--- _id: '12237' abstract: - lang: eng text: 'The effectiveness of controlling nitrogen (N) to manage lake eutrophication is debated. Long-term, whole-lake case studies are required to determine whether diazotrophic cyanobacteria can fix sufficient N to offset a reduction of N-inputs. We document the recovery of shallow, productive Lake Müggelsee (Germany) over 37 yr (sampling interval 1–2 weeks) during a decrease of N and phosphorus (P) loading of 79% and 69%, respectively. Nitrogen concentrations in the lake responded immediately to loading reduction whereas P concentrations remained elevated for about 20 yr. Total nitrogen (TN) in the lake was always lower than TN in the inflow. Accordingly, estimated denitrification and N-burial rates substantially exceeded N2 fixation rates in the long term. Phosphorus was growth limiting in spring whereas N was clearly limiting in summer due to high sediment P-release. TN : TP ratios, normalized to phytoplankton biovolume by regression, were 25.5 (weight) in spring and 3.3 in summer. During the study period, dissolved inorganic N (DIN) concentrations in summer decreased and the duration of low DIN concentrations increased by ca. 100 d. The biovolume of cyanobacteria and total phytoplankton decreased by 89% and 76%, respectively. The proportion of N2-fixing cyanobacteria during summer decreased from 36% to 14% of the total phytoplankton biovolume. The total concentration of heterocysts and estimated total N2 fixation did not change over time. In the long term, decreasing N-inputs effectively controlled summer cyanobacteria including N2-fixing taxa, which did not compensate for the N-deficit. A P-only control strategy would not have been as successful.' author: - first_name: Tom full_name: Shatwell, Tom id: '86424' last_name: Shatwell orcid: 0000-0002-4520-7916 - first_name: Jan full_name: Köhler, Jan last_name: Köhler citation: ama: 'Shatwell T, Köhler J. Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake. Limnology and Oceanography. 2018;64(S1). doi:10.1002/lno.11002' apa: 'Shatwell, T., & Köhler, J. (2018). Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake. Limnology and Oceanography, 64(S1). https://doi.org/10.1002/lno.11002' bjps: 'Shatwell T and Köhler J (2018) Decreased Nitrogen Loading Controls Summer Cyanobacterial Blooms without Promoting Nitrogen‐fixing Taxa: Long‐term Response of a Shallow Lake. Limnology and Oceanography 64.' chicago: 'Shatwell, Tom, and Jan Köhler. “Decreased Nitrogen Loading Controls Summer Cyanobacterial Blooms without Promoting Nitrogen‐fixing Taxa: Long‐term Response of a Shallow Lake.” Limnology and Oceanography 64, no. S1 (2018). https://doi.org/10.1002/lno.11002.' chicago-de: 'Shatwell, Tom und Jan Köhler. 2018. Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake. Limnology and Oceanography 64, Nr. S1. doi:10.1002/lno.11002, .' din1505-2-1: 'Shatwell, Tom ; Köhler, Jan: Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake. In: Limnology and Oceanography Bd. 64. Hoboken, NJ, Wiley (2018), Nr. S1' havard: 'T. Shatwell, J. Köhler, Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake, Limnology and Oceanography. 64 (2018).' ieee: 'T. Shatwell and J. Köhler, “Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake,” Limnology and Oceanography, vol. 64, no. S1, 2018, doi: 10.1002/lno.11002.' mla: 'Shatwell, Tom, and Jan Köhler. “Decreased Nitrogen Loading Controls Summer Cyanobacterial Blooms without Promoting Nitrogen‐fixing Taxa: Long‐term Response of a Shallow Lake.” Limnology and Oceanography, vol. 64, no. S1, 2018, https://doi.org/10.1002/lno.11002.' short: T. Shatwell, J. Köhler, Limnology and Oceanography 64 (2018). ufg: 'Shatwell, Tom/Köhler, Jan: Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake, in: Limnology and Oceanography 64 (2018), H. S1.' van: 'Shatwell T, Köhler J. Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake. Limnology and Oceanography. 2018;64(S1).' date_created: 2024-12-08T20:29:40Z date_updated: 2024-12-09T10:18:21Z department: - _id: DEP8022 doi: 10.1002/lno.11002 extern: '1' intvolume: ' 64' issue: S1 language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1002/lno.11002 oa: '1' place: Hoboken, NJ publication: Limnology and Oceanography publication_identifier: eissn: - 1939-5590 issn: - 0024-3590 publication_status: published publisher: Wiley quality_controlled: '1' status: public title: 'Decreased nitrogen loading controls summer cyanobacterial blooms without promoting nitrogen‐fixing taxa: Long‐term response of a shallow lake' type: scientific_journal_article user_id: '83781' volume: 64 year: '2018' ... --- _id: '12238' abstract: - lang: eng text: Phytoplankton growth depends not only on mean intensity but also on the dynamics of the light supply. In surface mixed layers, phytoplankton may rapidly move between strong light and almost darkness. The nonlinear light‐dependency of growth may differ between constant and fluctuating light because of the different frequency distribution of light and/or acclimation processes. The present study compares for the first time light‐dependency of photosynthesis and growth of phytoplankton communities in situ under defined mixing conditions and at fixed depths. Maximum growth rates per day were not significantly different, but the growth efficiency was much higher under constant light than under fluctuating light of sub‐saturating daily irradiance. Phytoplankton incubated under fluctuating light needed about three times higher mean daily irradiances to balance photosynthesis and losses than under constant light. The difference in growth efficiency was mostly caused by the different frequency distribution of underwater light, as was estimated by a photosynthesis model of sufficient temporal resolution. The present study indicates a considerable overestimation of phytoplankton growth at sub‐saturating light in well‐mixed water layers by the common growth measurements under constant light. This implies an underestimation of the compensation light intensities and respective overestimations of the critical mixing depths. author: - first_name: Jan full_name: Köhler, Jan last_name: Köhler - first_name: Lan full_name: Wang, Lan last_name: Wang - first_name: Alexis full_name: Guislain, Alexis last_name: Guislain - first_name: Tom full_name: Shatwell, Tom id: '86424' last_name: Shatwell orcid: 0000-0002-4520-7916 citation: ama: Köhler J, Wang L, Guislain A, Shatwell T. Influence of vertical mixing on light‐dependency of phytoplankton growth. Limnology and Oceanography. 2017;63(3):1156-1167. doi:10.1002/lno.10761 apa: Köhler, J., Wang, L., Guislain, A., & Shatwell, T. (2017). Influence of vertical mixing on light‐dependency of phytoplankton growth. Limnology and Oceanography, 63(3), 1156–1167. https://doi.org/10.1002/lno.10761 bjps: Köhler J et al. (2017) Influence of Vertical Mixing on Light‐dependency of Phytoplankton Growth. Limnology and Oceanography 63, 1156–1167. chicago: 'Köhler, Jan, Lan Wang, Alexis Guislain, and Tom Shatwell. “Influence of Vertical Mixing on Light‐dependency of Phytoplankton Growth.” Limnology and Oceanography 63, no. 3 (2017): 1156–67. https://doi.org/10.1002/lno.10761.' chicago-de: 'Köhler, Jan, Lan Wang, Alexis Guislain und Tom Shatwell. 2017. Influence of vertical mixing on light‐dependency of phytoplankton growth. Limnology and Oceanography 63, Nr. 3: 1156–1167. doi:10.1002/lno.10761, .' din1505-2-1: 'Köhler, Jan ; Wang, Lan ; Guislain, Alexis ; Shatwell, Tom: Influence of vertical mixing on light‐dependency of phytoplankton growth. In: Limnology and Oceanography Bd. 63. Hoboken, NJ , Wiley (2017), Nr. 3, S. 1156–1167' havard: J. Köhler, L. Wang, A. Guislain, T. Shatwell, Influence of vertical mixing on light‐dependency of phytoplankton growth, Limnology and Oceanography. 63 (2017) 1156–1167. ieee: 'J. Köhler, L. Wang, A. Guislain, and T. Shatwell, “Influence of vertical mixing on light‐dependency of phytoplankton growth,” Limnology and Oceanography, vol. 63, no. 3, pp. 1156–1167, 2017, doi: 10.1002/lno.10761.' mla: Köhler, Jan, et al. “Influence of Vertical Mixing on Light‐dependency of Phytoplankton Growth.” Limnology and Oceanography, vol. 63, no. 3, 2017, pp. 1156–67, https://doi.org/10.1002/lno.10761. short: J. Köhler, L. Wang, A. Guislain, T. Shatwell, Limnology and Oceanography 63 (2017) 1156–1167. ufg: 'Köhler, Jan u. a.: Influence of vertical mixing on light‐dependency of phytoplankton growth, in: Limnology and Oceanography 63 (2017), H. 3,  S. 1156–1167.' van: Köhler J, Wang L, Guislain A, Shatwell T. Influence of vertical mixing on light‐dependency of phytoplankton growth. Limnology and Oceanography. 2017;63(3):1156–67. date_created: 2024-12-08T20:31:00Z date_updated: 2024-12-09T10:16:41Z department: - _id: DEP8022 doi: 10.1002/lno.10761 extern: '1' intvolume: ' 63' issue: '3' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1002/lno.10761 oa: '1' page: 1156-1167 place: 'Hoboken, NJ ' publication: Limnology and Oceanography publication_identifier: eissn: - 1939-5590 issn: - 0024-3590 publication_status: published publisher: Wiley quality_controlled: '1' status: public title: Influence of vertical mixing on light‐dependency of phytoplankton growth type: scientific_journal_article user_id: '83781' volume: 63 year: '2017' ...