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Background: Synchronopatric plant species, coexisting and flowering simultaneously, often engage in intense competition for pollen deposition on shared pollinators. This study focuses on the intricate dynamics of chiropterophilous flowers within the neotropical bat-pollination plant guild, specifically investigating the mechanical fit of reproductive structures to pollinating bats at the community level. Methods: Utilizing a diverse guild of bat-pollinated plant species from the Caatinga, the largest dry forest in the Neotropics, our research integrates various key components. Initially, we identified specific contact sites for floral reproductive structures on the bat's body, exploring diverse pollen placement strategies. Subsequent efforts involved characterizing floral traits within the guild and examining their associations with different pollen placement strategies. Precision in the contact of floral reproductive structures was estimated, and findings were integrated by associating pollen placement strategies and precision with the investment in pollen production. Results: We found that certain bat body parts, particularly the face and neck, were more frequently contacted by reproductive structures. The three identified categories of pollen placement strategies were evenly distributed among plant species, each linked to specific floral traits. Notably, the absence of oriented herkogamy prevailed in 70% of the species. Morphometric analyses unveiled significant variations in operative distances among species, emphasizing exceptional variability in certain outliers. While precision in pollen transfer was influenced by key factors, surprisingly, investment in pollen production did not differ among plants with distinct pollen placement strategies. Furthermore, it showed no correlation with fundamental accuracy. Conclusions: The subsequent exploration delves into the intricate associations between distinct floral characteristics and various pollen placement strategies, shaping the complex pollen landscape on bat bodies. This research provides valuable insights into the community-level dynamics of chiropterophilous flowers in the Caatinga Dry Forest, emphasizing the role of different pollen deposition strategies in facilitating the coexistence of multiple plant species within the chiropterophilous guild. [ABSTRACT FROM AUTHOR]

Background: Sicariidae is a small family of cryptic and recluse spiders, with 178 species grouped into three genera: Hexophtalma, Loxosceles and Sicarius. Only the last two occur in Brazil, where 29 species are recorded, with a greater number of records in the Southeast and South regions. To date, there is no regionalized study of the distribution of these spiders in the Northeast of Brazil. We presented more than four decades of data on the distribution of sicariid spiders in the state of Bahia. Our research aimed to identify and evaluate the distribution of sicariid species in this region, characterizing them in their biomes and phytophysiognomies. Methods: Data covers a period from 1983 to 2024, obtained from articles describing species recorded in Bahia and from three scientific collections from Brazilian institutions: Universidade Federal da Bahia (MHNBA); Instituto Butantan (IBSP); Universidade Federal de Minas Gerais (UFMG). Maps were produced using the QGIS 3.34.1 software, based on geographic coordinates obtained from the original literature, when provided. Species without information on geographic coordinates were georeferenced using the SpeciesLink (geoLoc tool) for the municipalities. Biomes were consulted on the georeference Brazilian institute website and the phytophysiognomies were ignored when not specified in the data of collections or original literature. Results: We confirmed 14 species of sicariid spiders in the state of Bahia, eight from the genus Loxosceles (i) and six from Sicarius. The species were recorded in 48 municipalities, located mainly in the Caatinga biome. We recorded a distribution expansion of seven species: Loxosceles amazonica, L. chapadensis, L. karstica, L. similis, Sicarius cariri, S. ornatus and S. tropicus. There is a difference in species composition in the two regions separated by the São Francisco River, an important geographic barrier especially for small invertebrates. More than 75% of the species were registered in the east side and about 20% exclusively in the west side: L. boqueirao, L. cardosoi, L. carinhanha. This suggests the need for future studies to evaluate additional variables that determine community structure, especially considering their low vagility and reclusive behavior. Although Sicarius are found almost exclusively in the Caatinga, there are isolated records from Restinga and dry forest enclaves in the Cerrado domain and Atlantic Forest areas. This reinforces the possibility of them being able to adapt to slightly wetter environments erase colonize and survive in seasonally dry rainforest areas. Unlike Sicarius (i), Loxosceles (i) occupy a wide variety of habitats in natural, urban and domiciliary situations. Many of the records here such as for Loxosceles boqueirao, L. cardosoi, L. carinhanha, L. chapadensis, L. karstica and L. troglobia were obtained at caves or nearby areas, which appear to be attractive habitats for these nocturnal spiders. [ABSTRACT FROM AUTHOR]

