Jan Karlsson

@article{https://doi.org/10.1111/gcb.15448,

title = {Integrating carbon emission, accumulation and transport in inland waters to understand their role in the global carbon cycle},

author = {Dominic Vachon and Ryan A Sponseller and Jan Karlsson},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15448},

doi = {https://doi.org/10.1111/gcb.15448},

year  = {2021},

date = {2021-01-01},

journal = {Global Change Biology},

volume = {27},

number = {4},

pages = {719-727},

abstract = {Abstract Inland waters receive a significant quantity of carbon (C) from land. The fate of this C during transit, whether it is emitted to the atmosphere, accumulated in sediments or transported to the ocean, can considerably reshape the landscape C balance. However, these different fates of terrestrial C are not independent but are instead linked via several catchment and aquatic processes. Thus, according to mass conservation, any environmental change inducing a shift in a particular C fate should come at the expense of at least one other fate. Nonetheless, studies that have investigated C emission, accumulation and transport concertedly are scarce, resulting in fragmented knowledge of the role of inland waters in the global C cycle. Here, we propose a framework to understand how different C fates in aquatic systems are interlinked and covary under environmental changes. First, to explore how C fates are currently distributed in streams, rivers, reservoirs and lakes, we compiled data from the literature and show that ‘C fate allocation’ varies widely both within and among inland water systems types. Secondly, we developed a framework that integrates C fates in any inland water system by identifying the key processes underlying their linkages. Our framework places the partitioning between the different C forms, and how this is controlled by export from land, internal transformations and hydrology, as central to understanding C fate allocation. We argue that, by focusing on a single fate, studies could risk drawing misleading conclusions regarding how environmental changes will alter the role of inland waters in the global C cycle. Our framework thus allows us to holistically assess the consequences of such changes on coupled C fluxes, setting a foundation for understanding the contemporary and future fate of land-derived C in inland water systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/lol2.10135,

title = {Paired O2–CO2 measurements provide emergent insights into aquatic ecosystem function},

author = {Dominic Vachon and Steven Sadro and Matthew J Bogard and Jean-François Lapierre and Helen M Baulch and James A Rusak and Blaize A Denfeld and Alo Laas and Marcus Klaus and Jan Karlsson and Gesa A Weyhenmeyer and Paul A del Giorgio},

url = {https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.1002/lol2.10135},

doi = {https://doi.org/10.1002/lol2.10135},

year  = {2020},

date = {2020-01-01},

journal = {Limnology and Oceanography Letters},

volume = {5},

number = {4},

pages = {287-294},

abstract = {Scientific Significance Statement Metabolic stoichiometry predicts that dissolved oxygen (O2) and carbon dioxide (CO2) in aquatic ecosystems should covary inversely; however, field observations often diverge from theoretical expectations. Here, we propose a suite of metrics describing this O2 and CO2 decoupling and introduce a conceptual framework for interpreting these metrics within aquatic ecosystems. Within this framework, we interpret cross-system patterns of high-frequency O2 and CO2 measurements in 11 northern lakes and extract emergent insights into the metabolic behavior and the simultaneous roles of chemical and physical forcing in shaping ecosystem processes. This approach leverages the power of high-frequency paired O2–CO2 measurements, and yields a novel, integrative aquatic system typology which can also be applicable more broadly to streams and rivers, wetlands and marine systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1111/gcb.14521,

title = {Bottom-up and top-down effects of browning and warming on shallow lake food webs},

author = {Francisco Rivera Vasconcelos and Sebastian Diehl and Patricia Rodríguez and Per Hedström and Jan Karlsson and Pär Byström},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14521},

doi = {10.1111/gcb.14521},

year  = {2019},

date = {2019-01-01},

journal = {Global Change Biology},

volume = {25},

number = {2},

pages = {504-521},

abstract = {Abstract Productivity and trophic structure of aquatic ecosystems result from a complex interplay of bottom-up and top-down forces that operate across benthic and pelagic food web compartments. Projected global changes urge the question how this interplay will be affected by browning (increasing input of terrestrial dissolved organic matter), nutrient enrichment and warming. We explored this with a process-based model of a shallow lake food web consisting of benthic and pelagic components (abiotic resources, primary producers, grazers, carnivores), and compared model expectations with the results of a browning and warming experiment in nutrient-poor ponds harboring a boreal lake community. Under low nutrient conditions, the model makes three major predictions. (a) Browning reduces light and increases nutrient supply; this decreases benthic and increases pelagic production, gradually shifting productivity from the benthic to the pelagic habitat. (b) Because of active habitat choice, fish exert top-down control on grazers and benefit primary producers primarily in the more productive of the two habitats. (c) Warming relaxes top-down control of grazers by fish and decreases primary producer biomass, but effects of warming are generally small compared to effects of browning and nutrient supply. Experimental results were consistent with most model predictions for browning: light penetration, benthic algal production, and zoobenthos biomass decreased, and pelagic nutrients and pelagic algal production increased with browning. Also consistent with expectations, warming had negative effects on benthic and pelagic algal biomass and weak effects on algal production and zoobenthos and zooplankton biomass. Inconsistent with expectations, browning had no effect on zooplankton and warming effects on fish depended on browning. The model is applicable also to nutrient-rich systems, and we propose that it is a useful tool for the exploration of the consequences of different climate change scenarios for productivity and food web dynamics in shallow lakes, the worldwide most common lake type.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{diehlinverse,

title = {Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N2 fixers and light},

author = {Sebastian Diehl and Gustaf Thomsson and Maria Kahlert and Junwen Guo and Jan Karlsson and Antonia Liess},

doi = {https://doi.org/10.1111/fwb.13103},

year  = {2018},

date = {2018-03-30},

journal = {Freshwater Biology},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vasconceloseffects,

title = {Effects of Terrestrial Organic Matter on Aquatic Primary Production as Mediated by Pelagic--Benthic Resource Fluxes},

author = {Francisco Rivera Vasconcelos and Sebastian Diehl and Patricia Rodríguez and Jan Karlsson and Pär Byström},

doi = {https://doi.org/10.1007/s10021-017-0217-x},

year  = {2018},

date = {2018-01-17},

journal = {Ecosystems},

pages = {1--14},

publisher = {Springer US},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vasconcelos2016asymmetrical,

title = {Asymmetrical competition between aquatic primary producers in a warmer and browner world},

author = {Francisco Rivera Vasconcelos and Sebastian Diehl and Patricia Rodríguez and Per Hedström and Jan Karlsson and Pär Byström},

doi = {https://doi.org/10.1002/ecy.1487},

year  = {2016},

date = {2016-01-01},

journal = {Ecology},

volume = {97},

number = {10},

pages = {2580--2592},

publisher = {Ecological Society of America},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hotchkiss_2015,

title = {Sources of and processes controlling CO2 emissions change with the size of streams and rivers},

author = {E R Hotchkiss and Hall R O Jr and R A Sponseller and D Butman and J Klaminder and H Laudon and Martin Rosvall and Jan Karlsson},

url = {https://doi.org/10.1038%2Fngeo2507},

doi = {10.1038/ngeo2507},

year  = {2015},

date = {2015-08-01},

journal = {Nature Geoscience},

volume = {8},

number = {9},

pages = {696--699},

publisher = {Springer Nature},

keywords = {},

pubstate = {published},

tppubtype = {article}

}