title: Impacts of forestry planting on primary production in upland lakes from north-west Ireland.
abstract: Planted forests are increasing in many upland regions worldwide, but knowledge about their potential effects on algal communities of catchment lakes is relatively unknown. Here, the effects of afforestation were investigated using palaeolimnology at six upland lake sites in the north-west of Ireland subject to different extents of forest plantation cover (4-64% of catchment area). (210)Pb-dated sediment cores were analysed for carotenoid pigments from algae, stable isotopes of bulk carbon (δ(13)C) and nitrogen (δ(15)N), and C/N ratios. In lakes with >50% of their catchment area covered by plantations, there were two- to sixfold increases in pigments from cryptophytes (alloxanthin) and significant but lower increases (39-116%) in those from colonial cyanobacteria (canthaxanthin), but no response from biomarkers of total algal abundance (β-carotene). In contrast, lakes in catchments with <20% afforestation exhibited no consistent response to forestry practices, although all lakes exhibited fluctuations in pigments and geochemical variables due to peat cutting and upland grazing prior to forest plantation. Taken together, patterns suggest that increases in cyanobacteria and cryptophyte abundance reflect a combination of mineral and nutrient enrichment associated with forest fertilization and organic matter influx which may have facilitated growth of mixotrophic taxa. This study demonstrates that planted forests can alter the abundance and community structure of algae in upland humic lakes of Ireland and Northern Ireland, despite long histories of prior catchment disturbance.
authors.affiliation: School of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Stevenson
authors.affiliation: School of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.|School of Geography, University of Nottingham, Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia.
authors.forename: Suzanne
authors.initials: S
authors.lastname: McGowan
authors.affiliation: Department of Geography, Loughborough University, Leicestershire, LE11 3TU, UK.
authors.forename: N John
authors.initials: NJ
authors.lastname: Anderson
authors.affiliation: School of Biological Sciences, Queen's University Belfast, Belfast, BT9 7BL, UK.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Foy
authors.affiliation: Limnology Laboratory, Biology Department, University of Regina, Regina, SK, S4S 0A2, Canada.|Institute of Environmental Change and Society, University of Regina, Regina, SK, S4S 0A2, Canada.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Leavitt
authors.affiliation: Agri-Environment Branch, Agri-Food & Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, UK.
authors.forename: Yvonne R
authors.initials: YR
authors.lastname: McElarney
authors.affiliation: St. Croix Watershed Research Station, Science Museum of Minnesota, Marine on St. Croix, MN, 55047, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Engstrom
authors.affiliation: Department of Geography, Loughborough University, Leicestershire, LE11 3TU, UK.
authors.forename: Sergi
authors.initials: S
authors.lastname: Pla-Rabés
mesh_terms: D002244:Carbon / Q000032:analysis; D044785:Cryptophyta / Q000302:isolation & purification; D000458:Cyanobacteria / Q000302:isolation & purification; D017377:Diatoms / Q000302:isolation & purification; D005308:Fertilizers; D016468:Forestry; D019015:Geologic Sediments / Q000032:analysis; D007494:Ireland; D060106:Lakes / Q000382:microbiology*; D009584:Nitrogen / Q000032:analysis; D010860:Pigments, Biological / Q000032:analysis
chemical_list: D005308:Fertilizers; D010860:Pigments, Biological; D002244:Carbon; D009584:Nitrogen
keywords: afforestation; carotenoid pigments; catchment disturbance; forest plantations; land-use change