Chapada Diamantina Mountains Research Articles

A new species of Oxalis sect. Thamnoxys (Oxalidaceae) from the state of Bahia, Brazil

Oxalis jacobinensis, a new species of Oxalis sect. Thamnoxys, is described from the State of Bahia, in the northern sector of the Chapada Diamantina mountains. It can be distinguished from other species of the section by the leaves usually grouped at the stem apex, terminal leaflet blades rhombic-ovate to lanceolate, usually appearing grayish when fresh on the abaxial side, pedicels articulated at ca. 1/3 of their length, usually leaving a conspicuous foot, and capsules with two-seeded carpels narrowing distally, and abaxially covered with short stalked glandular hairs. We provide a description, illustrations, a geographic distribution map, a preliminary evaluation of its conservation status, and taxonomic notes.

Four new species of Mimosa sect. Batocaulon ser. Cordistipulae (Leguminosae) from Bahia, Brazil

Four new species of Mimosa series Cordistipulae (Leguminosae: Caesalpinioideae: Mimosoid clade) are described from Bahia state, Brazil: M. crassifolia, M. bahiana and M. confusa from rupestrian grasslands (campo rupestre vegetation) of the Chapada Diamantina mountain range, and M. melosa from inland dry scrub on sand dunes of the São Francisco River. We provide illustrations, comments on the geographical distribution, preliminary conservation assessments, and morphological affinities.

Bauhinia orbiculata (Cercidoideae, Leguminosae), a new species from Chapada Diamantina, Bahia, Brazil

Bauhinia orbiculata is a new species of Leguminosae found in the northern portion of the Chapada Diamantina mountain range in the state of Bahia, northeastern Brazil. It occurs in the seasonally dry shrubby vegetation locally known as ‘carrasco’, and is characterized by entire unifoliolate leaves with nine primary veins, rounded to obtuse apex and cordate base, dark ferruginous lower leaf surface, and linear and smooth floral buds. A detailed description, distribution map and illustrations are provided and its relationship with other eastern Brazilian species with entire leaves is discussed.

Effects of ENSO events on the intensity, seasonality, and diversity of reproductive phenology of Miconia (Melastomataceae) species in tropical rainforest.

We evaluated the phenology and reproductive phenological diversity of three sympatric species of Miconia in a gallery forest in the Chapada Diamantina mountains, Bahia, Brazil. The reproductive phenophases (bud, flower, immature fruit, and mature fruit) of M. alborufescens (N=38), M. holosericea (N=46), and M. prasina (N=44) were evaluated monthly, between June/2008 and June/2015. The Fournier index was used to assess the intensities of the reproductive phenophases; synchrony and seasonality were analyzed using circular statistics and the Rayleigh (Z) test. The Frideman and Wilcoxon tests were used to verify interannual variations in phenological patterns. Reproductive phenological diversity was measured by calculating the Shannon-Wiener index; ANOVA tested possible differences in the means of diversity among the different years. The reproductive phenophases of the studied Miconia species occurred sequentially (M. alborufescens, then M. holoserica, followed by M. prasina), in the transition between the dry and rainy seasons, with little overlap between them. In general, the species showed seasonal and synchronic phenological patterns, with some variations that coincided with El Niño and/or La Niña events, e.g., demonstrating changes in the periodicity, synchrony, and intensity of their phenophases. The intensity of fruiting, for example, showed increases during La Niña years. Reproductive phenological diversity appears to respond to climate changes resulting from El Niño events and periods of prolonged drought, with high Shannon-Wiener index values. The results also suggest that the effects of global climatic phenomena (El Niño and La Niña) that alter regional climatic seasonality can also cause variations in the reproductive phenological rhythms of the Miconia species studied.

