Caatinga Region Research Articles

Subsidies for a poorly known endemic semiarid biome of Brazil: non-volant mammals of an eastern region of Caatinga

The mammalian fauna of the eastern Caatinga, a Brazilian semiarid biome, was surveyed in the dry and wet seasons aiming to contribute to the knowledge of this poorly known region. Complementary live-trap survey methods were employed for sampling small non-volant mammals and transects along roads for medium and large mammals. Seventeen mammalian species were recorded, with five new records for Sergipe state, two being endemic to Caatinga. More individuals were captured in the dry season, although species number was the same for both seasons. Medium- and large-sized mammalian species were not encountered in the region, which was also true for some small-sized species hunted for consumption. These findings corroborate the importance of using complementary methods for sampling small non-volant mammals in the Caatinga and indicate that the mammalian fauna of this region, suffering a severe anthropogenic pressure, requires strong measures for its preservation.

Effect of water restriction on total phenolics and antioxidant properties of Amburana cearensis (Fr. Allem) A.C. Smith cotyledons during seed imbibition

Amburana cearensis (Fr. Allem) AC Smith is a native Caatinga species commonly found in the semiarid region of North East of Brazil, which possesses resistance to temperature and drought stress and is widely used in the folk medicine. This study aimed at a better understanding of seed imbibition and germination as well as to evaluate the effect of water restriction on total phenolics and antioxidant properties in cotyledons of A. cearensis (Fr. Allem) A.C. Smith. Seeds were imbibed in water (control) or PEG 8000 solution (−1.2 and −1.4 MPa). Germinability was evaluated up to 180 h of seed imbibition, whereas cotyledons were collected at 0, 24, 48, 72 and 96 h of imbibition. The radical scavenging ability was enhanced in response to the water restriction after 96 h of imbibition as compared to the control. Water restriction affected water uptake and seed germinability while inducing a faster response in terms of biosynthesis of phenolic compounds, although total phenolic content decreased as compared to control. There is a high correlation between total phenolics and antioxidant activity for the seeds subjected to the water restriction conditions. These findings provide insights into the mechanisms underlying plant adaptation to harsh environmental conditions during germination, which would be very helpful to develop germination and seedling production protocols aimed at strategies for the sustainable exploitation of A. cearensis by local folk communities under the typical harsh conditions of the Brazilian Caatinga and semiarid regions.

The introduced tree Prosopis juliflora is a serious threat to native species of the Brazilian Caatinga vegetation

Despite its economic importance in the rural context, the Prosopis juliflora tree species has already invaded millions of hectares globally (particularly rangelands), threatening native biodiversity and rural sustainability. Here we examine seedling growth (leaf area, stem diameter, plant height) and seedling mortality across five native plant species of the Caatinga vegetation in response to competition with P. juliflora. Two sowing treatments with 10 replications were adopted within a factorial 2×5 randomized block design. Treatments consisted of P. juliflora seeds sowed with seeds of Caesalpinia ferrea, Caesalpinia microphylla, Erythrina velutina, Mimosa bimucronata and Mimosa tenuiflora (one single native species per treatment), while seeds of native species sowed without P. juliflora were adopted as controls. Overall, our results suggest that P. juliflora can reduce seedling growth by half and cause increased seedling mortality among woody plant species. Moreover, native species exhibit different levels of susceptibility to competition with P. juliflora, particularly in terms of plant growth. Such a superior competitive ability apparently permits P. juliflora to establish monospecific stands of adult trees, locally displacing native species or limiting their recruitment. The use of less sensitive species, such as C. ferrea and M. tenuiflora, to restore native vegetation before intensive colonization by P. juliflora should be investigated as an effective approach for avoiding its continuous spread across the Caatinga region.

