Ecology and restoration of ecounits in a forest fragment in Piracicaba region, SP

Author(s)

Andre Augusto Jacinto Tabanez

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 1995-12-13
• Advisor: Virgilio Mauricio Viana

Abstract

The structure of ecounits was evaluated in terms of quantitative features of the forest in a fragment of semi-deciduous forest. Restoration practices were also studied. The study was conducted in a 86 ha forest fragment in Piracicaba, state of São Paulo, Brazil. There are no records that this fragment suffered any large anthropic disturbance like extensive woodfires or clearcut. The ecounits study was done using three 10m wide transects which cut across the fragment from side to the other. All trees 5cm DBH or more had their DBH measured and were identified. The total area of study was 1,39ha. Four ecounits were identified within the fragment, based on the vegetation fisiognomy: "low 'capoeira''' , ''bamboo forest", ''high 'capoeira"' and ''mature forest". The ecounits differed in tree basal area and density, liana leaf cover, Shannon-Weaver diversity index, and also in importance of liana-dominated trees, light demanding pioneer, gap oportunists, shade tolerants and shade reproducing species. The ''low 'capoeira"' proved to be the lowest developed ecounit, followed very closely by the ''bamboo forest". High capoeira is intermediate between bamboo forest and mature forest, the most developed ecounit. The liana seems to play a fundamental role on the dynamic of these ecounits, specially in low and ''high 'capoeira'". Based on the ecounit analysis, different restoration practices were used in low and ''high 'capoeira"' areas. ln 25 plots of ''low 'capoeira"' five treatments were applied: liana control with enrichment planting (three different tree associations were used, treatments 1, 2 and 3), liana control without enrichment planting (treatment 4) and control (treatment 5). ln 10 ''high 'capoeira"' plots two treatments were applied: liana control (treatment 1) and control (treatment 2). ln 18 months the treatments in "low 'capoeira"' proved very effective in increasing the tree density, basal area and crown area in the plots, specially treatments 1 to 3, compared to treatment 5. The costs for a two years treatment were US$1,786. 11/ha for treatment 1, 2 and 3 and US$387.29/ha for treatment 4. For ''high 'capoeira"' treatment just the costs are discussed, since the experiment period was not enough to have meaningful analysis of vegetation dynamics. The costs of a two years treatment were US$ 116.13/ha. These costs indicate that both restoration experiments are technical and economic feasible. Sugestions for future experiments are done (AU)