Journal of Tropical Ecology



Resilience of secondary forest regrowth after slash-and-burn agriculture in central Amazonia


Christoph Gehring a1c1, Manfred Denich a2 and Paul L. G. Vlek a2
a1 Agroecologia, Universidade estadual de Maranhão, São Luis, Brazil
a2 Center for Development Research (ZEF), Univ. Bonn, Germany

Article author query
gehring c   [PubMed][Google Scholar] 
denich m   [PubMed][Google Scholar] 
vlek pl   [PubMed][Google Scholar] 

Abstract

This study describes forest succession following slash-and-burn agriculture in central Amazonia, based on four chronosequences (22 sites) of 2- to 25-y-old secondary regrowth and mature forest. Biomass accumulated in the form of a saturation curve: 25 y of regrowth restored half of the mature-forest biomass, 75% would be restored after an estimated 175 y. Biomass accumulation was accompanied by a rapid decrease in woody plant density and an increase of the positive skew of plant size distribution. Liana biomass share declined from 5.0% in young to 1.9% in old regrowth, and 1.3% in mature forest, whereas the share of palms was low (0.5%) in young regrowth and high in old regrowth (1.8%) and mature forest (2.2%). 25-y-old regrowth was similar with mature forest in respect to woody plant density and growth-form composition, but both the plant size distribution and the number of stems per plant differed strongly from mature forest. A moderate increase in land use had only minor effects on biomass accumulation, but profoundly changed structural characteristics of regrowth, pointing to a high vulnerability to degradation. Thus, the sustainability of slash-and-burn in central Amazonia may be lower than the rapid initial biomass accumulation would make it seem.

(Accepted February 3 2005)


Correspondence:
c1 Corresponding author. Dr. Christoph Gehring, Curso de Mestrado em Agroecologia Laboratório de solos, C.P. 3004; 65054-970 São Luis, MA, Brazil. Emails: cgehring@uema.br; christophgehring@yahoo.com.br