Phenology of riparian tree species in a transitional region in southeastern Brazil

This study characterizes the phenological behavior of the most abundant species of riparian vegetation (Pandeiros river, southeast Brazil) in a transition region of Caatinga and Cerrado biomes and relates its phenophases to climatic variables. Among the ten most abundant species of each five sites studied between August 2008 through July 2009, individuals were marked for phenological monitoring, totaling 31 species and 964 individuals. For each sampled individual, the presence or absence of reproductive and vegetative phenophases was recorded and related to the climatic variables of precipitation, temperature, and relative humidity. The period with the greatest amount of vegetative and reproductive phenological activity was in the dry season. Among the climatic variables, the vegetative phenophases were most correlated by temperature, while the reproductive phenophases were most influenced by relative humidity. The species studied presented phenological behavior similar to their typical occurrence area, like in cerrado and caatinga phytophysiognomies, contradicting the phenological pattern expected for riparian forest. However, this behavior also demonstrated adaptations for survival in a transitional environment, leading to the formation of a phenological pattern that is unique to the riparian forest studied.

Biogeography, vicariance and conservation of snakes of the neglected and endangered Caatinga region, north‐eastern Brazil

AbstractAimOur aims were to test the predictions of the vicariance model, searching for natural, non‐random biogeographical units using data on snake distributions, and to assess the conservation of biogeographical patterns and underlying processes in the poorly studied Caatinga region.LocationCaatinga region, north‐eastern Brazil.MethodsWe revised and georeferenced 7352 snake occurrence records at point localities, by direct examination of voucher specimens in zoological collections and revision of literature data. We tested two predictions of the vicariance model via biotic element analysis using two datasets (all taxa and endemics) mapped onto a 1° × 1° square grid across the Caatinga. Finally, we examined the overlap between recovered biogeographical units and spatial patterns of habitat loss and protected area coverage.ResultsWe recorded 112 snake species from the Caatinga, of which 22 (20%) are endemics. The predictions of the vicariance model were corroborated by the detection of groups of species with significantly clustered ranges (biotic elements). The analysis with the full dataset detected eight biotic elements, and three endemic biotic elements were found when only using endemics. The three endemic biotic elements correspond to core areas of biotic elements detected with the larger dataset. The average habitat loss for species forming biotic elements was 46%, and was similar among biotic elements. Protected area coverage is different for species from different biotic elements, and most species' ranges are very poorly represented in protected areas.Main conclusionsThe Caatinga harbours a peculiar snake fauna with significantly clustered species ranges concordant with the predictions of the vicariance model. Our results, representing the first formal test of vicariance patterns in the Caatinga, detected poor overlap between biotic elements and protected areas, indicating that biogeographical patterns and processes are largely unprotected in this imperilled and neglected Neotropical region.

Diversity and distribution of mollusks along the Contas River in a tropical semiarid region (Caatinga), Northeastern Brazil

An inventory of macroinvertebrates conducted in the Contas River basin in Northeastern Brazil found 13 species of freshwater mollusks. Most of the community was represented by pulmonate gastropods, including Physa acuta, Drepanotrema anatinum, D. cimex, D. lucidum, Biomphalaria straminea?, Gundlachia radiata?, G. ticaga and Hebetancylus moricandi; the prosobranchs Pomacea archimedis?, Melanoides tuberculata and Littoridina sp. were also found. Bivalves were less diversified, represented only by Pisidium pulchellum? and Eupera simoni?. The taxonomic composition and the small size of many species reflect the intermittent condition of the basin. Additionally, the occurrence of shells of five terrestrial species (Helicina angulata, Gastrocopta pellucida hordeacella?, Beckianum beckianum, Succinea sp. and Systrophiidae gen. et sp. indet.) in the rivers reflects the occasional heavy rainfalls and floods in the region. The invasive gastropod M. tuberculata was the most abundant and widely distributed species. All 13 species were found in the lower course, in the Atlantic Forest region, and most, but not all, were recorded in the upper course, in the Caatinga region. The distribution and the occurrence of the bivalve species exclusively in the Atlantic Forest region indicate that the locally higher annual precipitation provides favorable conditions for the survival of these mollusks, such as a more stable hydroperiod.

