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Your search keyword '"Rusak, James A."' showing total 4 results
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4 results on '"Rusak, James A."'

1. Forest defoliator outbreaks alter nutrient cycling in northern waters.

Author

Woodman SG, Khoury S, Fournier RE, Emilson EJS, Gunn JM, Rusak JA, and Tanentzap AJ

Subjects
Animals, Biomass, Carbon, Climate Change, Ecosystem, Insecta, Lakes, Ontario, Disease Outbreaks, Ecology, Forests, Nutrients, Plant Diseases
Abstract

Insect defoliators alter biogeochemical cycles from land into receiving waters by consuming terrestrial biomass and releasing biolabile frass. Here, we related insect outbreaks to water chemistry across 12 boreal lake catchments over 32-years. We report, on average, 27% lower dissolved organic carbon (DOC) and 112% higher dissolved inorganic nitrogen (DIN) concentrations in lake waters when defoliators covered entire catchments and reduced leaf area. DOC reductions reached 32% when deciduous stands dominated. Within-year changes in DOC from insect outbreaks exceeded 86% of between-year trends across a larger dataset of 266 boreal and north temperate lakes from 1990 to 2016. Similarly, within-year increases in DIN from insect outbreaks exceeded local, between-year changes in DIN by 12-times, on average. As insect defoliator outbreaks occur at least every 5 years across a wider 439,661 km 2 boreal ecozone of Ontario, we suggest they are an underappreciated driver of biogeochemical cycles in forest catchments of this region., (© 2021. The Author(s).)

Published
2021
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2. Synchronous dynamics of zooplankton competitors prevail in temperate lake ecosystems

Author

Vasseur, David A, Fox, Jeremy W, Gonzalez, Andrew, Adrian, Rita, Beisner, Beatrix E, Helmus, Matthew R, Johnson, Catherine, Kratina, Pavel, Kremer, Colin, de Mazancourt, Claire, Miller, Elizabeth, Nelson, William A, Paterson, Michael, Rusak, James A, Shurin, Jonathan B, and Steiner, Christopher F

Subjects
Biological Sciences, Ecology, Animals, Biota, Crustacea, Europe, Lakes, Models, Biological, North America, Population Dynamics, Seasons, Time Factors, Wavelet Analysis, Zooplankton, synchrony, compensatory dynamics, zooplankton, wavelet, Agricultural and Veterinary Sciences, Medical and Health Sciences, Agricultural, veterinary and food sciences, Biological sciences, Environmental sciences
Abstract

Although competing species are expected to exhibit compensatory dynamics (negative temporal covariation), empirical work has demonstrated that competitive communities often exhibit synchronous dynamics (positive temporal covariation). This has led to the suggestion that environmental forcing dominates species dynamics; however, synchronous and compensatory dynamics may appear at different length scales and/or at different times, making it challenging to identify their relative importance. We compiled 58 long-term datasets of zooplankton abundance in north-temperate and sub-tropical lakes and used wavelet analysis to quantify general patterns in the times and scales at which synchronous/compensatory dynamics dominated zooplankton communities in different regions and across the entire dataset. Synchronous dynamics were far more prevalent at all scales and times and were ubiquitous at the annual scale. Although we found compensatory dynamics in approximately 14% of all combinations of time period/scale/lake, there were no consistent scales or time periods during which compensatory dynamics were apparent across different regions. Our results suggest that the processes driving compensatory dynamics may be local in their extent, while those generating synchronous dynamics operate at much larger scales. This highlights an important gap in our understanding of the interaction between environmental and biotic forces that structure communities.

