Circumference At Breast Height Research Articles

Dinâmica estrutural em uma floresta tropical sazonalmente seca sob diferentes sistemas silviculturais

ABSTRACT Considering the importance of evaluating the compatibility between the exploration system usually used in the Caatinga and the vegetation regeneration process, this study aimed to evaluate the feasibility of recovering structural parameters in an experimental unit subjected to different management systems aged 9, 12, 16, 20 and 26 years post-exploitation. The area was subjected to clearcutting (CC) regimes and three types of selective cuttings (SC1 – selective cutting 1, cut of trees with diameter at the base – DAB < 15 cm; SC2 – selective cutting 2, cut of trees with DAB > 10 cm; and SC3 – selective cutting 3, cut of trees with DAB between 5 and 10 cm). In permanent plots of 20 m × 20 m, individuals with a circumference at breast height (CBH) ≥ 6 cm and a total height greater than 1.0 m were measured. Over the years of monitoring, the CC presented the lowest values of density, dominance, and volume, not obtaining a recovery in basal area and volume even after 26 years of regeneration. Treatments SC2 and SC3 stood out regarding recovery of the original woody biomass stock, presenting values higher than the original ones and indicating that the initial data did not correspond to the site's maximum potential. The forest dynamics pointed to the insufficiency of the 15-year clearcutting cycle in terms of recovering this region forest composition and structure.

Unlocking nature's hidden treasure: Unveiling forest status, biomass and carbon wealth in the Binsar Wildlife Sanctuary, Uttarakhand for climate change mitigation

In the context of present climate change concerns, the quantification of forest biomass and the comprehension of carbon stock distribution within protected areas are of paramount importance for exact carbon budgeting and the development of effective forest management strategies. This study conducted comprehensive field assessments with the primary objective of quantifying tree biomass and carbon stocks, as well as assessing structural attributes of forest stands. These assessments involved the meticulous collection of ground-based data encompassing various structural attributes, including circumference at breast height (CBH), stem height, basal area, stem density, frequency, girth class by utilizing a simple random sampling methodology. The results of this study unveiled substantial variations in all tree structural attributes across different forest stands along altitudinal gradients. Notably, species richness, tree density and species diversity exhibited an upward trend with increasing altitude. The maximum tree species richness (25) and tree density (1068 ± 102.2 individuals ha−1) were recorded at stand-IV, situated between 2200 to 2400 m, however, stand-I exhibited the maximum basal area. The highest aboveground, belowground, total biomass, and carbon stock was estimated in the stand-IV, with values of 279.12 ± 17.56 Mg ha−1, 65.58±11.20 Mg ha−1, 344.70 ± 20.66 Mg ha−1, and 163.73 ± 10.33 Mg ha−1, respectively. The study further revealed a positive correlation between elevation and species richness, biomass, and carbon stock. Additionally, it demonstrated positive correlations between total biomass and carbon stock with species richness, total basal area, and tree density. These findings convey immediate significance for the development and implementation of climate change mitigation policies and practices, particularly within the context of protected areas in the Himalayan landscape.

Optimising carbon fixation through agroforestry: Estimation of aboveground biomass using multi-sensor data synergy and machine learning

As agricultural land expansion is the primary driver of deforestation, agroforestry could be an optimal land use strategy for climate change mitigation and reducing pressure on forests. Agroforestry is a promising method for carbon sequestration. With recent advancements in geospatial and data science technology, the ability to predict aboveground biomass (AGB) and assess ecosystem services in agroforestry is rapidly expanding. This study was conducted in the Belpada Block of Balangir, Odisha, a forest-dominated region of eastern India. We recorded species occurrence and measured plant parameters, including Circumference at Breast Height (CBH), height, and geolocation, in 196 plots (0.09 ha) in agroforestry intervention sites and noted the tree species. This study used Sentinel-1 and Sentinel-2 multi sensor data to achieve data synergy in AGB estimation. Three machine learning models were used: Random Forest (RF), Support Vector Machine (SVM), and Artificial Neural Network (ANN). The RF model exhibited the highest level of prediction accuracy (R2 = 0.69 and RMSE = 17.07 Mg/ha), followed by the ANN model (R2 = 0.63 and RMSE = 19.35 Mg/ha), SVM model (R2 = 0.54, RMSE = 21.97 Mg/ha. The spectral vegetation indices that are (Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), Enhanced Vegetation Index (EVI), Modified Simple Ratio (MSR), Modified Soil-Adjusted Vegetation Index (MSAVI), Difference Vegetation Index (DVI), and SAR backscatter values, were found important variables for AGB prediction. The findings revealed that agroforestry interventions and plantations resulted in an average carbon stock increase of 15 Mg/ha over five years in the study area. The Plant Value Index (PVI), which indicates the importance of species in the local economy and biomass carbon storage, showed that Tectona grandis was the dominant species with the highest PVI value (88.35), followed by Eucalyptus globulus (56.87), Mangifera indica (53.75), and Azadirachta indica (15.45). This approach enables the expansion of monitoring efforts to assess carbon stock in agroforestry systems, thereby promoting effective management strategies.

