Navegando por Autor "Meira-Neto, João Augusto Alves"

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Composição florística de um trecho de cerradão e cerrado sensu stricto e sua relação com o solo na floresta nacional (FLONA) de Paraopeba, MG, Brasil
(Revista Árvore, 2006-04-05) Campos, Érica Pereira de; Duarte, Temilze Gomes; Neri, Andreza Viana; Silva, Alexandre Francisco da; Meira-Neto, João Augusto Alves; Valente, Gilmar Edilberto
O presente trabalho foi realizado na FLONA de Paraopeba, MG, e teve como objetivo o levantamento florístico das fanerófitas, ao longo de um gradiente de cerradão e cerrado sensu stricto, em uma área de 2.600 m^2. Foram encontradas 91 espécies, pertencentes a 71 gêneros de 41 famílias. As famílias mais representativas foram Leguminosae, Myrtaceae, Malpighiaceae, Vochysiaceae, Rubiaceae e Melastomataceae. Os gêneros Miconia, Myrcia, Erythroxylum e Qualea foram os mais ricos. Magonia pubescens destacou-se em número de indivíduos. A similaridade florística mostrou a separação das parcelas em dois grupos, em que o primeiro apresentou um nível de similaridade de cerca de 45%, e o segundo foi dividido em dois grandes subgrupos, sendo que o primeiro mostrou nível de similaridade de cerca de 38%, enquanto as demais parcelas não formaram grupos definidos. A ordenação das espécies pela análise de correspondência canônica sugeriu que Magonia pubescens, Bauhina holophylla e Terminalia brasiliensis tenderam a ser mais abundantes nas áreas com valores mais altos de pH, Ca, Mg e H+Al. A variação não explicada das demais espécies pode estar associada a outras variáveis não analisadas, além de um complexo conjunto de fatores que estão envolvidos na determinação da composição da vegetação.
Composição florística de uma floresta estacional semidecidual montana no município de Viçosa-MG
(Revista Árvore, 2002-06-20) Meira-Neto, João Augusto Alves; Martins, Fernando Roberto
O objetivo do presente estudo foi investigar a composição florística arbórea da Mata da Silvicultura (20º45'S e 42º55'W), município de Viçosa, Zona da Mata de Minas Gerais, com o intuito de avaliar sua similaridade com outras florestas. Para comparação florística foi utilizada a análise de agrupamentos pelo método de médias aritméticas não-ponderadas (UPGMA), a partir dos índices binários de similaridade de Sørensen entre as florestas comparadas. Foram relacionadas 154 espécies de 47 famílias botânicas para a Mata da Silvicultura. Esta mata mostrou-se mais similar às florestas semideciduais de altitude de Lavras (MG) e de Atibaia (SP) e menos similar às florestas submontanas e litorâneas. Estes resultados evidenciam uma importante influência das temperaturas na determinação do tipo florístico das florestas do Sudeste e Sul brasileiros.
Early Acacia invasion in a sandy ecosystem enables shading mediated by soil, leaf nitrogen and facilitation
(Biological Invasions, 2018-06) Meira-Neto, João Augusto Alves; Silva, Maria Carolina Nunes Alves da; Tolentino, Gláucia Soares; Gastauer, Markus; Buttschardt, Tillmann; Ulm, Florian; Máguas, Cristina
Australian species of the genus Acacia are amongst the most invasive trees. As nitrogen fixers, they are able to invade oligotrophic ecosystems and alter ecosystem functioning to their benefit. We aimed to answer three questions: How does early Acacia invasion influence nitrogen and light in a sandy savanna? How does early Acacia invasion impact biodiversity? Does early invasion alter ecosystem functioning towards the dominance of Acacia? We analyzed (using generalized linear mixed models and richness estimators) paired plots focused on plants of Acacia mangium (Fabaceae) and plants of Marcetia taxifolia (Melastomataceae) by taking hemispherical photos and sampling plants, leaves and soil for measurements of light, richness, leaf nitrogen, leaf δ15N, soil nitrogen and soil coarse sand. The results suggest that early Acacia invasion alters the control of soil and of leaf nitrogen and increases shading, enabling a much wider range of light variation. The δ15N results suggest that the nitrogen taken up by Acacia is transferred to neighboring plants and influences the light environment, suggesting facilitation. The enrichment of plant species observed during early Acacia invasion is consistent with the wider range of light variation, but the forecasted leaf nitrogen conditions during the established phase of Acacia invasion might cause loss of light-demanding species because of increased shading. If early Acacia invasion turns into an established phase with highly increased shading, Acacia seedlings might be favored and ecosystem functioning might change towards its dominance.
