Document Type : Research Paper
Authors
1
Ph.D. Student, Department of Forestry and Forest Economics, University of Tehran, Karaj, I.R. Iran
2
Assoc. Prof., Department of Forestry and Forest Economics, University of Tehran, Karaj, I.R. Iran
3
Prof., Department of Range and Watershed Management, University of Tehran, Karaj, I.R. Iran
4
Prof., Department of Forestry and Forest Economics, University of Tehran, Karaj, I.R. Iran
5
Assoc. Prof., Department of Agriculture, Division of Agricultural, Forest and Biosystems Engineering, University of Napoli Federico II, 100-80055 Portici (NA) Italy.
Abstract
Even though vegetation are well recognized by their effects on hillslope hydrology and stability state, the hydrological effect of different types of forest covers are yet to be quantified. To address this gap, two adjacent hillslopes with different vegetation cover (a deciduous forest and a grass cover) were selected. The random-systematic method was used to determine nine sampling points on each hillslope. A PR2/6 profile probe was then used to monitor the soil water content at different depths of soil during the growing season of 2015. A soil water retention curve (SWRC) was made for each soil depth to facilitate the estimation of the equivalent matric suction of the monitored soil water content. Based on the results, the value of soil matric suction tends to be significantly higher in deciduous hillslope than the grassed hillslope (P<0.05). In addition, soil matric suction at depth 30cm was found to be significantly higher than depths 60 and 100cm (P<0.01). The value of soil matric suction tends to increase during the study period from April to September, with the lowest value in April. Based on this work, the deciduous forest cover was found to be more effective on soil hydrologic condition and they also extended their hydrological effects to a larger depth of soil compared to the grass cover.
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