Establishment of white poplar clonal plantations by stools

The results of white poplar clonal plantation establishment by stools are presented. The trials were established at three sites, characterized by favorable water regime for growth and development of poplars. Also, the effect of different factors on survival rate, diameter at breast height and plants' height was analyzed. Results suggest that similar high survival rate (90-100%) was achieved by planting of stools on depth of 2.5 m (deep planting), as it was achieved by planting of rooted cuttings at the depth of 0.8 m, which is a comon practise in the establishment of white poplar plantations. The survival rate of planted stools did not decrease signifficantly between the end of the first and second growing season. Selected clones achieved survival rate of Villafranca clone with both methods of planting. Two-year old rootless shoots (2/0 type of plantings) achieved higher survival rate than the one-year old ones (1/0 type) and two-year old rooted cuttings (2/2 type). Survival rate of one-year old rootless shoots (1/0 type) planted at the depth of 0.8 m was not significantly lower than of those planted at the depth of 2.5 m, but it was notably lower than survival rate of rooted cuttings (1/1 type). Establishment of white poplar clones by stools could significantly improve white poplar wood production, considering the benefits of plants production in stool beds. The potential for improvement of the establishment of white poplar plantations on sandy soils with relatively deep level of underground water, and the potential for successful planting of difficult-to-root white poplar genotypes, should be the subject of further studies.

First occurrence of Spodoptera cosmioides (Walker, 1858) (Lepidoptera: Noctuidae) on eucalyptus seedlings after field transplantation in Rio Grande do Sul State, Brazil

This study reports the first occurrence of Spodoptera cosmioides (Walker, 1858) (Lepidoptera: Noctuidae) larvae causing defoliation in transplanted seedlings in a clonal plantation of Eucalyptus urophylla S.T. Blake (Myrtaceae), in Butiá municipality, Rio Grande do Sul State (30°9’45” S; 51°59’42” W). The S. cosmioides caterpillars are polyphagous, including eucalyptus among their host plants. It was observed that the caterpillar infestation damaged 80% of the seedlings, while the defoliation varied from 13% to 24% per plant. This is the first record of S. cosmioides caterpillars causing injuries in a new plantation of E. urophylla.

Respuesta de material genético de Paulownia spp a tratamiento silvicultural, como estrategia para evaluar su adaptabilidad a condiciones climáticas de estepa espinosa Montano Bajo, Ecuador/Response of Paulownia spp genetic material to silviculture, as a s

El propósito de la investigación consistió en estudiar la respuesta de Paulownia elongata, P. fortunei y un híbrido (Paulownia fortunei x elongata) a un sistema de recepa y evaluar el desempeño de los brotes juveniles, como estrategia para confirmar su adaptabilidad a las condiciones bioclimáticas de estepa espinosa Montano Bajo. El ensayo se instaló en diciembre del 2 015, en una plantación clonal de dos años de edad, plantada por INIAP y ESPOCH en la granja Tunshi, Ecuador. Se establecieron 9 bloques por especie para un total de 27 parcelas experimentales, con 9 observaciones por parcela neta. El tratamiento silvicultural ejecutado fue poda de renovación/recepa, realizando un corte del tallo en bisel a dos centímetros de altura desde el suelo. Las variables evaluadas fueron: Días a la brotación, número de brotes por tocón, diámetro a la base del brote y altura del brote. Los tres materiales estudiados respondieron positivamente a la práctica silvicultural, 90% de tocones brotados a los 61 días de haber realizado el ensayo. A los 29 días de la recepa ya se encontraron brotes epicórmicos en las tres especies de Paulownia, presentando entre 1 y 13 brotes por tocón. En crecimiento dasométrico, P. fortunei experimentó el mayor promedio en altura (81,85 cm), seguida por P. elongata (70,51 cm) y Paulownia hibrido (65,53 cm), siendo 3,5 veces mayor a los promedios de altura y 4 veces mayor en diámetro a la altura de la base del tallo, de los reportados en el primer año de evaluación. Estos resultados avizoran probables comportamientos adecuados y adaptación como una especie forestal-agroforestal de interés para características similares del sitio de estudio. This study is aimed to evaluate the response Paulownia elongata, P. fortunei and hibrid (Paulownia fortunei x elongata) to renewal pruning system and evaluate to develop the juvenile sprout of plants as a strategy to assess its adaptability to the bioclimatic conditions of thorny steppe Montano Bajo, Ecuador. The essay was install in December, 2 015 in one clonal plantation two years old, establish by INIAP and ESPOCH in Tunshi farm, Ecuador. This was established in nine blocks per species for a total of 27 experimental plots with nine observations per net plot. The selviculture treatment executed was renewal pruning, making a bevel cut stem two feet high from the ground. The variables evaluated were: Days sprouting, number of sprouts per stump diameter at the base of the outbreak and height of the outbreak. The three materials studied responded positively to silvicultural practice and 90% of erupted stumps at 61 days responded to development essay. At 29 days from the development the recepa presented epicormics sprout in the three Paulownia species; P. fortunei experienced the greatest average height (81,85 cm), followed by P. elongata (70,51 cm) and hybrid Paulownia (65,53 cm), being 3,5 times greater than the average height and 4 times greater in diameter at the base than those reported in the first year evaluation, these results foresee probable behaviors adapted and adequate as a forestry-agroforestry species of interest from the site of study. Palabras clave: recepa, poda, silvicultura, dendroenergía. Keywords: recepa, pruning, silviculture, wood energy.