Environmental filtering of agroforestry systems reduces the risk of biological invasion
(Agroforestry Systems, 2015-04) Ramos, Nina Celli; Gastauer, Markus; Cordeiro, Anaïs de Almeida Campos; Meira-Neto, João Augusto Alves
Prevention is the most effective way of mitigating the negative impacts of exotic species invasions on biodiversity. Preventative measures include inhibiting the further dispersal and recruitment of established invasive species. We expect coffee production in agroforestry systems to reduce the recruitment of exotic species relative to monoculture stands because intercropped trees function as environmental filters that select for individuals with traits such as shade tolerance. If ecologically similar species are also closely related phylogenetically, such environmental filters should reduce phylogenetic diversity, supporting the coexistence of closely related species. Here, we test whether the taxonomic and phylogenetic diversity of native and exotic species in agroforestry systems is lower than in monocultures. We sampled the understory in 180 plots distributed in both habitats in three study sites within the Araponga municipality, Brazil, and measured understory light availability. Phylogenetic diversity was calculated as the net relatedness index (NRI) and the nearest taxon index (NTI). Understory light availability was lower in agroforestry systems. Of the 48 species found, 25 occurred in agroforestry systems, three of which were exotics. Forty-two species were found in monoculture stands (including 13 exotics). As expected, NRI and NTI indicated lower phylogenetic diversity in agroforestry systems than in monoculture stands. Agroforestry systems provide less favorable habitats for exotic species, filtering them from the understory. The mechanisms that select against exotic species remain unknown; however, shading might exclude predominantly heliophytic exotic species from the agricultural matrix. Therefore, agroforestry systems may function as buffer zones preventing invasion into sensitive ecosystems.
Evaluation of biotope’s importance for biotic resource protection by the Bonner Approach
(Ecological Indicators, 2013-01) Gastauer, Markus; Trein, Linda; Meira-Neto, João Augusto Alves; Schumacher, Wolfgang
In this article we present the Bonner Approach to evaluate a biotope's importance for biotic resource protection from the criteria naturalness, rarity and endangerment, substitutability, intactness and importance for the ecosystem structure. Each criterion is evaluated separately from 0 to 5 points which are summed up to the biotic value. According to this biotic value the biotope is classified in six categories from very low or no to international importance for the biotic resource protection. Furthermore, the Bonner Approach is applied in two case studies evaluating different biotopes from a Central European landscape, Nettersheim, North Rhine-Westphalia, Germany, and from a Neotropical region within the Atlantic Rain Forest, Viçosa, Minas Gerais, Brazil. These outcomes are compared to evaluations from the IUCN schemata to identify Key Biodiversity Areas (KBA) and the index of naturalness. Case studies show that biotope's ranking differs between frameworks because each approach is based on different evaluation criteria. Compared to the other frameworks, the Bonner Approach outmatches because this framework considers the influence of evaluated biotopes for biotic resources of surrounding biotopes or landscapes. Furthermore, classification in six categories is wide enough to identify areas of low importance where inevitable impacts might be carried out as well as areas of medium, high, very high or even international importance to elaborate their conservation activities. As the biotic value is of numeric character, the findings can be used to outline compensatory measures. The necessity to consider zoological data given by the Bonner Approach is lacking in other frameworks. The Bonner Approach is transferable to other biogeographical regions due to abstract formulation of criteria. High reproducibility and easy and fast application underline the universal character of the Bonner Approach encouraging its adoption in landscaping and planning conservation activities.
