Caracterização estrutural e potencial florestal para o manejo comunitário da Floresta Nacional do Purus, Amazônia Ocidental

Purus National Forest (PNF), located in the municipality of Pauiní, Amazonas state, Brazil, has a high conservation status and a population of about one thousand inhabitants. However, the scarcity of environmental studies in a suitable scale for the PNF management planning demands studies that quantify and qualify the stock of resources, that identify the community demand and set sustainable forest production techniques. Thus, the objective of the present work was to analyze the floristic composition, forest structure and the forest management potential of part of a "terra firme" dense ombrophylous forest located in the Forest Management Unit (UMF-1) of Céu do Mapiá village, the largest populational nucleus of PNF. To do so, a forest inventory was made, sampling in a block of 12 parcels of 50x50m, and all trees with DBH ≥ 10 cm were measured. The floristic composition was carried out and the Shannon-Wiener diversity index and Pielou equability index were used to assess the biodiversity and the uniformity of the community. The structural forest analysis was based on the absolute and relative values of density, dominance, frequency, importance value and diameter distribution of the basal areas and volumetric estimates of the population. A total of 1,764 individuals, pertaining to 35 botanic families, 91 genera and 163 possible specimens were registered, emphasizing that less than 40% (65) were identified at the species level. The UMF-1 is characterized by the high floristic diversity (H'= 4.10), few dominant species (J = 0.81) and many species with low abundance. Out of the commercial species used by the community, three are among the ten species with the greatest importance value, a total of 26 possible commercial species of sustainable exploitation.A Floresta Nacional (FLONA) do Purus, situada no município de Pauiní-AM, apresenta elevado estado de conservação e uma população de aproximadamente mil habitantes. No entanto, a carência de estudos ambientais em escala adequada para o planejamento da gestão da FLONA torna imprescindíveis levantamentos que quantifiquem e qualifiquem o estoque de recursos, identifiquem a demanda comunitária e fundamentem técnicas de produção florestal sustentável. Nesse sentido, o objetivo do presente trabalho foi analisar a composição florística, a estrutura florestal e o potencial de manejo florestal de um trecho de floresta ombrófila densa de terra firme, localizado na Unidade de Manejo Florestal-1 (UMF-1) da Vila Céu do Mapiá, maior núcleo populacional da FLONA. Para tanto, foi realizado um inventário florestal por amostragem aleatória de 12 parcelas de 50x50m, sendo mensurados todos os indivíduos com DAP ≥ 10 cm. Foi realizada a análise da composição florística, bem como utilizados os índices de diversidade Shannon-Wienere de equabilidade de Pielou, para avaliar a diversidade e uniformidade da comunidade. A análise da estrutura da floresta foi baseada nos valores absolutos e relativos de densidade, dominância, frequência, valor de importância e distribuição diamétrica, da área basal e estimativas volumétricas do povoamento. Foram registrados 1.764 indivíduos, pertencentes a 35 famílias botânicas, 91 gêneros, e 163 possíveis espécimes, ressaltando que menos de 40% (65) foram identificadas em nível de espécie. A UMF1 caracteriza-se pela alta diversidade florística acumulada da comunidade arbórea amostral (H'= 4,10), poucas espécies dominantes (J = 0,81) e muitas espécies de baixa abundância. Das espécies comerciais utilizadas na comunidade, três figuram entre as dez espécies com maior valor de importância, em um total de 26 espécies comerciais possíveis de exploração sustentável

