Biogeographic Domains Research Articles

The invasive indo-asiatic horntail snail ARIOPHANTIDAE Tanychlamys indica (Godwin-Austen, 1883) in Santa Catarina State/ SC, Brazil: general status of its knowledge seven (7) years after the first report of their discovery in the Brazilian territory and the earth’s American ecozones

Introduction: Seven (7) full years have passed since the initial report of its occurrence in the Neotropical continental territory of Brazil (discovered/ detected its introduction on “September 16, 2017” in the geopolitical state of Santa Catarina/ SC). Tanychlamys indica (Godwin-Auster, 1833), alien indo-Asiatic pulmonate terrestrial gastropod representative of the family Ariophantidae, is confirmed for the first time in the Americas and the Caribbean basin, presumably introduced unnoticed through the international trade of citrus fruit seedlings. Objective: Updated general rеᴠiеw of the geographical occurrence situation of this introduced species in the Santa Catarina State/ SC, the Brazilian territory and the Earth’s American Ecozones. Methodology: Extensive review of general available information (field encounters, reports obtained directly from collaborators, data contained in the "Taxonomic Catalog of the Brazilian Fauna - Mollusca", journalistic informations & records on the international citizen science platform "íNaturalist") up to December 2024. Results and Conclusions: Today, the regional known of the occurrence of this alien species is restricted to Brazil, the only country in South America where its presence has been reported/ confirmed, verified in the Federal District (D.F.) and seventeen (17) of its twenty-sixth (26) geopolitical states, present in their every one six (6) terrestrial epicontinental biogeographic domains/ biomes: Amazon, Caatinga, Cerrado, Atlantic Forest, Pampa or Southern Fields & Chaco-Pantanal. Additional information available about its recent presence in the rest of the Earth's American Ecozones (Neotropical & Nearctic territories) is also presented, obtained through so-called citizen science.

Paleo‐Suture Zone Disrupted by Thrusting: Example From East Junggar (NW China), Southern Altaids

AbstractUnderstanding the tectonic evolution of ancient orogens relies on reconstructing the primary architecture of suture zones that may be modified by post‐subduction events. Modifications in East Junggar, southern Altaids, have led to controversial interpretations about the Paleozoic tectonic evolution. To clarify these relationships, we report the Mesozoic thrust horizon in East Junggar that has displaced the Baishanbao Klippe, which contains siltstone, sandstone, conglomerate and biogeographical Tuva‐Mongolia Tuvaella fauna. This klippe is distinct from units in the footwall that contain Ordovician‐Early Devonian accretionary complexes with dismembered basalts, cherts and deep marine tuffaceous siltstones, Carboniferous volcanic rocks and granites, Middle‐Late Jurassic sediments, and Kazakhstan biogeographic Ordovician‐Late Devonian coral‐brachiopod‐ammonoid fauna. The thrust horizon and the aforementioned units are unconformably capped by Late Jurassic‐Early Cretaceous alluvial fan deposits; it constrains the thrust to a Mesozoic age. These two biogeographic domains were separated by the Paleo‐Asian Ocean until the Late Paleozoic, as evidenced by the 478 Ma Kujibai MOR‐type ophiolite that involved into subduction zone in the Carboniferous. This Mesozoic thrust transported the Baishanbao Klippe for over 100 km southwards from its root in the Altay‐Fuyun area and crossed a cryptic suture zone of the Paleo‐Asian Ocean as an allochthonous unit in East Junggar. It extensively disrupted the primary Paleozoic orogenic architecture of East Junggar that leads to misinterpretation of the regional tectonic evolution. A lesson from disruption of this Mesozoic thrusting is that care must be taken in studies of the architecture of paleo‐suture zones.

