BIODIVERSITY OF THE MEDIA AND LOW BASIN OF THE CUNAS RIVER

Abstract

The investigation was carried out in the basin of the Cunas river, from April 2010 to March  2011, with the objective of evaluating the current state of the biodiversity of the vegetable communities and of the aquatic ecosystem, by means of structure indicators and diversity. The sampling of the terrestrial flora was carried out by means of the methods of the lines of Canfield and that of area. The evaluation of the vegetable diversity, was carried out based on the structure and diversity of the vegetable communities. The structure, was determined by means of the Index of Value of Importance and the diversity, by means of the indexes of wealth of species, of Simpson and of Shannon Wiener. The results indicate that the species that present the but high index of value of importance is Agave americana, Eucaliptus globulus and Baccharis sp, with values of 99,63%, 58,06% and 49,7%, respectively, while the species that present the but index first floor of value of importance, they are Cassia sp, Opuntia ficus indicates and Alnus jurullensis with values of 8,16%, 7,69% and ,73%, respectively. The index of wealth of species (S = 10), it indicates that in the study area 10 vegetable species exist. The index of Simpson (λ = 0,25148), does it indicate a probability of 0,25148 that if we take two individuals at random of a sample, be of the same species. The index of Shannon Wiener (H ´ = 0,3085), it indicates that the grade average of uncertainty in predicting to that species a chosen individual will belong at random of a collection it is of 0,3085. The communities biological present in the aquatic ecosystem, they were conformed by plankton, benthos, nekton and aquatic vegetation. Being concluded that the diversity of the terrestrial flora and of the flora and aquatic fauna in the half basin and it gets off the river Cradles, it presents certain alteration grade, due to the different activities human developed in the influence area.