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Human-caused trampling that results from excessive recreational use has caused damage to soil and vegetation in forest ecosystems in the Belgrad Forest of Istanbul. The objectives of this study were to examine effects of exclosure on selected soil properties and to determine the recovery time required for soil characteristics in a broadleaf forest recreation site.Litter biomass and topsoil (0-15 cm) were sampled in the forest, exclosure and recreational sites, and soil samples were analysed for saturation capacity, permeability, bulk density, total porosity, organic matter, root biomass, electrical conductivity and soil pH.Results showed that saturation capacity, permeability, total porosity and organic matter increased whereas bulk density decreased significantly in the topsoil under the exclosure, and all these soil properties in the topsoil of the exclosure were greater than those of recreational site. When effects of main factors were compared, averaging over sampling year and soil sampling depth, soils from the exclosure had significantly greater saturation capacity, permeability, total porosity, organic matter and litter biomass and lower bulk density values than the soils from recreational site.Six years of exclosure was effective in improving most of the soil properties in the topsoil. When topsoil and subsoil are considered together, it is obvious that a longer time period is needed for soil recovery in the forest recreational sites.

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The effect of 11% thinning on selected stream water properties in an oak-beech forest ecosystem in the Belgrad Forest of Istanbul, Turkey was studied with a paired catchment experiment. Regression equations for some physical properties of the stream water were developed between control (W-I) and treatment (W-II) watersheds for calibration (with their 95% confidence limits) and treatment periods. The study discovered significant linear regressions between control and treatment watersheds for color, turbidity, air and water temperatures, suspended sediment concentration, pH and electrical conductivity in the calibration period but not turbidity and suspended sediment concentration in the treatment period. The impact of the timber removal was calculated as the difference between measured and predicted values derived from calibration equations. Results showed that timber harvest caused significant decreases in the color, turbidity, temperature, pH, and electrical conductivity values of the stream water and air temperature under the canopy but did not affect the suspended sediment concentration in the stream water.

No abstract