Phylogenomic insights into the worldwide evolutionary relationships of the stingless bees (Apidae, Meliponini)

Stingless bees (tribe Meliponini) are remarkable for their characteristically large social colonies, their capacity to produce honey and other useful products, and their morphological and behavioral diversity. They have a disjunct pan-tropical distribution, primarily occurring in warm and humid environments in the Neotropical, Afrotropical, and Indo-Australasian regions. Even though phylogenetic hypotheses have been proposed for Meliponini based on morphology and molecular data, many questions are still unsolved regarding the evolutionary relationships and systematics of the tribe. In this contribution, we present a large phylogenomic dataset comprising over 2500 ultra-conserved element (UCE) loci sequenced for 153 species of Meliponini, representing all known genera of stingless bees. The genera Camargoia, Paratrigonoides, Plectoplebeia, Cleptotrigona, Ebaiotrigona, Papuatrigona, Pariotrigona, Platytrigona, and Sahulotrigona were included in molecular phylogenetic analyses for the first time. Concatenated and species-tree analyses were performed using different partitioning strategies and summary methods. We performed gene-genealogy interrogation (GGI) on several recalcitrant nodes to resolve discordances among recovered tree topologies. Results were mostly consistent among analyses, recovering three main lineages of Meliponini congruent with the biogeographic domains to which they are associated. Within major clades, discordances were found in relation to previous works. The genus Frieseomelitta was recovered as paraphyletic in relation to Trichotrigona, and the genus Lepidotrigona was revealed to be composed of two independent lineages. Even though concatenated and weighted ASTRAL analyses were mostly effective in recovering the relationships favored by GGI, they retrieved different results in relation to the phylogenetic placements of Oxytrigona and Cephalotrigona. The most favored hypothesis in GGI analyses was not found in any other analyses, being more congruent with morphological evidence and highlighting the relevance of exploring the support given to alternative hypotheses through topological tests. Recent advances in our capacity to generate molecular sequences from old specimens using modern sequencing methods allowed for unparalleled sampling across genera, yielding a backbone for the phylogenetic relationships of stingless bees, which will further investigations into their systematics and evolution.

A multifaceted approach to expanding conservation efforts in the Pan-Himalayan landscape

The Pan-Himalayan biogeographic domain is a significant region for biodiversity conservation and climate resilience. This region has both tropical and extratropical flora and holds ecological, cultural, and socio-economic importance. However, knowledge about the spatial distribution and threats to threatened plant species in the study area is still poorly known. In this study we evaluate the phylogenetic diversity and phylogenetic endemism of threatened flora in the region, and also examine the effect of rapid land cover transformation and landscape fragmentation between 2000 and 2020 on the preservation of distinct evolutionary lineages. Phylogenetic metrics provide a better understanding of ecological, historical, and evolutionary factors that shape plant communities in highly biodiverse regions. Our result show that current protected areas are insufficient for preserving Pan-Himalayan biodiversity, and also reveal a significant gap in conservation efforts within these areas. We highlight conservation priorities areas in the western Himalayan belt encompassing 2.43 million km2 and covering 26.73% of the total area. However, a large conservation gap encompassed 22.67% (2.06 million km2) hotspots of total study area, whereas non-hotspot priorities covered 67.62% (0.77 million km2) of the total protected area, revealing a mismatch between biodiversity hotspots and protected areas. In addition, biodiversity priority areas have been threatened by rapid land cover transformation and landscape fragmentation between 2000 and 2020. There were 6.93% increase in cropland area and 172.64% increase in impervious surface, while an increase in landscape fragmentation and a decrease in landscape cohesion in different hotspots within protected areas. The biodiversity hotspot regions emphasize the need to conserve unique evolutionary lineages and high species occurrence areas with targeted conservation strategies. Mountainous, but cross-border international cooperation is highly recommended for effective preservation strategies. Our study has implications for advancing biodiversity preservation and sustainable ecosystem management not only in the Pan-Himalayan but also in similar regions, as well as for achieving the 2030 protection goal.