Geological and sociological factors influencing the construction and occupation of historic stone mining shelters, Bahia State, Brazil, 1844 – present

The geological and sociological factors that influenced the construction and habitation of the “toca” rockshelters built and occupied by diamond miners starting in 1844 are discussed. Extensive field excursions were made into the Chapada Diamantina Mountains, in what is now the Chapada Diamantina National Park, over a period of more than 40 years to document the archaeological vestiges of the diamond rush there. A total of 650 archaeological features were identified, geo-referenced, photo-documented, and classified; 286 of those features were “toca” rockshelters and 53 were stone houses. The local geology, water resources, regional climate, and human factors dictated the construction and occupation of those shelters, including the availability of appropriate overhanging rock ledges, the proximity of potable water, site humidity, and the proximity of diamond-bearing formations. The “toca” shelters themselves share a number of common features, including fire pits, a lack of windows, construction without the use of mortar, and the avoidance of East-facing sites.

Floristics, phytosociology and biogeography of capitinga vegetation in a white sand habitat in the Chapada Diamantina Mountains, Brazil

Abstract Capitinga is poorly studied vegetation growing on small, scattered islands of fine, white sand surrounded by the latosol forests on the eastern flank of the Chapada Diamantina Mountains in northeastern Brazil. Our study characterized capitinga vegetation, its environmental features, and compared its flora with the vegetation mosaic within the Espinhaço and Chapada Diamantina ranges. Floristic data was collected from 1999-2006, and phytosociological surveys were undertaken in 2004-2005 and 2016-2017 within fifteen 50 x 2 m plots (100 m2 each, 1500 m2 in total). Multivariate grouping and ordination analysis were used to examine the floristic affinities of capitinga vegetation. Sixty different species from 36 families were recorded overall, while a total of 4945 individuals distributed among 25 families and 33 species were recorded in the plots. The richest families were Fabaceae (7) and Apocynaceae (5), while the most abundant families were Arecaceae (61.5% of all individuals) and Velloziaceae (18.4%), represented by Syagrus harleyi and Vellozia dasypus respectively. Capitinga represents a distinct habitat conditioned by edaphic features, and its flora is unlike other vegetations in the Espinhaço or Chapada Diamantina ranges, with several locally endemic species.

Comparing Data Collection Methods in Phenological Evaluations of Himatanthus drasticus

We present a case study focusing on collection methods and phenological data analyses. Qualitative, semi-quantitative, and quantitative approaches were compared in terms of their efficiencies for describing flowering and fruiting intensities and phenophase synchrony in Himatanthus drasticus growing in a gallery forest in the Chapada Diamantina mountains, Brazil. Our results showed that phenophase intensity and synchrony were respectively each best. Determined using quantitative and qualitative methods We reinforce the importance of clearly defining research aims, as quantitative data collections require considerably greater field efforts than qualitative evaluations, especially concerning forest trees.

Identification of priority areas for Eschweilera tetrapetala (Lecythidaceae) conservation in response to climate change

Abstract Eschweilera tetrapetala is a tree endemic to Submontane Seasonal Forests in inland Atlantic forest areas of the Chapada Diamantina Mountains, Northeastern Brazil. The effects of climate change on the spatial distribution pattern of that species were investigated to identify priority areas for its conservation. Distribution patterns and population densities were obtained by sampling individuals in ten 200 x 10 m transects, and in thirty additional 10 x 10 m border and interior forest plots. The occurrence data were subjected to Ecological Niche Modelling using Bioclim, Maxent, and Support Vector Machine algorithms. The predicted model for the current distribution of E. tetrapetala, using the Bioclim, Maxent, and Support Vector Machine algorithms, evidenced stable areas of strong environmental suitability in the east of the Chapada Diamantina. The models also show an expansion of areas with environmental suitability during the Mid-Holocene, with retraction in the present and greater reductions predicted in future global warming scenarios. The number of individuals in the plots varied from zero to 14, indicating an aggregated distribution. Morisita’s index indicated a random distribution along a forest edge but aggregated in the forest interior. Eschweilera tetrapetala is sensitive to climatic change and anthropogenic pressure, at both regional and local scales.

Paragoniosomatinae, a new subfamily of Gonyleptidae (Arachnida: Opiliones), based on a new species from the Chapada Diamantina relict cloud forests, Brazil.

