Flávio Fonseca do Carmo

Plant communities on ironstone outcrops: a diverse and endangered Brazilian ecosystem

Mountain areas are recognized centres of endemism and diversity on account of their isolation and altitudinal diversity. In tropical regions, mountain tops usually stand as islands of xeric vegetation among mesophytic assemblages. Unlike the vegetation growing on other rock outcrops lithologies, such as inselbergs (granite/gneiss) or campos rupestres (quartz/arenite), ironstone outcrop plant communities still lack systematic studies in Brazil. These outcrops (locally known as canga) share most of the characteristics of other rock outcrops, such as isolation and edapho-climatic harshness, but differ in that they are the object of opencast mining, and thus subjected to irrecoverable degradation. In addition, they are expected to harbour metal-tolerant and hyperaccumulator plant species. A botanical survey of two ironstone outcrop locations in the most important mining region of southeastern Brazil, the Iron Quadrangle, revealed a high within-site (138 and 160 species per site), and between-site diversity (only 27% of common species), totaling 64 families and 234 species among basal families and eudicots (154 species), monocots (68 species), and ferns (12 species). Canga crusts are rich in dicots, several of which play an important role in community structuring, together with the more usual monocot aggregations. Distinct plant communities are found associated to different microhabitats within the iron crust, depending primarily on the amount of soil and moisture retention in the different microtopographies. The environmental uniqueness, high diversity, lack of studies and rapid destruction of these ecosystems pose an immediate challenge for their conservation.

Estudo fitossociológico de uma comunidade vegetal sobre canga como subsídio para a reabilitação de áreas mineradas no quadrilátero ferrífero, MG

This work aimed to characterize the structure and composition of a Rupestrian field over ironstone as a basis for rehabilitation studies of areas degraded by iron mining activities. An ironstone outcrop at Serra do Rola Moca State Park, MG, was studied. In 30 plots of 2 m 2 , 2,151 individuals were found, belonging to 32 species and 16 families, with a diversity of 2.45 nats/ind. Mean height was 15.7 ± 16.3 cm, with 80% below 25 cm. The most important families were Orchidaceae, Poaceae, and Cyperaceae, and the species with highest importance value were Andropogon ingratus (Poaceae), Lychnophora pinaster (Asteraceae), Bulbostylis fimbriata (Cyperaceae), Sophronitis caulescens (Orchidaceae), and Sebastiania glandulosa (Euphorbiaceae). We suggest that these species, together with those presenting clonal growth, such as grasses, sedges and epilythic orchids; facilitators, such as Stachytarpheta glabra and Mimosa calodendron; and those tolerant to heavy metals, such as Vellozia spp., be priority candidates in restoration programs in areas degraded by iron ore extraction.

Soaring Extinction Threats to Endemic Plants in Brazilian Metal-Rich Regions

Environmental degradation due to mining activities is pervasive in most mineral-rich countries and has been given little attention by the authorities. Surface mining frequently targets very specific and evolutionary unique ecosystems, usually on mountaintops, and is characterized by high environmental impact and irreversibility (Jacobi and do Carmo 2008; Gibson et al. 2010). Recently, the negative impacts of coal surface mining were exposed in relation to ecosystem degradation and damages to human health, underlining the need to improve regulatory measures to mitigate them (Palmer et al. 2010). The loss of plant species associated with mineral-rich areas should be added to the list of ecologic and genetic damages recurrently derived from surface-mining activities.

A vegetação de canga no Quadrilátero Ferrífero, Minas Gerais: caracterização e contexto fitogeográfico

Abstract The vegetation in cangas (ironstone outcrops) houses dozens of rare species, several taxonomic novelties, and high alpha and beta diversity. Using a database consisting of 1080 angiosperm taxa, the vegetation associated with cangas in the Iron Quadrangle was characterized by its floristic elements, growth forms, and most frequent physiognomies. We analyzed the geographic distribution and the phytogeographic dominions of the 980 species. Also, in order to verify distinctions between canga vegetation in relation to five areas embedded in rupestral systems of Minas Gerais and Bahia, we analyzed the similarity of 920 angiosperm genera based in the species number. Compared to other rocky systems, especially those within the Espinhaco Range, canga vegetation is distinguished by the greater influence of floristic elements from the Atlantic dominion, greater frequency of arboreal and shrubby sinusiae, high abundance of genera like Solanum and Cattleya , and little physiognomic representation of some typically ‘campos rupestres’ genera. This distinction appears to be correlated with the geographic location of the Iron Quadrangle as well as the mineral and geomorphological characteristics of cangas.