Published
2014

3. Widespread diminishing anthropogenic effects on calcium in freshwaters

Author

Weyhenmeyer, Gesa A., Hartmann, Jens, Hessen, Dag O., Kopáček, Jiří, Hejzlar, Josef, Jacquet, Stéphan, Hamilton, Stephen K., Verburg, Piet, Leach, Taylor H., Schmid, Martin, Flaim, Giovanna, Nõges, Tiina, Nõges, Peeter, Wentzky, Valerie C., Rogora, Michela, Rusak, James A., Kosten, Sarian, Paterson, Andrew M., Teubner, Katrin, Higgins, Scott N., Lawrence, Gregory, Kangur, Külli, Kokorite, Ilga, Cerasino, Leonardo, Funk, Clara, Harvey, Rebecca, Moatar, Florentina, de Wit, Heleen A., Zechmeister, Thomas, Centre for Limnology. Institute of Agricultural and Environmental Sciences, Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), National Institute of Water and Atmospheric Research [Wellington] (NIWA), Swiss Federal Insitute of Aquatic Science and Technology [Dübendorf] (EAWAG), Research and Innovation Centre [Italie], Fondazione Edmund Mach - Edmund Mach Foundation [Italie] (FEM), Estonian University of Life Sciences, Inst Environm & Agr Sci, Ctr Limnol, Rannu, Tartu Country, Estonia, Institute of Agricultural and Environmental Sciences, Centre for Limnology, Estonian University of Life Sciences (EMU), Consiglio Nazionale delle Ricerche (CNR), Program in Genetics and Genomic Biology, Hospital for Sick Children-University of Toronto McLaughlin Centre, Department of Limnology and Bio-Oceanography, Universität Wien, International Institute for Sustainable Development (IISD), Institute of Agricultural and Environmental Sciences, GéoHydrosystèmes COntinentaux (GéHCO EA6293), Université de Tours (UT), Swedish Research Council2016-04153European Union (EU)643052Knut and Alice Wallenberg Foundation (KAW project) German Research Foundation (DFG)390683824, LIMNOLOGY DEPARTMENT OF ECOLOGY AND GENETICS UPPSALA UNIVERSITY UPPSALA SWE, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Institute for Geology, Universität Hamburg, Center for Earth System Research and Sustainability (CEN), Bundesstrasse 55, 20146, Hamburg, Germany, University of Oslo (UiO), Institute of Hydrobiology [Sádkách] (BIOLOGY CENTRE CAS), Biology Centre of the Czech Academy of Sciences (BIOLOGY CENTRE CAS), Czech Academy of Sciences [Prague] (CAS)-Czech Academy of Sciences [Prague] (CAS), Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), W. K. Kellogg Biological Station (KBS), Michigan State University [East Lansing], Michigan State University System-Michigan State University System, National Institute of Water and Atmosphere [Hamilton] (NIWA), RENSSELAER POLYTECHNIC INSTITUTE TROY USA, Department of Sustainable Agro-Ecosystems and Bioresources, Edmund Mach Foundation (FEM), Institute of Agricultural and Environmental Sciences (IAES), Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ), CNR Water Research Institute (IRSA), Dorset Environmental Science Centre, Ontario Ministry of the Environment and Climate Change, Department of Aquatic Ecology & Environmental Biology, Radboud university [Nijmegen], University of Vienna [Vienna], IISD EXPERIMENTAL LAKES AREA CAN, NEW YORK WATER SCIENCE CENTER US GEOLOGICAL SURVEY USA, CENTRE FOR LIMNOLOGY INSTITUTE OF AGRICULTURAL AND ENVIRONMENTAL SCIENCES OF ESTONIAN UNIVERSITY OF LIFE SCIENCES EST, University of Latvia (LU), U.S. Environmental Protection Agency, VERMONT DEPARTMENT OF ENVIRONMENTAL SERVICES USA, RiverLy (UR Riverly), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Norwegian Institute for Water Research (NIVA), BIOLOGICAL STATION LAKE NEUSIEDL ILLMITZ AUT, and Université de Tours

Subjects
[SDV]Life Sciences [q-bio], [SDE.MCG]Environmental Sciences/Global Changes, alkalinity, lcsh:Medicine, Article, Isolation, anthropogenic effects, Environmental impact, biogeochemistry, anthropique, Lake Geneva Abbreviations: BALO: Bdellovibrio and Like Organisms, Settore BIO/07 - ECOLOGIA, Element cycles, freshwaters, Bdellovibrio sp, freshwater, lcsh:Science, Ekologi, calcium, Ecology, BSA: Bovine Serum Albumin, lcsh:R, trend, eau douce, [SDU]Sciences of the Universe [physics], Bacterial Predator, SDS: Sodium Dodecyl Sulfate, [SDE]Environmental Sciences, articles, Freshwater ecology, lcsh:Q, Preys
Abstract

