Rupestrian Fields Research Articles

Vegetation mosaic shaping bryophyte diversity in a threatened ecosystem: A case study of Brazilian Cangas (ferruginous rupestrian fields)

The Canga vegetation in Brazil is a unique ecosystem found on ironstone outcrops, known as ferruginous rupestrian fields, and is considered one of the most diverse in the world. This mosaic landscape, comprised of trees, shrubs, and herbaceous vegetation, is home to a diverse range of plants, including angiosperm, bryophytes, and lichens. To understand the effect of Cangas' patchy landscape, here called mesohabitats, on bryophyte communities, we asked the following questions: Do the diversity parameters such as richness, abundance and composition of bryophytes differ along the different Cangas’ mesohabitats? Do bryophyte assemblages group by functional traits and filter per mesohabitat? We surveyed eight sites in the Quadrilátero Ferrífero (Iron Quadrangle), southeast Brazil. We collected and analysed data on bryophyte diversity and functional traits in three different mesohabitats: exposed areas (EA), shrub associations (SA), and tree associ ations (TA). The diversity of both groups was tested using one-way ANOVA; and functional traits were addressed with a Factorial Analysis of Mixed Data (FAMD). There are significant differences in the diversity of bryophytes among the mesohabitats, with TA having the highest diversity and abundance of liverworts and mosses, followed by SA and EA. The study also found bryophyte assemblies with similar functional traits in similar mesohabitats across the Brazilian Quadrilátero Ferrífero. The research revealed that the different mesohabitats provided important and distinct niches for bryophytes in Cangas, and this threatened ecosystem's high diversity must be considered when developing conservation strategies. This entails land managers adopting effective approaches aimed at improving both the quality and connectivity of habitats, fostering biodiversity, and bolstering the resilience of the ecosystem.

Paleobiogeoclimatic reconstruction of the Monte Cristo cave, Minas Gerais, Brazil, through phytolith analysis

This study aims to contribute to the understanding of possible paleoclimatic variations during the Quaternary in the Serra do Espinhaço Mountain Range, Minas Gerais, Brazil, based on phytolith analysis. Two soil profiles were collected from the Monte Cristo cave, which is formed in quartzite, the first being an Organosol outside the cave and the second consisting of mostly sandy material from inside the cave, in layers varying between light and dark tones. The results showed that both profiles present a high stock of phytoliths. The phytoliths are well preserved, with a predominance of Spheroid echinate and Spheroid ornate morphotypes, in addition to the presence of Bulliform flabellate, Cross, Bilobate, Rondel, and Trapezoid. The tree density index (D/P) is between 0.19 and 0.36, indicating open vegetation. The values of the Bi% index (32.8–53%) indicate moderate water stress, which is similar to previous studies in nearby regions. The Ic (climatic) index showed variations in plant adaptation at lower temperatures, with a predominance of C3 grasses, while the Pa/P index (palm tree density) indicated the presence of palm trees along both profiles. The ages obtained using 14C-AMS in the Organosol were from 4440/4230 to 2740/2430 years cal BP, and the ages of the sandy material inside the cave were from 1000/920 to 660/550 years cal BP. The phytoliths found inside the cave may be an indication that this material has an allochthonous origin, probably transported by flooding in periods under different hydrogeomorphological conditions, which is one of the hypotheses that will continue to be investigated. The vegetation type remained stable during the analyzed period, being characteristic of rupestrian fields with the presence of trees in more humid environments.

Lineage diversification of the Sky Island treefrog Scinax curicica (Anura, Hylidae) in the Espinhaço Mountain Range

Abstract Sky Islands present unique landscapes for organismal evolution because they comprise high mountain peaks separated by low valleys with vastly different environmental conditions. The Espinhaço Mountain Range in eastern Brazil is formed of groups of Sky Islands in the states of Minas Gerais and Bahia. Several phylogeographic studies have discovered strong genetic structure among populations of organisms occupying the campo rupestre (rupestrian fields) in the mountains of the Espinhaço. In this study, we aimed to test the hypothesis of spatio-temporal structuring of populations of Scinax curicica in the campo rupestre of the Espinhaço. We recovered three lineages of S. curicica: one lineage occurs in the north portion of the Espinhaço (North Lineage) in an area called Chapada Diamantina, and other two occur in the south portion of the Espinhaço (South 1 and South 2 Lineages) in Minas Gerais. All three lineages showed stable population sizes through time, probably due to the climatic stability of mountaintop areas, which was supported by ecological niche modelling.