How Forest Management with Clear-Cutting Affects the Regeneration, Diversity and Structure of a Seasonally Dry Tropical Forest in Brazil

In Brazil, logging in the Seasonally Dry Tropical Forest (SDTF) under management plans that include clear-cutting has increased in recent decades, and the structure, composition, diversity and functioning of the forest likely must have been affected. The aim of this study was to understand the growth dynamics of shrub–tree biomass (STB), species richness and vegetation structure as a function of regeneration time after clear-cutting (treatments), taking the Legal Reserve (40 years of regeneration) as reference. The study was carried out in 2018 at the Ramalhete Settlement, General Sampaio, in the state of Ceará. All plants with a circumference at breast height (CBH) ≥ 6 cm were identified and the CBH was measured across 42 sample plots (20.0 m × 20.0 m), using seven plots per treatment (3, 5, 8, 11 and 15 years after clear-cutting, and the Legal Reserve, 40 years of regeneration). The following were determined: STB (total and by species), density and basal area (by ecological group and diameter class), basal area (species of higher added value), diversity (Hill numbers), and the importance value index (IVI). It was found that during the early years (up to at least 11 years), many important forest characteristics related to the composition of the ecological groups and vegetation structure were strongly affected, and major impacts can be seen, the effects of which, however, decreased over time of regeneration, having almost no effect after 15 years. After 15 years following clear-cutting, the SDTF presented accumulated STB, species richness and structure similar to the area undergoing regeneration for 40 years. However, the small number of indicator species of more-preserved areas (even at T15 and T40) points out that management needs to be improved. However, promoting species of greater added value and determining whether the forest recovers its structure and diversity after successive cutting cycles also still need to be addressed.

Distribution of thornless Mimosa tenuiflora, Piptadenia stipulacea and Cnidoscolus quercifolius in a seasonally dry tropical forest remnant

ABSTRACT The density and distribution of three tree species of local economic importance with, but sometimes without, thorns (Mimosa tenuiflora, Piptadenia stipulacea) or urticating hairs (Cnidoscolus quercifolius) thriving in native seasonally dry tropical forests, were assessed in a 43.5-hectare cattle-grazed caatinga remnant, located in Patos/Paraíba, Brazil. We recorded and georeferenced all the thorny and thornless regenerant plants (≥50 cm high and circumference at breast height (CBH) < 6 cm). We also recorded and georeferenced all the mature thorny and thornless trees (CBH ≥ 6 cm); in addition all the thornless mature trees and their respective nearest thorny mature plant were measured. Thornless M. tenuiflora, P. stipulacea and C. quercifolius totaled 560, 9 and 13 plants, respectively. The thornless plants formed groups and the mature ones showed height and CBH similar to their respective nearest mature thorny neighbor. Based on our data and on published data, we suggest management practices aiming at replacing thorny trees by thornless trees, including among others: the planting of 15 groups/ha of, respectively, 7, 2 and 2 thornless M. tenuiflora, P. stipulacea and C. quercifolius seedlings. Such a progressive replacement of the thorny trees by thornless trees would facilitate grazing and the management of the forest.