Knowledge, use and management of native wild edible plants from a seasonal dry forest (NE, Brazil)

BackgroundDespite being an ancient practice that satisfies basic human needs, the use of wild edible plants tends to be forgotten along with associated knowledge in rural communities. The objective of this work is to analyze existing relationships between knowledge, use, and management of native wild edible plants and socioeconomic factors such as age, gender, family income, individual income, past occupation and current occupation.MethodsThe field work took place between 2009 and 2010 in the community of Carão, Altinho municipality, in the state of Pernambuco in northeastern Brazil. We conducted semi-structured interviews with 39 members of the community regarding knowledge, use and management of 14 native wild edible plants from the Caatinga region, corresponding to 12 vegetable species. In parallel, we documented the socioeconomic aspects of the interviewed population (age, gender, family income, individual income, past occupation and current occupation).ResultsKnowledge about edible plants was related to age but not to current occupation or use. Current use was not associated with age, gender or occupation. The association between age and past use may indicate abandonment of these resources.ConclusionBecause conservation of the species is not endangered by their use but by deforestation of the ecosystems in which these plants grow, we suggest that the promotion and consumption of the plants by community members is convenient and thereby stimulates the appropriation and consequent protection of the ecosystem. To promote consumption of these plants, it is important to begin by teaching people about plant species that can be used for their alimentation, disproving existing myths about plant use, and encouraging diversification of use by motivating the invention of new preparation methods. An example of how this can be achieved is through events like the “Preserves Festival”.

LEVANTAMENTO FLORÍSTICO DO MUNICIPIO DE PEDRA PRETA-RN: SUBSÍDIOS PARA EMPREENDIMENTOS FUTUROS

The town of Pedra Preta in the state of Rio Grande do Norte has been the target of numerous claims of enterprises, especially for electric power generation from wind energy. However, the said council is in the Caatinga region of great importance and sensitivity for the northeast region. This paper seeks to situate geographically the area studied, considering not only the physical aspects of regional, but performing a semi-quantitative survey of floristic elements that constitute the zone of influence of the said municipality. Such information could be used for comparative evaluation of aspects / impacts and estimates of scenarios for environmental license in that region. The observations show that the situation of the vegetation in the study area is affected by human action. However, you can still find the natural vegetation of Caatinga of hiperxerófila, composed of its typical species. As the negative impacts to vegetation generated by the implementation of industrial enterprises as well as for the same operation are minimal and reversible, such activities do not show aggressive vegetation of the Caatinga.

Low legitimate pollen flow in distylic Turnera hermannioides (Passifloraceae) and its consequences on fruit and seed set

Turnera hermannioides is a ruderal distylic subshrub, native to NE-Brazil. In the Catimbau National Park, situated within the semi-arid Caatinga region, we studied the pollination ecology of this species, emphasizing (1) effective pollinators; (2) characteristics of short- and long-styled flowers; (3) intra- and intermorph pollen flow; and (4) fruit and seed set. Short and long-styled morphs differ in pollen size and ornamentation, stigmatic surface, style and stamen length and nectar production. The flowers are obligate intermorphic outcrossers and depend on animals for pollination. The flowers of T. hermannioides attracted insect visitors of 25 species, among them butterflies, beetles, but mainly bees. Polylectic bees, such as Apis mellifera, stingless bees, and solitary Callonychium brasiliense were the most frequent visitors and the principal pollinators. The frequency of visits, however, was very low (on average 1.9 visits/flower/day), resulting in a low and unbalanced legitimate pollen flow, i.e. a much lower number of pollen grains from short-styled flowers reaching stigmas of long-styles than vice versa, which in turn compromised fruit and seed set. Surprisingly, Protomeliturga catimbaui and P. turnerae, both oligolectic on flowers of the Turneraceae-clade of the Passifloraceae s.l., were very rare flower visitors and did not contribute significantly to the pollination of Turnera hermannioides. We discuss how the low visitation rate and the inefficiency of pollinators (i.e. inefficiency in promoting legitimate pollination) compromise pollen flow and, consequently, fruit and seed set in this species.