The Caatinga, an exclusive biome in Brazil, is the largest tropical dry forest area in the Americas. It is characterized by a semi-arid climate and various soils that harbor a great diversity of flora and fauna. Novel records of aerial insectivorous bat species in the family Molossidae in the Chapada Diamantina, northeastern Brazil are presented. The study is based on field sampling of 115 molossid bat specimens from six genera and 12 taxonomically confirmed species, along with four taxa requiring further evaluation for definitive species identification. All specimens were obtained using mist nets around a small freshwater lagoon surrounded by semideciduous dry forest. The verified genera were Cynomops, Eumops, Molossops, Molossus, Neoplatymops, and Nyctinomops. Our findings enhance the understanding of bat diversity in the Brazilian Caatinga, with the first records of Eumops delticus, E. bonariensis, and Molossus currentium. The most abundant species were Molossus rufus, Eumops glaucinus, Cynomops planirostris, Nyctinomops laticaudatus, and Molossus molossus. Previously unreported morphological and morphometric variations for these Caatinga taxa were examined. Additionally, information on sexual dimorphism in craniodental characteristics of Molossops temminckii and variations in the presence of the sagittal crest in Neoplatymops mattogrossensis are provided. Based on the voucher specimens from this study, the recognized number of species of Molossidae known from the Caatinga has increased to 21. Our results offer new insights into the taxonomy and biogeography of Neotropical molossids, highlighting their importance as members of bat communities in dry forest ecosystems from northeastern South America. [ABSTRACT FROM AUTHOR]

The relationships between host phylogenetics, functional traits and parasites in wildlife remain poorly understood in the Neotropics, especially in habitats with marked seasonal variation. Here, we examined the effect of seasonality and host functional traits on the prevalence of avian haemosporidians (Plasmodium and Haemoproteus) in the Brazilian Caatinga, a seasonally dry tropical forest. 933 birds were evaluated for haemosporidian infections. We found a high parasitism prevalence (51.2%), which was correlated with phylogenetic relatedness among avian species. Prevalence varied drastically among the 20 well-sampled species, ranging from 0 to 70%. Seasonality was the main factor associated with infections, but how this abiotic condition influenced parasite prevalence varied according to the host-parasite system. Plasmodium prevalence increased during the rainy season and, after excluding the large sample size of Columbiformes (n = 462/933), Plasmodium infection rate was maintained high in the wet season and showed a negative association with host body mass. No association was found between non-Columbiform bird prevalence and seasonality or body mass when evaluating both Plasmodium and Haemoproteus or only Haemoproteus infections. Parasite community was composed of 32 lineages including 7 new lineages. We evidenced that even dry domains can harbour a high prevalence and diversity of vector-borne parasites and pointed out seasonality as a ruling factor. [ABSTRACT FROM AUTHOR]

Drastic changes in vegetation structure caused by exceeding ecological thresholds have fueled the interest in tropical forest responses to climate and land-use changes. Here, we examine the potential successional trajectories experienced by the largest dry tropical forest region in South America, driven by climate conditions and human disturbance. We built potential distribution models for vertebrate taxa associated with forest or shrub habitats to estimate natural vegetation cover. Distribution patterns were compared to current vegetation across the entire region to identify distinct forest degradation levels. Our results indicate the region has climatic and soil conditions suitable for more forest cover than is currently found, even in some areas with limited precipitation. However, 11.04% of natural cover persists across such an immense region, with only 4.34% consisting of forest cover. Forest degradation is characterized by the dramatic expansion of shrubland (390%), farming, and non-vegetation cover due to changes in land-use, rather than climatic conditions. Although different climate conditions have been the principal drivers for natural forest distribution in the region, the forest seems unable to resist the consequences of land-use changes, particularly in lower precipitation areas. Therefore, land-use change has exceeded the ecological thresholds for the persistence of forests, while climate change may exacerbate vegetation-type transitions. [ABSTRACT FROM AUTHOR]

A new termite species, Cryptotermes pugnus sp. nov., is described from northeastern Brazil. The winged imago of C. pugnus is distinguished from most congeners by the lack of arolia and the multiple branches connecting the median vein to the radial sector. The soldier is unique among South American Cryptotermes by its cuboidal head capsule and very rugose postclypeus. The new species constitutes the fourteenth Cryptotermes species on the continent for which we provide a key to soldiers. [ABSTRACT FROM AUTHOR]