Quantitative and molecular analysis of Pinus elliottii Engelm. at six years of age using microsatellites markers

There are about 126 cataloged species within the Pinus genus, and the genus is the second most common in planted forests in Brazil, covering about 1.7 million hectares. Among the species used in commercial plantations, P. elliottii is particularly important; its wood is mainly used in the furniture industry, for resin production, and in some cases in the chemical and pharmaceutical industry for its volatile derivatives. The objective of this study was to conduct a quantitative and molecular analysis of six-year-old stands of P. elliottii at two sites, one located on Fazenda Monteiro in the city of Apia´ı, and the other on Fazenda Palmeiras, Ribeirao Branco, both located in São Paulo state (SP), Brazil. Height and circumference at breast height (CBH) were analyzed. Genetic parameters were estimated, with the coefficients of genetic variation for height ranging from 2.03% to 2.62% and from 2.43% to 4.51% for CBH. At Fazenda Monteiro, the narrow-sense heritability and within progeny heritability values for height (0.23; 0.20) and CBH (0.26; 0.22) were considered medium. In Fazenda Palmeira, the values obtained for narrow-sense heritability were considered low magnitude for CBH (0.04; 0.02), while for height they were considered medium (0.09). Low magnitude values were found for heritability within progeny (0.08). Molecular analyses of heterozygosity showed low levels of heterozygosity, but with the possibility of gains. The G×E data showed that progeny F30 performed best in both environments, but a breeding program for both environments is not recommended. The analysis of quantitative and molecular characteristics facilitates and improves the accuracy of selection processes performed by breeders.

Best practices to use the iPad Pro LiDAR for some procedures of data acquisition in the urban forest

The search for means to improve urban forest inventories is challenging for small communities and cities with a limited budget. Mobile applications on iPad or iPhone seem promising equipment to make some inventory practices cheaper and faster, although procedures of use are still limited. So, we tested the LiDAR scanner application on an iPad Pro 2020 for trunk perimeter measures and the position for 10 different groups of species in the Polish Airmen Park, Kraków (Poland). For each group, in 10 trees, we measured the perimeter at breast height (PBH) and relative tree trunk position. The first procedure tested the estimation of PBH according to the distance of an iPad Pro from the trunk, the time of 3D data acquisition and the number of turns around trees. The second procedure tested PBH estimations according to the number of trees scanned in just one try (3, 6 and 10 trees). The third procedure tested the estimation of the relative position of tree trunks from other trees. In each procedure, we compared 3D point clouds generated by an App running on iPad Pro with data from a measuring tape and FARO FOCUS 3D (TLS) point clouds. The results showed that the shorter the distance from the iPad Pro to the trunk surface, the more precise the PBH estimation, not significantly different (p > 0,01) from TLS values. Distances between 1.0 and 2.0 m would be most suitable for the iPad Pro application but performing two turns around the tree trunk would improve results for PBH measurements. Trees scanned as 3-tree groups with the iPad Pro presented the smallest PBH differences compared to TLS point clouds. No significant differences (p > 0,01) were found between the methods for estimating the distance among trees, which shows that the iPad Pro can deliver a precise relative position of tree trunks.

A new synergistic approach for Sentinel-1 and PALSAR-2 in a machine learning framework to predict aboveground biomass of a dense mangrove forest

Mangroves are well-recognized for their very high carbon sequestration potential. However, studies on their role in global carbon cycling and climate change are hindered due to lack of operational methodologies to model and map their biophysical properties. This study establishes a robust methodological protocol for aboveground biomass (AGB) estimation using i) field measurements, ii) a generic (in the absence of species-specific) allometric equation, iii) multi-sensor/polarization SAR data and derived variables thereof, and iv) machine learning models; that demonstrated high prediction accuracy (R2 = 0.93) and low uncertainty (mean ≤ 3% and median ≤ 1.5%) for a mangrove forest. Following stratified random sampling and on-field accessibility criteria, we laid out 314 elementary sampling points of 0.04 ha each at Bhitarkanika wildlife sanctuary (BWS), India and measured circumference at breast height (CBH) and canopy tree height for 18 species. The estimated AGB range of a generic allometric equation was 9–474 Mg/ha for BWS, with a major representation of 9–347 Mg/ha. We utilized Sentinel-1 and ALOS-2/PALSAR-2 and derived their variables for AGB prediction. Compared to single sensor-based model, we observed higher prediction accuracy for combined sensor data (R2 = 0.63, 0.87, 0.93; RMSE = 66.75, 39.95, 28.35 Mg/ha; MAE = 52.63, 24.21, 19.55 Mg/ha; and Bias = 3.42, 0.22, 2.15 Mg/ha for C, L and C & L bands respectively using a Generalized Additive Model (GAM) over Random Forest (RF), Gradient Boosting Machines (GBM) and Support Vector Regression (SVR). The higher uncertainty pixels represented seasonal grassland and scrubs in the swampy areas and along the fringes of the creeks that experience diurnal tidal fluctuations. This robust methodology can be replicated for AGB estimates in other mangrove ecosystems to meet the operational carbon accounting requirements of various entities.

