Cutting Edge: A Comparison of Contemporary Practices of Riparian Buffer Retention Around Small Streams in Canada, Finland, and Sweden

Abstract

Forested riparian buffers are recommended to mitigate negative effects of forest harvesting on recipient freshwater ecosystems. Most of the current best practices of riparian buffer retention aim at larger streams. Riparian protection along small streams is thought to be lacking; however, it is not well documented. We surveyed 286 small streams flowing through recent clearcuts in three timber-producing jurisdictions-British Columbia, Canada (BC), Finland, and Sweden. The three jurisdictions differed in riparian buffer implementation. In BC, forested buffers are not required on the smallest streams, and 45% of the sites in BC had no buffer. The average (±SE) width of voluntarily retained buffers was 15.9 m (±2.1) on each side of the stream. An operation-free zone is mandatory around the smallest streams in BC, and 90% of the sites fulfilled these criteria. Finland and Sweden had buffers allocated to most of the surveyed streams, with average buffer width of 15.3 m (±1.4) in Finland and 4 m (±0.4) in Sweden. Most of the streams in the two Nordic countries had additional forestry-associated impairments such as machine tracks, or soil preparation within the riparian zone. Riparian buffer width somewhat increased with stream size and slope of the riparian area, however, not in all investigated regions. We concluded that the majority of the streams surveyed in this study are insufficiently protected. We suggest that a monitoring of forestry practices and revising present forestry guidelines is needed in order to increase the protection of our smallest water courses. The effectiveness of riparian buffers depends on a number of factors such as the conditions of the buffer (e.g., width, forest structure and composition, and level of tree retention), the properties of adjacent harvested areas, and the properties of the streams themselves (Kreutzweiser et al., 2010; Lidman et al., 2017; Richardson et al., 2012). Stream properties vary across the fluvial network as they are related to stream size and network position. For example, headwater streams (the smallest streams in the network) usually differ from higher order streams into which they flow in topographical, hydrological, and ecological aspects, including gradient, discharge, and/or dominant sources of water, and riparian vegetation (

Assessing Optimal Digital Elevation Model Selection for Active River Area Delineation Across Broad Regions

“…Delineating the functional riparian area extent, however, is not a straightforward task and may require the understanding of local-scale environmental conditions since riparian functional attributes depend on sitespeci c variations such as landscape composition and environmental setting (Naiman and Décamps 1997). Given these challenges, riparian management projects have typically applied a " xed-width buffer guideline" (Kuglerová et al 2020). Unfortunately, xed-width buffers may ultimately fail in meeting management goals as they do not account for variations in site-speci c attributes (e.g., river slope and bank topography), and likely underestimate the full extent of riparian areas (Kuglerová et al 2014).…”

Blue consequences of the green bioeconomy: Clear‐cutting intensifies the harmful impacts of land drainage on stream invertebrate biodiversity

“…they were not measured in situ), inspection of GFC (Global Forest Change, loss-year data in 2001-2017) maps revealed no clear-cuts in the immediate vicinity (within 30 m) of any of the sampling sites. In addition, a recent survey of buffer management in Finland demonstrated that intact buffers around streams were on average 15 m wide (Kuglerová et al, 2020). The impairment of macroinvertebrate communities in small but not in large streams potentially reflects higher connectivity of headwater streams to their catchments (Gomi et al, 2002;Kuglerová et al, 2017) and/or dissipation of elevated nutrient and carbon concentrations towards downstream reaches (Futter et al, 2010;Schelker et al, 2014Schelker et al, , 2016.…”

“…For example, peatland drainage can elevate nutrient concentrations in recipient fluvial networks even 60 years after draining (Nieminen, Sallantaus, et al, 2017), whereas harvesting typically increases nutrients only for 5-10 years (Futter et al, 2016). Also, the negative effects of clearcutting alone are relatively manageable by retaining intact buffers between the stream and the harvested area (Kuglerová et al, 2020), whereas the impacts of forest harvest on drained peatlands are variable and extremely challenging to control .…”

Pressures on Boreal Riparian Vegetation: A Literature Review

“…While riparian buffers can come in many forms, which also brings different functionality (Kuglerová et al, 2020;Sonesson et al, 2020), all types of buffering imply some sort of limit to harvesting in the riparian zone. Limited logging and insufficient buffer width can still lead to changes in microclimatic conditions (Jyväsjärvi et al, 2020;Berrigan et al, 2021), which means that vegetation can also change in buffers.…”