Functional biogeography of coastal marine invertebrates along the south‐eastern Pacific coast reveals latitudinally divergent drivers of taxonomic versus functional diversity

Characterizing the spatial structure of taxonomic and functional diversity (FD) of marine organisms across regional and latitudinal scales is essential for improving our understanding of the processes driving species richness and those that may constrain or enhance the set of species traits that define the functional structure of communities. Here, we present the functional diversity of coastal invertebrate macrofaunal species along the south‐eastern Pacific from 7°N to 56°S, describe spatial variation of species traits, and examine the relationship with environmental variables. For that, we defined the functional traits and distribution ranges of 2350 marine macroinvertebrates calculated eight metrics of FD. Random forest regression was applied to identify significant relationships between FD and six environmental variables. Finally, functional β‐turnover was estimated to detect alongshore shifts in functional structure and their coincidence with biogeographical domains. Our results show, in contrast with taxonomic richness that measures of trait differences, functional space and functional specialisation increase with latitude, while functional evenness exhibits a non‐linear shape, peaking at mid latitudes. Functional redundancy decreased significantly poleward, while indicators of vulnerability increase. In contrast to taxonomic richness, FD was tightly connected to variables indicative of stress and productivity, such as dissolved oxygen and nutrients. Sea surface temperature and coastal area best explained the increased FD redundancy and richness towards the tropics. The high spatial correlation between taxonomic and functional turnover suggests environmental filters play an important role in the functional structure of the seascape. Our findings suggest that processes favouring taxonomic richness are latitudinally divergent from those favouring functional diversity. Correlations with environmental variables suggest that increased sea surface temperature and measures of stability increase redundancy, while variations in dissolved oxygen and nutrients positively affect functional diversification. Moreover, the functional diversity patterns suggest low resilience of high latitude coastal ecosystems, which are heavily exploited and threatened by climate change, hence highlighting the urgent need for effective conservation policies.

Life history variation of the Hairy-tailed Akodont (Necromys lasiurus, Rodentia, Sigmodontinae) in the Caatinga biome of northeastern Brazil

Abstract Rodents are notable for their unique life history traits that render a fast-breeding capacity. Their short generation times allow local adaptations to appear, and several studies have tried to understand if—and how—geographical variables influence local adaptation in life history traits. We compared demographic and life history traits of the Neotropical cricetid Necromys lasiurus based on 7,400 museum specimens collected daily and simultaneously over 5 years at several sites in the Caatinga biogeographic domain subject to heterogeneous geographic and climatological variables. This sample, assembled by the National Plague Service between 1951 and 1955, includes skulls, skins, and individual specimen data currently deposited in the Museu Nacional (Rio de Janeiro, Brazil). Based on this material, we analyzed population fluctuation, breeding season, sexual size dimorphism, sexual maturity, and litter size. We also hypothesized that geographic variables (elevation, rainfall, temperature, longitude, and latitude) influence key life history traits, such as size at birth and litter size. Overall, N. lasiurus showed plastic reproductive patterns, with few traits shared among populations. Notably, there is strong seasonal variation in population fluctuation patterns, breeding events clumped in early dry season and old individuals distributed throughout all the year, as has been seen for populations in other biomes. Geography had no influence on size at birth but litter size was explained by the interaction between maternal weight and geographical variables. Plastic life history traits so intimately responsive to climatological variables likely contribute to N. lasiurus having one of the largest geographic ranges among Neotropical cricetids, as well as to its status as the most important plague reservoir in the Caatinga domain.

Variable exposure to multiple climate stressors across the California marine protected area network and policy implications

Abstract The efficacy of marine protected areas (MPAs) may be reduced when climate change disrupts the ecosystems and human communities around which they are designed. The effects of ocean warming on MPA functioning have received attention but less is known about how multiple climatic stressors may influence MPAs efficacy. Using a novel dataset incorporating 8.8 million oceanographic observations, we assess exposure to potentially stressful temperatures, dissolved oxygen concentrations, and pH levels across the California MPA network. This dataset covers more than two-thirds of California’s 124 MPAs and multiple biogeographic domains. However, spatial-temporal and methodological patchiness constrains the extent to which systematic evaluation of exposure is possible across the network. Across a set of nine well-monitored MPAs, the most frequently observed combination of stressful conditions was hypoxic conditions (<140 umol/kg) co-occurring with low pH (<7.75). Conversely, MPAs exposed most frequently to anomalously warm conditions were less likely to experience hypoxia and low pH, although exposure to hypoxia varied throughout the 2014–2016 marine heatwaves. Finally, we found that the spatial patterns of exposure to hypoxia and low pH across the MPA network remained stable across years. This multiple stressor analysis both confirms and challenges prior hypotheses regarding MPA efficacy under global environmental change.

