Estimating Aboveground Biomass Loss from Deforestation in the Savanna and Semi-arid Biomes of Brazil between 2007 and 2017

Brazilian Savannas and Semi-arid woodlands biomes exhibit high levels of aboveground biomass (AGB) associated with high rates of deforestation. The state of Minas Gerais (MG), southeast of Brazil, encompasses landscape variations ranging from Savanna and Atlantic Forest to Semiarid woodlands. The understanding of land-cover changes in these biomes is limited due to the fact that most of the efforts for estimating forest cover changes has been focused on the tropical rain forests. Hence, the question is: What is the total amount of AGB loss across Savanna and Semi-arid woodland biomes in MG state, during the period 2007–2017? We first used a total of 1914 field plots from a forest inventory to model the AGB using a combination of remote sensing and spatio-environmental predictor variables to produce a spatial-explicit AGB map. Second, from a global map of forest cover change (GFC), we obtained deforestation patches. As a result, from 2007 to 2017, the Savanna and the Semiarid woodland biomes lost together 508,042 ha of native vegetation in MG state, leading to 21,182,150 Mg of AGB loss (4.65% of total AGB). In Savannas and Semi-arid woodland biomes in MG state, conservation initiatives must be implemented to increase the forests protection and expand AGB

Tree population dynamics in alluvial forest fragments in south of Minas Gerais, Brazil

The present study aimed to evaluate the tree population dynamics in forest fragments, in the municipality of São Sebastião da Bela Vista, MG. For this sake, all living trees with diameter at breast height (DBH) higher than 5 cm, present in the sampled units, were measured (DBH and height) and identified in 2005 and monitored in 2007 and 2009 (remeasured and mortality evaluation), when all individuals reaching the minimum diameter of inclusion, on the occasion of a possible recruitment, were recruited. The annual dynamics rates (mortality, recruitment, turnover and net change) were calculated for all populations. Dynamics instability was observed, indicated by the steady reduction of abundance and the higher number of species with negative balance in abundance (period 2005 a 2007 = 13 e 2007 a 2009 = 17) than positive balance (2005 a 2007 = 9 e 2007 a 2009 = 14). The richness changes were insignificant, with the gain of two species and loss of just one. The present study demonstrated that, despite the observation of no qualitative (floristic) changes, the evaluated area showed a dynamics with structural instability, with higher mortality than recruitment.O presente estudo objetivou avaliar a dinâmica de populações arbóreas em fragmentos florestais em São Sebastião da Bela Vista, MG. Para isso, todos os indivíduos arbóreos com diâmetro na altura do peito (DAP) maior do que 5 cm, presentes nas unidades amostrais, foram medidos (DAP e altura) e identificados no ano de 2005 e monitorados nos anos 2007 e 2009 (remedição e verificação de mortalidade), quando também foram medidos os indivíduos que alcançaram o diâmetro mínimo de inclusão por ocasião de um eventual recrutamento. Foram calculadas as taxas de dinâmica anual (mortalidade, recrutamento, rotatividade e mudanças líquidas) para todas as populações. Foi observada instabilidade da dinâmica, indicada pela redução constante da abundância e pelo maior número de espécies com balanço negativo de número de indivíduos (período 2005 a 2007 = 13 e 2007 a 2009 = 17) do que balanço positivo (2005 a 2007 = 9 e 2007 a 2009 = 14). As mudanças de riqueza foram insignificantes, com o ganho de duas espécies e o desaparecimento de uma. O estudo demonstrou que, apesar de não apresentar mudanças qualitativas (composição florística), a área demonstrou instabilidade estrutural, com mais populações com maior taxa de mortalidade que de recrutamento

Relação Espacial do Carbono da Vegetação e Matéria Orgânica do Solo na Serra da Mantiqueira

O presente trabalho objetivou analisar o comportamento espacial do estoque de carbono presente no fuste da vegetação (ECV) e da matéria orgânica do solo (MO) em uma floresta ombrófila densa na Serra da Mantiqueira, no Estado de Minas Gerais, por meio de krigagem. Pretendeu-se também testar a utilização da MO superficial como variável auxiliar na predição do ECV com o uso da cokrigagem. Para isso, foram analisados dados georreferenciados de 25 pontos amostrais de MO em três profundidades, 0-20 cm (P1), 20-50 cm (P2) e 50-100 cm (P3), e de 12 parcelas amostrais de 400 m2 de vegetação. As variáveis apresentaram estrutura de dependência espacial (maior em ECV e menor em MO em P1) e o semivariograma cruzado refletiu a correlação espacial entre ECV e MO em P1. O mapa de interpolação gerado por cokrigagem foi satisfatório na detecção de tendências da variável ECV, conservando os mesmos padrões do mapa gerado por krigagem ordinária para essa variável. Considera-se que, na área estudada, MO em P1 pode ser utilizada como covariável na caracterização espacial geral do ECV, em situações de subamostragem de ECV

