Recuperação de áreas degradadas por meio da recomposição da cobertura vegetal e oasificação por nanobacias na Microrregião do Seridó Paraibano.

Abstract

The research aimed to construct an applicable methodology to Paraiban Homogeneous Microregion Seridó for recovery of degraded area through the restoration of vegetation cover and that takes into account the structure and composition of the woody component of the area, identifying the correct time for planting and tillage able to retain and to infiltrate 100% of rainwater through a technique oasification by nano hydrographic basins. The work was performed in a degraded area of Barra farm, nestled in the city of Santa Luzia,PB homogeneous micro region of paraiban serido, with an altitude of 299.0 m, 06º 52 '27'' south latitude and 36º 56' 00'' west of Greenwich. In an area of 1.88 ha, divided into two rooms: peripheral and central. In the study area was made a forest census in October 2008 with the aim of mapping the composition, structure and phytosociological diameter distribution of plant species found there. In floristic composition were found 20 species included in 17 genres and 12 families among the 2507 individuals, being 1021 in the peripheral environment and 1486 in the in central environment. To identify the deadlines planting native seedlings, a study was done based on the average of the historic series of rainfall data for the city of Santa Luzia, PB (1912 to 2011) and found that the rainy season begins in 5th week and ends on the 19th, about the May 15th. By the average of the series studied the wet season is only 10 days, corresponding to the period of March 25th and April 4th. The soil of the study area was classified as Orthic Luvisol chromic lytic. The environment for the research implantation was divided into two parcels with approximately 0.2 ha each, making up the planting of seedlings of native forest species. In one of the parcels was made the pit with 2.0 m distance following lines in level to the no tillage, and the other was done to prepare the soil with the construction manual hydrographic nanobacias, also in level and distance of 2, 0m. The forest seedlings transplanted were the species Anadenanthera macrocarpa (Benth.) Brenan, Myracrodruon urundeuva Allemão, Tabebuia caraiba (Mart.) Bur. Cnidoscolus phyllacanthus (M. Arg.) Pax & Hoffm, Caesalpinia ferrea Mart. ex Tul., Combretum leprosum Mart., Bauhinia cheilantha Stand., Erythrina mulungu Mart. Ex Benth and Tabebuia impetiginosa (Mart. ex DC.) Standl. The soil fertility in the degraded area studied increased in all chemical attributes analyzed, compared with values of soil fertility before the experiment. Compared with the nearby soil seedlings planted in soil without tillage, subject to erosion by rainwater, there was a retention of organic and mineral particles entrained into the interior of nanobacias and a consequent qualitative improvement in soil chemical properties nearby plant. The study of the floristic composition, the existence of an automatic weather station nearby and the proper preparation of the soil with hydrographic nanobacias were decisive in the results of this research.