Promising Uses of the iPad Pro Point Clouds: The Case of the Trunk Flare Diameter Estimation in the Urban Forest

The rule of thumb “the right tree in the right place” is a common idea in different countries to avoid damages caused by trees on sidewalks. Although many new planting techniques can be used, the estimation of the trunk flare diameter (TFD) could help the planning process to give tree roots more space to grow over the years. As such, we compared the applicability of point clouds based on iPad Pro 2020 image processing and a precise terrestrial laser scanner (TLS FARO) for the modeling of the TFD using different modeling procedures. For both scanning methods, 100 open-grown and mature trees of 10 different species were scanned in an urban park in Cracow, Poland. To generate models, we used the PBH (perimeter at breast height) and TFD variables and simple linear regression procedures. We also tested machine learning algorithms. In general, the TFD value corresponded to two times the size of a given DBH (diameter at breast height) for both methods of point cloud acquisition. Linearized models showed similar statistics to machine learning techniques. The random forest algorithm showed the best fit for the TFD estimation, R2 = 0.8780 (iPad Pro), 0.8961 (TLS FARO), RMSE (m) = 0.0872 (iPad Pro), 0.0702 (TLS FARO). Point clouds generated from iPad Pro imageries (matching approach) promoted similar results as TLS FARO for the TFD estimations.

Carbon Pool in &lt;i&gt;Quercus lanuginose&lt;/i&gt; (D. Don) Forest of Askot Wildlife Sanctuary, Western Himalaya in Relation to Stand Attributes

Following the acceptance of the Kyoto Protocol, data on forest biomass must be collected in order to determine the potential ability of forest stands to sequester atmospheric carbon and aid in the reduction of rising carbon dioxide levels in the atmosphere. The aim of this study was to estimate the amount of carbon fixed by one of the overexploited oak species ( Quercus lanuginosa ) in Askot Wildlife Sanctuary Western Himalaya, India. Thirty quadrats of 10x10 m size were placed randomly at three altitudes between 1900 and 2100 m asl and data on biomass and soil characteristics were collected. In three forest sites CBH (circumference at breast height) of 236 individuals with a diameter of ≥31 cm was measured and standing biomass was estimated following growing stock volume equations. Across the sites, the mean aboveground and belowground carbon stock was 475.8±84.9 and 119.8±18.1 Mg C ha -1 , respectively. The total tree carbon stock showed significant (P&lt;0.01) positive correlation with soil carbon (R 2 = 0.71) and nitrogen (R 2 = 0.99). Basal area showed significant positive while diversity showed significant negative correlation with carbon stock. High carbon accumulation potential in old-growth individuals of Rianj oak suggests that they should be maintained in the study area to mitigate the effect of climate change.Â

Linear and spatial variability of eucalyptus dendrometric attributes correlated with the properties of a Typic Haplustox soil (Oxisol) in the Brazilian savannah

Effects of soil attributes using the geostatistical tool improves the interpretation of specific soil management. Thus, this study aimed to evaluate the physical, chemical, and microbiological properties of a Typical Haplustox (Oxisol), identifying those with the best linear and spatial correlation with eucalyptus (Eucalyptus spp.) vegetative growth. The experiment was conducted at the Teaching, Research, and Extension Farm (FEPE) of the Universidade Estadual Paulista (UNESP), Campus of Ilha Solteira. Thirty-five points spaced 13 meters apart were demarcated for analysis, which were distributed in 5 rows of 7 points each. From each point, 2 soil samples were collected from the 0-10 cm depth layer. The physical, chemical, and microbiological soil properties evaluated were: sand, silt, and clay contents; penetration resistance (PR), gravimetric moisture (GM), real density (RD), microbial biomass carbon (MBC), respirometry (CO2-C), metabolic quotient (qCO2), organic matter content (OM), and hydrogenionic potential (pH). The eucalyptus attributes assessed were: plant height (PH) and circumference at breast height (CBH). Each attribute was analyzed by descriptive statistics using the SAS software. Data frequency distribution was verified by the Shapiro Wilk method, and geospatial changes were analyzed by the GS+ software. The soil property that best explained the variability in eucalyptus dendrometric attributes was real density (RD). Except for RD, all properties did not show spatial dependence (i.e., pure nugget effect), which significantly represents eucalyptus vegetative performance.