Stacked volume conversion factor for geometric volume of Eucalyptus sp.

Post-harvest, wood volume can be calculated with a stacking factor which can be influenced by diameter classes involved. Consequently, the following question arises: there is a difference between the volume conversion factor for stacked to geometric volume between piles of clonal plantation logs of different diameters classes? The hypothesis is: if smaller logs have a higher stacked to geometric volume conversion factor, between-log voids will be smaller and the overall stacks will therefore have lower volumes. Therefore, the objective of this study was to compare stacking and cubing factors in stacks of logs with different diameters for two Eucalyptus sp. clones. The study was conducted in Barra do Corda municipality, Maranhão State, Brazil. Timber was laid in piles of logs by diameter class, composed of logs of smaller (9-10.99 cm) and larger (11-13 cm) diameters. Stacking factor means for clone 1 were 1.88 for the larger diameter and 2.00 for the smaller diameter class, while for clone 2 mean values were 1.62 and 1.65, for stacks with larger and smaller diameter classes, respectively. For logs from the same clone there was no significant difference for the conversion factors between the stacks with the largest and smallest diameter. However, there was a significant difference in the conversion factors between the two clones, proving the hypothesis tested. Thus, for each genetic lineage, a proper stacking factor must be established so that the estimated volume comes close to the real value.

Hypsometric models for a clonal plantation of Tectona grandis Linn F. subjected to selective thinning

At a moment when the importance of planted forests in the Amazon region is increasing, hypsometric models become highly relevant tools as they allow monitoring of and planning for tree plantations in a way that is practical and economic for the producer. Thus, the objective of the current study was to select and adjust a model of hypsometric relationships for a clonal plantation of Tectona grandis Linn F., submitted to selective thinning, located in Capitão Poço municipality, Pará state, Brazil. Data were collected from permanent plots in five-year-old stands using the fixed area method and systematic process. The best adjusted model was selected with an adjusted determination coefficient (R²aj.%), residual standard deviation of the percentage estimate (Syx%), recalculated residual standard error (Syxr%), diagnosis of distribution of residuals as a percentage and the Percent Average Deviation (PAD%). Hyperbolic models 2 and 3 had the highest determination coefficients (83.42 and 83.40%) and lowest PAD (-0.006 and -0.154%). The polynomial (1) and hyperbolic models (2 and 3) showed the smallest errors in related to the estimates. Model 2 (hyperbolic) was found to generate the best estimate of total T. grandis clonal plantation height. Use of this hypsometric model will allow a significant reduction of costs and time in forest inventory studies.