EQUAÇÕES DE BIOMASSA PARA ESPÉCIES DA CAATINGA O objetivo deste trabalho foi determinar as proporções de fuste, galhos e folhas em relação a biomassa total seca acima do solo e ajustar modelos estatísticos para estimativa da biomassa das principais espécies arbustivo-arbóreas em uma área de Caatinga. O número de indivíduos abatidos e com a biomassa aérea total determinada foi de 15 para Anadenanthera colubrina, Aspidosperma pyrifolium, Cnidoscolus quercifolius, Mimosa ophthalmocentra, Mimosa tenuiflora, Poincianella bracteosa e, de 30 para Bauhinia cheilantha e Croton heliotropiifolius. Para ajuste dos modelos foram utilizados os dados de biomassa total seca acima do solo coletados como variável dependente e as variáveis independentes foram o diâmetro à altura do peito e a altura total dos indivíduos por espécie. Foram testados oito modelos para cada uma das espécies e para todas as espécies agrupadas. Para a seleção da melhor equação utilizou-se os tradicionais critérios estatísticos. As proporções de biomassa das espécies foram quantificadas, tanto para os seus compartimentos, quanto para o total e apresentaram uma grande variação entre espécies e indivíduos da mesma espécie. Equações de biomassa aérea seca foram ajustadas com boas estatísticas de precisão, podendo ser utilizadas para a sua estimativa de biomassa de maneira confiável em regiões de Caatinga.Palavras-chave: Análise de regressão, diâmetro à altura do peito, altura total. ABSTRACT:The objective of this work was to determine the proportions of stem, branches and leaves in relation to total dry aboveground biomass and adjust statistical models to estimate the biomass of the main species in an area of Caatinga. The number of trees cut and with the determined total aboveground biomass was 15 for Anadenanthera colubrina, Aspidosperma pyrifolium, Cnidoscolus quercifolius, Mimosa ophthalmocentra, Mimosa tenuiflora, and Poincianella bracteosa, and 30 for Bauhinia cheilantha and Croton heliotropiifolius. The data of total dry aboveground biomass were used as dependent variables and the diameter at breast height and total height of individuals per species were used as the independent variables for adjusting the models. Eight models were tested for each species and for all grouped species. Traditional statistical criteria was used for selecting the best equation. The proportions of the species were quantified for both their biomass compartments and for the total biomass, showing great variation between species and individuals of the same species. Dry aboveground biomass equations were developed with good precision statistics and can therefore be used for estimating biomass in Caatinga regions.Keywords: Regression analysis, diameter at breast height, total height.

In recent years, with the growing environmental concern regarding climate change, there has been a search for efficient alternatives in indirect methods for the quantification of biomass and forest carbon stock. In this article, we seek to obtain pioneering results of biomass and carbon estimates from forest inventory data and LiDAR technology in a dry tropical forest in Brazil. We use forest inventory data in two areas together with data from the LiDAR flyby, generating estimates of local biomass and carbon levels obtained from local species. We approach three types of models for data analysis: Multiple linear regression with principal components (PCA), conventional multiple linear regression and stepwise multiple linear regression. The best fit total above ground biomass (TAGB) and total above ground carbon (TAGC) model was the stepwise multiple linear regression, concluding, then, that LiDAR data can be used to estimate biomass and total carbon in dry tropical forest, proven by an adjustment considered in the models employed, with a significant correlation between the LiDAR metrics. Our finding provides important information about the spatial distribution of TAGB and TAGC in the study area, which can be used to manage the reserve for optimal carbon sequestration.

