Caloric content of leaves of five tree species from the riparian vegetation in a forest fragment from South Brazil

Conteúdo calórico de folhas de cinco espécies de árvores da vegetação ripária em um fragmento florestal do Sul do Brasil

Abstract

Aim: The measurement of the caloric content evidences the amount of energy that remains in the leaf and that can be released to the aquatic trophic chain. We assessed the energy content of leaves from five riparian tree species of a forest fragment in south Brazil and analyzed whether leaf caloric content varied between leaf species and between seasons (dry and wet). The studied sites are located in Northwest of Paraná State, inside a Semi-Deciduous Forest fragment beside two headwater streams.

Methods

Sampling sites were located along the riparian vegetation of these two water bodies, and due to its proximity and absence of statistical differences of caloric values, analyzed as one compartment.

Results

Caloric content varied significantly among species and among all pairs of species, with exception of Nectandra cuspidata Ness and Calophyllum brasiliensis Cambess. Two species presented significant differences between seasons, Sloanea guianensis (Aubl.) Ben and Calophyllum brasiliensis Cambess.

Conclusions

The absence of significant seasonal differences of energy content for some species may be due to the characteristics of the tropical forest, in which temperature did not varied dramatically between seasons. However, the energy differed between species and seasons for some species, emphasizing the necessity of a preliminary inspection of energy content, before tracing energy fluxes instead of using a single value to all species from riparian vegetation.

Keywords:
leaf litter; energy; allochthonous organic matter; headwater stream; Atlantic Forest