Tree species compositional change and conservation implications in the white-water flooded forests of the Brazilian Amazon

Albernaz, Ana Luisa, Pressey, Robert L., Costa, Luiz R.F., Moreira, Marcelo P., Ramos, Jose Ferreira, Assuncao, Paulo A., and Franciscon, Carlos H. (2012) Tree species compositional change and conservation implications in the white-water flooded forests of the Brazilian Amazon. Journal of Biogeography, 39 (5). pp. 869-883.

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Abstract

Aim: The aim of this study was to use compositional changes in tree species along the Amazon River floodplain in Brazil to identify and characterize biogeographic regions that would serve as broad surrogates for conservation planning.

Location: The main course of the Amazon River in Brazil, covering a river distance of approximately 2800 km.

Methods: Two sampling methods were employed at specific sites: standardized transects and/or individual-based samples. Seventy-three samples were collected from 26 sites at approximately 100-km intervals along the floodplain. Biogeographic regions were identified by non-metric multidimensional scaling (NMDS) ordination and by a hierarchical cluster analysis. The relative influence of environmental components (flood depths, annual rainfall, and length of the dry season) on tree species composition and one spatial component (longitude) were analysed by multiple regressions against a one-dimensional NMDS ordination axis.

Results: Based on tree species composition, three main biogeographic regions were identified: a western region between Tabatinga and the Negro River confluence; a central region from the Negro River confluence to the Xingu confluence; and an estuarine region from the Xingu confluence to Santana. The regions identified were consistent using different data sets and analytical techniques. Mixed environmental and spatial effects explained most of the variation, but the spatial effect alone had a greater influence on species composition than environmental effects alone.

Main conclusions: The regions delimited in the analyses differed from those based on geomorphology or World Wildlife Fund (WWF) ecoregions. These results reinforce the need for surrogates to be tested against biological data before they are used to shape approaches to conservation planning. Although a protected area coverage of 25% gives the impression of extensive conservation management on the floodplain, less than 1% of the Amazon's floodplain in Brazil is strictly protected. The significant compositional differences between regions and the strong spatial variation along the Amazon indicate that strict protection areas should be distributed much more evenly within and between regions.

Item ID: 20730
Item Type: Article (Refereed Research - C1)
Keywords: Amazonian floodplains, community patterns, conservation biogeography, conservation planning, flooded forests, surrogates for conservation, tree species, varzea, WWF ecoregions
ISSN: 1365-2699
Date Deposited: 06 Mar 2012 04:47
FoR Codes: 05 ENVIRONMENTAL SCIENCES > 0502 Environmental Science and Management > 050202 Conservation and Biodiversity @ 100%
SEO Codes: 96 ENVIRONMENT > 9606 Environmental and Natural Resource Evaluation > 960699 Environmental and Natural Resource Evaluation not elsewhere classified @ 100%
Citation Count from Web of Science Web of Science 2
Downloads: Total: 4
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