical reservoirs. Here, we investigated the synchrony patterns of the zooplankton community in the tropical Serra do Facao reservoir, located in the Parana River basin (GO, Brazil), considering limnological, climatic, and operational variables. While overall spatial synchrony was low, we identified a complex geography of synchrony that was significantly associated with local environmental drivers, such as physical and productivity-related variables, for specific taxa. Physical and productivity-related variables correlated with the synchrony of particular taxa (e.g., Daphnia gessneri and Diaphanosoma sp.), whereas climatic and operational factors did not exhibit a significant influence. These findings contrast with studies in temperate reservoirs, suggesting that intrinsic environmental heterogeneity and anthropogenic management suppress broad synchrony patterns. Our results highlight the importance of monitoring local variables in conservation programs for tropical reservoirs and question the effectiveness of approaches based on broad taxonomic groups in detecting synchronized responses. This study provides valuable insights into the sustainable management of aquatic ecosystems under anthropogenic pressure, emphasizing the need for research on larger spatial scales and the consideration of trophic variables to fully comprehend the dynamics of these systems.
The Amazon basin, spanning approximately 540,000 km2, exhibits distinct fluviometric surfaces that differentiate between the dry and rainy seasons. This seasonality, along with hydrological connectivity and the creation of new habitats during the rainy season, significantly promotes the migration, reproduction, and feeding of potamodromous fishes. To estimate the realized niches of species, species distribution models (SDMs) employ the extrapolation of environmental predictors and species occurrence data. Our objective was to compare the spatial distribution of migratory fish species in the Amazon basin using SDMs based on variables characterizing the dry season, rainy season, and a combination of both. All evaluated treatments demonstrated high performance and exhibited different distribution ranges in the applied SDMs, particularly when combining environmental variables with occurrence data during the rainy season. These findings support the hypothesis that spatial distribution is influenced by seasonality. The increased fluviometric surface and enhanced connectivity of the rainy season favor both longitudinal and lateral migrations of Amazonian migratory catfishes. Moreover, the spatial distribution reveals four critical spatial overlap (CSO) regions with higher population densities regardless of the season. These CSOs primarily coincide with the Amazon alluvial plain, which exhibits the highest rates of endemism, species richness, and abundance of organisms. Considering the discontinuous and heterogeneous nature of fluviometry when performing niche modeling processes is pivotal, although SDMs applied in the Amazon generally ignore such regional seasonality.
Orchid bees (Hymenoptera: Apidae) are exclusively Neotropical insects that occur naturally from Mexico to Argentina. Eufriesea species are the least studied among the five genera because they are often univoltine and active for a few months. Eufriesea brasilianorum is seldom collected and is one of the least-known species. We analyzed the data for this rare and threatened species using Maxent and an ensemble of models to determine distribution hypotheses for E. brasilianorum in Brazil. A small area of high suitability was found in eastern Brazil, including Atlantic Forest remnants. More studies must be developed to validate our predictions for E. brasilianorum. Future validation of the predictions obtained for E. brasilianorum will allow further discussion to list E. brasilianorum as a threatened species in the most recent National Action Plan for Conservation of Pollinator Insects Threatened by Extinction.
Abstract: Aim Assessing the damage caused to natural environments and native biodiversity by alien species is challenging. We tested whether the number of detections of alien species is affected by total alien or total invader alien species richness, considering the importance of predicting which species are more probable future invaders. Methods We summarized a research information survey conducted on alien amphibians, annelids, aquatic macrophytes, cnidarians, crustaceans, fish, microorganisms, mollusks, nemathelminths, platyhelminths, and reptiles, and for Brazilian watersheds. We used linear regressions between detections and total alien species richness and between detections and invader species richness. Results We obtained 1,896 alien detections of 183 aquatic species in Brazil. Fish and mollusk species were the commonest invaders due to their detections being more frequent than expected by chance, considering all the alien species occurring in Brazilian freshwater ecosystems. We also found positive and robust linear relationships between alien species detections and alien species richness. Conclusions Our results illustrate how Brazilian freshwater systems are fragile to alien invasions and highlight the need for effective action to address this question. Scientific uncertainty in Brazil regarding the status of some alien species and their potential harm is high, highlighting the need for a cautionary overview of invaders. Despite this scenario, new policies create opportunities for aquatic parks with exotic organisms to spread further in Brazil, which, in actual Brazilian conditions, is likely to increase the pressure on natural ecosystems and native species. This reinforces the already expressed need by the scientific community for greater attention to the issue.