Under continuous human disturbance, regeneration is the basis for biodiversity persistence and ecosystem service provision. In tropical dry forests, edaphic ecosystem engineering by biological soil crusts (biocrusts) could impact regeneration by influencing erosion control and soil water and nutrient fluxes, which impact landscape hydrology, geomorphology, and ecosystem functioning. This study investigated the effect of cyanobacteria-dominated biocrusts on water infiltration and aggregate stability in a human-modified landscape of the Caatinga dry forest (NE Brazil), a system characterized by high levels of forest degradation and increasing aridity. By trapping dust and swelling of cyanobacterial filaments, biocrusts can seal soil surfaces and slow down infiltration, which potentially induces erosion. To quantify hydraulic properties and erosion control, we used minidisc-infiltrometry, raindrop-simulation, and wet sieving at two sites with contrasting disturbance levels: an active cashew plantation and an abandoned field experiencing forest regeneration, both characterized by sandy soils. Under disturbance, biocrusts had a stronger negative impact on infiltration (reduction by 42% vs. 37% during regeneration), although biocrusts under regenerating conditions had the lowest absolute sorptivity (0.042 ± 0.02 cm s-1/2) and unsaturated hydraulic conductivity (0.0015 ± 0.0008 cm s-1), with a doubled water repellency. Biocrusts provided high soil aggregate stability although stability increased considerably with progression of biocrust succession (raindrop simulation disturbed: 0.19 ± 0.22 J vs. regenerating: 0.54 ± 0.22 J). The formation of stable aggregates by early successional biocrusts on sandy soils suggests protection of dry forest soils even on the worst land use/soil degradation scenario with a high soil erosion risk. Our results confirm that biocrusts covering bare interspaces between vascular plants in human-modified landscapes play an important role in surface water availability and erosion control. Biocrusts have the potential to reduce land degradation, but their associated ecosystem services like erosion protection, can be impaired by disturbance. Considering an average biocrust coverage of 8.1% of the Caatinga landscapes, further research should aim to quantify the contribution of biocrusts to forest recovery to fully understand the role they play in the functioning of this poorly explored ecosystem. [ABSTRACT FROM AUTHOR]

La Montaña region, in southern Mexico, is characterized as a highly human-modified landscape with a rough topography, extreme poverty and structural violence. In this region, Xuajin Me'Phaa, an Indigenous non-governmental organization conformed by ca. 300 peasants, implements productive restoration projects and trades organic hibiscus (Hibiscus sabdariffa L.) as its main monetary income. Nonetheless currently, organic hibiscus yield is low compared to the potential yields in the region. Thus, it is necessary to explore alternative sustainable land management systems which enable farmers to increase hibiscus crop productivity, while halting land degradation. This study assessed the impact of six different agroecological fertilization protocols (AFPs) on hibiscus productivity planted in an alley cropping system with Calliandra houstoniana trees. The AFPs were based on the combination of three local plant amendments: C. houstoniana mulch, Mucuna pruiriens var. utilis green manure and hibiscus stover, and a commercial bio-fertilizer (Azospirillum + Rhizophagus). Simultaneously, the performance of C. houstoniana trees was assessed. The AFPs were applied in the alley cropping system and evaluated from 2016 to 2018. After 3 years, in the AFPs which included C. houstoniana mulch, hibiscus yielded significantly more (419 ± 27 kg dry calyxes ha-1 in average) than AFPs which did not include this species (264 ± 15 kg ha-1). The 18-month-old C. houstoniana trees yielded 0.6 t ha-1 of dry biomass and 1.12 t ha-1 of wooden stakes, a relatively low production. In conclusion, our results show that alley cropping with a denser arrangement of C. houstoniana trees in combination with mulching of this tree species, and use of mucuna green manure represent a promising agroforestry system for organic hibiscus production. [ABSTRACT FROM AUTHOR]