Evolutionary history of campo rupestre: an approach for conservation of woody plant communities
(Biodiversity and Conservation, 2018-09) Pontara, Vanessa; Bueno, Marcelo Leandro; Rezende, Vanessa Leite; Oliveira-Filho, Ary Teixeira de; Gastauer, Markus; Meira-Neto, João Augusto Alves
The campo rupestre sensu lato is among the most species-rich vegetation in the world, harbouring a high proportion of endemic species. We aimed to identify the processes that could generate a high level of phylogenetic diversity (PD) in campo rupestre for woody species and point out biodiversity hotspot areas which may provide additional information for conservation planning. We compiled a database of 2049 woody species from 185 community inventories. We calculated the evolutionary history using species richness (SR), PD, mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardised (ses.PDss, ses.MPD, ses.MNTD), evolutionary distinctiveness (ED), and biogeographically weighted evolutionary distinctiveness (BED). Cloud dwarf-forests had the highest SR, PD, MPD and ses.MPD and lowest MNTD, while rupestrian cerrado presented the highest ses.PD and ses.MNTD. All areas are important for conservation, but the intersections between the hotspots should receive special attention in future conservation actions. The grids identified as hotspots by three or more metrics were localized mainly in Espinhaço Range in Minas Gerais State and a further expansion of protected areas is required. Moreover, the intersections between the hotspots obtained by mean ED and ses.PD are concentrated in the rocky dwarf forest and rupestrian cerrado, with considerable conservation gaps. The degree of protection of campo rupestre was low with unprotected areas comprising 56% of the species. Our results show an urgent need for increasing protected areas of campo rupestre in order to avoid the loss of valuable, endemic species with unique evolutionary history.
Facilitation as a driver of plant assemblages in Caatinga
(Journal of Arid Environments, 2017-07) Carrión, Juan Fernando; Gastauer, Markus; Mota, Nayara Mesquita; Meira-Neto, João Augusto Alves
Nurse plants reduce the environmental severity experienced by neighboring plants by providing shade, enabling nutrient accumulation or protection from herbivores within patches of vegetation. Nurse plants should preferentially promote the coexistence of ecologically dissimilar species with little niche overlap, and if ecological traits are conserved within evolutionary lineages, this should result in phylogenetic overdispersion. In contrast to competition, facilitation is expected to increase species richness. Therefore, to examine the role of facilitation as a driver of plant assemblages in Caatinga, we quantified the functional traits of nurse species and compared species richness, phylogenetic diversity, phylogenetic structure of the tree layer and of the herbaceous layer between patchy Caatinga and Caatinga with segregated plants. Results show that functional traits related to resilience and resistance against herbivory seem to be crucial for facilitation in Caatinga. Autochory occurs at a higher frequency in nurse plants than in Caatinga in general. The herbaceous layer of patchy Caatinga is richer in species than of Caatinga with segregated plants, and facilitation is the suggested cause. As the whole community of the 196 patches is phylogenetically overdispersed compared to the null expectations, facilitation seems to predominantly promote the coexistence of dissimilar species with little niche overlap.
Fitossociologia de campos rupestres quartzíticos e ferruginosos no Quadrilátero Ferrífero, Minas Gerais
(Acta Botanica Brasilica, 2012-01) Meira-Neto, João Augusto Alves; Messias, Maria Cristina Teixeira Braga; Leite, Mariangela Garcia Praça; Kozovits, Alessandra Rodrigues
Foram realizados estudos fitossociológicos de duas áreas em campos rupestres quartzíticos e ferruginosos (sobre itabirito) de MG. Objetivou-se verificar se os litotipos e as geoformas influenciam a vegetação dessas comunidades. Os campos rupestres de ambas litologias foram estratificados pelas geoformas e fitofisionomias em: 1. Áreas inclinadas, com campos limpos 2. Platôs, com campos limpos e 3. Porções inferiores dos perfis, com campos sujos. Amostraram-se 60 parcelas (10x10m), 10 em cada habitat. Estimou-se a cobertura e calculou-se a frequência, dominância e valor de importância (VI) das espécies. Calculou-se a diversidade pelo índice de Shannon-Wiener (H') e equabilidade de Pielou (J') para cada habitat e a similaridade florística entre eles pelo índice de Jaccard e análise de agrupamentos. Inventariou-se 165 espécies nos campos quartzíticos e 160 nos ferruginosos. Nos campos rupestres declivosos e nos platôs ferruginosos Vellozia compacta foi a espécie de maior VI. Nos campos inclinados com afloramentos quartzíticos Lagenocarpus rigidus foi a espécie com maior VI, seguida por algumas fanerófitas. Echinolaena inflexa foi a espécie de maior importância nos platôs sobre quartzito, seguida por algumas fanerófitas e várias hemicriptófitas. Os campos sujos sobre itabirito foram dominados por E. erythropappus e V. compacta enquanto que os campos sujos sobre quartzito por Echinolaena inflexa, Eremanthus erythropappus e outras fanerófitas. Os campos sujos foram mais diversos que os campos limpos. Os campos rupestres ferruginosos apresentaram menor diversidade (H'=2,92) e equabilidade (J'=0,58) do que os quartzíticos (H'=3,36; J'=0,66). A análise de agrupamentos indicou a formação de grupos definidos pelas diferentes litologias e geomorfologias. Os resultados evidenciaram que a geologia e as geoformas influenciam a composição florística de campos rupestres.
