Multiple stressors in small streams in the forestry context of Fennoscandia : The effects in time and space

• Published in: Science of The Total Environment
• Main Authors: Kuglerová, Lenka, Hasselquist, Eliza Maher, Sponseller, Ryan Allen, Muotka, Timo, Hallsby, Goran, Laudon, Hjalmar
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: best management practice; boreal forest; forestry; headwaters; stream networks; stressors; streams; small streams; Fennoscandia; disturbances; forestry rotation cycle; aquatic multiple stressors; forestry dominated landscapes; experimental approaches; time and space; Finland; Sweden; metsät; joet; virtavedet; hakkuut; vesiekosysteemit; ojitus; hyvät käytännöt; tienrakennus; ympäristövaikutukset; Fennoskandia; Suomi; Ruotsi; Fennoscandian
• Online Access: http://hdl.handle.net/10138/335534; https://doi.org/10.1016/j.scitotenv.2020.143521

Highlights • Streams in Fennoscandian production forests are subject to number of disturbances. • Operations during the forestry rotation cycle introduce stressors to small streams. • Individual stressors interact in time and space causing multiple stressor phenomena. • Aquatic multiple stressors are not well understood in forestry dominated landscapes. • Future research should focus on multiple stressors using experimental approaches. In this paper we describe how forest management practices in Fennoscandian countries, namely Sweden and Finland, expose streams to multiple stressors over space and time. In this region, forestry includes several different management actions and we explore how these may successively disturb the same location over 60–100 year long rotation periods. Of these actions, final harvest and associated road construction, soil scarification, and/or ditch network maintenance are the most obvious sources of stressors to aquatic ecosystems. Yet, more subtle actions such as planting, thinning of competing saplings and trees, and removing logging residues also represent disturbances around waterways in these landscapes. We review literature about how these different forestry practices may introduce a combination of physicochemical stressors, including hydrological change, increased sediment transport, altered thermal and light regimes, and water quality deterioration. We further elaborate on how the single stressors may combine and interact and we consequently hypothesise how these interactions may affect aquatic communities and processes. Because production forestry is practiced on a large area in both countries, the various stressors appear multiple times during the rotation cycles and potentially affect the majority of the stream network length within most catchments. We concluded that forestry practices have traditionally not been the focus of multiple stressor studies and should be investigated further in both observational and experimental fashion. Stressors accumulate across time and ...