Eucalyptus (Eucalyptus spp., Mirtaceae) stands out for its remarkable regeneration capacity, making it a valuable tool for recovering degraded areas and reforestation. Despite its origins in Australia, eucalyptus has shown remarkable adaptation to the Brazilian tropical climate, contributing significantly to the wood productivity of the country. However, the extensive monoculture of eucalyptus can increase the incidence of pests, representing a significant challenge for the forestry sector, with production losses of up to 30%. In our study, we analyzed the occurrence of 11 pest insect species in 450 eucalyptus stands over nine years in the southeastern region of Brazil. We related pest occurrences to specific year periods and climatic variations using circular uniformity analysis and zero-inflated models. We found that the species generally have isolated peaks of occurrence during the year and that the increase in the occurrence of at least five species was related to temperature or rainfall. The results highlight the sensitivity of pests to climatic conditions, showing the importance of management strategies to ensure the sustainability and productivity of eucalyptus plantations. We can develop more effective management strategies by understanding how these variables interact with insect populations, contributing to the sustainability and productivity of eucalyptus plantations with less aggressive environmental practices.
Abstract Elaborate sexual ornaments and weapons used in extravagant displays and ritualistic combats are among the most fascinating traits in nature. The evolution of this morphological and behavioral diversity is usually studied focusing on how selection operates via interactions between competitors of the same sex or mating partners. However, abiotic factors also play a significant role in the evolution of behavior and morphology, creating links between climate and the expression of sexually selected traits. This chapter explores different ways in which climate change (CC) may affect the evolution of insect ornaments and weapons directly or indirectly by affecting processes related to mate choice, intra-sexual competition, alternative mating tactics and intra-sexual dimorphisms. It also discusses how sexual dimorphism and species recognition mechanisms might be affected by CC. Finally, the chapter discusses the relationship between the strength of sexual selection and how insect species can adapt to environmental change.
Predicting the spread of invasive species and understanding the role of niche dynamics in niche transferability are critical challenges in the management of biological invasions, both theoretically and practically. We used complementary species distribution modelling approaches, such as multivariate niche analysis and reciprocal distribution models, to test the niche conservatism hypothesis and to predict the potential distribution of the fishhook waterflea, Cercopagis pengoi. Our analysis indicated a significant similarity between its native and invasive ranges, suggesting that a subset of the Ponto-Caspian propagules may have been the founders of European populations. However, our results contradict the niche conservatism hypothesis, showing that C. pengoi has not fully occupied the available niche within its current invasive ranges. Moreover, we observed a notable niche expansion, reflecting a significant shift in niche following its intercontinental introduction in North America. Given the suitability of new environments for the expansion of C. pengoi and its tendency to evade detection prior to population surges, we recommend a focus on early detection through monitoring of both water columns and bottom sediments. This should be complemented by strict enforcement of ballast water regulations to curtail its spread in North America, Europe, and other suitable non-native regions globally.
Climate change affects ecosystems in different ways. These effects are particularly worrying in the Neotropical region, where species are most vulnerable to these changes because they live closer to their thermal safety limits. Thus, establishing conservation priorities, particularly for the definition of protected areas (PAs), is a priority. However, some PA systems within the Neotropics are ineffective even under the present environmental conditions. Here, we test the effectiveness of a PA system, within an ecotone in northern Brazil, in protecting 24 endangered bird species under current and future (RCP8.5) climatic scenarios. We used species distribution modeling and dispersal corridor modeling to describe the priority areas for conservation of these species. Our results indicate that several threatened bird taxa are and will potentially be protected (i.e., occur within PAs). Nonetheless, the amount of protected area is insufficient to maintain the species in the ecotone. Moreover, most taxa will probably present drastic declines in their range sizes; some are even predicted to go globally extinct soon. Thus, we highlight the location of a potentially effective system of dispersal corridors that connects PAs in the ecotone. We reinforce the need to implement public policies and raise public awareness to maintain PAs and mitigate anthropogenic effects within them, corridors, and adjacent areas, aiming to conserve the richness and diversity of these already threatened species.