Nymphaea vanildae (Nymphaeaceae): A new species from the Caatinga in Brazil

Nymphaea vanildae (Nymphaeaceae) is described and illustrated as a new species from the Caatinga region in Brazil, and placed in Nymphaea subg. Hydrocallis. This species is characterized by having nocturnal flowers, elliptic and delicate leaves, a clear distinction between the perianth and androecium, linear carpellary appendages and four or more series of proliferate pseudanthia, which distinguishes it from all species in the genus.

Evaluation of mechanisms involved in the antinociception of the ethanol extract from the inner bark of Caesalpinia pyramidalis in mice

Ethnopharmacological relevanceCaesalpinia pyramidalis Tul. (Fabaceae) is an endemic tree of the Northeast region of Brazil, mainly in the Caatinga region. More commonly, inner bark or flowers are traditionally used to treat many painful and inflammatory processes. A common use of this plant is made by macerating a handful of its stem bark in a liter of wine or sugarcane brandy. It is drunk against stomachache, dysenteries, and diarrheas. Materials and methodsThe ethanol extract of Caesalpinia pyramidalis inner bark was used in mice via oral route, at the doses of 10, 30, and 100mg/kg, in behavioral models of nociception and investigates some of the mechanisms underlying this effect. ResultsThe ethanol extract (30 and 100mg/kg, P<0.001), given orally, produced dose dependent inhibition of acetic acid-induced visceral pain. The ethanol extract also caused significant and dose-dependent inhibition of capsaicin-(100mg/kg, P<0.001) and glutamate-(10, 30, and 100mg/kg, P<0.01) induced pain. The antinociception caused by the ethanol extract (30mg/kg) in the abdominal constriction test was significantly attenuated (P<0.001) by intraperitoneal treatment of mice with l-arginine (600mg/kg). ConclusionsCollectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis produced dose-related antinociception in several models of pain through mechanisms that involved both glutamatergic system and/or the l-arginine–nitric oxide pathway, supporting the folkloric usage of the plant to treat various painful processes.

Phenology of Spondias tuberosaArruda (Anacardiaceae) under different landscape management regimes and a proposal for a rapid phenological diagnosis using local knowledge

BackgroundStudies aimed at investigating the influence of habitat change on species phenology. Studies that investigate people's perceptions of the phenology of certain species still area few; yet this approach is important for effective decision-making for conservation. The aim of this study was to investigate the phenology of Spondias tuberosa Arruda (Anacardiaceae), a native species of economic and ecological importance in northeastern Brazil, in five landscape units (LUs) (Mountain, Mountain Base, Pasture, Cultivated Areas and Homegardens) of a Caatinga region in Altinho, Pernambuco, northeastern Brazil. These data could then be compared with local people's perceptions of the species’ phenophases.MethodCollection of phenological data was carried out monthly from February 2007 to January 2009 and included activity, intensity and synchronization of reproductive and vegetative phenophases. Ethnobotanical data were gathered using a collaborative approach to access local people’s knowledge about the species’ phenological schedule.ResultsThere were no significant differences in the intensity of phenophases among LUs, and there was a correspondence between people’s perception of phenophases and the phenological data collected. The data show that the different management practices for LUs did not influence the phenology of the species.ConclusionThe main conclusion of this study is the use of traditional knowledge as interesting tool for rapid phenological diagnosis. However further studies need to be developed to test this tool in other environments and cultural contexts.

A new species of Centris (Paracentris) Cameron, 1903 from northeastern Brazil, with a key for the Centris species of the Caatinga region (Hymenoptera: Apidae)

A new species of Centris (Paracentris) Cameron, 1903 from northeastern Brazil, with a key for the Centris species of the Caatinga region (Hymenoptera: Apidae)

Uso e diversidade de plantas medicinais em uma comunidade quilombola no Raso da Catarina, Bahia

