Effect of vegetation change from forest to herbaceous vegetation cover on soil moisture and temperature regimes and soil water chemistry

Abstract

Objective of this study was to compare the effects of forest and herbaceous vegetation covers on soil temperatures (average daily maximum, minimum, and mean daily temperatures), soil moisture, and chemical content of the soil water. Soil moisture and soil temperature were monitored at three different soil depths (40, 80 and 120 cm) and rain water samples and soil water samples from 40 cm and 80 cm soil depths were collected for 20 weeks on a weekly basis depending on precipitation events. Soil water samples were analyzed for total alkalinity, total nitrogen, calcium hardness, chloride, electrical conductivity, organic matter, pH, potassium, sodium, sulfate, and total hardness. Experiment was as a 3-way factorial in a split plot design with whole plots in blocks and repeated measures with two replications. Data were analyzed by using ANOVA and means were separated with Tukey test. Soils under the forest and herbaceous vegetation covers showed significant difference in terms of overall mean daily maximum, minimum, and average daily temperatures. Overall average daily maximum and minimum temperatures were 9.94 degrees C and 9.75 degrees C, respectively for the soils in the forest plot while they were 11.08 degrees C and 10.87 degrees C for those in the herbaceous plot. Woody vegetation removal significantly increased overall mean daily temperature from 9.84 degrees C to 10.98 degrees C and overall mean daily volumetric soil moisture content of the soils from 32% to 48%. Chemical content of the soil water from both study sites were similar except for chloride and sulfate content. Soil water from forestland had a lower chloride but higher sulfate content than the soils from herbaceous vegetation covered area. On the other hand, chemical content of the soil water from forestland did not show significant changes with soil depth while total alkalinity, calcium hardness, electrical conductivity, pH, sodium, sulfate, and total hardness increased significantly with soil depth in the soils under herbaceous vegetation cover. (C) 2016 Elsevier B.V. All rights reserved.