AbstractThe introduction of bees for agricultural production in distinct parts of the world and poor management have led to invasion processes that affect biodiversity, significantly impacting native species. Different Bombus species with invasive potential have been recorded spreading in different regions worldwide, generating ecological and economic losses. We applied environmental niche and potential distribution analyses to four species of the genus Bombus to evaluate the similarities and differences between their native and invaded ranges. We found that B. impatiens has an extended environmental niche, going from dry environmental conditions in the native range to warmer and wetter conditions in the invaded range. Bombus ruderatus also exhibited an extended environmental niche with drier and warmer conditions in the invaded range than in its native range. Bombus subterraneus expanded its environmental niche from cooler and wetter conditions in the native range to drier and warmer conditions in the invaded range. Finally, B. terrestris showed the most significant variation in the environmental niche, extending to areas with similar and different environmental conditions from its native range. The distribution models agreed with the known distributions for the four Bombus species, presenting geographic areas known to be occupied by each species in different regions worldwide. The niche analysis indicate shifts in the niches from the native to the invaded distribution area of the bee species. Still, niche similarities were observed in the areas of greatest suitability in the potential distribution for B. ruderatus, B. subterraneus, and B. terrestris, and to a lesser degree in the same areas with B. impatiens. These species require similar environmental conditions as in their native ranges to be established in their introduced ranges. Still, they can adapt to changes in temperature and humidity, allowing them to expand their ranges into new climatic conditions.
Accurate intraspecific variation assessment is the prerequisite for determining subspecies, evolutionarily significant units, or management units across a species range. However, intraspecific variation assessment is often hindered by inaccurate morphological results from traditional methods or high-cost genetic analyses. Geometric morphometrics is a promising technique for quantifying and visualizing intraspecific diversity. We used landmark-based geometric morphometrics to investigate forewing shape variation and microtaxonomy of populations of Apis florea Fabricius 1787 (Apidae: Apini), which originated from some parts of Asia and Africa based on the 19 landmarks plotted at the venation intersections of forewings. We collected samples of 162 colonies from 36 different localities. On average, 13 workers per colony were analyzed (1,851 bees in total). Distinct spatial structures and significant differences in wing shape between the studied populations were revealed using canonical variate analysis, and no considerable overlap was detected between the colonies belonging to the western and eastern populations. The populations at higher latitudes showed significantly larger centroid sizes than those at lower latitudes, and a clinal variation in forewing size was confirmed. Significant distance-decay relationships between the studied populations were observed so that the populations located at the maximum geographical distance (∼ 7,000 km) showed the most significant distance from each other and vice versa. Wing geometric morphometrics was an accurate tool for the reliable estimation of the population structure of the red dwarf honeybees. It is essential to increase the reliability of these variations by combining the results with further molecular data.
Cabassous tatouay occurs in moist forests, savannas, and grasslands of south, central, and northeastern Brazil, eastern Paraguay, northeastern Argentina, and Uruguay. Despite its wide distribution range, C. tatouay is scarcely recorded in some regions. This study aimed to: present new records of C. tatouay; compile the localities where the species was recorded according to published scientific accounts; and model its distribution range along South America. We present five new records of C. tatouay from Goias and Minas Gerais states, Brazil. The review of published accounts resulted in 99 studies, which provided 279 occurrences of C. tatouay to Brazil, Argentina, Paraguay, and Uruguay. The great majority of records are from Brazil, mainly from the Atlantic Forest (119), Cerrado (52), and Pampas (49) biomes. Most records from the Cerrado are placed close to or in transition zones with the Atlantic Forest. Five records are within the Caatinga, but restricted to humid montane forest enclaves. The species distribution models indicate that C. tatouay is probably absent to Amazonia and Pantanal. The higher suitability for the species occurs in eastern Paraguay, northeastern Argentina, and south central Brazil, specifically in the Pampas, Atlantic Forest, and the southern part of the Cerrado.
We evaluated the genetic structure and ecological niche segregation of Apis florea Fabricius 1787 (Apidae: Apini) across its native range using genetic and ecological niche data. The bee samples were from 62 colonies representing 40 localities across Iran, Iraq, Pakistan, Oman, and Egypt. Ecological niche divergence was estimated based on a principal component analysis of climatic/ecological variables. We confirmed the presence of two distinct lineages (eastern and western) for the species using mtDNA. There was no significant climatic heterogeneity between the lineages and their ecological niches are likely to be somewhat conserved. They were probably separated from each other during the Pleistocene and evolved in isolation. The two lineages of A. florea can be considered separate conservation units and used to develop strategies for effectively conserving this keystone pollinator species in Asia.