Dung beetles (Coleoptera: Scarabaeidae) in grazing lands of the Neotropics: A review of patterns and research trends of taxonomic and functional diversity, and functions

Dung beetles are one of the most representative groups of insects associated with livestock, as they take advantage of the manure of livestock for food and reproduction. They have been widely used as a bio-indicator group to evaluate their responses to land-use change and other environmental disturbances by analyzing species diversity at different spatial and temporal scales. However, the impacts of livestock management practices, forms, and history on dung beetle diversity are still poorly understood. This paper is an exhaustive and systematic review of the existing peer-reviewed and indexed literature on the taxonomic diversity (species richness and composition), functional diversity, and ecological functions of dung beetles from different provinces and biogeographic domains in tropical grazing lands of the Neotropics. We analyzed the timeline of the studies conducted so far, and we detected increasing literature produced mainly in South America. We included the most frequent objectives, tendencies, software, and statistical analyses. Given the significant heterogeneity of livestock landscapes in the Neotropics, the reviewed studies have conceptualized broadly what a pasture is, and the authors have used different descriptions of other grazing lands. Additionally, management data and livestock practices vary widely among studies, and management history is poorly described. In future research, it is relevant to include as much information as possible and the consequences of different livestock management practices on additional ecological attributes of dung beetle assemblages at different landscape scales (spatial and temporal) to predict how ecological processes change in Neotropical landscapes. Considering the importance of the data to be included in future work, we propose a collection format to unify the information collected in the field when conducting ecological studies in grazing lands. Moreover, we define a classification system to homogenize the features that distinguish the multiple tropical grazing lands reported in the literature. Preserving dung beetle diversity and associated ecological functions is urgent for maintaining ecosystem services in grazing lands. The challenge for research institutions is to continue filling gaps in knowledge to help those who work in transferring knowledge, to help ranchers exercise better options for more sustainable livestock farming, and to publish results for conservation decision-making.

Fire probability mapping and prediction from environmental data: What a comprehensive savanna-forest transition can tell us

The Cerrado-Amazon transition (CAT) is located between the two largest biogeographic domains of the Neotropical region, coinciding with the “Arc of Deforestation”, an agricultural frontier that expands towards the Amazon. Fire plays an important role in the landscape changes that have been occurring in this transition. Thus, the objectives of this study were (i) evaluate the accuracy of different algorithms/techniques in predicting fires in the CAT; (ii) investigate the season of highest fire probabilities in the CAT; and (iii) identify, among anthropic, climatic, topographic and soil variables, the main drivers of fires spatial distribution in the CAT. Fire occurrence data (active fire pixels) from the MODIS sensor were used as input data in species distribution models. The SDM allowed the construction of monthly fire probability models for the study area. The model's quality was assessed by R-squared, RMSE, AUC and TSS metrics. In addition, we assessed the weight of variables in building the models. To obtain the fire seasonality, we used the bootstrap technique to calculate the 95% confidence interval (CI) about the mean. As result, we found that all algorithms obtained satisfactory performance, as well as the ensemble model technique used, which obtained an average AUC of 0.812 ± 0.001. The algorithm with the best individual performance was Random Forest, with a mean AUC 0.851 ± 0.002. Similar patterns were found when considering TSS metrics. The predicted and observed fire occurrences showed strong association (R2 = 0.81). The high fire probability area was higher during the dry season (15304.37 ± 41.65), showing a significant difference (p-value ≤ 0.05) from the rainy season. The variables that most explained the fire occurrences along the CAT were 'Silt Fraction', 'Distance from Agriculture' and 'Maximum Temperature'. In addition, ‘Distance from Roads’, ‘Distance from Protected Areas’ and Elevation’ were relevant for the monthly models. Anthropogenic variables were more important during the dry season. The results demonstrate that SDMs can be adequately used in fire prediction. Protected areas have shown an important role in acting as a fire barrier. However, many of these areas are vulnerable, surrounded by high fire probabilities during the dry season, predominantly anthropic, putting the natural dynamics of fire in the region and the local biodiversity at risk. Our approach can be useful in environmental protection and monitoring, in addition to facilitating the understanding about the CAT ecological complexity and the high anthropogenic pressure happening there.

