Supplying and decomposition of burlap in a fragment of Cerrado sensu stricto

Abstract

Considering the importance of nutrient cycling as an indicator in the maintenance of the ecosystem productivity, the present study aimed to assess the seasonal dynamics of production and decomposition rate of litter in a fragment of Cerrado sensu stricto. The litter collections were carried out monthly from june 2016 to may 2017, after which the leaves, branches and reproductive material were separated. The litter decomposition was evaluated using the litter bags method, with a random distribution of 288 litter bags. The annual production of litterfall was quantified in 6.042,50 kg.ha-1.yr-1, in which the leaf prevalent fraction presented a production of 4.644,40 kg.ha-1.yr-1, then, the fractions branches (1.084,10 kg.ha-1.yr-1) and reproductive material (329,90 kg.ha-1.yr-1). The litterfall obtained higher production in july with 1.464,00 kg.ha-1 and lower production in the month of December (138,70 kg.ha-1). A significant negative correlation was observed between litterfall and its fractions with the precipitation and relative humidity. The decomposition of foliar mass reached 49% and 50% of twigs during the nine-month period, in which the decomposition constant (k) for leaf mass and for branches was 0.0030g g-1day-1. For this constant, the estimate for the disappearance of total mass has been estimated to be 1.000 days (29 months). The breakdown proved to be slow for both leaves and branches thus obtaining the value of the constant of decomposition 0.0030g g-1 day-1for both.