Abstract
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.
Highlights
Araucaria or Brazilian pine (Araucaria angustifolia (Bertol.) Kuntze) is a dioecious species characteristic of the mixed ombrophilous forest in south Brazil
The present study evaluate crown efficiency of Araucaria angustifolia as a function of the number of pine cones·tree-1, annual periodic increment in diameter and morphometric variables in different forest sites in south Brazil, with the purpose of explaining their production and assisting with proposition for better efficiency and production of pine cones
The adjustments of the models showed precision and explained the variation of crown efficiency, indicating for all sites that the increase in crown size decreases its efficiency and this is correlated with pine cones production
Summary
Araucaria or Brazilian pine (Araucaria angustifolia (Bertol.) Kuntze) is a dioecious species characteristic of the mixed ombrophilous forest in south Brazil. It is of extreme importance due to the commercial value of its wood and edible seeds with pine cones production (Figures 2C and 2D). Silvicultural treatments and sustainable management for the use of wood are prohibited by law, being only the exploitation of its pine cones allowed. Their amount (pine cones and edible seeds) depends on tree age, crown size, light, density, crown efficiency, growth, availability and dispersal of pollen from tree males. The organ responsible for this process is the crown Variables such as surface of the crown, diameter and crown length are directly related to growth and production (wood and non-wood) of trees
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