A Pantropical Overview of Soils across Tropical Dry Forest Ecoregions

Pantropical variation in soils of the tropical dry forest (TDF) biome is enormously high but has been poorly characterized. To quantify variation in the global distribution of TDF soil physical and chemical properties in relation to climate and geology, we produced a synthesis using 7500 points of data with gridded fields representing lithologic, edaphic, and climatic characteristics. Our analyses reveal that 75 TDF ecoregions across five biogeographic domains (Afrotropical, Australasian, Indo-Malayan, Neotropical, and Oceanian) varied strongly with respect to parent material: sediment (57%), metamorphic (22%), volcanic (13%), and plutonic (7%). TDF ecoregions support remarkably high variability in soil suborders (32), with the Neotropical and Oceanian realms being especially diverse. As a whole, TDF soils trend strongly toward low fertility with strong variation across biogeographic domains. Similarly, the exhibited soil properties marked heterogeneity across biogeographic domains, with soil depth varying by an order of magnitude and total organic C, N, and P pools varying threefold. Organic C and N pool sizes were negatively correlated with mean annual temperature (MAT) and positively correlated with mean annual precipitation (MAP). By contrast, the distribution of soil P pools was positively influenced by both MAT and MAP and likely by soil geochemistry, due to high variations in soil parent material across the biogeographic domains. The results summarized here raise important questions as to how climate and parent material control soil biogeochemical processes in TDFs.

Aquatic Macrophytes in Southern Amazonia, Brazil: Richness, Endemism, and Comparative Floristics

Southern Amazonia harbors a wide diversity of aquatic macrophyte species because of its diverse wetland habitats and location in the Amazon-Cerrado transition zone, which spans the two largest biogeographic domains in South America. We investigated the taxonomic diversity of aquatic macrophytes in the region with a focus on endemism, species richness, and life forms. We present new records of aquatic macrophyte species and compare our results with other Brazilian phytogeographic domains. We found a high number of species of aquatic macrophytes for the southern Amazon region, comparable to extensive inventories in southern, northeastern, and northern regions of Brazil. We recorded 709 species of aquatic macrophytes in 313 genera and 97 families, which includes 90 species endemic to Brazil and five species endemic to the Brazilian Amazonia. The macrophyte species list of southern Amazonia showed < 25% similarity to inventories in Amazonia and Cerrado. This high diversity of aquatic macrophytes in southern Amazonia, with endemic species and others with restricted ranges, emphasizes the need for conserving these wetlands and vegetation types.

Extent of Utilization of Various Government Tribal Development Schemes by Primitive Tribes Living in Biodiversity Zone of Nilgiri District in Tamil Nadu

Biodiversity hotspots have set up to protect at least 10 per cent of world's ecological regions in order to conserve biodiversity and safeguard many facilities provided by natural ecosystems. Biosphere Reserves are representative areas of natural and cultural landscapes that span a large area of agricultural, marine, or coastal ecosystems, or a combination of them, as well as representative bio-geographic domains or kingdoms. The Nilgiri Biosphere Reserve has richness and diversity, to protect it, the district has been declared as “Organic district” on July 2019. It is also the home to a wide range of human cultural diversity and especially the primitive and vulnerable tribes live in these areas. They are the designated tribal settlers identified by the government and these have their own religious believes, culture and traditions which is extremely different from others customs. They are called as "Adivasi" or "Aboriginals". So as to improve their life style and lead a better life like others, central government along with state government had bought several development schemes and plans under Ministry of tribal affairs. The Tribal Development Plan (TDP) was developed to proactively solve tribal issues and provide culturally compatible solutions, specifically considering indigenous people. The main objective of this study is the adoption level of government tribal development schemes and plans among the primitive tribes living in the biodiversity zone of Nilgiri biosphere. Thus the vulnerable and primitive tribal societies of like Toda, Kota, Kurumba, Paniya, Kattu naickan and Irular of Nilgiri district have been chosen for the investigation with the sample size of 120, in which 20 from each tribes have been chosen. Pre-tested and well-structured interview schedule have been made and thereby undergone survey. Thus it provided an overall picture about the level of adoption about various government tribal development schemes for their betterment and upliftment in among Nilgiri tribes.