Variation in vascular epiphytic assemblage along altitudinal zone in Temperate forest ecosystem

The focus of ongoing research in forest ecosystems is highly biased towards vascular epiphytes that grow non-parasitically on host trees and contribute substantially in shaping biodiversity. In this communication, an effort has been made to understand the vascular epiphytic assemblage and richness along the altitudinal gradients in temperate forests of Darjeeling Himalaya. Additionally, influence of environmental variables was also analyzed. Orchidaceae was the dominant family followed by Polypodiaceae and Ericaceae in terms of species abundance. The epiphytic richness and diversity were greater towards lower altitudinal tier compared to the higher. The epiphytic diversity was positively correlated with host tree CBH (circumference at breast height) and bark texture, while bark pH showed a negative correlation. The outcome of this study establishes a baseline of epiphytic characteristics with respect to elevational range and environmental variables in temperate Himalaya. However, a detailed study on population dynamics, habitat evaluation and geographic aspects with further development on monitoring and conservation effort is of utmost necessity.

Forest structural analysis of a seasonal semideciduous area in the northeast Brazil

As a prominent aspect of forest fragmentation, arboreal individuals’ diameter and height structure are impaired. The forest structure allows identifying each population’s behavior and habit and collects information on growth and survival that assists in establishing and managing conservation strategies. This work aimed to perform the diametric and height distribution of an adult tree community and the five highlighted species of the area located in the Northeast Brazil. We implanted 20 permanent plots with 250 m² and measured all arboreal individuals sampled with a circumference at breast height (CBH) ≥ 15 cm in addition to heights. The tree community presented a graph of the negative exponential type in the diametric distribution and a higher concentration in the 6-8 m in height median class, a typical pattern found in remnants of Atlantic Forest. Guapira nitida, Manilkara sp., Byrsonima crassifolia, and Sloanea obtusifolia presented the same pattern as the community due to their ecological attributes as succession group and dispersion syndrome. These data are compatible with the ecological succession process of Brazilian’s northeast Seasonal Semideciduous Forest. Moreover, the species Buchenavia tetraphylla diverged because of its ecological characteristics that do not allow new individuals to develop in the study area. The fragment was classified according to CONAMA Resolution n°. 31 as secondary vegetation in the medium regeneration stage. The analyzed remnant is still in the regeneration process, resulting from the disturbances caused. The most important species of the fragment still present young individuals, representing young communities with potential for establishment.

Using crown characterisation variables as indicators of the vigour, competition and growth of Brazilian pine

Crown variables are used in growth and production models to increase the accuracy of estimates. These variables are costly and difficult to measure, mainly in dense native forests such as mixed ombrophilous forests (MOF), where Araucaria angustifolia is the predominant species. Thus, this study aimed to evaluate the effect of qualitative and quantitative variables to describe the vigour of the crown, competition and growth of A. angustifolia in Southern Brazil MOF. We selected trees in the MOF area and measured circumference at breast height (CBH) and total height (h). For the crowns, a ranking of values was established in the variables: Crown Shape (CS), Vertical crown Shape (VS), Distance between Branches (DB), Sociological Position (SP), percentage of Green Leaves (GL) and Crown Size (CZ). Periodic Annual Increment in basal area (PAIg) and a Competition Index (CI) were calculated. We used principal component analysis (PCA) and Hierarchical Cluster Analysis (HCA) to describe and classify the sampled trees. Two groups were generated: i) dominant and codominant trees, with higher growth, better vigour and better crown quality; and ii) suppressed trees with low vigour, consequently low increment and worse crown quality. The CI, when based only on diameter information, was inadequate to describe the competitive status of the trees, so information about crowns was necessary. Qualitative crowns variables are important to classify the vigour, current level of competition and to understand the different trends in A. angustifolia growth.

