A Survey of Remote Sensing Methods for Mapping Second Growth Forests in Amazônia
Dar
Alexander
Roberts, UCSB Department of Geography, dar@geog.ucsb.edu
(Presenting)
William
Salas, Applied Geosolutions, wsalas@agsemail.com
Second-growth forest, resulting from disturbance, forest conversion or pasture abandonment is widely considered to be one of the most important land-cover types in Amazônia. Second-growth forest plays a key role as a part of forest succession, swidden-agriculture sustainability, and basin wide carbon dynamics. However, second-growth forest is not defined consistently, and considerable variability exists in the methods used to map it, the types of sensors used and the measures typically reported. These differences make it difficult to perform regional comparisons of the extent, duration and properties of second-growth forest in Amazônia. Regional comparisons are likely to be critical in that the role of these forests as a potential sink for carbon and their viability in swidden systems varies depending on management practices, climate and soils.
A survey was developed to provide a better sense of the range of definitions, methods and measures of second-growth forest within the LBA community. This survey was developed as part of two second-growth workshops and designed in consultation with all of the members. Questions include 1) study site locations; 2) definition of and criteria for second-growth; 3) type of remotely sensed data used and whether multi-temporal information was used; 4) methods for mapping second-growth forest; 5) measures reported for second-growth forest, such as height, area or ratio of second-growth to cleared area; 6) presence of prior land-use history; and 7) existence of ancillary data. Responses were solicited from 15 researchers known to use remote sensing to map second growth and additional respondents were encouraged. In this presentation, we will summarize the first results from the survey. We anticipate this survey will lead to a follow-up study providing cross-team, intra-regional comparisons.
Submetido por Dar A. Roberts em 17-MAR-2004
Tema Científico do LBA: LC (Mudanças dos Usos da Terra e da Vegetação)