Climate change forecasts suggest that the conservation area network in the Cerrado-Amazon transition zone needs to be expanded

Climate change impacts are important in shaping large ecotones, such as the transition zone between the Cerrado and Amazon rainforest (CAT) biogeographical domains. The accelerating rate of conversion of native vegetation, the most important factor for biodiversity loss in the Anthropocene, compounded by projected climate change impacts, requires a review of the effectiveness of existing designated protected areas (PA) and indigenous land (IL), where low-intensity and low-impact land use prevails. We identified priority tree species for conservation and quantified changes in their projected spatial distribution in future climate scenarios to estimate the conservation effectiveness of the current network of PA and IL in the CAT. Applying niche-based models to compare the geographical range of species in current and future climates, we estimated the displacement of species from their current distribution owing to projected climate change. We used four different IPCC emission scenarios for 2050 and quantified the losses or gains in species richness in PA and IL. All species were projected to suffer a reduction of climatically suitable area and a consequent range reduction. Inside both PA and IL there was a projected decrease in richness of the target species under climate change. The current PA network and designated IL in the CAT do not appear to safeguard future conservation of the species they currently contain. The future ‘climate refugia’ that our work identified could form the basis of plans to expand the protected area network in a region that remains under ever increasing pressure of deforestation in Brazil.

Biogeography of different life forms of the southernmost neotropical tank bromeliad

AbstractAimFactors affecting bromeliad distribution depend on the life forms of the studied species; some could grow as terrestrial, saxicolous, or epiphytic depending on the type of habitat. We analysed the distribution patterns of the life forms of a bromeliad species in different biogeographic domains and associated them with environmental variables and vegetation types.LocationChaquenian, Amazonian, and Seasonally Dry Tropical Forest domains; South America.TaxonThe tank bromeliad Aechmea distichantha (Bromeliaceae: Bromelioideae).MethodsWe compiled records of the biogeographic distribution and the vegetation types where A. distichantha occurs based on bibliographic data, digital datasets, herbaria, and personal observations. We associated the distributional records of this species with altitude, five selected bioclimatic variables, four soil variables, and with the vegetation types where it occurs.ResultsA. distichantha has been recorded as epiphytic, terrestrial and saxicolous in all biogeographic domains but showed contrasting patterns in life form proportions among them. In the Amazonian domain, characterized by evergreen tropical and subtropical forests with high precipitation, it mainly grows as epiphytic. In the Chaquenian domain, dominated by xerophytic forests with low rainfall, high soil pH and base saturation, it mainly grows as terrestrial, whereas in the Seasonally Dry Tropical Forest domain, the three life forms were recorded in similar proportions. In azonal plant communities of all domains, it mainly grows as saxicolous.Main ConclusionsThis tank bromeliad species can thrive in sites with contrasting habitat and environmental conditions. Its ability to survive in different environments could be associated with its high frost tolerance, the presence of the CAM photosynthetic pathway, a well‐developed phytotelma, and high phenotypic plasticity. The life form prevailing in each domain is influenced by water availability (i.e., the quantity of water available during each year, the precipitation in the driest month, and the plant water supply relative to demand).

