Afinidades geoquímicas entre sedimentos (solos) e vegetação (gramíneas e cultivares), além de cabelo de ribeirinhos, ao longo das praias de rios da bacia do Juruá, no Estado do Acre e sua importância ambiental

Abstract

The State of the Acre is located in the southwestern extremity of the Brazilian Amazonia, in an area of 153.149 km², with a low population density (3,66 inhabitants/km²). The studied area comprehends the basin of the Juruá River between the cities of Feijó and Cruzeiro do Sul, including Tarauacá and Rodrigues Alves. In the basin, the main rivers are: Juruá, Tarauacá, Envira, Muru and Moa. The same carry in great amounts of sediments by traction and suspension from siltic-argillaceous rocks of the Solimões Formation and deposit it in beaches formed along the rivers. In drought periods the beaches (point bars) are displayed in its meanders and benefit the riparians that use them for leisure and short cycle agriculture. The beaches sometimes are used to cultivate maize (Zea-Mays) and beans (Vigna unguiculata (l) Walp). These beaches also present a vegetational succession of canarana grass (Costus spicatus) and orvalho grass (Brachiaria decumbes). Resumo de Tese Afinidades geoquímicas entre sedimentos (solos) e vegetação (gramíneas e cultivares), além de cabelo de ribeirinhos, ao longo das praias de rios da bacia do Juruá, no Estado do Acre e sua importância ambiental (Geochemical affinities in sediments (soils), vegetation (gramíneas and crop) and in hair samples of riparians, along the beaches of Juruá basin in the State of Acre and its environmental importance)