Climate classification systems are tools that facilitate the analysis, grouping, delimitation, and dissemination of the climatic characteristics of a region, contributing to the circumscribing of areas suitable for the agriculture and to the validation of various models of climate change. In this study, Brazilian life zone types were identified by using the initial variant of the well-known Holdridge eco-climatological classification, under different climate change scenarios. To describe current conditions in Brazil, daily time series of temperature and precipitation for the period 1989–2019 are used, derived from the National Aeronautics and Space Administration/Prediction of Worldwide Energy Resources (NASA/POWER) platform. Climate change was considered through four alternative scenarios. According to the original classification, under current conditions, the dominant life zone type is the type tropical basal moist forest, covering 60.57% of the country. An increase in temperature can cause a decrease in the dominance of this life zone type, though approximately half of the country may be covered by this type. Furthermore, in case of an increase of 3 °C, the type tropical basal dry forest could already cover a third of Brazil. An increase of 30% in precipitation could cause the emergence of several new life zone types, while the extent of the type tropical basal moist forest could then decrease to 50.12%. Due to the high variability of the life zone types obtained, the Holdridge system can be considered a useful tool to illustrate climate change impacts. [ABSTRACT FROM AUTHOR]

The contingent valuation method employs a hypothetical scenario to record a person's declared preference with regard to their willingness to pay for an environmental asset or willingness to accept (WTA) compensation for not using it. Many studies have evaluated the inclination to conserve watersheds, forest areas, or certain species. In this study, we reported the economical values of medicinal species based on the perceptions of locals living within a protected area in a seasonal dry tropical forest in Northeastern Brazil. Moreover, we assessed the effects of socioeconomic variables (gender, family income, and family size) on the WTA compensation for not using the species. We interviewed 96 household heads from seven communities to obtain their socioeconomic data and WTA values. Additionally, we used data from a plant inventory to gather information on species abundance. We found that the selected socioeconomic variables are a poor predictor of the WTA values. Our findings also demonstrate that women accept lower WTA values to not use some species. Additionally, individuals from bigger families accept lower WTA values to not use just one of the plant species. Species abundance did not influence informants' WTA values. Generally, informants overestimated bids, which may hinder biodiversity conservation. Socioeconomic and ecological factors may not have an influence on WTA values in communities that inhabit protected areas. [ABSTRACT FROM AUTHOR]

Copyright of Rodriguésia is the property of Revista Rodriguesia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Brazilian dry forest (Caatinga) is located in one of the world's largest tropical semiarid regions, and it occurs on two large geological environments named the crystalline and sedimentary basins. In order to determine the structure and the main drivers of the composition of communities of arbuscular mycorrhizal fungi (AMF) in the Caatinga, we collected soil samples from the rhizosphere of Jatropha mollissima, J. mutabilis, and Mimosa tenuiflora, species that occur in crystalline and sedimentary areas. Ninety-six AMF taxa were identified from soils collected directly in the field and trap cultures. Acaulospora, Glomus, and Rhizoglomus represented almost 49% of the taxon richness. The composition of the AMF communities differed between the crystalline and sedimentary areas and between the rhizospheres of the three plant species. Coarse sand, total sand, natural clay, calcium, soil particles density, flocculation, pH, and base saturation were the principal edaphic variables related to the distribution of these organisms. We registered nine and 17 AMF species classified as indicators, for the geological environments and plant species, respectively. Glomerospores of Glomerales predominated in crystalline basins, whereas glomerospores of Gigasporales prevailed in sedimentary areas; among the plant species, lower number of glomerospores of Archaeosporales and Glomerales was recorded in the rhizosphere of J. mollissima. The results show that the AMF community composition is shaped by geological environments and plant hosts. In addition, soil characteristics, mainly physical attributes, significantly influence the structure of Glomeromycota communities occurring in areas of the Brazilian semiarid. [ABSTRACT FROM AUTHOR]