Influência topo-edafo-climática na vegetação de um fragmento de Mata Atlântica na Serra da Mantiqueira, MG

Compreender as correlações existentes entre variáveis ambientais e a distribuição das espécies em uma floresta, sua dinâmica e estoque de carbono é um dos principais objetivos em ecologia florestal. Nesse sentido o presente trabalho objetivou correlacionar aspectos da vegetação com variáveis topo-edafo-climáticas em um remanescente florestal em Bocaina de Minas, Serra da Mantiqueira, MG. Técnicas multivariadas de ordenação (PCA e CCA) e regressões múltiplas foram utilizadas para representar essas correlações. Altitude teve destaque como fator ambiental síntese, compreendendo vários gradientes existentes na área (em especial edáfico e de conservação) sendo, portanto, a variável que mais explicou distribuição de espécies, dinâmica florestal e estoque de carbono na área

Patterns of gall infestation in Heteropterys byrsonimifolia A. Juss. in a forest-savannah ecotone

ABSTRACT Galls are the result of a specific interaction between an inducer and a host plant. The species Heteropterys byrsonimifolia A. Juss. occurs in abundance in semideciduous seasonal forest ecotones and adjacent open formations. In the ecological reserve Quedas do Rio Bonito, located in the state of Minas Gerais, Brazil, this species is affected by a single gall morphotype. The present study aimed to evaluate whether the structural complexity of the host (test of the structural complexity hypothesis) and the distance between hosts (test of the resource concentration hypothesis) affect gall density in H. byrsonimifolia and to characterize the spatial distribution of the infestation. The results corroborate the two hypotheses tested, suggesting a metapopulation pattern of gall infestation in H. byrsonimifolia. Gallers were more successful in abrupt forest-savannah transition environments, which may be associated with greater stress-induced host vulnerability that plants usually experience in ecotones

Tree Responses to Soil and Edge Effects in a Semideciduous Forest Remnant

ABSTRACT The present study seeks to characterize the composition, structure, and functional traits of the tree stratum of a Semideciduous Forest in Pouso Alegre, MG, Brazil (22º12’43”S and 45º59’30”W), by comparing Edge and Interior habitats and their relation to human impacts and soil variables. The tree community (diameter at 1.3 m (DBH) higher than 5 cm) was inventoried using the point-centered quarter method by laying out 12 transects of 450 m each (six transects in the Edge and six in the Interior). Functional traits – wood density and seed mass – were obtained by genus. The impact evaluation and soil sample collection were realized per transect. We found significant differences in terms of the basal area (higher in Interior), diversity (higher in Interior) and community seed mass (higher in Edge). The effects of higher values of soil traits such as Calcium, Magnesium, cation sum (CS) and base saturation (V) on species composition were stronger in the Interior, while human induced impacts and soil Potassium had an overwhelming effect on the Edge

Tree responses to soil and edge effects in a semideciduous forest remnant

The present study seeks to characterize the composition, structure, and functional traits of the tree stratum of a Semideciduous Forest in Pouso Alegre, MG, Brazil (22º12’43”S and 45º59’30”W), by comparing Edge and Interior habitats and their relation to human impacts and soil variables. The tree community (diameter at 1.3 m (DBH) higher than 5 cm) was inventoried using the point-centered quarter method by laying out 12 transects of 450 m each (six transects in the Edge and six in the Interior). Functional traits – wood density and seed mass – were obtained by genus. The impact evaluation and soil sample collection were realized per transect. We found significant differences in terms of the basal area (higher in Interior), diversity (higher in Interior) and community seed mass (higher in Edge). The effects of higher values of soil traits such as Calcium, Magnesium, cation sum (CS) and base saturation (V) on species composition were stronger in the Interior, while human induced impacts and soil Potassium had an overwhelming effect on the Edge

Tree stem data from: Temporal vegetation changes in a Seasonally Dry Tropical Forest enclave in an ecotonal region between Brazil’s savanna and semiarid zones

This data represents stem diameters of tree stems from 30 plots of Seasonally Dry Tropical Forest in an enclave forest patch in Minas Gerais, Brazil. Plots 1-10 are plots on the edge, 11-20 are plots 100m into the forest, and plots 21-30 are plots in the interior of the forest (200m from the edge). Data for years 2007 and 2014 are provided