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.

DO FOLIAGE LEAVES AND BRACTS HAVE USEFULNESS IN THE SEPARATION OF STENOCEPHALUM (VERNONIEAE, ASTERACEAE) SPECIES?

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.

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

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.

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

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.

Ocorrência de Pachymerus nucleorum Fabricius predando sementes de Syagrus glaucescens Glaziou ex Becc em Diamantina, Minas Gerais, Brasil

Resumo. Syagrus glaucescens Glaziou ex Becc (Arecaceae) é uma palmeira pequena, endêmica da região do Espinhaço Meridional, Minas Gerais, Brasil. Esta espécie ocorre em campos rupestres da Serra do Cipó e é muito abundante na região de Diamantina, Minas Gerais, Brasil. Em trabalhos de campo, foi observado ataque em seus frutos por um coleóptero, identificado como Pachymerus nucleorum Fabricius (Coleoptera, Chrysomelidae, Bruchinae). O dano causado por este coleóptero inviabiliza a germinação das sementes de S. glaucescens, o que, aliado às queimadas frequentes pode diminuir a população desta palmeira, que por ser endêmica já apresenta elevado risco de extinção. Deste modo, é importante dimensionar os efeitos decorrentes desta predação na dinâmica populacional desta espécie.Occurrence of predation in seeds of Syagrus glaucescens Glaziou ex Becc by Pachymerus nucleorum Fabricius in Diamantina, Minas Gerais, BrazilAbstract. Syagrus glaucescens Glaziou ex Becc (Arecaceae) is a small palm tree, endemic to the Southern Espinhaço, Minas Gerais, Brazil. This species occurs at rupestrian fields in Cipó mountain range and it is very abundant in Diamantina, Minas Gerais, Brazil. In field work, an attack on its fruits was observed by a beetle, identified as Pachymerus nucleorum Fabricius (Coleoptera, Chrysomelidae, Bruchinae). The damage caused by this beetle prevents the germination of S. glaucescens seeds, which, together with the frequent burning, can decrease the population of that palm tree, which, because it is endemic, already presents a high risk of extinction. Therefore, it is important to know the effects of this predation on the population dynamics of this species.

PHYSIOLOGICAL AND PHENOLOGICAL VEGETATIVE RESPONSES OF Campomanesia adamantium (Cambess) O. Berg (Myrtaceae) TO THE HYDRIC SEASONALITY OF RUPESTRIAN FIELDS

ABSTRACT The rupestrian fields have two well-defined seasons throughout the year, with rainfall rates that reflect the rainy and dry seasons. This distinction in water availability affects the morphology, physiology and chemistry of plants, among other characteristics. Thus, it is aimed at evaluating the leaf water status, vegetative phenology and photosynthetic behavior of Campomanesia adamantium from a rupestrian field during the dry and rainy season. The study was conducted in Serra do Cipó, Minas Gerais, Brazil. From November 2011 to November 2012 it was examined vegetative phenophases and development of six individuals. Water potential, stomatal conductance, quantum yield and concentration of pigments were evaluated from four leaves of 3rd node per individual (n = 4-5) in the dry and rainy seasons. C. adamantium is an evergreen type and presents mature leaves and sprouting throughout the year. This species showed strategies that reduce water loss during the dry season in rupestrian field, such as decrease in stomatal conductance throughout the day, also associated with a reduction in leaf water potential. However, low water availability did not affect the photosynthetic performance, which enables the construction of new leaves and renovation of the crown even in dry periods. Finally, little reduction in the values of Fv/Fm throughout the day and increase the values of ΔF/Fm' in warmer times, both in the dry season, reiterates the ability of C. adamantium to adjust their physiology to seasonal water deficit of the rupestrian field.

Assemblage of squamate reptiles in a natural remnant of Cerrado in southern Minas Gerais, Brazil

Considered one of the most threatened biomes, the Cerrado currently has more than half of its original area converted into other types of land-use and little is known about the reptiles inhabiting this biome in Minas Gerais state. We quantified the species richness of Squamata and assessed the faunal composition in the Reserva Biológica Unilavras – Boqueirão. We recorded six snake species and 10 lizard species in the various physiognomies. The highest species richness was observed in the gallery forest, followed by the cerrado sensustricto and rupestrian fields. Gallery forest and cerrado sensustricto had similar compositions. The rarefaction curves suggest it is possible that other species may occur in the study area as well as new occurrence records of some species and the distribution expansion of others for this biome in Minas Gerais.