Abstract

DALMASSO, Antonio Daniel. Revegetation of degraded areas with native species. Bol. Soc. Argent. Bot. [online]. 2010, vol.45, n.1-2, pp.149-171. ISSN 1851-2372.

The area of work is located in the South of Malargüe, Mendoza. The climate is arid, mean annual rainfall is 134 mm, and mean annual temperature 13.3°C. An assessment is made of the results of revegetation with native species in lands degraded by oil production, aimed at achieving higher stability in disturbed ecosystems for them to revert to conditions prior to the impact. A geomorphological and vegetation survey was conducted, and dynamic hypotheses were established regarding vegetation. Through a geosynphytosociological approach, and according to plant dynamics, a total of 10 species were selected, reproduced in greenhouse and established in three oil well areas, in both autumn and spring. The experimental design consisted of random plots with 10 species and 20 repetitions in each oil well area. The soil was plowed and the plants established in all three trial areas. After four years of records, a statistical analysis was performed of the temporal evolution of the variables height, canopy diameter and percentage of survival per species. For these same variables, the average behaviours of the different species were compared using ANOVA and Fisher's LSD test (a= 5%). Plant populations used in the trial were fitted to a normal distribution with nonhomogeneous variances (Kolmogorov-Smirnov and Bartlett). On the fourth year after plant establishment, the degree of plant cover in oil well areas was assessed, as compared to the natural Monte. Analyses showed statistically significant differences among planted species, with Atriplex lampa, Prosopis flexuosa var. depressa and Cercidium praecox ssp. glaucum being outstanding for their great ability to cover the ground in all three trial areas. In one oil well area, plant diversity four years after establishment represented 61% of the diversity in the Monte, whereas in the other two areas the level of diversity reached was higher than or close to that of the natural Monte. It is concluded that selecting native species within the theoretical framework of geosynphytosociology is effective for the recovery of degraded lands, that assisted establishment of native species in these lands reduces the time for recovery of plant cover and structure, and that planting of plant species in the area generates appropriate conditions for the spontaneous establishment of other species from contact communities.

Keywords : Revegetación; Recuperación; Áreas degradadas; Especies nativas; Revegetation; Recovery; Degraded areas; Native species.

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