A contribuição dos povos afrodescendentes é de extrema importância para a formação da cultura brasileira. Esses povos são em parte representados pelas comunidades remanescentes de quilombos, que mantém costumes e conhecimentos sobre utilização e manejo dos recursos vegetais. Esta pesquisa teve como objetivos inventariar as plantas medicinais utilizadas bem como medir a saliência cultural das mesmas, na comunidade Casinhas, município de Jeremoabo, estado da Bahia, localizada numa região de Caatinga. Para coleta dos dados foram realizadas entrevistas semi-estruturadas com sete pessoas reconhecidas pela comunidade como os maiores detentores do conhecimento sobre plantas. Os resultados indicam que 87 espécies são utilizadas na medicina tradicional local, merecendo destaque Poincianella pyramidalis (catingueira), que apresentou maior freqüência de citação e maior valor de saliência. O sistema digestório teve o maior número de indicações de plantas relacionadas às suas afecções (21 espécies); as folhas (36%) e as cascas (30%) foram as partes mais citadas nas indicações terapêuticas; o chá foi a forma de uso mais indicada (49%). A comunidade estudada depende diretamente dos recursos vegetais para suas práticas de cura. Os resultados dessa pesquisa podem servir como base para bioprospecção bem como subsídio para seleção de espécies da caatinga prioritárias para estudos posteriores de ecologia de populações, visando o seu uso e manejo sustentável.

Trophic niche breadth and niche overlap in a guild of flower-visiting bees in a Brazilian dry forest

Trophic niche breadth and niche overlap of bees were studied in a region of Caatinga (a deciduous dry thorn scrub forest) in Brazil with the lowest mean annual rainfall of the country, highly seasonal environmental variation, and an unpredictable rainy season. A null model approach was used to determine if the observed niche overlap in the community differed from that expected by chance. In general, even bee species with wider trophic niches concentrated foraging efforts on flowers of only a few of the available plant species, with low trophic niche overlap between pairs of species and among all species in the community. A randomization test showed niche overlap among the 10 common species in the guild to be significantly less than expected by chance, suggesting the existence of functional complementarity. The structure of communities defined by high functional complementarity is likely to be more sensitive to variation in available resources (e.g., richness and abundance of floral resources for bees). Ecosystem services provided by such communities may be more greatly affected by environmental changes (anthropogenic activities and climate change) than are services provided by communities with greater functional redundancy.

A new species of Centris (Paracentris) Cameron, 1903 from northeastern Brazil, with a key for the Centris species of the Caatinga region (Hymenoptera: Apidae)

Centris (Paracentris) Cameron is one of the subgenera with the greatest species richness of the bee tribe Centridini. Inthis paper, Centris nordestina, a new Brazilian species of the subgenus is described, and due to its close relationship witha clade of Andean species, a new biogeographical track is defined uniting northeastern Brazil with the Andes. For the first time a key for the species of the Caatinga region, the semiarid region of northeastern Brazil, is provided.

In VitroandIn VivoAntimalarial Activity of Essential Oils and Chemical Components from Three Medicinal Plants Found in Northeastern Brazil

The prophylactic and therapeutic arsenal against malaria is quite restricted and all the antimalarials currently in use have limitations. Thus, there is a need to investigate medicinal plants in the search for phytochemicals which can be developed into drugs. In our investigation, essential oils (EOs) were obtained from Vanillosmopsis arborea (Gardner) Baker, Lippia sidoides Cham. and Croton zehntneri Pax & K. Hoffm., aromatic plants abundant in northeastern Brazil, which are found in the caatinga region and are used in traditional medicine. The chemical composition of these EOs was characterized by GC-MS, and monoterpenes and sesquiterpenes were well represented. We assessed the in vitro activity of these EOs and also individual EO chemical components against the human malaria parasite Plasmodium falciparum (K1 strain) and the in vivo activity of EOs in mice infected with Plasmodium berghei. The acute toxicity of these oils was assessed in healthy mice and in vitro cytotoxicity was determined at different concentrations against HeLa cells and mice macrophages. The EO of V. Arborea was partially active only when using the subcutaneous route (inhibited from 33 up to 47 %). In relation to the EOs, L. sidoides and C. zehntneri were active only by the oral route (per gavage) and partially inhibited the growth of P. berghei from 43 up to 55 % and showed good activity against P. falciparum in vitro (IC (50) = 7.00, 10.50, and 15.20 µg/mL, respectively). Individual EO constituents α-bisabolol, estragole, and thymol also exhibited good activity against P. falciparum (IC (50) = 5.00, 30.70, and 4.50 µg/mL, respectively). This is the first study showing evidence for the antimalarial activity of these species from northeastern Brazil and the low toxicity of their EOs.

