%0 Journal Article
%4 sid.inpe.br/mtc-m12@80/2006/08.02.15.10
%2 sid.inpe.br/mtc-m12@80/2006/08.02.15.10.25
%@issn 0167-8809
%T Area and age of secondary forests in Brazilian Amazonia 1978-2002: an empirical estimate
%D 2006
%9 journal article
%A Neeff, Till,
%A Lucas, Richard M.,
%A Santos, Joćo Roberto dos,
%A Brondizio, Eduardo S.,
%A Freitas, Corina Costa,
%@affiliation Biometry Department, University of Freiburg, Freiburg Breisgau, Germany
%@affiliation Institute of Geography and Earth Sciences, University of Wales, Aberystwyth, Ceredigion SY23 3DB, Wales, UK;
%@affiliation Institute of Geography and Earth Sciences, University of Wales, Wales, UK
%@affiliation Anthropological Center for Training and Research on Global Environmental Change (ACT), Indiana University, Student Building 331, Bloomington, IN 47405, USA
%@affiliation Anthropological Center for Training and Research on Global Environmental Change (ACT), Indiana University, Bloomington, USA
%B Agriculture, Ecosystems and Environment
%V 9
%P DOI: 10.1007/s10021-006-0001-9
%K SENSORIAMENTO REMOTO APLICADO Ą ECOSSISTEMAS TERRESTRES, Amazōnia (Regićo), uso da terra, floresta, area-age distribution, forest, age, land-use model, secondary forest, succession.
%X In quantifying the carbon budget of the Amazon region, temporal estimates of the extent and age of regenerating tropical forests are fundamental. However, retrieving such information from remote- sensing data is difficult, largely because of spectral similarities between different successional stages and variations in the reflectance of forests following different pathways of regeneration. In this study, secondary-forest dynamics in Brazilian Amazonia were modeled for the 19782002 period to determine area and age on a grid basis. We modeled the area, age, and age class distribution of secondary forests using empirical relationships with the percentage of remaining primary forest, as determined from large-area remote-sensing campaigns (the Pathfinder and Prodes projects). The statistical models were calibrated using detailed maps of secondary-forest age generated for seven sites in the Brazilian Legal Amazon. The areaage distribution was then specified from mean age by a distribution assumption. Over the period 19782002, secondary-forest area was shown to have increased from 29,000 to 161,000 km2 (that is, by a factor of 5). The mean age increased from 4.4 to 4.8 years. We generated a time series of secondary-forest area fractions and successional stages that provides wall-to-wall coverage of the Brazilian Amazon at a spatial resolution of 0.1 decimal degrees (approximately 11 km). Validation against reference data yielded root mean squared errors of 8% of the total area for estimate of secondary-forest area and 2.4 years for mean secondary-forest age. Using this approach, we provide the first published update on the state of secondary forests in Amazonia since the early 1990s and a time series of secondary-forest area over the 25-year period.
%@language en
%3 corinaartigo.pdf