Functional antagonism between nitrogen-fixing leguminous trees and calcicole-drought-tolerant trees in the Cerrado
(Acta Botanica Brasilica, 2017-01) Meira-Neto, João Augusto Alves; Tolentino, Gláucia Soares; Silva, Maria Carolina Nunes Alves da; Neri, Andreza Viana; Gastauer, Markus; Magnago, Luiz Fernando Silva; Yuste, Jorge Curiel; Valladares, Fernando
The Cerrado is the largest savanna of South America and its physiognomy varies from savanna to woodlands. There are two main types of woodlands in the Cerrado: dystrophic woodlands, dominated by N-fixing leguminous trees (LEG), and mesotrophic woodlands dominated by non-leguminous drought-tolerant trees (DRY), which are calcicoles and sensitive to Al3+. The working hypothesis is that LEG and DRY are functional antagonists in terms of the acidification/alkalization processes involving different forms of inorganic nitrogen and pH, Ca2+ and Al3+ in soil. Tree species basal area and soil properties were used to investigate the antagonism between LEG and DRY using generalized linear models. The results suggest that LEG and DRY are antagonists. The LEG were positively associated with Al3+, NO3- and NH4+ content and negatively related to increasing Ca2+ content, whereas the DRY were negatively associated with Al3+, NO3- and NH4+ and positively associated with increasing Ca2+ content. The upper soil layer in plots dominated by LEG species became more acidic and the upper soil layer in plots dominated by DRY species became more alkaline. The results suggest that LEG and DRY are functional antagonists and their preferences for NH4+ or NO3- might influence the way the Cerrado woodland changes.
Habitat quality of the woolly spider monkey (Brachyteles hypoxanthus)
(Folia Primatologica, 2009-11-03) Silva Júnior, Wilson Marcelo da; Meira-Neto, João Augusto Alves; Carmo, Flávia Maria da Silva; Melo, Fabiano Rodrigues de; Moreira, Leandro Santana; Barbosa, Elaine Ferreira; Dias, Luiz Gustavo; Peres, Carlos Augusto da Silva
This study examines how habitat structure affects the home range use of a group of Brachyteles hypoxanthus in the Brigadeiro State Park, Brazil. It has been reported that most of the annual feeding time of woolly spider monkeys is spent eating leaves, but they prefer fruits when available. We hypothesise that the protein-to-fibre ratio (PF; best descriptor of habitat quality for folivorous primates) is a better descriptor of habitat quality and abundance for these primates than the structural attributes of forests (basal area is the best descriptor of habitat quality for frugivorous primates of Africa and Asia). We evaluated plant community structure, successional status, and PF of leaf samples from the dominant tree populations, both within the core and from a non-core area of the home range of our study group. Forest structure was a combination of stem density and basal area of dominant tree populations. The core area had larger trees, a higher forest basal area, and higher stem density than the non-core area. Mean PF did not differ significantly between these sites, although PF was influenced by differences in tree regeneration guilds. Large-bodied monkeys could be favoured by later successional stages of forests because larger trees and denser stems prevent the need for a higher expenditure of energy for locomotion as a consequence of vertical travel when the crowns of trees are disconnected in early successional forests. Forest structure variables (such as basal area of trees) driven by succession influence woolly spider monkey abundance in a fashion similar to frugivorous monkeys of Asia and Africa, and could explain marked differences in ranging behaviour and home range use by B. hypoxanthus.