Life-forms, pollination and seed dispersal syndromes in plant communities on ironstone outcrops, SE Brazil

Afloramentos rochosos tem um papel importante na diversidade vegetal de ecossistemas montanos. As cangas (afloramentos ferruginosos) estao entre os litotipos menos conhecidos e mais ameacados do sudeste do Brasil, devido as atividades minerarias. Alem da composicao de especies, um aspecto fundamental para promover sua conservacao e restauracao e o conhecimento das formas de vida, sindromes de polinizacao e dispersao de sementes dominantes. As analises foram baseadas em listas floristicas publicadas de cangas do sudeste do Brasil. Um total de 353 especies de angiospermas (70 familias) foi distribuido entre as duas fisionomias predominantes (areas abertas e capoes de mata) em cangas. Dezesseis familias foram responsaveis por 70% do total de especies. Comparado ao espectro normal de Raunkiaer, fanerofitos estiveram super-representados e terofitos sub-representados. Os primeiros foram a forma de vida predominante em capoes, enquanto que os hemicriptofitos o foram em areas abertas. A entomofilia foi a sindrome de polinizacao dominante em ambos os habitats. A zoocoria foi dominante em capoes e foi ultima em areas abertas, onde a anemocoria e autocoria prevaleceram. Considerando que ambas as fisionomias estao sujeitas as mesmas condicoes climaticas, os resultados corroboram a influencia de componentes geoedaficos nos tres atributos analisados.

Rupestrian Grassland Vegetation, Diversity, and Origin

Rupestrian grasslands (campos rupestres) are tropical landscapes consisting of a mosaic of herbaceous and shrubby physiognomies on quartzite or ironstone that occur in highlands , usually above 900 m. These landscapes encompass a high diversity of habitats , under different environmental conditions, such as on rock outcrops dominated by desiccation-tolerant species, as well as grasslands and shrublands dominated by resprouter species. Therefore, water availability is one of the most significant selective pressures on rock outcrops, while fire is more important on grasslands and shrublands. Poaceae and Velloziaceae are the two dominant plant families in terms of cover area. There is predominance of hemicryptophytes, chamaephytes, and phanerophytes. Autochory is the main dispersal syndrome and contributes to high plant endemism. Floristic and vegetation structural patterns are affected by geology, geography, habitat, and disturbance. Rupestrian grasslands are Old Stable Landscapes and high specialization, phylogenetic conservatism, and low dispersal ability characterize most lineages in these landscapes. Rather than plant refuges during the warmer and moister Pleistocene interglacial periods, highlands have probably worked as refuges for fire-sensitive lineages since the expansion of fire-prone savannas (cerrados) in the late Tertiary. Most lineages from these mountain ranges then diversified during the Quaternary as rupestrian grasslands were finely fragmented by fire-prone landscapes. The fragmented and rich biodiversity in rupestrian grasslands is naturally vulnerable to anthropogenic disturbances. Therefore, protected areas even if small, scattered along the whole landscape, will help to protect them for a while. However, areas suitable for rupestrian grasslands will probably be greatly reduced in the next few decades as seasonality increases. This scenario calls for immediate ex situ conservation measures.