In this paper, we describe a new subfamily of Gonyleptidae, Paragoniosomatinae subfam. nov., based on a new genus and species, Paragoniosoma cachaceiro gen. nov., sp. nov., found in an upper montane cloud forest of Chapada Diamantina mountains, one of the small interior patches of Atlantic Forest. This discovery suggests that the narrow-restricted cloud forests are old relicts of an Atlantic Forest hotspot. Paragoniosoma cachaceiro gen. nov., sp. nov. is characterized by the presence of four areas on the dorsal scutum, serose dry mark in areas III-IV, seven basal setae in penis (macrosetae A and B) in two rows, and very large tarsal process. We performed a phylogenetic analysis based on morphological characters that revealed a close relationship of the new species with Goniosomatinae, a subfamily that includes six genera and 38 valid species distributed throughout the coastal Atlantic Forest. The new species also has the same habitat and other behavioural and ecological traits as Goniosomatinae, furnishing great insights on the evolution of their characteristic biology, e.g., subsocial behavior. Field surveys of harvestmen from the type locality and nearby lowland seasonal forests indicate a unique fauna, including additional new, undescribed species. In addition to phylogenetics, this dissimilarity with other regions and the presence of endemic species of other animal and plant taxa provide support for the consideration of the cloud montane patches of Chapada Diamantina as relicts. We discuss this rule in the historical biogeographic context of Atlantic Forest and suggest that the new species represents evidence of an Atlantic Forest that was more widespread in the past.

Phenological diversity of Maprounea guianensis (Euphorbiaceae) in humid and dry neotropical forests

Phenological diversity, seasonality and leaf longevity may affect leaf habits, reflecting plant responses to environmental conditions. Maprounea guianensis Aubl. is a widespread species in Brazil that is associated with different forest types. We investigated how phenological diversity, seasonality and leaf longevity affect leaf habits of its populations growing in humid and dry forests in the Chapada Diamantina mountains. We made monthly observations of leaf budding and fall in 62 individual trees between 2004 and 2012 (84 months), estimating leaf longevity based on phenophase evaluations. We made use of circular statistics, cross correlations and the Shannon–Wiener Index to evaluate our data. There was little variation in rainfall distribution between the study years, although water availability differed at each site. Phenophase seasonality was found to be negatively correlated with rainfall but positively correlated with photoperiod. Low phenological diversity was observed within each site, but not between sites, and leaf longevity was reduced in the dry forest. Although macroclimatic conditions were similar throughout the range of occurrence of M. guianensis in the region, we found that phenological behaviour and leaf longevity differed according to micro-site differences, demonstrating the plasticity of the species, which may favour its occupation of different environments.

Ecological aspects of arbuscular mycorrhizal fungal communities in different habitat types of a Brazilian mountainous area

AbstractIncreasing elevation affects many abiotic factors, such as a temperature decrease and an increase in radiation, as well as multiple biotic characteristics such as richness and composition of plant communities, both of which contribute to the formation of different habitats in mountainous landscapes. Both biotic and abiotic factors also affect belowground arbuscular mycorrhizal fungi (AMF) communities, but there is scarce information available from tropical mountain ecosystems. The objective of this study was to determine the diversity and distribution of AM fungi in different mountainous habitat types in the Chapada Diamantina mountain range in Bahia (NE Brazil). Soil samples were collected in five habitats types: high‐altitude cerrado savannas (HAC), natural grasslands (GRA), gallery forests (GAF), in natural rocky rupestrian fields (shrublands; CAR) and in rocky, rupestrian field in the regeneration stage (CRR). A total of 49 AMF species were identified, of which Glomeraceae and Acaulosporaceae species were the most representative families. The AMF communities did not follow the shifts in plant communities. The composition of the AMF communities differed only between CAR and HAC and between CRR and GAF, while the other habitats had similar AMF communities. Our conclusion is that the AMF community assemblages in tropical mountains are related to the heterogeneity of habitats of these ecosystems. In our study, silt and coarse sand contents were the main factors related to the community composition of AMF in the different habitats.