Novelties in Stigmatodon (Bromeliaceae, Tillandsioideae), a genus endemic to Brazil: three new species, one new combination, and two new stigma types

The authors describe, discuss, and illustrate three epilithic new species of Stigmatodon, S. ilhanus, S. itamarajuensis, and S. viridibracteatus, restricted to vertical rock walls in inselbergs located in the states of Bahia and Espírito Santo, Brazil, and propose a new combination, transferring the endemic Vriesea vexata from rupestrian fields in Minas Gerais state to Stigmatodon. The stigma morphology of Stigmatodon, which is one of the most important distinctive features of this genus, is reevaluated and illustrated, with the recognition of two new types, the convolute-blade type III (stigmadontoid type) and the tubo-laciniate type II. These new stigma types suggest a morphological bridge between the typical tubo-laciniate type I and the convolute-blade types I and II and represent a relevant progress in understanding the morphological boundaries of Stigmatodon.

Susceptibility to wildfire in a conservation unit located in the transition region of Cerrado and Atlantic Forest Biomes, Brazil

Created in 2014, the Serra da Gandarela National Park (SGNP), is repeatedly affected by wildfires. This Conservation Unit is located in the Iron Quadrangle (MG), in a transition zone between the Cerrado and the Atlantic Forest biomes, and is characterized by a complex mosaic of phytophysiognomies. The aim of this investigation was to compare the performance of two risk mapping models for forest fire in the SGNP and its surroundings, based on two different approaches, being one by multicriteria analysis, AHP method and the other a simple probability method, called Hot Spot History, which provided information on the areas of highest and lowest risk and their environmental and human characteristics. Spatial data from remote sensing and GIS were used to simulate, in sequence, the fire ignition, the fire spread and, finally, the risk of wildfire. The validation of the risk models was performed by the Kappa coefficient (K). The results showed that the model based on the History of Hot Points obtained greater accuracy (0.61) than the model generated by the AHP method (0.54). The Brazilian Savanna, Rupestrian Fields and Field coverings were the most susceptible to wildfire, as they are formed by herbaceous vegetations and are located very close to urban agglomerations and roads. The slopes oriented to the North and West were important for the prediction of wildfires slope and, on the other hand, the slope of the terrain was not important to discretize the areas of greater and lesser fragility to the referred ecological disturbance.

Redes de beija-flor-planta em campos rupestres e florestas ripárias em áreas de altitude do Parque Nacional da Serra da Canastra, Minas Gerais, Brasil

Abstract: Hummingbirds are specialized in consumption of nectar and play an important role in Neotropical plant communities acting as pollinator organisms. Despite the importance of this mutualistic interaction, studies about hummingbird-plant relationships remain scarce regarding the Cerrado domain (Brazilian savanna). In this study, we aimed to describe the interaction network between hummingbirds and plants in rupestrian fields and riparian forests located in altitudinal areas of the Serra da Canastra National Park. We established two transects in each phytophysiognomy, that were sampled monthly for four days, from November 2018 to October 2019. Flowering plants in each transect were observed each survey, and all the visiting hummingbirds were recorded. Networks were constructed using the R bipartite package, considering each phytophysiognomy type, and grouping data of both environments. From these three network arrangements, we extracted complementary metrics at the community level (modularity, nestedness, and network specialization index), and at the species level (species specialization index and species strength in the network). We recorded 647 interactions between 10 hummingbird species and 23 flowering plant species. The hummingbird Colibri serrirostris was responsible for most of observed bird-plant interactions and the plant Qualea cordata was the most visited. The general network was significantly modular, comprising four modules, and showed considerable high specialization and low nestedness. The interaction network in the rupestrian field showed a higher specialization, nestedness, and modularity index when compared to riparian forests, while the metrics of this ecosystem did not differ from those of the general network. However, the metrics at hummingbird species level did not differ significantly between phytophysiognomies. This study corroborated some findings about hummingbird-plant networks in other areas of the Cerrado domain, but also pointed idiosyncrasies in networks of the investigated phytophysiognomies, especially the rupestrian fields.

