Peter Trüby

APORTE DE SERAPILHEIRA E NUTRIENTES EM UMA FLORESTA ESTACIONAL DECIDUAL NA REGIÃO CENTRAL DO RIO GRANDE DO SUL

The objective of this study was to quantify the deposition and nutrients input by litter in the fragment of Seasonal Deciduous Forest, in Itaara, Rio Grande do Sul state, Brazil. Thirty circular metal collectors were allocated in six plots. The deposited material in this structure was separated in leaves, identified by species, fine branches (diameter autumn>winter>summer. The nutrients input follow the order: N>Ca>K>Mg>S>P (macronutrients) and Fe>Mn>B>Zn>Cu (micronutrients). The higher nutrient depositions by litter was Parapiptadenia rigida , following of Ocotea pulchella and Matayba elaeagnoides.

MICRONUTRIENTES NA BIOMASSA ACIMA DO SOLO EM UMA FLORESTA ESTACIONAL SUBTROPICAL

In the above ground biomass of a native forest or plantation are stored large quantities of nutrients, with few studies in the literature, especially concerning micronutrients. The present work aimed to quantify the micronutrients in above ground biomass in a Seasonal Subtropical forest in Itaara-RS, Brazil. For the above ground biomass evaluation, 20 trees of five different diameter classes were felled. The above ground biomass was separated in the following compartments: stem wood, stem bark, branches and leaves. The contents of B, Cu, Fe, Mn and Zn in the biomass samples were determined. The stock of micronutrients in the biomass for each component was obtained based on the estimated dry biomass, multiplied by the nutrient content. The total production of above ground biomass was estimated at 210.0 Mg.ha-1. The branches, stem wood, stem bark and leaves corresponded to 48.8, 43.3, 5.4 and 2.4% of the above ground biomass. The lower levels of B, Cu, Fe and Mn are in stem wood, except for Zn; in the branches and trunk wood are the largest stocks of B, Cu, Fe and Mn. In the branches, leaves and trunk bark are stored most micronutrients, pointing to the importance of these to remain on the soil.

Biomassa e macronutrientes de uma floresta estacional decidual em Itaara-RS, Brasil

The present study was conducted in a fragment of a seasonal deciduous forest in Itaara-RS, Brazil. The objective of this work was to quantify the nutrient in above ground biomass of forestry species. For the above ground biomass evaluation, 20 trees were cut down according to five different diameter classes (3,2-13,5 cm; 13,6-23,9 cm; 24,0-33,6 cm; 33,7-44,6 cm; 44,7-55,0 cm). The above ground biomass was separated in the compartment trunk wood, trunk bark, branches and leaves. The contents of N, P, K, Ca, Mg and S in the biomass samples were determined. The stock of nutrients in the biomass for each component was obtained based on the estimated dry biomass, multiplied by the nutrient content. The total production of above ground biomass was estimated at 210.0 Mg ha-1. The branches, trunk wood, trunk bark and leaves corresponded to 48.8, 43.3, 5.4 and 2.4% of the above ground biomass. The largest contents of N, P, K, Mg and S were verified in leaves; while greatest Ca content was found in trunk bark. The trunk wood was the component that showed the lowest concentration of nutrients in its biomass. In general, Ca, N and K are the nutrients with the largest stock in the above ground biomass. The largest stocks of nutrients are present in branches, which is mainly due to the great biomass, followed by trunk wood.