Centrosema sericiflorum (Leguminosae, Papilionoideae), a New Species Endemic to the Caatinga of Bahia, Brazil, and a Key to the Bahian Species of the Genus

Centrosema is a genus of the papilionoid legume tribe Phaseoleae (subtribe Clitoriinae) including about 35 species from the Neotropical region, characterized by the resupinate flowers and the standard petal provided with a spur on the outer surface. During a survey of the species from eastern Brazil, in the state of Bahia, a new species was found and is here described and illustrated. Centrosema sericiflorum differs from other species of the genus mainly by the sericeous indumentum of the outer surface of the calyx and the standard petal (vs. puberulous, pubescent, or villous). The new species occurs in semideciduous forests of the Chapada Diamantina mountain range and is only known from a restricted area in Central Bahia. It was informally assessed as Endangered following IUCN criteria because of its restricted range and occurrence in areas cleared for coffee plantation.

Two New Rupicolous Species of Chresta (Asteraceae, Vernonieae) from the Brazilian Caatinga

Two new rupicolous and endangered species from the Caatinga are described and illustrated. Chresta heteropappa is restricted to the brejos de altitude (montane forests) from Northeastern Ceara, growing on granite inselbergs. Chresta subverticillata occurs in Northern Bahia, inhabiting quartzitic outcrops on the Chapada Diamantina mountain range. Relationships of the two new taxa to other Chresta species are discussed, and a key for all species occurring in the Caatinga domain is presented, as well as maps and illustrations, including field pictures.

The influence of El Niño and edge effects on the reproductive phenology and floral visitors of Eschweilera tetrapetala Mori (Lecythidaceae), an endemic species of the Atlantic Forest of northeastern Brazil

ABSTRACT We compared the reproductive phenology and floral visitors of Eschweilera tetrapetala growing along the edge and in the interior of a submontane forest in the Chapada Diamantina mountains, Bahia State, Brazil. We sought to determine if there were inter-annual differences in intensity and seasonality associated with environmental conditions, and if there were differences in floral visitors between the two environmental contexts. Phenological observations were performed for three years, and included the occurrence of an El Nino event. We applied circular statistics to detect seasonal trends, performed cross correlations between phenophases and climate, Kruskal-Wallis and Wilcoxon signed-rank tests for inter-annual variation, and the Wilcoxon-Mann-Whitney test for edge-interior differences in the species richness of floral visitors. We observed inter-annual variations in the intensity and seasonality of flower production that accompanied variations in rainfall, possibly associated with El Nino events. Floral visitor richness differed between the forest edge and interior, with seven species recorded for the interior and only one for the edge. Reduced fruit set was also observed at the forest edge. This study contributes to our understanding of the influence of El Nino and edge effects on the reproductive phenologies of tropical plants.

The roles of rainfall, soil properties, and species traits in flowering phenology along a savanna-seasonally dry tropical forest gradient

We investigated flowering phenology in a semiarid macroclimate along an environmental gradient encompassing neotropical savanna, transition, and seasonally dry tropical forest (SDTF) areas in the Chapada Diamantina Mountains, northeastern Brazil. We expected to find divergence in flowering patterns between the plant communities studied that would be explained by distinct functional traits selected by differences in rainfall volumes and soil properties. Bud and flower productions were monitored in 809 individuals between January 2010 and March 2012. The savanna exhibited a continuous flowering pattern, while the transition and SDTF areas showed seasonal flowering associated with rainfall. Environmental variables and plant traits (wood densities, water potentials, and water storage capacities) were related to the observed flowering strategies of woody species. The high diversity of functional groups in the savanna was determined by higher plant water potentials that were related to low wood densities and the availability of soil water. The role of rainfall, especially the rainfall volumes during the dry season, is critical in defining different flowering patterns at the community level. The physical properties of the soil selected the presence of species with distinct water-use strategies (low wood density species in savanna areas, and high wood density species in the transition zone and forest), which in turn affected their flowering.

Checklist, new species and new records of Cerambycidae (Insecta: Coleoptera) from Chapada Diamantina, Bahia state, Brazil.