Alcaligenes faecalisassociated with Mimosa calodendron rizhosphere assist plant survival in arsenic rich soils

The ferruginous rupestrian grasslands (FRG) in the Iron Quadrangle (IQ) are ecosystems characterized by rocky soils with reduced availability of water and nutrients, but high levels of metals. In order to comprehend the interference of microorganisms on the adaptive process of endemic plant Mimosa calodendrum (Fabaceae), bacteria associated with its roots and rhizosphere were isolated. Fourteen isolates were obtained and subsequently grown in the presence of different concentrations of arsenic (As) species. The isolate Mc250, an Alcaligenes faecalis strain, resisted to 10 mM of As (III) and 800 mM of As (V). In the presence of this strain, atomic spectrometer detected a reduction of 55% for As (III) and 72% for As (V) respectively in 10 mM and 500 mM solution. Scanning electron microscopy of this isolate demonstrated morphological modification and EDX spectroscopy revealed the presence of both As species adsorbed on the membrane, justifying the removal observed in the in vitro assays. To validate this potential removal of As in vivo, tomato plants were used as grown model in the presence and absence of A. faecalis in soil previously contaminated with 5 mM of As (III). After 14 days, plants from contaminated soil had their growth improved when compared to untreated control plants. All these results suggest for the first time that plant-associated bacteria from FRG-IQ present potential for soil rhizoremediation and may benefit the adaptive processes of plants in extreme environments including application in recovering degraded areas.

Brazilian Ironstone Plant Communities as Reservoirs of Culturable Bacteria With Diverse Biotechnological Potential

Extensive mineral extractivism in the Brazilian Iron Quadrangle (IQ) region has destroyed large areas of land, decimating plant species, and their associated microbiota. Very little is known about the microbiota of the region; hence, cultivable bacteria associated with plants of its soils were investigated for their biotechnological potential. Samples were collected from nine plant species and six soils, and 65 cultivable bacterial isolates were obtained. These represent predominantly gram-positive bacilli (70%) capable of producing amylases (55%), proteases (63%), cellulases (47%), indole acetic acid (IAA) (46%), siderophores (26%), and to solubilize phosphate (9%). In addition, 65% of these were resistant to ampicillin, 100% were sensitive to tetracycline, and 97% were tolerant to high arsenic concentrations. Three isolates were studied further: the isolate FOB3 (Rosenbergiella sp.) produced high concentrations of IAA in vitro in the absence of tryptophan – shown by the significant improvement in plant germination and growth rate where the isolate was present. For isolates C25 (Acinetobacter sp.) and FG3 (Serratia sp.), plasmids were purified and inserted into Escherichia coli cells where they modified the physiological profile of the transformed strains. The E. coli::pFG3B strain showed the highest capacity for biofilm production, as well as an increase in the replication rate, arsenic tolerance and catalase activity. Moreover, this strain increased DNA integrity in the presence of arsenic, compared to the wild-type strain. These results help to explain the importance of bacteria in maintaining plant survival in ferruginous, rocky soils, acting as plant growth promoters, and to highlight the biotechnological potential of these bacteria. IMPORTANCE The Iron Quadrangle region is responsible for ∼60% of all Brazilian iron production and, at the same time, is responsible for housing a wide diversity of landscapes, and consequently, a series of endemic plant species and dozens of rare species – all of which have been poorly studied. Studies exploring the microbiota associated with these plant species are limited and in the face of the continuous pressure of extractive action, some species along with their microbiota are being decimated. To understand the potential of this microbiota, we discovered that cultivable bacterial isolates obtained from plants in the ferruginous rocky soil of the Iron Quadrangle region have diverse biotechnological potential, revealing a genetic ancestry still unknown.

Check-list of vascular plant communities on ironstone ranges of south-eastern Brazil: dataset for conservation

Abstract Background Ironstone ranges are considered hotspots for higher plants α and β diversity. The lack of studies and the intense degradation of the ironstone ranges, due to mining, motivated us to compile, for the first time, a list of vascular plants collected on iron-rich derived substrates from ancient landscape of south-eastern Brazil. All existing records in the Brazilian Virtual Herbarium of Flora and Fungi for each of the 43 municipalities containing ironstone ranges were downloaded, resulting in 17,954 vouchers identified to the species level. We found 2,933 species belonging to 160 families and 818 genera. New information For the first time, we identified 148 species mentioned in endangered flora official lists and 48 narrow endemic species. Collecting efforts must still be supported to properly sample the vegetation since, for 143 sites, less than 10 records/site were found. This dataset will assist with the indication of dozens of plant species whose threat criteria must be urgently assessed to subsidise public policies on the use and conservation of the Brazilian flora.