Assessment of fire hazard weather indices in the eastern Amazon: a case study for different land uses

ABSTRACT The fire frequency in the Amazon increased rapidly after the 1990s due to deforestation and forest degradation, and it is expected to increase in response to climate change. We analyzed the fire occurrence and assessed seven fire hazard indices in the municipality of Canaã dos Carajás, in the eastern Amazon, for different land use and land cover (LULC) types. We used data from three weather stations located at different heights to compare the performance of the indices using skill scores and success percentages for each LULC. Overall most hotspots occurred in deforested areas and native forests, which were the main LULC types, while few were observed in rupestrian fields, urban areas, and mining areas. However, forests presented the lowest number of hotspots per unit area, especially inside protected areas, and all hotspots in forest areas were observed after a severe drought in 2015. The performance of the fire indices varied as a function of the LULC class and the weather station considered, which indicates the importance of choosing the most appropriate location of the station according to the purpose of the monitoring. The Keetch-Byram Drought Index showed the best performance for predicting fire occurrence for all LULC classes, and forests and deforested areas individually. Despite its simplicity, the Angstrom index stood out due to its good performance in the prediction of days with more than six hotspots.

Raridade e endemismo da flora em campo rupestre (OCBIL) na Reserva da Biosfera da Serra do Espinhaço

Rare and endemic species are particularly important from the point of view of conservation, ecology and evolutionary biology. e aim of the study was to evaluate the rarity and endemism of species sampled in an area of rupestrian grassland. Data were collected in March 2019, ending in June of the same year. e method used in the sampling was the qualitative random walk. e Rabinowitz methodology was used to segregate species into rare or common, considering three variables: geographic distribution, habitat specificity and population size. Of the 100 species, 71% were rare and 29% were common. 78% of species were classified as endemic and 22% non-endemic. Of the species, 25% were exclusive to rupestrian fields and 75% occurred in other phytophysiognomies. is analysis contributed to the understanding of the rarity of species in the studied region and can contribute to conservation actions in Ocbil regions.

FOLHAS E BRÁCTEAS TÊM UTILIDADE NA SEPARAÇÃO DE ESPÉCIES DE STENOCEPHALUM (VERNONIEAE, ASTERACEAE)?

It is well known that the leaf structure has usefulness in the Asteraceae taxonomy. Foliage leaves and bracts (involucral bracts) of six Stenocephalum Sch. Bip. species were investigated with the main purpose of indicating characters for diagnose of species. Leaves e bracts were obtained from herbarium and from the rupestrian fields, and sectioned in rotation microtome. Both leaves were investigated using light microscope and scanning electron microscope. Foliage leaves have epidermis with stomata and glandular and non-glandular trichomes, and are dorsiventral. Bracts also have stomata, indumentum, and parenchymatous and sclerenchymatous mesophyll. The structure of the foliage leaves and bracts has little diagnosis value, but the study allowed to separate some species, mainly those closely related within the genus, as S. hexanthum and S. megapotamicum.

Chemical constituents isolated from Clusia criuva subsp. Criuva and their chemophenetics significance

Clusia criuva belongs to the Clusiaceae family and it is endemic to the rupestrian fields in Chapada Diamantina National Park (Brazil). Phytochemical investigation of C. criuva trunks led to the isolation of five triterpenoids [winchic acid (1), betulinic acid (2), lupeol (3), friedelin (4), and friedelinol (5)], four steroids [lanosterol (6), stigmasterol (7), β-sitosterol (8), and sitostenone (9)], seven polyprenylated benzophenone derivatives [propolone A (10), propolone B (11), propolone C (12), propolone D (13), sampsonione B (14), hyperisampsin E (15), and hyperisampsin F (16)], four xanthones [neriifolone C (17), 6-deoxyisojacareubin (18), osajaxanthone F (19), and brasilixanthone B (20)], two biphenyls [aucuparina (21) and 2,2-dimethyl-5-hydroxy-7-phenylchromene (22)], and two tocotrienol derivatives [2Z- and 2E-δ-tocotrienoloic acids (23 and 24)]. Compounds 1, 11, 12, 15, and 16 were isolated for the first time in the Clusiaceae family, compounds 17, 19 and 21 were isolated for the first time in the genus Clusia, whereas 2–10, 13, 14, 18, 20, 22–24 were isolated for the first time in Clusia criuva. Compounds 1, 2, 11, 12, 13 and 15 showed potent in vitro cytotoxic activity against GL-15 glioblastoma-derived human cell line. Chemophenetics significance of these compounds is described herein.