Dynamic Satellite Seascapes as a Biogeographic Framework for Understanding Phytoplankton Assemblages in the Florida Keys National Marine Sanctuary, United States

Physical, chemical, geological, and biological factors interact in marine environments to shape complex but recurrent patterns of organization of life on multiple spatial and temporal scales. These factors define biogeographic regions in surface waters that we refer to as seascapes. We characterize seascapes for the Florida Keys National Marine Sanctuary (FKNMS) and southwest Florida shelf nearshore environment using multivariate satellite and in situ measurements of Essential Ocean Variables (EOVs) and Essential Biodiversity Variables (EBVs). The study focuses on three periods that cover separate oceanographic expeditions (March 11-18, May 9-13, and September 12-19, 2016). We collected observations on bio-optical parameters (particulate and dissolved spectral absorption coefficients), phytoplankton community composition, and hydrography from a ship. Phytoplankton community composition was evaluated using 1) chemotaxonomic analysis (CHEMTAX) based on high-performance liquid chromatography (HPLC) pigment measurements, and 2) analysis of spectral phytoplankton absorption coefficients (aphy). Dynamic seascapes were derived by combining satellite time series of sea surface temperature, chlorophyll-a concentration, and normalized fluorescent line height (nFLH) using a supervised thematic classification. The seascapes identified areas of different salinity and nutrient concentrations where different phytoplankton communities were present as determined by hierarchical cluster analyses of HPLC pigments and aphy spectra. Oligotrophic, Mesotrophic and Transition seascape classes of deeper offshore waters were dominated by small phytoplankton ( 60 %). Spectral analysis of aphy indicated higher absorption levels at 492 and 550 nm wavelengths in seascapes carrying predominantly small phytoplankton than in classes dominated by larger taxa. Seascapes carrying large phytoplankton showed absorption peaks at the 673 nm wavelength. The seascape framework promises to be a tool to detect different biogeographic domains quickly, providing information about the changing environmental conditions experienced by coral reef organisms including coral, sponges, fish and higher trophic levels. The effort illustrates best practices developed under the Marine Biodiversity Observation Network (MBON) demonstration project, in collaboration with the South Florida Ecosystem Restoration Research (SFER) project managed by the Atlantic Oceanographic and Meteorological Laboratory of NOAA (AOML-NOAA).

Interactions between climate and soil shape tree community assembly and above-ground woody biomass of tropical dry forests

The resilience or sensitivity of seasonally dry tropical forests (SDTF) to climate change remains an important issue because of their biodiversity and ecosystem services provision. Understand the underlying ecological processes of SDTF is crucial for the development of conservation and management strategies. We tested the hypotheses that SDTF tree species richness, above-ground woody biomass (AGWB), species and phylogenetic compositions are related to climate, soil and their interactions. We sampled 16 old-growth forest sites (313 plots) of SDTF within a 290 km latitudinal gradient. The sites are located in the transition zone between Caatinga and Cerrado biogeographic domains, and are near from Atlantic domain (~100 km). In each site we collected data on vegetation (trees with diameter at breast height ≥3 cm) and soil, and obtained climate data from WorldClim. Almost all vegetation attributes were significantly related to climate and soil. Soil texture mediated the effects of precipitation for tree species richness, AGWB and phylogenetic composition. Tree species richness decreases with annual precipitation but increases under less seasonal conditions; water availability leads to increases in AGWB and drives changes in both taxonomic and phylogenetic composition in these environments. Our findings indicate that tree species richness, above-ground woody biomass, taxonomic and phylogenetic composition of SDTFs are, in general, vulnerable to drought events even from local to regional scales and show the importance of local-scale aspects to understand SDTF diversity and ecosystem functioning; and provide useful information for conservation and management strategies.

Drivers of floristic variation in biogeographic transitions: insights from the ecotone between the largest biogeographic domains of South America

ABSTRACT Ecological transitions usually represent vulnerable ecosystems and high biodiversity. Investigating their drivers is important from both biogeographic and conservationist perspectives. One of these transitions is situated between the two largest biogeographic domains of South America - the Amazon and the Cerrado. We evaluated variation in tree floristic composition throughout this transition and assessed which factors explain this variation. We used 17,240 records of occurrences of 2,530 tree species from the NeotropTree database. We investigated variation in floristic composition using UPGMA cluster analysis with bootstrap resampling and NMDS ordination, and modeled the distribution of species in relation to environmental and spatial predictors by means of transformation-based Redundancy Canonical Analysis (tb-RDA) and variance partitioning. We found four general floristic groups: 1) flooded forests; 2) white sand dwarf-forests; 3) savannic and dwarf forests; and 4) non-flooded forest types. Floristic variation along the transition was influenced by the environment, especially variables related to fire and soil moisture, and by space, especially variables acting on broader scales. Correspondence between the environmental heterogeneity found throughout the transition and our results demonstrates once again the importance of conserving biogeographical transition zones in general, and the most comprehensive of South America in particular.

