Epsilon Open Archive

Abstract

Willow stands on a short rotation basis are introduced in Sweden as an alternative crop for energy purposes. The changes in water balance when growing these stands have been studied by simulations with a mathematical model and by an hydrological object-reference study on a peat bog. The short-rotation forests are geographically spread, grown on different soils and with varying management. This gives a spread in water balance results. The studies show that the total evaporation from short-rotation forest is higher than from virgin peatland. The total evaporation from a fertilized irrigated stand exceeds the Penman estimate while from an extensively managed stand the total evaporation is less than or equal to the Penman estimate. To reach high production figures a good supply of water is needed. The irrigation should be carefully performed as to avoid production losses or leakage of fertilizers. The changes in runoff is highly dependent on management factors such as drainage and irrigation. When growing short-rotation forests the groundwater level and the soil water storage decreases during the growth season but is recharged during the winter. The snow storage increases while the frost depth decreases.