Copyright of Rodriguésia is the property of Revista Rodriguesia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bat caves are very special roosts that harbour thousands of bats of one or more species. Such sites may hold an incredible "dark fungal diversity" which is still underestimated. We explored the culturable fungal richness in the air, on bats, and in the guano in a bat cave in Brazil's Caatinga dry forest. Fungal abundance was 683 colony-forming units (CFU) in the guano, 673 CFU in the air, and 105 CFU on the bats. Based on morphological and phylogenetic analysis of ITS, LSU, and TUB2 sequences, fungal isolates of 59 taxa belonging to 37 genera in the phyla Ascomycota (28 genera, including Aspergillus, Penicillium, Cladosporium, and Talaromyces), Basidiomycota (eight genera, including Rhodotorula and Schizophyllum), and Mucoromycota (only Rhizopus) were identified. The fungal richness in the air was 23 taxa (especially Aspergillus taxa), mainly found at 15 m and 45 m from the cave entrance; on the bodies of bats it was 36 taxa (mainly Aspergillus taxa), especially on their wing membranes (21 taxa, nine of which were exclusively found in this microhabitat); and in guano 10 fungal taxa (especially Aspergillus and Penicillium) were found. The fungal richness associated with guano (fresh and non-fresh) was similar from bats with different eating habits (insectivorous, frugivorous, and haematophagous). Sampling effort was not sufficient to reveal the total fungal taxa richness estimated. Eight (21.6%) of the 37 genera and 17 (53.1%) of the 32 identified fungal species are reported for the first time in caves. Our results highlight bat caves in Brazil as hotspots of fungal diversity, emphasizing the need to protect such special roosts. [ABSTRACT FROM AUTHOR]

Background: Biological invasion is one of the main threats to tropical biodiversity and ecosystem functioning. Prosopis juliflora (Sw) DC. (Fabales: Fabaceae: Caesalpinioideae) was introduced in the Caatinga dry forest of Northeast Brazil at early 1940s and successfully spread across the region. As other invasive species, it may benefit from the soils and seed dispersal by livestock. Here we examine how seed dispersal ecology and soil conditions collectively affect seed germination, early seedling performance and consequently the P. juliflora invasive potential. Methods: Seed germination, early seedling survival, life expectancy and soil attributes were examined in 10 plots located across three habitats (flooding plain, alluvial terrace and plateau) into a human-modified landscape of the Caatinga dry forest (a total of 12,000 seeds). Seeds were exposed to four seed dispersal methods: deposition on the soil surface, burial in the soil, passed through cattle (Boss taurus) digestive tracts and mixed with cattle manure and passed through mule (Equus africanus asinus × Equus ferus caballus) digestive tracts and mixed with mule manure. Seeds and seedlings were monitored through a year and their performance examined with expectancy tables. Results: Soils differed among habitats, particularly its nutrient availability, texture and water with finely-textured and more fertile soils in the flooding plain. Total seed germination was relatively low (14.5%), with the highest score among seeds buried in the flooding plain (47.4 ± 25.3%). Seed dispersal by cattle and mule also positively impacted seed germination. Early seedling survival rate of P. juliflora was dramatically reduced with few seedlings still alive elapsed a year. Survival rate was highest in the first 30 days and declined between 30 and 60 days with stabilization at 70 days after germination in all seed treatments and habitats. However, survival and life expectancy were higher in the flooding plain at 75 days and lower in the plateau. Prosopis juliflora seedling survival and life expectancy were higher in the case seeds were mixed with cattle manure. Synthesis: Prosopis juliflora seeds and seedlings are sensitive to water stress and habitat desiccation. Therefore, they benefit from the humid soils often present across human-disturbed flooding plains. This plant also benefits from seed deposition/dispersal by livestock in these landscapes, since cattle manure represents a nutrient-rich and humid substrate for both seeds and seedlings. The quality of the seed dispersal service varies among livestock species, but this key mutualism between exotic species is due to the arillate, hard-coated and palatable seeds. Prosopis juliflora traits allow this species to take multiple benefits from human presence and thus operating as a human commensal. [ABSTRACT FROM AUTHOR]