Background: Dry tropical forests in arid lands cover large areas in Brazil, but few studies report the total biomass stock showing the importance of height measurements, in addition to applying and comparing local and pan-tropical models of biomass prediction for the domain of trees and shrubs found in that environment. Here, we use a biomass data set of 500 trees and shrubs, covering 15 species harvested in a management plan in the state of Pernambuco, in Brazil. We seek to develop local models and compare them with the equations traditionally applied to dry forests-showing the importance of tree height measurements. Due to the non-linear relationships with the independent variables of the tree, we used a nonlinear least squares modeling technique when adjusting models, we adopted the cross-validation procedure. The selection of the models was based on the likelihood measures (AIC), total explained variation (R2) and forecast error (RSE, RMSE and Bias). Results: In summary, our above-ground biomass data set is best represented by the Schumacher-Hall equation: exp [3.5336 + 1.9126 × log (D) + 1.2438 × log (Ht)], which shows that height measurements are essential to estimate accurately biomass. The biggest prediction errors observed when testing pan-tropical models in our data demonstrated the importance of developing new local models and indicated that careful considerations should be made if generic "pantropical" models without height measurements are planned for application in dry forests in Brazil. Conclusions: Thus, local equations can be used for carbon accounting in REDD + and sustainable incentive projects that initiate the development of dry forests and assess ecosystem services.

A expansão urbana sem planejamento adequado promoveu uma série de efeitos nocivos para a população das cidades, tanto ambiental quanto socialmente. Contudo, cada vez mais a vegetação vem sendo associada à qualidade de vida, devido aos comprovados benefícios que ela promove no ambiente urbano. Esta pesquisa objetivou classificar a cobertura vegetal de Olinda - Pernambuco, visando a quantificar sua floresta urbana. Para isso, utilizou-se uma imagem do satélite SENTINEL-2 com resolução espacial de 10 metros, para a classificação do uso do solo do município. Por meio do software QGIS 2.14.11, identificaram-se as classes de infraestrutura urbana, água, solo exposto, vegetação e nuvem, por meio da classificação supervisionada MaxVer, posteriormente divididas por regiões político administrativas para o mapeamento, sendo assim determinados e quantificados os índices de cobertura vegetal da cidade. A quantidade de vegetação nas regiões se mostrou variável, mas foram insatisfatórias para promover benefícios ambientais à população, com exceção da Zona Rural, local onde há maior quantitativo de vegetação da cidade. Observou-se que Olinda é uma cidade com déficit de cobertura vegetal, sendo possível perceber que o município carece de áreas vegetadas, bem como arborização.

Aims: Evaluate the phytosociological structure of natural regeneration, the ecological group and the species dispersion syndrome in an urban fragment of the Atlantic Forest, Pernambuco, Brazil. Study Design: Systematic sampling. Place and Duration of Study: Immaculate Catholic College Conceição do Recife (FICR), in the municipality of Recife, PE, in August 2019. Methodology: In the survey, 10 plots of 5 m x 5 m were sampled, and all living individuals with height ≥ 1 m and circumference at 1.30 m from the soil were sampled < 15 cm. The structure of natural regeneration was analyzed based on phytosociological parameters and distribution of individuals in height classes. Species diversity was estimated using the Shannon diversity and Pielou equability indices. Results: We sampled 236 individuals, belonging to 26 species. The estimated density and dominance were 9,940 ind.ha-1 and 5.27 m2.ha-1, respectively. The families with the highest species richness were Fabaceae, Myrtaceae and Bignoniaceae. The species that stood out when considering density, frequency, dominance, importance value and natural regeneration were Protium heptaphyllum, Eschweilera ovata, Casearia javitensis, Brosimum guianense, Handroanthus sp.1, Xylopia frutescens, Thyrsodium spruceanum and Myrciaria ferruginea, being considered well adapted, showing efficiency in the development and establishment of new individuals. The Elaeis guineensis it was also among those that stood out the most, and it was necessary to monitor and control, because it is an invasive alien species. The indices of Shannon diversity and Pielou equability were 2.56 nats.ind.-1 and 0.76, respectively. In the area, the initial secondary species with zoochoric dispersal syndrome predominated. The distribution of the number of individuals for height classes occurred in the following order: C3 > C1 > C2. Conclusion: The area is in the intermediate stage of ecological succession, with moderate species richness. It is necessary to monitor the area, aiming at the control of the species Elaeis guineensis and native species with low natural regeneration.