Effect of pine forest canopy removal on flatwood soil temperature and moisture regime.

anglais. Thesis (Master of Science) - University of Florida, Gainesville.

anglais. Soil temperature and moisture regimes in three site conditions control, (undisturbed) minimum preparation (harvested and burned) and maximum (harvest, sheared, chopped, and bedded) preparation were studied in a mixed slash (Pinus elliottii engelm. var. elleiottii) longleaf (Pinus palustris Mill.) pine flatwood forest in north Florida at 0,5, 10, 20 and 50-cm depths. Measurements were taken on the two dominant soil series in the area p electra and wauchula. Te area with the most intense site preparation had significantly higher maximum temperatures, follwed by minimum preparation and control areas. Overall mean and minimum temperatues were higher in the control areas followed by maximum and minimum preparation areas. Variations between maximum and minimum temperatures were higher in the maximum preparation floowed by minimum preparation and control areas. Temperatures at the various depths were significantly different for maximum and minimum temperatures and amplitudes. Higher temperature ocurred at surface follweed by 10, 20 and 50 cm depths. The opposite occurred in relation to minimum temperature. The amplitudes were greater at the surface than at 10, 20, and 50 cm depths. Temperature measurements were not significantly different between the two soils. Soil moisture regimes were also characterized on the two soil series three site conditions and soil depths. There were significant differences in soil moiture regime between the two soils, with soil moisture higher in the mauchula than the electra soil. The maximumsite preparation area possessed higher moisture contents followed by minimum site preparation and the control. The soil at 50 cm depths possessed significantly higher soil moisture, followed by soil at 5, 10 and 20 cm depths. Soil moisture was also compared in a control; minimum preparation unburned; minimum preparation, burned; and maximum preparation burned areas at 20 cm depth in the electra ann wauchula soils. There was a significant difference in water content between the two soils and site preparations. Wauchula possessed highter soil moiture contens than the electra. SOil moisture was in the order: maximum preparation, burned> minimum preparation, unburned>minimum preparation, burned>the control. The association between soil moisture, soil temperature and rainfall was evaluated for the 10, 20 and 50 cm depths in the electra soil in the undisturbed (control) forest. The regression evaluation fitted for the 20 cm depth indicated that rainfall made a greater contribution to the prediction of soil moisture than soil temperature.