Influence of macronutrients, sucrose and LED on in vitro culture of Lomatozona artemisiifolia (Asteraceae - Eupatorieae)

Abstract Balanced levels of macronutrients and sucrose may ensure the success of micropropagation of the endangered ones. This study aimed to evaluate the effect of levels of salts in the culture medium on in vitro culture of Lomatozona artemisiifolia, as well as to determine the influence of light emitting diode (LED) on the shoot proliferation and rooting of the species. Nodal segments were used to evaluate the different macronutrient concentrations of MS medium (25, 50 and 100%), as well as sucrose concentrations (0.0 mM; 0.34 mM; 0.68 mM and 1.03 mM). Five light conditions were evaluated at shoots proliferation and rooting [100% blue (455 nm); 100% red (630 nm); 30% blue + 70% red; 30% red + 70% blue or fluorescent white]. Low levels of macronutrients in MS (50% and 25%) and sucrose (0.00 mM and 0.34 mM) resulted in plants with higher height, number of shoots and higher production of photosynthetic pigments. The 100% red light promoted rooting of 100% of the plants, and in 100% red or 70% red + 30% blue, higher plants were observed. These results demonstrate that under in vitro conditions, L. artemisiifolia has low nutritional needs, typical of plants that live in rupestrian fields.

Cleistanthane diterpenoids from the resin of Vellozia pyrantha A.A.Conc and their chemotaxonomic significance

Vellozia pyrantha A.A.Conc. is endemic to the rupestrian fields in northern Chapada Diamantina National Park (Brazil). This species has the peculiar characteristic of only producing flowers after a massive fire event occurs in the surrounding areas. This is the first report on the assessment of the chemical composition of Vellozia pyrantha resin, where five cleistanthane diterpenoids (1–5) were identified. Their structures were proposed after careful analysis of 1H and 13C NMR, DEPT 135, HMBC, HMQC, and COSY spectra as well as comparison with the literature. Cleistanthane diterpenoids show great the potential to be used as chemosystematics biomarkers for the genus Vellozia and, therefore, their chemotaxonomic significance is discussed.

Influence of colorful light-emitting diodes on growth, biochemistry, and production of volatile organic compounds in vitro of Lippia filifolia (Verbenaceae)

Lippia filifolia Mart. & Schauer belongs to the Verbenaceae family and it is endemic from the rupestrian fields of the Espinhaço mountain range, located in Minas Gerais, Brazil. It is an aromatic species with medicinal potential due to the production of volatile compounds that constitute its essential oil. The objective of this work was to evaluate the effects of light quality using light-emitting diodes (LEDs) over the growth of L. filifolia grown in vitro after 45 days of culture, analyzing its volatile organic compounds (VOCs), biochemical, and biometric traits. This study had four treatments according to the wavelength of LED lamps: (i) white (control), (ii) blue, (iii) red, and (iv) a combination of red + blue (mix). The light quality influenced the growth, metabolism, and VOCs production of plantlets. The specimens showed higher height under red and white treatments and higher biomass accumulation, nodal segments, and shoot numbers under the mix treatment. Higher total carbohydrate content was also observed on the mix treatment, while the white LED provided higher chlorophylls and carotenoids contents. In addition, the lipid peroxidation was more pronounced in mix and white LEDs treatments, and it was also observed significant but not quite changes in VOCs profiles due to light quality. Eucalyptol was the compound found in a higher concentration among the VOCs of L. filifolia grown in vitro at all light quality treatments studied.

