The influence of bauxite tailings on the growth and development of Oryza glumaepatula was studied in Lake Batata, a clear water lake of the Amazon. Lake Batata is an unusual lake because 30% of its total area was covered by bauxite tailings as the result of aluminum mining, influencing many communities and ecological processes. Changes in length, growth rates, total biomass production, density, culm diameter, net primary production and percentage of different plant organs of Oryza glumaepatula were studied for two consecutive flood pulses in natural and impacted areas of Lake Batata. The aim of this research was to test the hypothesis that the growth and development of this aquatic macrophyte is negatively affected in the areas impacted by bauxite tailings. This hypothesis was rejected because most studied parameters were higher in the impacted area, indicating that the growth and development of O. glumaepatula was not negatively affected by the presence of the bauxite tailings. The better development of O. glumaepatula in the impacted area was attributed to the less available space for germination than in the natural area. The lower density of individuals at the impacted area prevented future density dependent mortality that was observed in the natural areas and did not seem to occur in the impacted area.
Bibliographical noteFunding Information:
We thank Anke Prast Enrich for drawing Fig. 3 and MRN (Mineracão Rio do Norte S.A.) for financial support and two anonymous reviewers for excellent suggestions and critics. The authors thank CAPES and CNPq for scholar and fellowships.
Copyright 2008 Elsevier B.V., All rights reserved.
- Anthropogenic impact
- Flood pulse
- Oryza glumaepatula
- Plant density mortality
- Primary production