caa a22 4500 605516502 CHVBK 20210128100714.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s10533-015-0105-4 doi (NATIONALLICENCE)springer-10.1007/s10533-015-0105-4 Spatiotemporal dynamics of boreal landscapes with ecosystem engineers: beavers influence the biogeochemistry of small lakes [Elektronische Daten] [Mia Vehkaoja, Petri Nummi, Martti Rask, Tiina Tulonen, Lauri Arvola] It has been suggested that beavers affect biogeochemical processes and the environment on a relatively large scale, thus acting as ecosystem engineers. In this long-term study we evaluated the effects of beavers on water chemistry in small boreal lakes of Southern Finland. We addressed the following three questions; does water chemistry differ between beaver and non-beaver lakes; does water chemistry differ between the flood years in comparison to the antecedent years; and does the flood impact downstream lakes? The results showed that beaver lakes had higher dissolved organic carbon (DOC) concentrations but lower dissolved oxygen (DO) concentrations than non-beaver lakes. DOC concentration increased during the first three beaver-impoundment years when compared to the pre-impoundment situation, and DO concentrations simultaneously decreased. Lake DOC concentrations furthermore declined back to initial levels after the impoundment had lasted for 4-6years. The opposite occurred with DO. No clear effects caused by beaver impoundments were found in downstream lakes however. Beaver activity had no effect on N and P concentrations in lakes, but our results emphasize that the beaver affects the carbon cycling in the boreal zone. Further research is therefore needed to clarify its effect on the carbon balance at different spatial scales. Springer International Publishing Switzerland, 2015 Beaver impoundment nationallicence Before-after setting nationallicence Biogeochemical hot spot nationallicence Boreal lakes nationallicence Carbon balance nationallicence Dissolved organic carbon nationallicence Nutrient pulse nationallicence Vehkaoja Mia Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut Nummi Petri Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut Rask Martti Evo Game and Fisheries Research, Finnish Game and Fisheries Research Institute, 16970, Evo, Finland aut Tulonen Tiina Lammi Biological Station, University of Helsinki, 16900, Lammi, Finland aut Arvola Lauri Lammi Biological Station, University of Helsinki, 16900, Lammi, Finland aut Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 405-415 0168-2563 124:1-3<405 2015 124 10533 https://doi.org/10.1007/s10533-015-0105-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-015-0105-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vehkaoja Mia Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut NATIONALLICENCE 700 1- Nummi Petri Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Helsinki, Finland aut NATIONALLICENCE 700 1- Rask Martti Evo Game and Fisheries Research, Finnish Game and Fisheries Research Institute, 16970, Evo, Finland aut NATIONALLICENCE 700 1- Tulonen Tiina Lammi Biological Station, University of Helsinki, 16900, Lammi, Finland aut NATIONALLICENCE 700 1- Arvola Lauri Lammi Biological Station, University of Helsinki, 16900, Lammi, Finland aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 405-415 0168-2563 124:1-3<405 2015 124 10533