Phytogeographic retrospective in ecotonal areas guided by soil attributes|
Monteiro, T.; Alvares, C. A.; Stott, D. E. & da Silva, A. M.
Re-establishing deforested ecosystems to presettlement
vegetation is difficult, especially in ecotonal
areas, due to lack of knowledge about the original physiognomy.
Our objective was to use a soils database that
included chemical and physical parameters to distinguish
soil samples of forest from those of savannah sites in a
municipality located in the southeastern Brazil region.
Discriminant analysis (DA) was used to determine the
original biome vegetation (forest or savannah) in ecotone
regions that have been converted to pasture and are
degraded. First, soils of pristine forest and savannah sites
were tested, resulting in a reference database to compare to
the degraded soils. Although the data presented, in general
had a high level of similarity among the two biomes, some
differences occurred that were sufficient for DA to distinguish
the sites and classify the soil samples taken from
grassy areas into forest or savannah. The soils from pastured
areas presented quality worse than the soils of the
pristine areas. Through DA analysis we observed that, from
seven soil samples collected from grassy areas, five were
most likely originally forest biome and two were savannah,
ratified by a complementary cluster analysis carried out
with the database of these samples. The model here
proposed is pioneer. However, the users should keep in
mind that using this technology, i.e., establishing a regional-
level database of soil features, using soil samples collected
both from pristine and degraded areas is critical for
success of the project, especially because of the ecological
and regional particularities of each biome.
Ecotone; Pristine forest soil; Soil database; Vegetation re-establishment