Geostatistical modeling and conservation implications for an endemic Ipomoea species in the Eastern Brazilian Amazon

The Canga ecosystem, in the Eastern Brazilian Amazon, is a biodiversity and endemism hotspot as well a potential resource for iron mining, raising conflicts between conservation and economic development. Here, we collected data from 60 randomly selected points in the Canga ecosystem in the Carajás National Forest, Brazil, to analyze the spatial patterns of Ipomoea cavalcantei occurrence in different phytophysiognomies. Through ordinary kriging and a GLM model, we identified that this endemic species occupies a very restricted range within the Canga ecosystem, specifically in areas of Open Rupestrian Fields and Shrub Rupestrian Fields where the iron crust restricts the soil depth to a few centimeters and the vegetation is mainly herbaceous or savannah shrub vegetation, with low sparse tree canopies. These conditions increased the passage of sunlight, revealing the importance of light conditions for the species. However, because the species occurs in suitable mining sites, there is continuing conflict between environmental and economic decisions. Spatial data showed that mining has increased in Carajás National Forest over the last 32 years, reducing the potential locations for I. cavalcantei to less than 50 % of its original range. Mining will potentially occupy the entire species range over the next three decades. Restoration outside its original habitat is difficult in the short term, because there is no knowledge of the species’ capacity for growth, survival, and replication. Conservation initiatives for the Canga ecosystem should prioritize strategies that reduce regional dependence on mining and provide alternative economic activities, such as sustainable exploitation of bio-products and ecological tourism.

Bird community of upper-montane rupestrian fields in South of Minas Gerais State, Southeastern Brazil

Studies about the birds of rupestrian fields in the south of Minas Gerais State in Southeastern Brazil are incomplete, although this region is ornithologically well studied. This bird community has closely associated ecology with fields and the most endangered species of the Cerrado domain. The objective of this manuscript is to create a list of birds which occur in the rupestrian fields of seven municipalities in the south of Minas Gerais State, and further to analyze the birds’ distribution, the endangered species (and their conservation status), and generate bases for future conservation actions. We evaluated seven cities in the south of Minas Gerais State between 2012 and 2018 by using binoculars and cameras. We found a high richness in relation to other open areas, with the Tyrannidae and Trochilidae families being the most representative. We highlight the endangered species in the Cerrado domain which of these species are closely linked to rupestrian fields. The composition is similar to closer areas, with exception to São Thomé das Letras city because it suffers an influence of mining areas. We suggest creating a wildlife protected area to preserve and conserve a great area of rupestrian fields and consequently the associated biota, especially the bird communities

Yeast in plant phytotelmata: Is there a "core" community in different localities of rupestrian savannas of Brazil?

Ephemeral microbial communities usually undergo priority effect and result in higher diversity with a few representatives of each species. Community structure of yeasts in bromeliad tanks was compared between two rupestrian savanna (Cerrado) areas in Brazil and to yeasts isolated from water holes in the same areas. Water samples were collected from 60 tanks of bromeliads Bromelia karatas and Encholirium sp. and rock holes at the Karstic Area of Aurora, Tocantins State and 60 tanks of Vriesea minarum (Bromeliaceae) and Paepalanthus bromelioides (Eriocaulaceae) at Serra do Cipó National Park, Minas Gerais State in Brazil. The yeast diversity comprised 90 species from which 60% are basidiomycetous yeasts usually associated with phylloplane, soils, and aquatic habitats. The species Papiliotrema laurentii, Rhodotorula mucilaginosa, Pa. nemorosus, and Pseudozyma hubeiensis were the most frequent species associated with bromeliads. Eighteen yeast species, two ascomycetous and 16 basidiomycetous, were consistently isolated from the substrates in both areas and may represent a core community in bromeliads in rupestrian fields. Singlets occurred in 38 to 69% of samples, and 32 species were isolated only once. Our findings reinforce the ephemeral nature of the yeast communities associated with tank-forming plants in which individual phytotelmata act as patches or aquatic islands prone to rapid colonization-extinction rates receiving inocula from plant and soil debris. Ephemeral rock holes also represent a transitory habitat for yeast species associated with plants and soil.

