Efeito da manipulação da camada de serapilheira sobre as concentrações de carbono e nitrogênio em vegetação secundária, Amazônia Oriental.

Abstract

The evaluation of the removal of the litter layer on the carbon and nitrogen litter concentrations was conducted in freshwater fish farming station (EPAD), in the municipality of Castanhal (1º19 'S, 47º57' W) during the period January December 2008 in secondary vegetation 21 years as part of the Water Handling Project and secondary Nutrients in Forest Ecosystem in Eastern Amazonia (Manflora). The design was a randomized block with factorial treatment 2x12 considering two treatments, control and fortnightly removal of litter, and twelve months of 2008 monitoring, totaling 24 treatments. Each sample unit was made up of 20 x 20 m plots with the sampling area of 10m x 10 located in the central part and containing three collectors 1m² each litter. The data were submitted to normality test later analysis of variance and comparison of means by Tukey test (t <0.05). The average annual contribution was 6.65 Mg ha-1 yr-1 in the treatment of litter control and 6.24 Mg ha-1 yr-1 in the fortnightly removal of litter, with no statistical difference between treatments (p = 0.079030 ). However, the contribution made to seasonal (p = 0.000000), with production peaks in July with a monthly average of 1.03 and 0.91 Mg ha-1 yr-1 in the treatment control and removal, respectively, corresponding to the end of the rainy season and early rainy season less. The average annual return of carbon and nitrogen nutrients was 3.01 and 0.12 Mg ha-1 yr-1 in the treatment and control in removing the values were 2.74 and 0.10 Mg ha-1 yr-1 with contribution peaks also in July. The study showed statistical significance on the management for both treatments (p = 0.012011 and 0.004111) and sampling months (p = 0.000000 and 0.000000).