Influência da cobertura e do solo na composição florística do sub-bosque em uma floresta estacional semidecidual em Viçosa, MG, Brasil
(Acta Botanica Brasilica, 2005-07) Meira-Neto, João Augusto Alves; Martins, Fernando Roberto; Souza, Agostinho Lopes de
A relação ecológica planta-luz tem sido estudada desde o início do século XX. As análises da relação da luminosidade ao nível das comunidades florestais têm se valido de medições indiretas por meio de índices de cobertura, mas sem a aplicação da fotogrametria para estimar essa cobertura. Este trabalho foi idealizado para utilizar fotogrametria do dossel, tornando-a aplicável ao estudo da luminosidade no sub-bosque herbáceo-arbustivo. Teve como objetivos estabelecer a relação existente entre espécies do estrato herbáceo-arbustivo e a cobertura do dossel e averiguar a existência de correlações entre espécies, luminosidade e variáveis pedológicas. Para tanto, foram tiradas fotografias em preto e branco nos períodos seco e chuvoso, em 100 (1 m×1 m) parcelas aplicadas para a amostragem da vegetação herbácea. Foram colhidas amostras de solo em cada parcela. A partir dos valores médios das medidas de cobertura estimada pelas fotografias dos períodos seco e chuvoso calculou-se o valor médio de cobertura para cada espécie amostrada. Por meio do teste "t" student e da Análise de Correspondência Canônica foram determinadas as relações entre as espécies, a luminosidade e as variáveis pedológicas no estrato herbáceo-arbustivo. A cobertura não foi significativamente diferente nas épocas seca e na chuvosa. Apenas três espécies, Heisteria silviani, Calathea brasiliensis e Psychotria conjugens, tiveram médias de cobertura significativamente maiores que a média amostral e outras três, Olyra micrantha, Lacistema pubescens e Pteris denticulata, tiveram médias menores. As distribuições de parcelas pelos valores de cobertura, de tamanho de clareiras e pelo número de clareiras mostraram-se similares às distribuições encontradas na literatura para outras florestas tropicais e, portanto, o método da fotogrametria revelou-se adequado para a avaliação da cobertura. Verificou-se que os teores de cálcio, magnésio e potássio estavam correlacionados positivamente entre si e negativamente aos teores de alumínio. A cobertura revelou-se correlacionada negativamente aos teores de alumínio. Foram detectados cinco grupos de espécies segundo as preferências que apresentaram aos teores de cálcio, magnésio, potássio, alumínio e a valores de cobertura. Os teores de alumínio revelaram-se os maiores determinantes da variação encontrada na vegetação de sub-bosque. As variáveis pedológicas mostraram-se mais importantes que a variação de cobertura encontrada no sub-bosque para determinar alterações estruturais no estrato herbáceo-arbustivo.
Interactions, environmental sorting and chance: phylostructure of a tropical forest assembly
(Folia Geobotanica, 2014-09) Gastauer, Markus; Meira-Neto, João Augusto Alves
Density dependence, environmental sorting and chance have been discussed for the purpose of understanding, predicting and explaining the species richness, composition and structural parameters of living communities. Different ecological mechanisms occur individually in an overlapping manner, so the structure of each local community is influenced by an independent mixture of these factors. To identify which of these factors prevails in organizing the species-rich tree community from 100 plots of 10 × 10 m in a primary forest patch (the Forest of Seu Nico – FSN, from the Atlantic Forest domain), we analyzed species-environment correlations via canonical correspondence analysis and identified two different pedo-environments. We analyzed the community’s phylogenetic structure using Phylocom 4.2 software to calculate the net relatedness index (NRI) and the nearest taxon index (NTI). Furthermore, we partitioned the total phylogenetic diversity into independent α and β components (ΠST). To reveal the overlap of ecological mechanisms such as neutrality, environmental filtering and density-dependent factors, we analyzed the phylogenetic structure in both pedo-environments. The species-environment correlations observed in the FSN are weak in comparison with those found in other studies, although the permanent plot presents a short environmental gradient, dividing the plot into an upper, more acidic hillside and a lower, more fertile bottom. The overall phylogenetic structure of the FSN community shows strong and significant phylogenetic overdispersion. This overdispersion indicates that density-dependent factors, such as interspecific competition, play an important role in maintaining the species richness and community structure in megadiverse ecosystems such as the FSN when we assume traits to be conserved within evolutionary lineages. The NRI and NTI are correlated positively with the soil pH and negatively with the soil’s aluminum concentration, so the bottom plots show higher phylogenetic overdispersion and lower ΠST values than the hillside plots. This pattern can be explained by the greater importance of environmental filters in more acidic soils that form less favorable habitats, while the influence of competition and therefore also the rate of competitive exclusion are higher in the more favorable, less acidic plots.
