The effects on Amazon floodplains of the dynamics between the water and land

Waters and lands in the Amazon, especially near the Solimões/Amazonas Rivers, are very dynamic, recreating the landscapes along the rivers’ paths. The waters transport and deposit eroded materials, causing changes in the lifestyles of the meadow’s residents. In addition to this, there are the recent climatic changes caused by the El Niño phenomenon, intensifying the meadows’ transformations. This research explored the quantitative and qualitative values of knowledge of local people in order to understand the environment in which they live. With an understanding of the islands’ environmental system and the perceptions of seventeen female farmers of the amazon meadow, coupled with appropriate theory and methods, it was possible to explore and execute this research. Valha-me-Deus and Chaves, both in the county of Jurupis, PA, were the islands chosen for the study. The goal of the study was to characterize the dynamics of the waters and lands of the Amazon River together with the re-creation of the river islands and the effects of climate change over the floodplains. The data show meaningful changes in the studied environmental systems, resulting in irreversible losses in the cultivation of food crops such as papaya, cocoa, manioc and bananas, especially after the intense river flooding of 2009.

O MANEJO SUSTENTÁVEL DAS ÁREAS ALAGÁVEIS DA AMAZÔNIA CENTRAL E AS COMUNIDADES DE HERBÁCEAS AQUÁTICAS

Herbaceous species in the Amazon floodplains particularly C4 plants may exhibit NPP values about three times those of the floodplain forest. Although restricted to relatively small areas, they show high diversity and are very important in the carbon and nutrient budgets of the region, enriching the aquatic system and associated floodplains through their decomposition, both during the aquatic and terrestrial phases of the hydrologic cycle. Sustainable management systems for Amazon floodplains should consider the importance of herbaceous vegetation in the nutrient budget of the region. Because of favorable nutrient conditions várzea forests are frequently replaced by farms and pasture lands for cattle and buffalo ranching. The substitution of the forest by herbaceous plant communities has little effect on total primary production because these communities are often more productive than the forest itself, but it affects strongly biomass. On the other hand, massive removal of herbaceous plants for the introduction of less adapted crops w ill reduce species diversity and the fertility of the várzea, and w ill require additional fertilization. Susceptibility of these degraded systems to fire increases during the terrestrial phase, resulting in losses of crops and pastures, and leading to further degradation of the natural plant communities and associated animals of the floodplains, w ith fare reaching negative consequences for human life.