The threat of emerging and re-emerging pathogenic Sporothrix species.

Sporotrichosis is a neglected subcutaneous mycosis of humans and animals acquired by traumatic inoculation of soil and plant material (classical route) contaminated with infectious propagules of the pathogen or being bitten/scratched by infected cats (alternative route). Within a genus composed of 53 species displaying an essentially environmental core, there are only a few members which have considerable impacts on human or animal health. Infections are typically caused by S. brasiliensis, S. schenckii or S. globosa. Rare mammal pathogens include members of the S. pallida and S. stenocereus complexes. To illustrate the tremendous impact of emerging zoonotic sporotrichosis on public health, we discuss the main features of the expanding epidemics driven by S. brasiliensis in cats and humans. The cat entry in the transmission chain of sporotrichosis, causing epizooties (cat-cat) or zoonosis (cat-human), has contributed to the definition of new paradigms in Sporothrix transmission, reaching epidemic levels, making the disease a serious public health problem. Indeed, S. brasiliensis infection in humans and animals is likely to become even more important in the future, with projections of its expansion in biogeographic domains and host range, as well as greater virulence in mammals. Therefore, lessons from a long-standing outbreak in the state of Rio de Janeiro about the source and distribution of the etiological agents among outbreak areas can be used to create better control and prevention plans and increase awareness of sporotrichosis as a serious emerging zoonotic disease.

A biogeographic and evolutionary analysis of the flora of the North-eastern cerrado, Brazil

ABSTRACTBackground: The forest-savanna habitat switching is thought to have been a recurrent event in evolutionary history. Notwithstanding, the centre of the Cerrado, a large biogeographic domain, may be hypothesised to be a region with historical climatic stability and thus is predicted to contain high richness of cerrado species and the presence of few species from adjacents domains.Aims: We tested if today’s flora of the north-eastern cerrado (NC), a peripheral province of the domain, demonstrated an observable gradient in their distribution from centre of the Cerrado towards adjacents domains.Methods: We compiled vegetation survey data for 178 sites in the cerrado of north-eastern Brazil. Distribution patterns of plant taxa were assessed using multivariate techniques.Results: We recorded 1071 species in 390 genera and 85 families. Almost 40% were monogeneric families and ca. 50% were monospecific genera. The species composition in the NC followed a gradient related to the distance from the centre of the Cerrado towards its periphery.Conclusions: We show that the NC flora is unique and much richer than previously thought and that it is likely to be an outcome of evolutionary processes and of today’s intermixing of species from adjacent formations.

Species tolerance degree to soil conditions shaping plant communities

Understanding vegetation-environment relationships enables perceiving past and present patterns and to predict responses to future scenarios, thereby being useful for conservation and understanding evolutionary processes. In this context, the objective of our study was to test the hypothesis that niche processes at local scales (< 1 km2) are significantly expressive in plant communities structuring. For this, we selected the more representative and widely distributed sampled species, and then modelled their representativeness as a function of edaphic variables. The data were obtained in four fragments of seasonal semi-deciduous forests located in a transition area between the Atlantic and Cerrado biogeographic domains, Brazil. A total of 92 plots with 63 of 400 m2 and 29 of 300 m2 were randomly distributed in the fragments. Individuals that reached the inclusion criterion (circumference at breast height ≥ 15.7 cm) in each plot were measured and identified and soil samples were also collected. Then, we calculated the relative abundance and relative basal area in each plot. All species showed significant relationships with the soil variables, as their representativeness showed to be correlated (positively and/or negatively) with at least one restrictive fertility or texture condition. Therefore, the results confirm the tested hypothesis, evidencing the niche processing role in community structuring through the species tolerance degree to soil conditions.