OS SOLOS DAS CAMPINARANAS NA AMAZÔNIA BRASILEIRA: ECOSSISTEMAS ARENÍCOLAS OLIGOTRÓFICOS

http://dx.doi.org/10.5902/1980509820581“Campinaranas” are sandy ecosystems of great extension in the Brazilian Amazon, and are determinant for the great systems of rivers with black waters. Due to the lack of studies on this ecosystem, the objective of the present work was to study the distribution of “Campinaranas” and their relationship with the predominant soils and geology in the western portion of the Brazilian Amazon. We used geographic data of vegetation, geology and soils, and analytical data of the soil profiles collected by the RADAMBRASIL project, updated and systematized by IBGE, and data from reference profiles collected in the National Park of Viruá, are predominantly sandy, developed on parent materials rich in quartz. The overlaying of geological data with areas dominated by “Campinaranas”, reveals the prevalence of recent sedimentary formations (Quaternary), constituted mainly of sandy materials. Based on the studied dataset, we suggest a minimum limit of 55 dag kg-1 of sand in the soils for the occurrence of “Campinaranas”.  Soils with higher clay content are present only in Forest-Campinaranas transitions, adjacent to the sandy deposits. It is verified the absolute prevalence of Spodosols and Psamments in “Campinaranas”. Even in different geological formations and under distinct pedogenetic processes, these soils possess similar morphological, chemical and physical properties. In spite of the pedological diversity found in the transitional areas, the soils keep similarities with the soils of “Campinaranas”. http://dx.doi.org/10.5902/1980509820581As Campinaranas são ecossistemas arenícolas de grande extensão na Amazônia brasileira, determinantes para os grandes sistemas de rios de águas pretas. Em vista da carência de estudos nestes ecossistemas, este trabalho teve como objetivos gerais estudar a distribuição das Campinaranas e suas relações com os solos predominantes e sua geologia na porção ocidental da Amazônia brasileira. Foram utilizados dados analíticos dos perfis de solos coletados pelo Projeto RADAMBRASIL, atualizados e sistematizados pelo IBGE, somados a perfis de referência coletados no Parque Nacional do Viruá, Roraima. De modo geral, os solos das Campinaranas são predominantemente arenosos, desenvolvidos sobre materiais de origem de natureza arenoquartzosa. Do cruzamento dos dados geológicos com áreas dominadas por Campinaranas, tem-se um predomínio das formações sedimentares recentes (Quaternário), constituídas principalmente de materiais arenosos. A partir da análise dos dados, sugere-se um limite mínimo de 55 dag kg-1 de areia nos solos para a ocorrência das Campinaranas. Os solos mais argilosos são reportados apenas para as áreas ecotonais Florestas - Campinaranas, marginais aos corpos arenosos. Verifica-se predomínio absoluto dos Espodossolos e Neossolos Quartzarênicos nas Campinaranas. Mesmo em diferentes formações geológicas e com processos pedogenéticos distintos, estes solos possuem características morfológicas, químicas e físicas muito semelhantes. Apesar da diversidade pedológica das áreas ecotonais, os solos encontrados guardam semelhanças com os solos das Campinaranas

Dependência espacial de variáveis dendrométricas em diferentes idades e intensidades amostrais em povoamento de eucalipto