Life-form spectra of quartzite and itabirite rocky outcrop sites, Minas Gerais, Brazil
(Biota Neotropica, 2011-04) Meira-Neto, João Augusto Alves; Messias, Maria Cristina Teixeira Braga; Leite, Mariangela Garcia Praça; Kozovits, Alessandra Rodrigues
Vascular species and their respective life-forms and coverage were recorded in a Brazilian quartzite and itabirite rocky outcrop site at Serra de Ouro Preto, producing the floristic, frequency and vegetational spectra. Three habitats in both lithologies were defined by geomorphology as: 1) Sloped areas near the mountain summit, with grasslands; 2) Plateaus in the middle of the slope, with grasslands; and 3) Lower and/or concave parts of the slopes, with woody savannas. The life-forms followed Raunkiaer's System. We aimed to answer the following questions: Do quartzite and itabirite rocky outcrops have different biological spectra? Are the biological spectra different in the geomorphologic habitats? Do the floristic, vegetational and frequency spectra differ from one another? What spectrum stacks up to a rocky outcrop physiognomy description? The results portrayed that: a) the most represented life-forms were the phanerophytes and hemicryptophytes; b) the floristic and frequency spectra did not differ from each other, but both differed from the vegetational one; c) all the floristic spectra were similar, but there were significant differences in the frequency and vegetational spectra among the lithology and geomorphology habitats; d) higher phanerophyte and lesser hemicryptophyte coverages were found in the itabirite areas and also in the lower or concave parts of the slopes of both lithologies; and e) the vegetational spectrum was more efficient for the studied rocky outcrop comparison. Relationships between the environmental aspects and life-form spectra are discussed. This study will help advance the development of restoration projects for these areas by adding knowledge of their flora composition, structure and function.
Microclimatic conditions at forest edges have significant impacts on vegetation structure in large Atlantic forest fragments
(Biodiversity and Conservation, 2015-07-14) Magnago, Luiz Fernando Silva; Rocha, Mariana Ferreira; Meyer, Leila; Martins, Sebastião Venâncio; Meira-Neto, João Augusto Alves
Forest fragmentation creates forest edges, and the effect of those edges increases as the size of forest fragments decreases. Edge effects include changes to microclimatic conditions at the forest edge, which affect vegetation structure. No previous studies have directly tested the relationship between microclimate and vegetation structure (for instance, basal area, trees mean height, dead trees and damage trees) at the edge of forest fragments in the Atlantic Forest domain. We tested the following three hypotheses: (i) the microclimatic conditions differ between the edge and the interior of the forest, (ii) the forest structure differs between the edge and the interior of the forest and (iii) changes to microclimatic conditions at the forest edge negatively affect vegetation structure at the edges. Our results demonstrate that edge habitats are significantly more susceptible to strong winds, lower humidity and higher air temperatures than forest interiors. The microclimate may be considered the principal factor that explains the difference between the vegetation structure of the forest edge and the forest interior. Our results suggest that even large forest fragments in the Brazilian Atlantic Forest may be impacted by negative edge effects.
