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.
Silvicultural interventions are necessary to control the competition and to maintain the forest structure. Thus, this work aimed to know the interactions between dendro/morphometric variables to indicate density interventions in Brazilian pine Forest. Dendrometric and morphometric variables were measured from 186 individual trees of this species, which were distributed in diametric classes at three sites. With the variables were fitted models for the relationships between the degree of slenderness and the potential crown diameter as a function of the number of trees per hectare. The fit indicated that the variables showed interaction and the relationship can be described by linear function explaining between 51.9 and 99.3% of the variance between morphometry and forest density. This adjustment and information can be used to indicate the optimum density according to the amplitude of each index. The results show that the morphometric indexes and their interaction indicate the period of the interventions, having relation with the characteristics of the site, the diametric structure and the dynamics of the forest growth.
Background: Vegetative propagation from superior individuals allows multiple copies of plants that are genetically identical to the parent plant to be obtained. However, vegetative propagation success varies among individual genotypes, with some clones having more difficulty forming roots than others. The aim of this study was to evaluate the genetic gain in Sequoia sempervirens (D.Don) Endl. clones using parameters describing vegetative propagation success and initial growth in field. Methods: Vegetative propagation success was quantified for 16 clones in a completely randomised design consisting of 10 replications, each containing 10 mini-cuttings. At 90 days, rooting (RT), survival (SV) and the number of new shoots (NS) were evaluated. Performance after planting in the field was assessed using 13 clones from the previous experiment, arranged in linear parcels of 10 plants with 8 replicates. After 18 months, survival (SV), stem diameter (SD), height (H) and dominance breakdown (DB) were assessed. Estimates of variance components, heritability and genetic correlations were obtained using the Selegen-REML/BLUP software. Results: The mini cuttings of the 16 clones had a coefficient of genetic variation (CVgi%) of 32.32% for RT, 5.44% for SV and 5.35% for NS. The heritability of the total genetic effects (H2 g) for RT was 0.68. The clones with the best predicted genotypic classifications for the characteristics evaluated in the field were A116, A140 and A138 for SV, A126, A140 and A138 for SD, A138, A140 and A117 for H and A138, A228 and A116 for DB. Conclusions: In general, it was possible to obtain high genetic gain for rooting and medium gain for dendrometric variables in the field.
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