Photosynthesis and antioxidant activity in Jatropha curcas L. under salt stress

Biodiesel is an alternative to petroleum diesel fuel. It is a renewable, biodegradable, and nontoxic biofuel. Interest in the production of biodiesel from Jatropha curcas L. seeds has increased in recent years, but the ability of J. curcas to grow in salt-prone areas, such as the Caatinga semiarid region, has received considerably meager attention. The aim of this study was to identify the main physiological processes that can elucidate the pattern of responses of J. curcas irrigated with saline water, which commonly occurs in the semiarid Caatinga region. This study measured the activity of the antioxidant enzymes involved in the scavenging of reactive oxygen species, which include catalase (CAT) and ascorbate peroxidase (APX), as well as malondialdehyde (MDA) levels. The levels of chlorophyll (Chl), carotenoids, amino acids, proline, and soluble proteins were also analyzed. The net carbon assimilation rate (P N), stomata conductance (g s), and transpiration rate (E) decreased with salt stress. The activities of CAT and APX were decreased, while H2O2 and MDA levels as well as electrolyte leakage were significantly increased in salt-stressed plants compared to the untreated ones. These observations suggest that the ability of J. curcas plants resist to salt stress is associated with the activities of protective enzymes and their defensive functions. However, our results indicate that the reactive oxygen species scavenging system is not sufficient to protect J. curcas leaves against oxidative damage caused by salt stress, and, therefore, it cannot be treated as a salt tolerant plant species.

Mating behavior and female accompaniment in the whiptail lizard Cnemidophorus ocellifer (Squamata, Teiidae) in the Caatinga region of northeastern Brazil

We report here a set of observations on mating behavior and female accompaniment by the whiptail lizard Cnemidophorus ocellifer in an area of Caatinga (xerophilous open forests) in the state of Rio Grande do Norte, northeastern Brazil. We observed a stationary male lizard performing repeated vibratory movements of the pelvis and tail base upon the sandy soil. Since that male was in front of a burrow in which a female of the same species was sheltered, we hypothesize that this behavior may be part of a courtship display. We continued the observation and later, when the female emerged from the burrow, the male climbed on her and the copulation occurred. The incident of accompaniment observed was characterized by one male continuously accompanying a female during foraging. Plausible functional explanations for a male accompany a female include mating guarding, post-copulatory courtship, and sperm loading. By accompanying females, males would be guaranteeing insemination by multiple copulation and stimulation of the female, and protecting their paternity by chasing away other males, diminishing the chances of extra-pair copulations.

A new annual killifish species of the Hypsolebias flavicaudatus complex from the S&amp;atilde;o Francisco River basin, Brazilian Caatinga (Teleostei: Cyprinodontiformes: Rivulidae)

The Hypsolebias fl avicaudatus species complex is a clade of annual killifishes inhabiting seasonal pools associated to São Francisco River basin, in the semi-arid Caatinga region of northeastern Brazil. The analysis of both morphological and molecular data supports recognition of a new species of that complex, herein named as Hypsolebias guanambi. It was collected in the upper section of the Carnaíba de Dentro River drainage and is distinguished from all other species of the complex by having the dorsal fin more posteriorly placed in females, presence of short fi lamentous rays on the dorsal and anal fins in males, and fewer teeth on the second pharyngobranchial bone. The recognition of a species of the H. fl avicaudatus complex endemic to the upper Carnaíba de Dentro River drainage corroborates this region as an important area of endemism for annual killifishes.