Origin and phytogeographic evolution of the Rupestrian Fields of the Espinhaço Chain

At the moment when new sketches of South American phytogeographic regions and morphoclimatic domains are frequently produced, the relevance of a review of the origin and evolution process of one of the most important geosystems of brazilian biodiversity is imminent: the Fields of Serra Espinhaço. This is because despite being within the most complex and biodiverse are also among the most endangered on the planet, either due to degrading activities in their region of occurrence, or the impact of climate change on the dynamics of functional of the ecosystem. In this sense, the objective of this paper is to review the process of origin and phytogeographic evolution of the Serra do Espinhaço Rupestrian Fields, in order to understand how these ecosystems emerged in the context of the Quaternary period, as they were established during the climate changes of the Holocene and Pleistocene, what are the current vegetation characteristics that can contribute to the understanding of this paleoecological dynamics and consequently of the evolutionary history of the Rupestrian Fields species. From the reading of the available works about the Rupestres Fields it is possible to assume that they represent a relictual vegetation, whose process of establishment took place throughout the Quaternary, however one cannot also rule out the influence of even older events in the process of origin of the Rupestrian Fields. Such complexity in geosystemic dynamics presupposes complex conservation models of this ecosystem, considering the contribution of each piece of this complex puzzle to define the best strategies for maintaining the functional balance of vegetation.

Capões of Seasonal Semi-deciduous Forest in the Cerrados and Rupestrian Fields of the Espinhaço Chain

This work presents a review of Brazilian phytogeography focusing on the forest enclaves that occur in the form of Capões de mata. The objective is to support the understanding of the phytogeography of these Capons in the region of the Serra do Espinhaço Meridional. The methods adopted was based on a bibliographical review, theoretical references that are found among the major works, as well as researchers of the most recent Brazilian phytogeography. The research results show a range of information that greatly contributes to the understanding of how they were formed, the distribution processes, and the functional ecology of these ecosystems. The final considerations lead to the understanding of the need to connect data from different knowledge areas such as climatology, geomorphology, botany, ecology, pedology, geology and anthropology so that these forest beds can be used as a basis for the phytogeographic reconstitution of the Serra do Espinhaço Meridional.

STRAINS OF Paraburkholderia ORIGINATED FROM RUPESTRIAN FIELDS PROMOTE THE GROWTH OF Mimosa foliolosa

ABSTRACT Mimosa foliolosa is a promising native species of rupestrian fields for revegetation of degraded areas in this ecosystem. The symbiosis between leguminous plants and N2-fixing bacteria may play an important role in the recovery of these areas, since these plants have better development and are more resistant to the attack of pathogens. In addition to the biological nitrogen fixation (BNF), these bacteria can promote plant growth through other processes, such as phosphate solubilization and siderophore production. We studied the cultural and genetic characteristics of 11 bacterial strains, isolated from rupestrian field soils using Mimosa tenuiflora as “trap” plant. We evaluated these strains considering their symbiotic characteristics such as nodulation, and growth-promotion of Mimosa foliolosa, as well as their ability for siderophore production and phosphate solubilization. Native N2-fixing bacterial strains belonging to the Paraburkholderia genus (UFLA01-750, UFLA01-728, UFLA01-725, and UFLA01-757), showed high symbiotic efficiency with M. foliolosa. These strains also solubilized calcium phosphate and produced siderophores, exhibiting high functional diversity and potential for use in revegetation projects.

Oxidative metabolism in plants from Brazilian rupestrian fields and its relation with foliar water uptake in dry and rainy seasons

In an altitudinal Brazilian ecosystem, fog is a frequent event in both the dry and rainy seasons. The drought stress is aggravated in the dry season due to elevated evaporative demand and this constraint can induce oxidative stress in plants. In this ecosystem, there are plants which present different foliar water uptake (FWU) capacities - species that absorb less water more quickly (LQ) and those that absorb more water more slowly (MS). In this study, the relationship between oxidative stress responses and the different FWU strategies was evaluated in dry and rainy seasons. The oxidative stress was assessed by H2O2 production and lipid peroxidation as well as by the antioxidant enzymes system as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). During the dry season, plants had higher oxidative stress compared to rainy season plants which exhibited moderate oxidative damage. The FWU strategies were closely related to oxidative stress responses, since the LQ species presented the higher H2O2 content and oxidative defense system. Contrastingly, it was found that MS species have the lowest values of H2O2 and less SOD, CAT and APX activities. However, the lipid peroxidation did not present any relation with FWU strategies. Altogether results revealed that plants, which present MS strategy, are more adapted to cope with the higher H2O2 concentrations generated in the dry season and drought stress events than those that present LQ strategy.