Epsilon Archive for Student Projects

Abstract

Streamside riparian zones are the interface between the aquatic and terrestrial ecosystem. They have a unique microclimate, differing from the microclimatic conditions in upland forest. This unique microclimate favours biota adapted to humid and cool conditions. The insufficient protection of riparian microclimate can decrease abundance of species sensitive to microclimate changes. In Sweden, it is common to leave narrow buffer strips (<5 m) along small streams during final harvest. These buffer strips are insufficient to protect the functions of riparian buffers, including the microclimate control. We need to gain better understanding of how different buffer management practices will affect microclimate.
Within my thesis I contribute to a better understanding on how different buffer management practices along a small stream affect microclimate after final harvesting in Sweden. I did this by examining mean solar radiation, maximum air temperature, minimum relative humidity and maximum water temperature in a case study consisting of a control site and three different treatment sites. I identified treatment specific differences in the response of riparian microclimate to harvest of the adjacent forest. Leaving a narrow buffer on one side of the stream will affect the microclimatic preconditions on the other side of the stream. Gap-Cutting treatment increased solar radiation and air temperature significantly. Further it decreased relative humidity significantly. Leaving variable retention tailored to a soil moisture map led to a significantly increased solar radiation and air temperature, but no significant differences in relative humidity. Water temperature decreased in two of the examined sites and increased in one, after final harvest. The riparian management showed subordinate influence on water temperature, in comparison to the influence of the hydrological regime. I further found small-scale heterogeneity of microclimate responses. Therefore, riparian management aimed at microclimate protection should consider within site heterogeneity and focus on areas were changes in microclimate result in adverse ecological consequences.