Dendrometry and litterfall of neotropical pioneer and early secondary tree species

Abstract

The increased forest cover loss in the tropical and subtropical regions has stimulated the development of restoration methods through tree plantations. Based on the successional model of forest development the use of different successional groups can be seen as a strategy to accelerate the re-composition of forests and an attempt to recover ecological conditions prior to disturbance. Tree species have particular growth rates and ecological needs, and this knowledge is important in the development of high diversity models of forest restoration. The objective of this study was to compare the initial growth and litterfall of native pioneer versus early secondary tree species in a mixed plantation system, and to determine the relationships between guilds and measurements. The comparison among species and guilds was made based on dendrometric and allometric parameters, and in terms of annual litterfall. The study was carried out in the Guarita Indian Area, Tenente Portela, Rio Grande do Sul, Brazil. Dendrometry of seven species was evaluated, including the pioneer tree species Mimosa scabrella Bentham, Trema micrantha (L.) Blume, Schinus molle L., Enterolobium contortisiliquum (Vell.) Morong, and the early secondary tree species Peltophorum dubium (Spreng.) Taub., Cedrela fissilis Vell. and Tabebuia alba (Cham.) Sandwith. The litterfall was quantified for the first six species. The pioneer tree species exhibited higher average height, stem diameter and crown width than the early secondary tree species. The pioneer species (except E. contortisiliquum) showed also higher values of average annual litterfall. A positive interspecific correlation between stem diameter and annual litterfall was observed. The data indicate that the choice of the species and guilds is significant to the quality of the restoration. Nevertheless, the aboveground architecture may depend on species-specific allometric characteristics and a distinction among guilds was not observed.