Generatation of models for the management of Araucaria forests in southern Brazil using morphometric relationships with density is still scarce. Changes in the dynamics of the shape and size of trees in the forest indicate the need to regulate the density of trees (silvicultural intervention) or self-adjustment of the species to shape structure, living space, competition, growth rate and resource use. Trees with larger crowns show higher growth rate and their size inform the vital space of growth and support management density of the forest. This information is important to support forest management and can be used to build individual tree growth models. Management models built based on the relationship between forest density and morphometric variables are powerful tools to achieve sustainable yield. Thus, the purpose of this study was to adjust equations to express the diameter, the shape of the crown in function of morphometric/dendrometric variables and to relate the dynamics of the changes in crown surface area and the number of trees per hectare with the diameter and crown surface area. Morphometric and dendrometric data were measured from individual trees in 25 permanent plots located in 84 hectares of a natural forest with predominance of Araucaria angustifolia (Bertol.) Kuntze species. The diameter at breast height, total height, crown insertion height and four crown radius were measured, including 330 trees. The data were subjected to Pearson correlation analysis and regression conditioners (normality and homogeneity of variance). All the equations proposed in the objectives were generated using generalized linear models (GLM) techniques, which showed accuracy and precision with low values of deviation and Akaike criterion. The results showed that there is interaction between crown shape, density and diameter, indicated by Pearson correlation higher than 0.9. The interactions of crown and density variables identified requirements of silvicultural interventions and the period to perform these activities according to the mean diameter of the forest or to a desired diameter. This is important information for the conservation of the Araucaria Forest structure.
ResumoConhecer a morfometria de uma espécie e descrever suas relações auxilia no planejamento e uso sustentável da floresta. O trabalho objetivou analisar relações morfométricas, a fim de ajustar modelos que representem 121 árvores de Araucaria angustifolia amostradas em dois sítios em São José do Cerrito, Planalto Catarinense. Foram mensurados: diâmetro à altura do peito (Dap), altura (h), altura de inserção de copa (hic), raio de copa (rc), comprimento de copa (cc), diâmetro de copa (dc), índice de abrangência (IA), índice de saliência (IS), grau de esbeltez (GE), formal de copa (FC), proporção de copa (Pc%) e a posição sociológica (PS) de cada indivíduo. Foi usada correlação de Person para avaliar as relações entre variáveis morfométricas. Empregou-se a análise de covariância para verificar diferença de nível e inclinação nos ajustes dos modelos para os sítios. O ajuste dos modelos foi realizado pelos modelos lineares generalizados (MLG) nos campos de distribuição gama e normal, função de ligação identidade e logarítmica para correlações maiores ou iguais a 0,7. A análise de covariância demonstrou diferenças nas relações para cada sítio, indicando o ajuste de equações distintas. As equações demonstraram variações nas relações morfométricas pela mudança formadimensão de cada árvore. Os resultados mostram a modificação na forma da copa, a partir da posição social de cada árvore, além da influência diamétrica e do espaço ocupado por cada árvore na floresta, competição e condições do sítio. As relações morfométricas estabelecidas foram importantes para explicar a dinâmica de crescimento da espécie e a aplicação de intervenções silviculturais. Palavras-chave: Morfometria; modelagem; manejo florestal. AbstractMorphometric relations for Araucaria angustifolia (Bertol.) Kuntze in Santa Catarina, Brazil. Knowing the morphometry of a species and describing its relations help us in the planning and in the sustainable use of the forest. The objective of this study was to analyze morphometric relationships in order to fit models representing 121 Araucaria angustifolia trees sampled at two sites in São José do Cerrito, Planalto Catarinense. The measures were: diameter at breast height (Dap), height (h), crown insertion height (hic), crown radius (rc), crown length (cc), crown diameter (dc), slenderness index (IS), degree of slenderness (GE), formal cup (HR), crown ratio (Pc%) and sociological position (PS) of each individual. Person correlation was used to evaluate the relationships between morphometric variables. The covariance analysis was used to verify difference of level and slope in the adjustments of the models for the sites. The fit of the models was done by generalized linear models (MLG) in the gamma and normal distribution fields, identity and logarithmic link function for correlations greater than or equal to 0.7. The covariance analysis showed differences in the relations for each site, indicating the adjustment of different equations. The equations showed variations in morphometric relationships due to the sh...
The sustainable management of mixed ombrophilous forest is an effective way to perpetuate the survival of Brazilian pine and to generate environmental, economic and social benefits. So, this study aimed to describe the dynamics of the diametric distribution to propose a management intervention using the Liocourt model for a natural forest of Araucaria angustifolia within 84 ha of forests located in Lages, SC, Brazil. A total of 25 permanent plots of 400 m² were evaluated in two periods (periodic inventory performed in 2012 and 2016). The diameters at the breast height and the total height of all Brazilian pine individuals with diameter from 10 centimeters were measured. For the calculation of the quotient "q" the individuals were divided into diametric classes with intervals of 5 cm. The cutting intensity and the cutting rate for the cutting cycles of 20, 25 and 30 years were also calculated. This Brazilian pine forest presented J-inverted distribution curve and the value for the quotient "q" was 1.32. The cutting rates were 44.89 m³. ha-1 , 63.64 m³. ha-1 and 86.52 m³. ha-1 for the cutting cycles of 20, 25 and 30 years, respectively. In conclusion, this work demonstrated a forest structure that allows the forest management activity and the use of Liocourt method as a tool to elaborate forest management plans and to improve the forest interventions in Brazilian pine forests.
Aspectos gerais e silviculturais de Cordia americana, Aspidosperma polyneuron, Toona ciliata e Khaya spp. ABSTRACTBrazil has a great diversity of forest species; however, the stands contain mostly species of Eucalyptus and Pinus. Faced with this, the present study is based on the analysis of the characteristics of native species with high potential and innovative character of timber species for cultivation. The Australian cedar (Toona ciliata) and African mahogany (Khaya spp.) are important species, mainly benefiting in reducing the exploitation of native forests remaining in the country. However, the species of (Cordia Americana) and (Aspidosperma polyneuron) show great potential yet to be explored, both in releasing commercial plantations and their proper use, that meets sustainability requirements.
Crown efficiency is a relation of growth with the area tree occupies (available area efficiency). Efficiency is associated with the vertical and lateral expansion capacity of the tree and crown, increase, density and light absorption. Thus, our study aimed to evaluate crown efficiency with pine cones∙tree-1 production and dendro/morphometric variables of individual araucaria trees in three forest sites in south Brazil. In each site of each tree, dendrometric and morphometric variables were measured and increment rolls were taken at the breast height diameter level. Together with these data, the morphometric indexes, annual periodic increment in diameter of the last ten years (APId) and efficiency of the crown as a function of APId by the horizontal projection area of the crown (hpac) and number of pine cones∙tree-1 (np) by hpac were calculated. Crown efficiency was modeled as a function of the independent variables hpac, APId, crown length (cl), crown ratio (cr) and np. The accuracy of the adjustment was evaluated by the statistics of the deviance, Akaike’s information criterion and graph of the residuals. The results show that the number of pine cones∙tree-1 increases with annual periodic increment in diameter and diameter. Crown efficiency decreases with increasing hpac, cl and cr, indicating silvicultural treatments should be performed with the removal of trees of larger diameter and crown size. A higher pine cones production and efficiency correlates with forest growth, shape, competition, sociological position (stratum tree occupies) and density.
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