Variation of biometric parameters and C, N, and P concentrations of Oryza glumaepatula at different depths of an amazonian lake impacted by bauxite tailings (Lake Batata, Pará, Brazil)
Braz. j. biol
;
62(1): 85-92, Feb. 2002. ilus, tab, graf
Artículo
en Inglés
| LILACS
| ID: lil-321290
RESUMO
Lake Batata is a typical Amazonian clear water lake which has undergone anthropogenic impacts. Thirty percent of its total area has been covered with bauxite tailings. Thus, it is possible to distinguish two areas in this ecosystem the impacted and the natural. The goal of this research was to study C, N, and P content variation and the values of biomass, length, density, and culm diameter of Oryza glumaepatula at different depths in the natural and impacted areas of Lake Batata. The results obtained in this research suggest that the availability of P and N, in both water and sediment, is lower at the shallow site when compared to the deeper sites. On the other hand, C concentrations decreased as P and N concentrations increased. This may be explained by the structural function of C in aquatic macrophytes. At shallower sites, due to the reduced water column, individuals invest in supporting structures that display high C concentrations. The higher density and biomass of O. glumaepatula at the intermediate site indicate that this area presents the best conditions for germination and establishment of individuals of this species. The chemical composition and biometric parameters of O. glumaepatula have shown that this population has higher spatial variation in the natural area. In the impacted area, the absence of significant variations in N and P concentrations in O. glumaepatula among the three sampled sites promotes higher homogeneity in the stands. The high CP and NP ratios indicate that, in the impacted area, P is more limiting to the development of O. glumaepatula than it is in the natural area. The reduced values of biomass and density of O. glumaepatula in the impacted area suggest that the bauxite tailings limit the development of this population
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Oryza
/
Contaminantes Químicos del Agua
/
Ecosistema
/
Óxido de Aluminio
País/Región como asunto:
America del Sur
/
Brasil
Idioma:
Inglés
Revista:
Braz. j. biol
Asunto de la revista:
Biologia
Año:
2002
Tipo del documento:
Artículo
País de afiliación:
Brasil
Institución/País de afiliación:
Universidade Federal do Rio de Janeiro/BR
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