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Forest harvesting, especially when intensified harvesting method as whole-tree harvesting with stump lifting (WTHs) are used, may increase mercury (Hg) and methylmercury (MeHg) leaching to recipient water courses. The effect can be enhanced if the underlying bedrock and overburden soil contain Hg. The impact of stem-only harvesting (SOH) and WTHs on the concentrations of Hg and MeHg as well as several other variables in the ditch water was studied using a paired catchment approach in eight drained peatland-dominated catchments in Finland (2008-2012). Four of the catchments were on felsic bedrock and four on black schist bedrock containing heavy metals. Although both Hg and MeHg concentrations increased after harvesting in all treated sites according to the randomized intervention analyses (RIAs), there was only a weak indication of a harvest-induced mobilization of Hg and MeHg into the ditches. Furthermore, no clear differences between WTHs and SOH were found, although MeHg showed a nearly significant difference (p = 0.06) between the harvesting regimes. However, there was a clear bedrock effect, since the MeHg concentrations in the ditch water were higher at catchments on black schist than at those on felsic bedrock. The pH, suspended solid matter (SSM), dissolved organic carbon (DOC), and iron (Fe) concentrations increased after harvest while the sulfate (SO4-S) concentration decreased. The highest abundances of sulfate-reducing bacteria (SRB) were found on the sites with high MeHg concentrations. The biggest changes in ditch water concentrations occurred first 2 years after harvesting.

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In this study, the first-year chemistry laboratory course was renewed and made more intensive, three weeks course. Students’ experiences of the renewed course were examined by analyzing their learning diaries which they were encouraged to keep during the whole course. The purpose of this study was to find out how the intense coursework affects students’ emotions and learning experiences. Thus, the learning diaries were analyzed in order to find out different emotions that students experienced during the course. These emotions were then classified and represented using a model based on a two-dimensional emotion theory. Diversity of students’ emotions during the course gave us important information how emotions influenced on student’s learning and achievement. For teacher it is valuable to understand and deal with the emotions experienced by students while planning and carrying out the laboratory course. This enables not only higher quality teaching, but also more positive learning outcomes for students regarding their chemistry laboratory studies. FULL TEXT IN FINNISH.