Background: This study sought to investigate the occurrence of taxonomic patterns between semi-arid and humid regions, verifying how the taxonomic affiliation can influence the selection of plants for medicinal purposes and act as a selection criterion. Methods: The relationship between the taxonomic affiliation and the selection of medicinal plants with four different communities was analyzed; two of them associated with a seasonally dry tropical forest and the other two associated with a tropical rain forest. We used the Utilitarian Equivalence Model (transposing the concept of ecological equivalence, proposed by Odum, for ethnobotany) to test the hypothesis that species that have the same taxonomic affiliation tend to have the same therapeutic applications in different environments (utilitarian equivalence). In addition, we used the Utilitarian Redundancy Model to verify whether, within the same medical system, plants of the same taxonomic affiliation tend to be redundant (treating the same diseases). Results: We found that a pair of plants of the same genus were 9.25 times more likely to be equivalent than a different genus pair (OR = 9.25, CI [1.68-51.02], p < 0.05). When we analyzed the species used by the same population, the chances of a pair having similar therapeutic uses (utilitarian redundancy) increased when they were species of the same family (OR = 1.94, CI [1.06-3.53]; p < 0.05). Conclusions: These findings confirm the hypothesis that there is an influence of taxonomic affiliation, in terms of genera and family, on the selection of medicinal plants in semi-arid and humid areas in Northeast Brazil. In addition, our Utilitarian Equivalence Model can be an important tool in the search for more common selection criteria, in order to identify the shared characteristics among the equivalent pairs and consequently the main types of perceptions or stimuli that led to the inclusion of such species in local pharmacopoeias. [ABSTRACT FROM AUTHOR]

Context: The role of protected areas as biodiversity repositories has become increasingly important in face of increased deforestation. By adding free-living exotic mammals, removing forest-dependent native ones, isolating forest patches from large protected areas and reducing landscape forest cover, human activities may drive mammal communities towards regional biotic homogenization. Objectives: We assessed how landscape forest cover and proximity to the largest and best-preserved area of the Catimbau National Park—one of the largest protected areas of the Brazilian Caatinga—affect α- and β-diversity of medium- and large-sized mammals, considering native and exotic species. Methods: Using camera traps (total effort of 2340 cameras/day), we obtained 823 records of 15 species (8 natives and 7 exotics) in 18 landscapes of 1-km radius. We estimated diversity metrics within and among landscapes and used generalized linear models to assess the effect of forest loss and isolation on diversity metrics. Results: As expected, forest loss decreased α-diversity of native species and increased the diversity and relative abundance of exotics. However, proximity to the preserved area showed weak effect on α-diversity, suggesting that this area does not work regionally as source for natives neither as ecological trap for exotics. Supporting the biotic homogenization hypothesis, β-diversity of natives decreased and β-diversity of exotics increased in more deforested landscapes. Yet, species composition was weakly related to forest cover and isolation. Conclusions: Our findings demonstrate that deforestation jeopardizes native species, favors exotics, and drives mammal communities towards biotic homogenization. Protected areas should be properly implemented to safeguard mammal diversity. [ABSTRACT FROM AUTHOR]

Research performed in recent years indicates that efforts are still needed to understand the advances in the Caatinga, an important dry seasonal forest, and identify its potential for bioprospecting. These efforts are also important for pinpointing the challenges that should be addressed in future research focused on identifying new candidates for pharmacological studies in this complex region. Thus, in this review, we present the main advances of studies on plants and medicinal animals in the Caatinga region and their implications for ethnopharmacology, and we then discuss future challenges to promote the search for candidates with pharmacological potential. Based on an exploration of the available literature, we performed a critical reading of the available evidence to provide a good scenario on the studies in the region. We find that despite the large number of studies available, it is necessary to organize efforts to fill gaps in different areas of knowledge and optimize the search for new natural products. [ABSTRACT FROM AUTHOR]

Background We describe the database of trees and shrubs of tropical dry forest patches of the Magdalena upper river basin in Colombia, preserved in the Herbarium of Universidad de Ciencias Aplicadas y Ambientales. The dataset includes 211 taxa, from which 156 were identified to species. We reported 48 families and 137 genera. The most species rich and abundant families were Fabaceae and Rubiaceae and the most abundant species was Talisia stricta (Sapindaceae). We found differences in diversity between north and south zones of the study area. New information The Magdalena river upper watershed region is an important tropical dry forest conservation area. Twenty nine species and 4 genera recorded in this study have not been reported in previous reviews of the region. Additionally, Oxandra espintana is reported in literature as critically endangered and Aspidosperma polyneuron is reported as endangered, but there are no studies about their conservation status in the region. Our results suggest the strong need to develop additional inventories of plants that contribute to the knowledge of the plant diversity of this ecosystem in the region and studies of their conservation status. [ABSTRACT FROM AUTHOR]

