Nitrogen and phosphorus concentration of different structures of the aquatic macrophytesEichhornia azureaKunth andScirpus cubensisPoepp & Kunth in relation to water level variation in Lagoa Infernão (São Paulo, Brazil)
✍ Scribed by Flávia Nogueira; Francisco Assis Esteves; Alex Enrich Prast
- Publisher
- Springer
- Year
- 1996
- Tongue
- English
- Weight
- 471 KB
- Volume
- 328
- Category
- Article
- ISSN
- 1573-5141
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✦ Synopsis
We evaluated the nitrogen and phosphorus concentration of floating meadows of Eichhornia azurea and Scirpus cubensis in Lagoa do Inferno (State of Sao Paulo, Brazil) . The chemical composition of these plants and of the water (littoral and limnetic zones) was determined during the period March 1987 to march 1988 . During high water, the water becomes enriched by soluble nutrients and particulates washed from the flooded areas adjacent to the lake, especially from areas situated between the river and Lagoa do Inferno . The soluble allochthonous material is rapidly assimilated and stocked in the plant tissues, which results in an increase in its concentration . Besides this, it was established that the aquatic macrophytes studied utilize the nutrients dissolved in the water of the floating meadow itself, these nutrients being derived principally from their own decomposition .
Since these are floating stands, the sediment does not function as a direct source of nutrients, and since concentrations in the water are low, the nutrients excreted by the aquatic macrophytes during growth and liberated during decomposition do not remain available in the water, but are rapidly absorbed by the young plants . This closed nutrient system makes possible the maintenance of the high biomass of the stands during the entire hydrological cycle .