Abstract The introduction of invasive alien species (IAS) is among the leading causes of biodiversity loss in the world. The arrival of these species causes several imbalances in the natural environment. The establishment of these species depends on their transport, entry, adaptive success, and interactions in the environment. This work aims to present 12 species of exotic invasive fish that occur in natural environments in Brazil in the form of a booklet and to discuss some aspects inherent to legislation changes related to the cultivation of these species. The target audience of this study is mainly fish farmers, fishermen, riverside dwellers, assistance technicians, schools, environmental departments, and rural communities. The list had as a criterion the selection of species that are raised in fish farming stations and that already have records of occurrence in natural ecosystems in the country. These are exotic species introduced (from other countries) and with high invasive potential in Brazilian continental waters. To compose the list of these species, national and international studies that discuss the subject were sought, the following species being selected: Ctenopharyngodon idella, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Cyprinus carpio, Oreochromis niloticus, Coptodon Rendalli, Oreochromis mossambicus, Oreochromis macrochir, Clarias gariepinus, Ictalurus punctatus, Oncorhynchus mykiss, Micropterus salmoides. In addition to presenting the impacts of invasive alien species on native ichthyofauna, this material will help disseminate technical information and may also be an aid to guide public policy decision making and awareness.
Bee pollination is an important ecosystem service related to the maintenance of many flowering plants. We evaluated the relationship between orchid bee foraging time and the density of flowering plants and whether visitation varied according to the sex and size class of bees, using Calathea mansonis as a model species. We monitored 10 plots between December 2009 and November 2010 in a forest fragment in Senador Guiomard, Acre, Brazil. We counted the number of flowering plants and flowers per plant and the behaviour of the observed bees. Additionally, we compared the bagged and exposed inflorescences for self-compatibility analysis. We sampled 173 orchid bees from 13 species, with Eulaema cingulata as the most abundant visitor. Eulaema (large bees) were more effective pollinators than Euglossa (small bees). We also found Eulaema polyzona individuals feeding on a Marantaceae species for the first time. The time spent by the bees visiting flowers did not differ with the density of flowering plants or the number of flowers per plant. However, flowers exposed to visitors produced 35% more seeds and 15% heavier seeds than bagged flowers. Considering plant–bee interactions, orchid bees may increase gene flow and compensate for the clonal reproduction of this herb.
Resumo A introdução de espécies exóticas invasoras (EEI) está entre as principais causas de perda da biodiversidade no mundo. A chegada dessas espécies provoca vários desequilíbrios no meio natural. O estabelecimento destas espécies depende do transporte, entrada, sucesso adaptativo e interações no ambiente. Este trabalho tem como propósito apresentar 12 espécies de peixes exóticos invasores que ocorrem em ambientes naturais no Brasil na forma de cartilha e discorrer sobre alguns aspectos inerentes as mudanças na legislação em relação ao cultivo destas espécies. O público-alvo desta cartilha são principalmente piscicultores, pescadores, ribeirinhos, técnicos assistencialistas, escolas, secretarias de meio ambiente e a comunidade rural. A lista de teve como critério a seleção de espécies que são criadas em estações de piscicultura e que já possuem registros de ocorrência em ecossistemas naturais do país. Sendo estas, espécies exóticas introduzidas (vindas de outros países) e com alto potencial invasor em águas continentais brasileiras. Para compor a relação destas, foram buscados trabalhos nacionais e internacionais que discorre sobre o tema, sendo selecionadas as seguintes espécies: Ctenopharyngodon idella, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Cyprinus carpio, Oreochromis niloticus, Coptodon rendalli, Oreochromis mossambicus, Oreochromis macrochir, Clarias gariepinus, Ictalurus punctatus, Oncorhynchus mykiss, Micropterus salmoides. Além disso, são apresentados os impactos das espécies exóticas invasoras sobre a ictiofauna nativa, o que ajudará na divulgação de informações técnicas e poderá ser também um auxiliar para nortear tomadas de decisões de políticas públicas e conscientização.