The litter is the most superficial layer in forest soils formed by leaves, twigs, flowers, fruits,
animal waste, among others. This material is configured on a site of intense interaction
between the cycling of elements and the transfer of energy, because it is the primary means of
displacement of the nutrients to the soil. One of the climatic variables that can influence on
your contribution and nutrient availability are temperature and precipitation. It should be
noted, too, that the type of vegetation and environmental conditions become determining
factors for its quantity and quality, because depending of the characteristics of each
ecosystem, a particular factor can prevail over the other. Therefore, this research aimed to
estimate the production of litter and establish the concentration of macronutrients in it
contained, calculating the efficiency of utilization of nutrients in the Tapajós national forest,
located in the city of Belterra, para. Litter sampling was given in four transects (1000 m x 50
m), where they were systematically distributed in each transect, 10 plastic circular collectors
with 0.22 m2 area each and background consisting of nylon fabric with 4 mm2 mesh, totaling
40 collectors. The collections were accomplished biweekly, from January 2002 to December
2004, where the material deposited in the baskets was collected and taken to a laboratory for
drying in an oven at 65 °C and subsequently segregated into four fractions: sheets, wood,
reproductive and miscellaneous. The amount of litter deposited in the collector was quantified
to kg ha-1 month-1 and kg ha-1 year-1, and also determined the concentrations and the contents
of macronutrients (N, P, K, Ca, Mg) contained in leaf litter and nutrient use efficiency. It was
used ANOVA (analysis of variance) of type factorial of repeated measurements for the
comparison of each fraction of production in seasons (dry and rainy) and years (2002 to
2004), considering the monthly figures. For determining the possible differences between the
productions over the years and in rainy and dry periods, it was considered that can generate
influence the three years and the two seasons (periods). The litter deposition was seasonal,
with higher production in the dry season and lower air temperatures, producing per year
average of 7154.98 kg ha-1 of litter. The larger fraction was the deposition of leaves, being
greater than 70%, being this and the miscellaneous fraction the ones that demonstrated the
greatest contributions of nutrients. Nitrogen and calcium were the macronutrients found in
higher concentrations and contents in all fractions studied. In general the litter production and
nutrient concentration showed the following order: leaves > Wood > Miscellaneous >
reproductive and N > Ca > Mg > K > P, respectively.
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