How are riparian buffer zones around Swedish headwaters implemented? : a case study

Abstract: Riparian zones are the transition zones between aquatic and terrestrial environments. They perform numerous important ecological functions. To protect these functions, keeping riparian buffer zones when performing forestry operations around streams is a commonly used practice. In this case study, I investigated how riparian buffer zones around 119 headwaters in northern and southern Sweden are implemented using Rapid Assessment Survey (RAS). I found that 11 % of streams had < 0.1 m wide buffer, 58 % had a buffer 0.1-5 m width, 26 % hade a buffer 5-15 m wide, and 5 % had a buffer wider than 15 m. Northern sites had significantly wider buffers than southern sites. Further, results indicated that neither size of the stream nor size of the clear-cut area influence which buffer width a stream would get. Tree type (coniferous/deciduous) composition of mature trees and saplings of retained buffers differed among buffer width categories and between southern and northern Sweden, and was to some degree a result of the forestry operations within buffers (selective logging). The results also supports that number of deadwood in the stream and shading of the stream are increasing, while the magnitude of impairments connected to forest operations are decreasing, with increasing buffer width. Knowledge of how Swedish headwaters are treated during forest operations, as demonstrated in this study, could help in assessing local effects on small streams due to forest operations as well as cumulative downstream effects on downstream reaches.