A checklist of Cerambycidae from three Brazilian localities of the Chapada Diamantina mountain range (Catolés, Piatã and Mucugê) is provided. These three localities are considered of great biological importance. A total of 38 species were collected, belonging to 29 genera, 18 tribes and two subfamilies. Ten new records for the state of Bahia are presented, and a new species, Desmiphora (Desmiphora) iwasarai (Desmiphorini, Lamiinae), is described and illustrated.

Phenodynamics of five orchids species growing on rock outcrops in the Chapada Diamantina Mountains in northeastern Brazil

We evaluated the vegetative and reproductive phenological patterns of the orchids Cattleya elongata, Cyrtopodium aliciae, Epidendrum orchidiflorum, Epistephium lucidum, and Sobralia liliastrum (Orchidaceae) growing on sandstone outcrops in the Chapada Diamantina Mountains in northeastern Brazil. Phenological events were associated with abiotic factors, leaf longevity, life form, plant growth pattern, and pollination syndrome. Phenological observations were made for 18 months and followed the phenophases of: stem/pseudobulb emission, leaf flush, leaf fall, flowering, immature fruit and mature fruit. Seasonality, synchrony, and correlations between phenophases and environmental variables were tested. The orchid species demonstrated aseasonal vegetative phenologies, except for pseudobulb emission. Reproductive events were seasonal, except for flowering in E. orchidiflorum. There was high flowering overlap between the species pairs S. liliastrum and C. aliciae (dry season) and C. elongata and E. lucidum (rainy season). Dispersal occurred during both the rainy and dry seasons. The vegetative phenophases exhibited low synchrony, and were related to certain morphofunctional characters (stems/pseudobulbs, CAM metabolism). The reproductive phenophases showed high synchrony consistent with the deceit pollination strategy usually associated with the group.

Philcoxia tuberosa (Plantaginaceae), a new species from Bahia, Brazil

Philcoxia tuberosa is proposed as a new species of Plantaginaceae from Bahia (Northeastern Brazil). It can be differentiated from the remaining three species of the genus by the presence of tubers in the branches, smaller flowers, pedicel and sepals sparsely glandular, bicolor corolla with purple tube and white limb, and longer sepals and filaments. This new species has a narrow geographical range in Morro do Chapeu municipality, on the Northern slopes of the Chapada Diamantina mountain range. It occurs in white sand dunes within a patch of Seasonally Dry Tropical Forest.

Dasyphyllum diamantinense (Asteraceae, Barnadesioideae): a new species from the Chapada Diamantina, Bahia State, Brazil

Dasyphyllum diamantinense is a new species endemic to the Chapada Diamantina Mountains in the northern section of the Espinhaço Range, in Bahia State, Brazil, which grows in rocky fields, forests and savannas, and on inselbergs. The new taxon is morphologically similar to Dasyphyllum leptacanthum. Affinities and diagnostic characters are discussed, and illustrations and a map are provided.

Self-compatible sympatric Chamaecrista (Leguminosae-Caesalpinioideae) species present different interspecific isolation mechanisms depending on their phylogenetic proximity

The mating system of seven sympatric taxa of Chamaecrista occurring in the Chapada Diamantina Mountains, northeastern Brazil, was studied to determine the occurrence of self-incompatibility and interspecific genetic isolation mechanisms within the group. Self- and cross-pollination experiments and inter-taxon bidirectional crosses were performed. All of the populations were self-compatible and showed high percentages of spontaneous seed abortion on both self- and cross-pollinated fruits. The inter-incompatibility among the taxa of Chamaecrista is directed by different mechanisms depending on their degrees of phylogenetic proximity. In the crosses between closely related taxa (same clade), seed inviability was observed in the crossing pairs C. desvauxii var. graminea × C. desvauxii var. latistipula, and C. chapadae × C. glaucofilix. Inter-compatibility between species of the same clade occurred in C. blanchetii and C. confertiformis, with the formation of viable seeds. Pre-zygotic gametophytic reproductive isolation was observed among taxa of different clades, without penetration of the pollen tube into the ovule, or post-zygotic isolation through embryo or endosperm inviability, with abortion of the seeds. Inter-incompatibility represents an important factor in reproductive isolation and thus in the maintenance of the genetic identity of sympatric taxa that flower in synchrony and share pollinators.