Pino, Delicia , Kessler, Michael , Hölscher, Dirk , Janovec, John .
Habitat Preferences of Brazil Nut (Bertholletia
excelsa, Lecythidaceae) in the Rio los
Amigos uplands, Southwestern Amazonia, Peru.
In natural forests of Amazonia, the Brazil Nut ( B. excelsa) suffers excessive exploitation and habitat degradation. It is thus considered a vulnerable species and its populations experience rapidly declining recruitments. An understanding of the edaphic requirements of this species can assist in the identification of appropriate habitats for its conservation. Our study was carried out at 2 sites (200 Â¯ 300 m asl) in the Los Amigos watershed, Madre de Dios, Peru. We evaluated the habitat preference of 96 Brazil nut trees on 51 transects of 500 Ã— 20m, with a special focus on soils. A mixed sample for the upper mineral soil (0 Â¯ 10 cm) was obtained from 2 samples per transect unit and analyzed chemically. Clumping of individuals was statistically analyzed using the chi 2 test. Plantâ€‘soil relationships were analyzed with simple and partial Mantel tests, based on dissimilarity matrices.
Multiple regression analyses on the same basis further characterized the plan-soil relationships. B. excelsa occurred in a clumped pattern at one of
the two study sites. The occurrence of B. excelsa correlated with pHH2O, total phosphorous
and aluminum (Al) at one site, and with carbon and Al at the other study site. Multiple regressions confirmed the positive correlation of B. excelsa with
pHH2O and the negative one with Al. Thus,
B. excelsa showed a preference for less acidic soils and was less tolerant to high soil Al content. Considering further analyses on seven other Lecythidaceae
tree species, our results recommend specific strategies for the effective conservation of a certain species in its preferred habitat.
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1 - University of Goettingen, Tropical Silviculture, Buesgenweg 1, Goettingen, Niedersachsen, 37077, Germany
2 - University of Goettingen, Systematic Botany, Untere Karspuele 2, Goettingen, Niedersachsen, 37073, Germany
3 - Botanical Research Institute of Texas, 509 Pecam Street, Fort Worth, Texas, 76102, USA
Presentation Type: Poster:Posters for Sections
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM