Silvana Lucia Caldato

Estrutura populacional de Ocotea porosa (Lauraceae) em uma Floresta Ombrófila Mista, em Caçador (SC).

The present work aimed to study the population structure of Ocotea porosa (Nees) L. Barroso in the Mixed Ombrophylous Forest, located at Cacador Forest Reserve in Santa Catarina State. The method of the conglomerate sample units, composite at 4 subunits (20 x 500 m) distributed in four cardinal directions was adopted. A total of 8 subunits were installed, composing two conglomerates and adding 8 hectares of sample area. The central line in the length of the subunits was demarcated to each 20 meters with a permanent stake, this way, each subunits was divided into 50 plots of 10 x 20 m, completing a total of 400 plots of 200 m 2 . In each plot all the individuals of O. porosa of size equal or higher than 10 cm of height were notified, being measured the stem diameter and/or height. The results have shown a prevalence of juveniles phases and intermediary diameters in the structure of the population.

Estructura poblacional de Ocotea puberula en un bosque secundario y primario de la selva mixta misionera.

The aim of this work was to study the population structure of Ocotea puberula (Nees et Mart.) Nees (Lauraceae), in a secondary and a primary forests Northeast of Misiones in Argentina, at 26o 15¢ S and 54o 15¢ W. Two permanent sampling plots of 3 hectares each were installed in the secondary and primary forest, respectively. Each sampling plot was divided into 75 subplots of 20 x 20 m. In each subplot all individuals of Ocotea puberula equal or greater than 20 cm of height were measured. The structure of size and spatial distribution was surveyed. Ocotea puberula was a secondary species, with a high number of individuals of natural regeneration in the secondary forest, and only adult trees in the primary forest. The species presented a clustered pattern of spatial distribution in both forests.

O USO DE ÁGUA PELAS PLANTAÇÕES FLORESTAIS - UMA REVISÃO

This review aims to present some of the main results and infer about the current state-of-the-art of the controversy related to the water use by forest plantations. Several studies have been carried out in this area in different regions, mainly in Australia, South Africa, Europe, India and Brazil. However, according to authors, the controversy persists and it is necessary that the scientific results are understood by the community in order to avoid the predominance of myths and half-truths. In this way, the current review intends to summarize some scientific results concerning the main hydrologic aspects of the plantations (interception, transpiration and catchment water balance), the relationship between the high productivity and the water use efficiency, and the importance of the establishment of forest management plan focused on the river watershed scale, in order to contribute to hydrological sustainability. The results coincide that the relationship between the forest plantations and the water depends on the region, species, environmental conditions and management practices on the watershed scale.

Efecto del control de malezas en el crecimiento de plantaciones de Pinus taeda, Pinus elliottii var. elliottii y Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis

Se estudio el efecto del control de malezas en el crecimiento de una plantacion de Pinus taeda L., Pinus elliottii Engelm. var. elliottii & L. & D. y Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis B. & G., de 4 anos de edad, localizada al NE de la provincia de Corrientes, Argentina. Fueron evaluados 21 tratamientos (3 especies x 2 intensidades de area con maleza controlada x 3 periodos de control de malezas + un testigo sin control de malezas por especie). Se utilizo un diseno estadistico de bloques completos al azar con 3 repeticiones y parcelas de 36 plantas. La sobrevivencia no fue afectada por el control de malezas. El control de malezas en la banda o en la totalidad del area no presento diferencias de crecimiento para las especies Pinus taeda y Pinus elliottii var. elliottii, generando una diferencia volumetrica con el testigo del 85,6% y 85,2% respectivamente. Para Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis la respuesta fue mayor al aumentar la superficie controlada, generando diferencias del 114,4% (total) y del 69,7% (banda). No existieron diferencias de crecimiento al ser realizado el control de malezas por 1, 2 o 3 periodos; la diferencia volumetrica media general con el testigo fue del 88,6%. La especie Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis presento los mayores crecimientos.

Producción y descomposición de hojarasca en la selva ombrófila mixta en el sur de Brasil

El objetivo del presente trabajo fue evaluar la produccion y descomposicion de hojarasca de la selva ombrofila mixta en el sur de Brasil. La vegetacion del area presento dos tipos forestales: I, cuyo dosel superior estaba dominado por Araucaria angustifolia y II, con mayor diversidad de especies arboreas predominando latifoliadas en el estrato superior. Para evaluar la produccion de hojarasca fueron instalados 20 colectores de 0,25 m2 de superficie. Para la cuantificacion del mantillo, mensualmente se retiraron 10 muestras de 0,25 m2. La descomposicion de la hojarasca fue determinada a partir de la tasa instantanea de descomposicion (K). De los resultados observados en tres anos de estudio se concluye que la produccion de hojarasca no difirio significativamente en los dos tipos forestales estudiados, con 7.661 kg ha-1ano-1 en el tipo forestal I y 8.624 kg ha-1ano-1 en el tipo forestal II. Los meses de mayor cantidad de hojarasca en el tipo forestal II estuvieron correlacionados con periodos de mayores precipitaciones (primavera y verano). Para el mantillo hubo diferencias significativas entre los dos tipos forestales, presentando mayor cantidad el tipo forestal I con valores de 9.924 kg ha-1 y de 7.906 kg ha-1 el tipo forestal II. El bosque con predominio de Araucaria angustifolia presento una tasa de descomposicion y una liberacion de nutrientes mas lentas.

Sobrevivência e crescimento inicial de mudas de Pinus taeda L. com diferentes diâmetros do colo

The aim of this research was to evaluate the survival and growth of Pinus taeda seedlings produced in containers and bare root with different collar diameters. Two trials were established in a poor drained area located in the Corrientes province, Argentina. The experimental design was randomized complete blocks, with 3 replications and experimental units with 64 seedlings with double lines buffer. The treatments evaluated on the trial 1 were seedlings produced in containers with collar diameter of 1,6 mm; 2 mm; 3mm and 4 mm and on the trial 2 were bare root seedlings with collar diameters of 3 mm; 4 mm; 5 mm and 6 mm. At 4-year-old the seedlings produced in containers did not showed significant differences in survival and growth however in the bare root seedlings production, the seedlings with 4 and 5 mm showed the best survival. No significant differences in growth were detected for all the treatments. For both types of seedling production the collar diameter did not showed significant influence in field growth.