Global climate change alters the dynamic of natural ecosystems and directly affects species distributions, persistence and diversity. The impacts of climate change may lead to dramatic changes in biotic interactions, such as pollination and seed dispersal. Life history traits are extremely important to consider the vulnerability of a species to climate change, producing more robust models than those based primarily on species distributions. Here, we hypothesized that rising temperatures and aridity will reduce suitable habitats for the endemic flora of the Caatinga, the most diverse dry tropical forest on Earth. Specifically, species with specialized reproductive traits (e.g. vertebrate pollination, biotic dispersal, obligatory cross-pollination) should be more affected by climate change than those with generalist traits. We performed two ecological niche models (current and future) to simulate the effects of climate change on the distribution area of endemic species in relation to life-history traits. We used the MIROC-ESM and CCSM4 models for both intermediate (RCP4.5) and highest predicted (RCP8.5) GHG emission scenarios, with a resolution of 30' (~1 km2). Habitat with high occurrence probability (>80%) of endemic species will be reduced (up to ~10% for trees, ~13% for non-arboreous, 10–28% for species with any pollination/reproductive system), with the greatest reductions for species with specialized reproductive traits. In addition, the likely concentration of endemic plants in the extreme northeastern portion of the Caatinga, in more mesic areas, coincides with the currently most human-modified areas of the ecosystem, which combined with climate change will further contract suitable habitats of endemic species. In conclusion, plant species endemic to the Caatinga are highly vulnerable to even conservative scenarios of future climate change and may lose much of their climatic envelopes. New protected areas should be located in the northeastern portion of the Caatinga, which hosts a more favorable climate, but is currently exposed to escalating agricultural intensification. [ABSTRACT FROM AUTHOR]

During faunal rescue activities for the construction of a wind farm in the Northeast Region of Brazil, a single specimen of the gymnophthalmid lizard Anotosaura vanzolinia was captured, which represents the first record of the species for the state of Piauí. We used this record, along with records found in the literature, to model the potential distribution of the species according to environmental suitability using the maximum entropy algorithm MaxEnt. The occurrence records of A. vanzolinia, as well as the model of its potential geographical distribution, revealed that it is more broadly distributed than previously considered. Anotosaura vanzolinia has a disjoint and relictual geographic distribution pattern due to its association with remnant forest environments within the Caatinga Domain. The variables that contributed the most to the model of its ecological niche were annual precipitation (48.9%), soil type (17.5%), and mean diurnal range (10.5%). The species remains endemic to the forest enclaves within the Caatinga Domain. [ABSTRACT FROM AUTHOR]

Context: Biodiversity is modulated by the spatial structure of the landscape. Thus, landscape metrics can be useful indicators of biota integrity and vulnerability, helping in conservation and management decisions.Objective: We performed the first quantitative analysis of the spatial structure of the Caatinga drylands. We estimated the habitat amount and the fragmentation pattern of this region using a multi-scale perspective.Methods: Using the Brazilian official database of native remnants, we calculated the number and percentage of remaining fragments per size class and we describe how habitat amount changes along the landscape. By simulating different dispersal capacities, we estimated the functional connectivity among remnants. We also calculated the cumulative core area as a function of different edge effect widths.Results: Caatinga is subdivided into 47,100 fragments. Although 91% of them are smaller than 500 ha, 720 fragments are larger than 10,000 ha, corresponding to 78% of the remaining vegetation. Potentially, 95% of the vegetation is accessible to species that can cross 1000 m of matrix. With one kilometer of edge effect, the core area is reduced to a quarter of the remaining vegetation. The habitat amount analyzes reinforced the regional differences in the spatial distribution of the remnants.Conclusions: Caatinga remains well connected for species with moderate and high dispersal capacities. However much of its remaining area is vulnerable to anthropogenic disturbances. Expansion of the protected area network and effective natural resource management to avoid overexploitation of the remnants are key strategies for maintaining the Caatinga biodiversity and its services. [ABSTRACT FROM AUTHOR]

