Análise de nutrientes do solo, na serrapilheira e influência de variáveis microclimáticas em floresta de terra firme, Caxiuanã-PA

Abstract

The importance of quantifying the production of burlap associated with the parameters that affect its variation is widely recognized for understanding the dynamics of ecosystems, as it is a fundamental process in the cycling of nutrients and is an important way of transferring organic matter and mineral elements from the vegetation to the soil surface in forest ecosystems. Several researchers argue that the total amount of litter produced and its components may be affected when they are under water stress, which consequently can also affect other mechanisms of water, carbon and nutrient cycling, in view of the above, this study aims to evaluate the influence of exclusion of rainwater on the variation of litter production and identify the main meteorological variables that influence the variation of litter production. The study area was the Scientific Station Ferreira Penna, municipality of Melgaço, Pará, within the LBA Program Project. We installed 40 apparatus for collection of burlap, in two plots of 1 hectare each (plots A and B), in the area of the ESECAFLOR experiment. The first plot where an attempt was made to exclude about 80 % of rainwater, the control plot remained under natural environmental conditions. In the period February/2001 to March/2003, monthly samples of burlap were collected for quantification of monthly production, nutrient analysis and moisture determination. Precipitation and temperature data were used to relate with the burlap production data and it was found that there is an inversely proportional relationship with precipitation. There is a significant influence of precipitation on the production of burlap, which increases its production in the less rainy season. The periods of highest and lowest production of burlap were from July to December, respectively. The temperature was a variable that did not influence the production of burlap due to little variation, with a monthly average around 24 to 26°C in the region of Caxiuanã.