Espécies vegetais para o manejo biotécnico de taludes e aspectos ambientais associados

Abstract

This study aimed to investigate the suitability of plant species for biotechnical management of slopes in oxisol soils. The studies began in March 2009, in the region of Cruz Alta-RS, South Brazil (28°23 28,14 S e 53°22 25,61 W), and it included a survey of the problems occurring in the embankments, establishing criteria for the selection of plant species, the search and selection of plant species with desirable traits, field testing the four selected species and observation of key environmental aspects. The main problems found were: laminar and furrow erosion and lack of slope stability, caused mainly by the lack of vegetation cover, excessive slope of the ramp, excessive runoff, desiccation, use and maintenance of inadequate techniques. The criteria for species selection involved biotechnical, biological, ecological and socioeconomic aspects, prioritized according to the needs of each case. The species Ipomea cairica, Pyrostegia venusta, Hedera canariensis, Mikania glomerata, Baccharis trimera, Petunia integrifolia, Rhynchosia corylifolia, Acanthospermun australe, Sambucus australis, Ateleia glazioviana, Hibiscus rosa-sinensis and Lagerstroemia indica, for their occurrences, frequencies, forms and growths, showed potential for use in the biotechnical management of slopes. The slopes can vary in fertility, temperature and humidity at levels that can impair the development of natural or cultivated revegetation. The geographic orientation of the slope and the occurrence of trees can significantly influence these factors. Ateleia glazioveana, Baccharis trimera, Pyrostegia venusta e Cynodom plectostachyus, exhibited characteristics that make them suitable for uses in the biotechnical management of slopes in oxisol soils. According to the conditions under which the trials were conducted, it can be concluded that: the results confirmed the hypothesis that there are species in southern Brazil suitable for biotechnical management and restoration of degraded areas and slopes that are not conventionally used. For growing plants on the slope, it is recommended the use of seedlings, soil fertilization and planting in periods less stringent, as important practices to ensure good survival, accelerate vegetative growth and optimize the protective effects during early development. Further studies on the biotechnical management of these species in slopes, especially on the efficiency of different methods of propagation, and the best ways of deployment and use are suggested.