Pattern and spatial associations of commercial trees in the Amazon

ABSTRACT: This study was conducted to establish the pattern and the spatial associations of the Amazon commercial tree groups. In a region extending across 2,000 ha in the Tapajós National Forest (FNT), Pará, a forest census was conducted. The census included commercial trees of perimeter at breast height (PBH), equal to or greater than 158 cm and the Cartesian coordinates of their bearings. Using Ripley’s K function, the spatial pattern was discerned, with 5 m radius being assumed, and maximum distances varying up to 1,500 m. Then, with 99.8% probability for both, 500 Monte Carlo simulations were performed for the univariate K function, and 500 toroidal simulations were done for the bivariate function.The commercial tree groups, which revealed an aggregated spatial pattern in a minimum of approximately 50% of the analysis distance were namely, Astronium lecointei, Bagassa guianensis, Couratari guianensis, Manilkara huberi, Mezilaurus itauba, and Vochysia maxima. In Brazil, the commercial tree groups, based on the commercialization criteria for tropical trees show random and aggregated spatial patterns with associations of spatial independence.

Comportamento de Paubrasilia echinata (Lam.) Gagnon, H. C. Lima &amp; G. P. Lewis (pau-brasil) em plantios homogêneos experimentais no Nordeste do Brasil

RESUMO: Na década de 60, em vários locais do país, foram instalados pequenos talhões experimentais de espécies florestais nativas e exóticas, entre elas Paubrasilia echinata, com o objetivo de avaliar o comportamento das mesmas em condições de plantios homogêneos, sendo que anos depois grande número dessas parcelas ficou sem manutenção e foi abandonada. Assim, o objetivo deste trabalho foi resgatar informações silviculturais e apresentar resultados do comportamento da espécie em plantios homogêneos experimentais realizados na zona litorânea da Região Nordeste, especificamente nos municípios de Camaragibe-PE, Lagoa de Itaenga-PE, São Lourenço da Mata-PE, Nísia Floresta-RN e Maceió-AL. Foram mensurados os indivíduos localizados no centro dos plantios, sendo coletadas as seguintes variáveis: circunferência na base (CNB), circunferência a altura do peito (CAP) e altura total. O volume foi estimado utilizando-se o fator de forma 0,5. Maior crescimento foi observado em Maceió-AL, com IMA (incremento médio anual) de 9,396 m³.ha-¹.ano-1 aos 36 anos de idade, onde o sítio apresenta maior fertilidade natural. Menores valores de IMA foram observados em Nísia Floresta-RN, 1,336m³.ha-¹.ano-1 aos 41 anos de idade, e Camaragibe-PE, 1,956m³.ha-¹.ano-1 aos 24 anos de idade. Apesar do crescimento da espécie ser considerado lento, observou-se que o incremento médio em altura e diâmetro dos plantios homogêneos avaliados foi superior ao quantificado para várias espécies da Floresta Amazônica e mesmo da Mata Atlântica.&#x0D; PALAVRAS-CHAVE: Espécie florestal, silvicultura, Mata Atlântica.

ASSESSING THE FEASIBILITY OF THE BDq METHOD FOR THE SUSTAINABLE MANAGEMENT OF THE CAATINGA

ABSTRACT The BDq method is based on the concept of a balanced forest, in which the current growth can be periodically removed while maintaining the initial diameter distribution of the forest. This study aimed to analyze the technical feasibility in the application of three cutting intensities and six scenarios in sustainably managed Caatinga vegetation. The study was carried out at the Fazendas Baixa da Oiticica, Rancho da Velha, and Tabuleiro de Dentro, located in the municipality of Upanema (state of Rio Grande do Norte), with an area of around 343 hectares. We established 11 plots of 20 × 20 m and measured all individuals with a circumference at breast height (CBH) ≥ 6 cm within these plots. The individuals were identified in the field, and the APG IV classification system was adopted to organize the list of scientific names and families. Three management alternatives were proposed, namely reducing 40% (Scenario 1), 50% (Scenario 2), and 60% (Scenario 3) of the basal area and the actual volume for the application of the BDq method. In total, 1,680 individuals distributed in 10 families, 18 species, 16 genera, and 7 diameter classes were inventoried. Considering rational, sustainable harvesting, and following the theoretical rules of dynamic processes, cuts may not be carried out in larger diameter class centers (22.45, 27.45, and 32.45 cm). Scenario 3 showed the most effective results, as it allows the harvesting of the highest number of individuals and provides a greater economic return.

