Restauração ecológica de área ciliar degradada da caatinga do rio São Francisco, Pernambuco

Abstract

This research aimed to study ecological processes and natural phenomena of the ecosystem to support the implementation of ecological restoration techniques in a degraded ciliar forest of the São Francisco river in Caatinga, Pernambuco backwoods. This work is organized in five chapters. In chapter one, it was evaluated the composition of the avifauna and the effect of the use of artificial and natural perches by the birds, in the restoration of a section of degraded ciliar forest. Underneath the perches, seed collectors were installed to evaluate seed rain in the area. The bird survey was carried out during 13 months of observation. Sixty - six species of birds were identified, distributed in 34 families, being the Tyrannidae family the one that presented the greatest species richness, with six species. The rainfall of seeds recorded on the collectors under the perches compared to the collectors without perches were different. The use of perches by birds and the rainfall of seeds registered under these emphasizes the importance of this technique in the restoration of ciliar forests of the region. In chapter two, it was evaluated how the biological invasion by Prosopis juliflora (algaroba) affects the richness and density of species in rainfall and soil seed bank in areas of altered ciliar forest and its implications for ecological restoration. Three areas were evaluated, being the areas I and II with and without invasion of algaroba, respectively, in which rainfall and seed bank were evaluated. In area III in the process of restoration, the soil seed bank and the regrowth and regeneration capacity of algaroba were evaluated. To evaluate seed rain a total of 50 collectors were installed and collected monthly from November / 2014 to October / 2015. For the soil seed bank, 25 samples of each layer (litter and soil of 0-5cm) per area were collected at two collection times (dry and wet periods). Seasonal variation for the bank and seed rain occurred during the evaluated period, with the highest contribution of rainfall in the rainy season and seed bank in the dry period. The biological invasion of algaroba affected the composition and diversity of seeds of shrubby-arboreal species in a negative way. In chapters three and five, among the techniques implemented to restore the area, this study aimed to evaluate the use of bioengineering works (living mat and live braid) and the biotechnical potential of cuttings of four species native to the caatinga. Semigloss stakes 30 cm long were collected from adult individuals of the species: Albizia inundata, Bauhinia pentandra, Mahiot carthagenensisand Senna splendida. Stakes of the species S. splendida and B. pentandrashowed desirable biotechnical characteristics for use in bioengineering techniques. The implanted works had direct benefits with the reduction of soil loss. In chapter four, in the technique with planting of seedlings evaluated the growth and survival of 14 shrubby-arboreal species of the caatinga. The average overall survival of the plantation was low with 30%, but in the area of the area closest to the river bank, with more clayey soil the survival was higher with 47% at the end of the monitoring. The need for better understanding and integration of ecological processes to increase the success of ecological restoration actions in the caatinga.