Partamona seridoensis is an endemic stingless bee from the Caatinga, a Neotropical dry forest in northeastern Brazil. Like other stingless bees, this species plays an important ecological role as a pollinator. The aim of the present study was to investigate the genetic structure and evolutionary history of P. seridoensis across its current geographic range. Workers from 84 nests from 17 localities were analyzed for COI and Cytb genic regions. The population structure tests (Bayesian phylogenetic inference, AMOVA and haplotype network) consistently characterized two haplogroups (northwestern and eastern), with little gene flow between them, generating a high differentiation between them as well as among the populations within each haplogroup. The Mantel test revealed no isolation by distance. No evidence of a potential geographic barrier in the present that could explain the diversification between the P. seridoensis haplogroups was found. However, Pleistocene climatic changes may explain this differentiation, since the initial time for the P. seridoensis lineages diversification took place during the mid-Pleistocene, specifically the interglacial period, when the biota is presumed to have been more associated with dry conditions and had more restricted, fragmented geographical distribution. This event may have driven diversification by isolating the two haplogroups. Otherwise, the climatic changes in the late Pleistocene must not have drastically affected the population dynamics of P. seridoensis, since the Bayesian Skyline Plot did not reveal any substantial fluctuation in effective population size in either haplogroup. Considering its importance and the fact that it is an endemic bee from a very threatened Neotropical dry forest, the results herein could be useful to the development of conservation strategies for P. seridoensis. [ABSTRACT FROM AUTHOR]

We investigated whether there were consistent differences in the physiological and anatomical traits and phenotypic variability of an invasive (Prosopis juliflora (Sw.) DC.) and native species (Anadenanthera colubrina (Vell.) Brenan) in response to seasonality in a tropical dry forest. The water potential, organic solutes, gas exchange, enzymes of the antioxidant system, products of oxidative stress and anatomical parameters were evaluated in both species in response to seasonality. An analysis of physiological responses indicated that the invasive P. juliflora exhibited higher response in net photosynthetic rate to that of the native species between seasons. Higher values of water potential of the invasive species than those of the native species in the dry season indicate a more efficient mechanism for water regulation in the invasive species. The invasive species exhibits a thicker cuticle and trichomes, which can reduce transpiration. In combination, the increased epidermal thickness and the decreased thickness of the parenchyma in the dry season may contribute to water saving. Our data suggest a higher variability in anatomical traits in the invasive species as a response to seasonality, whereas physiological traits did not present a clear pattern of response. [ABSTRACT FROM AUTHOR]

Calotropis procera is a soft-wooded, evergreen, perennial shrub species which grows in a variety of environments including dry habitats such as the Brazilian semi-arid region. This study aimed to evaluate the variation in the oil content and fatty acid composition of C. procera seeds from four climatically different locations in the state of Pernambuco in the northeast of Brazil. The seed oil content of C. procera ranged from 19.7 to 24.0 %. Five main fatty acids were identified, with a predominance of unsaturated linoleic and oleic acids (approximately 70 %). Our results suggesting that environmental conditions influenced the seed oil biosynthesis of C. procera, because the localities with high temperature and low precipitation had increased oil content and total biosynthesis of saturated fatty acids. Multivariate analysis showed high similarity among three localities which share certain physiographic characteristics and climatic conditions such as temperature and precipitation values. The oil profile of C. procera presents interesting features that highlight its potential as a future alternative for the biodiesel market, especially in semi-arid regions. [ABSTRACT FROM AUTHOR]

Arid and semi-arid environments correspond to one-third of the Earth's terrestrial surface. In these environments, precipitation is an essential and limiting element for vegetation growth and ecosystem biomass productivity. The semi-arid region of Brazil comprises around 11.5% of the national territory, where the Caatinga biome originally composed ~ 76% of this area, with water deficit as a prominent feature, annual rainfall lower than 800 mm, temperatures ranging between 25 and 30 °C, and potential evapotranspiration higher than 2000 mm/year. Research on the dynamics of mass and heat fluxes through techniques such as eddy covariance (EC) has contributed to estimate the magnitude and seasonal patterns of turbulent exchanges between ecosystems and the atmosphere. This study was conducted in an area of dense Caatinga (DC) and another of sparse Caatinga (SC) from 2013 to 2014. It was observed that albedo (α) and net radiation (Rn) were higher in the SC compared with DC since the magnitude of incoming shortwave radiation was higher in this area. It was found that most of the Rn is converted to sensible heat flux (H), mainly during the dry period in the SC, about 50% for H and 20% for λE. The energy balance closure showed that the turbulent fluxes (H + λE) were underestimated in comparison to the available energy at the surface (Rn − G). We also observed that this discrepancy was higher in the DC area, corresponding to ~ 30%. [ABSTRACT FROM AUTHOR]