SPATIAL DISTRIBUTION AND STRUCTURAL VARIATION OF Copaifera arenicola IN A CAATINGA FRAGMENT

The study of spatial distribution of tree populations has proven to be important for revealing how individuals are horizontally organized in the environment, facilitating the structural understanding and forms of colonization and dispersion of propagules. The present work aimed at studying the pattern of spatial distribution of tree species Copaiferaarenicola [(Ducke) J. Costa e L.P.Queiroz] and its structural relation with the altimetric profile in a Caatinga fragment in Ribeira do Pombal municipality, Bahia. Census of all individuals in the area with circumference at breast height (CBH) ≥ 6 cm was performed. The spatial distribution analysis was conducted for the whole population using Ripley K univariate function, with maximum search radius (h) of 128 m. 409 individuals were found, corresponding to absolute density of 89.49 ind. ha-1 and 0.681 m². ha-1 of basal area. The group of C. arenicola individuals corresponds to a stable population in expansion phase, presenting higher number of young and medium individuals. The pattern of spatial distribution of individuals in the area under study was the uniform arrangement. None of the altimetric classes of the area had a different influence on the structure and distribution of arboreal individuals.

Qualitative &amp; Quantitative Analysis of Adult Arboreal Individuals from the Afforestation in the Municipality of Várzea, Paraíba, Brazil

Aims: Perform a qualiquantitative analysis of adult arboreal individuals in urban roads in the municipality of Várzea, Paraíba, Brazil.&#x0D; Study Design: Census inventory.&#x0D; Place and Duration of Study: Várzea Municipality, Paraíba, Brazil from March to April 2018.&#x0D; Methodology: The qualitative and quantitative census inventory of adult shrubs-tree individuals was carried out in the urban roads of the municipality, the level of inclusion of the individuals was circumference at breast height (CBH) of (1.30 m) was ≥ 6 cm. Common name of the species was recorded, CBH measurements, height of the first bifurcation and total and physical conditions that were classified as good, regular, bad and dead. The data were tabulated, processed and presented in tables and graphs.&#x0D; Results: A total of 429 individuals were recorded on public roads distributed in 20 species. Azadirachta indica A. Juss and Ficus benjamina L. had the highest number of individuals.&#x0D; 85% of the species were exotic and 15% were native. 12 species offered direct nutritional benefit to man and local fauna as they were fruit trees. The physical conditions of the individuals were 55.94% good, 40.33% regular, 3.73% poor, however, 47.50% of individuals had some type of conflict. 41.72% of individuals were concentrated in the diametric class of 15-21 cm. 54.78% of individuals had height of the first bifurcation greater than 200 cm and 62% of the individuals medium size.&#x0D; Conclusion: The afforestation of the municipality was satisfactory in relation to plant health. Attention needs to be paid to the diversity of native species and the injuries caused to vegetation. The height of the first fork was adequate. The trees were medium sized. It is suggested that studies of perception of afforestation be carried out in the municipality.

Vegetação lenhosa de regiões semiáridas em diferentes altitudes

O objetivo deste trabalho foi avaliar diversidade florística em diferentes altitudes na região do Araripe em Pernambuco, Brasil. Metodologicamente, a região foi estratificada em três níveis de altitude: inferior (até 600 m), intermediário (maior que 600 e menor que 750 m) e superior (igual ou maior que 750 m). Foram inventariados nove fragmentos florestais, três por estrato altitudinal. Em cada fragmento, distribuíramse 20 unidades amostrais retangulares, de 250 m² cada, totalizando área amostral de 4,5 ha. Nas áreas amostrais foram quantificados, coletados e identificados todos os indivíduos lenhosos com nível de inclusão de circunferências a altura do peito (CAP) maior ou igual a 0,10 m (CAP a 1,30 m ≥ 0,10 m). Analisou-se, riqueza e similaridade florística entre fragmentos e níveis de altitudes. Foram amostrados 6.987 indivíduos, distribuídos em 35 famílias botânica, 82 gêneros e 153 espécies. A região apresenta grande riqueza florística, com variação entre e dentro dos três níveis altitudinais, com tendência de aumento na diversidade com a elevação da altitude. A maioria das espécies apresentaram pouca plasticidade fenotípica, com ocorrência e abundância restrita ao fragmento ou altitude. Em pequenas distâncias geográficas foram diagnosticadas relevantes variações fitofisionômicas, o que corrobora a importância da estratificação de altitudes e replicação de fragmentos na amostragem. Pelo nível de degradação antropogênica e a intensificação das atividades florestais da região, faz-se necessário e urgente a criação de políticas públicas voltadas para práticas sustentáveis no uso da floresta e seu processo de conservação. Para tanto, o negligenciamento a esta problemática, coloca em risco de extinção uma grande representação da diversidade vegetacional do nordeste brasileiro.