Phylogenetic structure is determined by patch size in rock outcrop vegetation on an inselberg in the northern Amazon region
(Acta Amazonica, 2018-07) Villa, Pedro Manuel; Gastauer, Markus; Martins, Sebastião Venâncio; Carrión, Juan Fernando; Campos, Prímula Viana; Heringer, Gustavo; Meira-Neto, João Augusto Alves; Rodrigues, Alice Cristina
Although inselbergs from around the world are iconic ecosystems, little is known on the underlying mechanisms of community assembly, especially in their characteristic patchy outcrop vegetation. Environmental constraints are expected to cause phylogenetic clustering when ecological niches are conserved within evolutionary lineages. We tested whether vegetation patches from rock outcrops of the Piedra La Tortuga Natural Monument, in the northern Amazon region, are phylogenetically clustered, indicating that environmental filtering is the dominant driver of community assemblage therein. We classified all patches according to their size as very small (< 1 m 2 ), small (1-4 m 2 ), medium-sized (4-8 m 2 ), and large patches (8-15 m 2 ). From each class, we randomly selected 10 patches, totalizing 40 patches covering 226 m 2 . All individuals found in the 40 isolated patches were identified to the species level. We also correlated measurements of phylogenetic community structure with patch size. We found that species from patches are restricted to the clades monocots, fabids, malvids, and lamiids. We conclude that vegetation in this rock outcrop is phylogenetically clustered. Furthermore, we found that phylogenetic turnover between pairs of patches increases with patch size, which is consistent with a scenario of higher environmental stress in smaller patches. Further research is necessary to identify nurse species in inselberg vegetation, which is pivotal for conservation and restoration of this particular ecosystem.
Preservation of primary forest characteristics despite fragmentation and isolation in a forest remnant from Viçosa, MG, Brazil
(Revista Árvore, 2015-10-29) Gastauer, Markus; Sobral, Marcos Eduardo Guerra; Meira-Neto, João Augusto Alves
According to its owners, the Forest of Seu Nico (FSN) from the Viçosa municipality, Minas Gerais, Brazil, never has been logged and is therefore considered a primary forest. Nevertheless, the forest patch suffered impacts due to selective wood and non-timber extraction, fragmentation and isolation. Aim of this study was to test if the FSN, despite impacts, preserved characteristics of primary forests, which are elevated percentages of non-pioneer (>90%), animal-dispersed (>80 %), understory (>50%) and endemic species (~40%). For that, all trees with diameter at breast height equal or major than 3.2 cm within a plot of 100 x 100 m were identified. With 218 tree species found within this hectare, the FSN's species richness is outstanding for the region. The percentages of non-pioneer (92 %), animal-dispersed (85 %), understory (55 %) and endemic species (39.2 %) from the FSN fulfill the criteria proposed for primary forest. Therefore, we conclude that the FSN maintained its characteristics as a primary forest which highlights its importance for the conservation of biotic resources in the region, where similar fragments are lacking or not described yet.
Structure of brazilian atlantic forests with occurrence of the woolly spider monkey (Brachyteles hypoxanthus)
(Ecological Research, 2009-07-18) Silva Júnior, Wilson Marcelo da; Melo, Fabiano Rodrigues de; Moreira, Leandro Santana; Barbosa, Elaine Ferreira; Meira-Neto, João Augusto Alves
This work examines patches of Atlantic forests in Minas Gerais State where woolly spider monkeys (Brachyteles hypoxanthus) are inhabitants in order to understand the effects of forest structure, diversity, and succession in B. hypoxanthus abundance. This study was carried out in three reserves: Rio Doce State Park (PERD), Mata do Sossego (Sossego), and Serra do Brigadeiro State Park (PESB). Structural studies were carried out by means of point-centered quarter samples in areas used by woolly spider monkeys. Evenness was lower in PERD than in the other two communities. By means of successional functional groups analysis and diametric structure, the PERD forest sample was shown to be in the later, and PESB forest sample in the earlier, stages of secondary succession. We found that tree species evenness and structural traits driven by succession were important factors in determining spider monkey abundance patterns. The PERD forest sample had lower evenness and had lower density of woolly spider monkeys than the Sossego forest sample. The lowest density of these primates was in the PESB forest sample, the earlier successional stage of secondary succession of this study.