Understanding the spatial variations of dendrometric variables in a continuous forest inventory is essential to support management actions, in addition to allowing sample intensities that reflect accuracy with lower inventory cost. The objective of this study was to evaluate the spatial dependence structure of dendrometric variables over time and in different sample intensities in eucalyptus stands. The hypotheses considered were that the spatial dependence structure of dendrometric variables changes along the growth in eucalyptus stands and the sample intensity influences this structure. The variables diameter at 1.30 m of soil, basal area, total height, mean height of dominant trees and volume of wood were obtained in continuous forest inventory, at 3.5, 4.5 and 5.5 years, from 80 plots (400 m²) distributed randomly in the stand (394 ha) located in Abaeté, Minas Gerais state. Were evaluated the sample intensities of one plot every 4.9 (n = 80), 7.3 (n = 54), and 16.4 (n = 24) hectares. The highest sample intensity was reference for the others. The spherical, exponential and gaussian semivariance models were adjusted to the experimental semivariogram, where the best fit model was used by ordinary kriging in the spatialization of the analyzed variables. The results showed a predominance of strong spatial dependence of dendrometric variables, regardless of age and sample intensity, especially for mean height of dominant trees and volume of wood. The lower sample intensity influenced negatively the spatial dependence of the basal area at all ages. The structure of spatial dependence is not influenced by the increase in the age of the stand, and the geostatistical analysis of these variables is recommended in a continuous forest inventory, considering the sample intensity of one plot of each 16.4 hectares.Compreender as variações espaciais de variáveis dendrométricas em inventário florestal contínuo é imprescindível para subsidiar ações de manejo, além de permitir intensidades amostrais que reflitam em acurácia com menor custo do inventário. Nesse contexto, o objetivo deste trabalho foi avaliar a estrutura de dependência espacial de variáveis dendrométricas ao longo do tempo e em diferentes intensidades amostrais em povoamento de eucalipto. As hipóteses testadas foram que a estrutura de dependência espacial de variáveis dendrométricas se altera com o crescimento em povoamentos de eucalipto e que a intensidade amostral influencia nesta estrutura. As variáveis diâmetro a 1,30 m do solo, área basal, altura total, altura média das árvores dominantes e volume de madeira foram obtidas em inventário florestal contínuo, aos 3,5, 4,5 e 5,5 anos, em 80 unidades amostrais permanentes (400 m²), distribuídas aleatoriamente em um povoamento de eucalipto (394 ha), localizado em Abaeté, Minas Gerais. Foram avaliadas as intensidades de uma unidade amostral a cada 4,9 (n = 80), 7,3 (n = 54) e 16,4 (n = 24) hectares. Considerou-se a maior intensidade amostral como referência para as demais. Os modelos de semivariância esférico, exponencial e gaussiano foram ajustados ao semivariograma experimental, em que o modelo de melhor ajuste foi utilizado pela krigagem ordinária na espacialização das variáveis analisadas. Os resultados demonstraram predominância de forte dependência espacial das variáveis dendrométricas, independentemente da idade e intensidade amostral, sobretudo para altura média das árvores dominantes e volume de madeira. A menor intensidade amostral influenciou negativamente na dependência espacial da área basal, em todas as idades. A estrutura de dependência espacial não é influenciada pelo aumento da idade do povoamento, sendo recomendada a análise geoestatística destas variáveis em inventário florestal contínuo, considerando a intensidade amostral de uma unidade amostral a cada 16,4 hectares

Beyond trees: Mapping total aboveground biomass density in the Brazilian savanna using high-density UAV-lidar data

Tropical savanna ecosystems play a major role in the seasonality of the global carbon cycle. However, their ability to store and sequester carbon is uncertain due to combined and intermingling effects of anthropogenic activities and climate change, which impact wildfire regimes and vegetation dynamics. Accurate measurements of tropical savanna vegetation aboveground biomass (AGB) over broad spatial scales are crucial to achieve effective carbon emission mitigation strategies. UAV-lidar is a new remote sensing technology that can enable rapid 3-D mapping of structure and related AGB in tropical savanna ecosystems. This study aimed to assess the capability of high-density UAV-lidar to estimate and map total (tree, shrubs, and surface layers) aboveground biomass density (AGBt) in the Brazilian Savanna (Cerrado). Five ordinary least square regression models esti-mating AGBt were adjusted using 50 field sample plots (30 m × 30 m). The best model was selected under Akaike Information Criterion, adjusted coefficient of determination (adj.R2), absolute and relative root mean square error (RMSE), and used to map AGBt from UAV-lidar data collected over 1,854 ha spanning the three major vegetation formations (forest, savanna, and grassland) in Cerrado. The model using vegetation height and cover was the most effective, with an overall model adj-R2 of 0.79 and a leave-one-out cross-validated RMSE of 19.11 Mg/ha (33.40%). The uncertainty and errors of our estimations were assessed for each vegetation formation separately, resulting in RMSEs of 27.08 Mg/ha (25.99%) for forests, 17.76 Mg/ha (43.96%) for savannas, and 7.72 Mg/ha (44.92%) for grasslands. These results prove the feasibility and potential of the UAV-lidar technology in Cerrado but also emphasize the need for further developing the estimation of biomass in grasslands, of high importance in the characterization of the global carbon balance and for supporting integrated fire management activities in tropical savanna ecosystems. Our results serve as a benchmark for future studies aiming to generate accurate biomass maps and provide baseline data for efficient management of fire and predicted climate change impacts on tropical savanna ecosystems

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