Calcium (Ca) is an essential element for almost all living organisms. Here, we examined global variation and controls of freshwater Ca concentrations, using 440 599 water samples from 43 184 inland water sites in 57 countries. We found that the global median Ca concentration was 4.0 mg L−1 with 20.7% of the water samples showing Ca concentrations ≤ 1.5 mg L−1 , a threshold considered critical for the survival of many Ca-demanding organisms. Spatially, freshwater Ca concentrations were strongly and proportionally linked to carbonate alkalinity, with the highest Ca and carbonate alkalinity in waters with a pH around 8.0 and decreasing in concentrations towards lower pH. However, on a temporal scale, by analyzing decadal trends in >200 water bodies since the 1980s, we observed a frequent decoupling between carbonate alkalinity and Ca concentrations, which we attributed mainly to the influence of anthropogenic acid deposition. As acid deposition has been ameliorated, in many freshwaters. Financial support was received from the Swedish Research Council (Grant No. 2016-04153), the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 643052 (C-CASCADES project), and from the Knut and Alice Wallenberg Foundation (KAW project). This work is part of the international Global Lake Ecological Observatory Network (GLEON). The work of J.H. is supported by the Deutsche Forschungsgemeinschaft (DFG) under Germany’s Excellence Strategy – EXC 20 2037 ‘Climate, Climatic Change, and Society’ – Project Number: 390683824, contribution to the Center for Earth System Research and Sustainability (CEN) of Universität Hamburg. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. We thank all data providers, listed in Supplementary Table 1. Financial support was received from the Swedish Research Council (Grant No. 2016-04153), the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 643052 (C-CASCADES project), and from the Knut and Alice Wallenberg Foundation (KAW project). This work is part of the international Global Lake Ecological Observatory Network (GLEON). The work of J.H. is supported by the Deutsche Forschungsgemeinschaft (DFG) under Germany’s Excellence Strategy – EXC 20 2037 ‘Climate, Climatic Change, and Society’ – Project Number: 390683824, contribution to the Center for Earth System Research and Sustainability (CEN) of Universität Hamburg. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. We thank all data providers, listed in Supplementary Table 1.

Published
2019

4. Forest defoliator outbreaks alter nutrient cycling in northern waters

Author

Erik J. S. Emilson, Andrew J. Tanentzap, Ronald E. Fournier, John M. Gunn, Sacha Khoury, James A. Rusak, Samuel G. Woodman, Woodman, Samuel [0000-0001-9725-5867], Khoury, Sacha [0000-0002-1980-5365], Fournier, Ronald E [0000-0001-5833-4677], Emilson, Erik JS [0000-0002-1516-9728], Rusak, James A [0000-0002-4939-6478], Tanentzap, Andrew [0000-0002-2883-1901], Apollo - University of Cambridge Repository, Woodman, Samuel G [0000-0001-9725-5867], and Tanentzap, Andrew J [0000-0002-2883-1901]

Subjects
0106 biological sciences, Nutrient cycle, Biogeochemical cycle, Insecta, 010504 meteorology & atmospheric sciences, Ecosystem ecology, Climate Change, Science, General Physics and Astronomy, Forests, 010603 evolutionary biology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Disease Outbreaks, Element cycles, Forest ecology, parasitic diseases, Temperate climate, 631/158/2459, Animals, Biomass, Ecosystem, 0105 earth and related environmental sciences, Plant Diseases, Ontario, Biomass (ecology), Multidisciplinary, Ecology, article, Boreal ecology, Biogeochemistry, 631/158/2454, General Chemistry, Nutrients, 15. Life on land, 704/158/2445, 6. Clean water, Carbon, 631/158/47/4112, Lakes, Deciduous, Boreal, 13. Climate action, 631/158/2449, Freshwater ecology, Environmental science
Abstract

Insect defoliators alter biogeochemical cycles from land into receiving waters by consuming terrestrial biomass and releasing biolabile frass. Here, we related insect outbreaks to water chemistry across 12 boreal lake catchments over 32-years. We report, on average, 27% lower dissolved organic carbon (DOC) and 112% higher dissolved inorganic nitrogen (DIN) concentrations in lake waters when defoliators covered entire catchments and reduced leaf area. DOC reductions reached 32% when deciduous stands dominated. Within-year changes in DOC from insect outbreaks exceeded 86% of between-year trends across a larger dataset of 266 boreal and north temperate lakes from 1990 to 2016. Similarly, within-year increases in DIN from insect outbreaks exceeded local, between-year changes in DIN by 12-times, on average. As insect defoliator outbreaks occur at least every 5 years across a wider 439,661 km2 boreal ecozone of Ontario, we suggest they are an underappreciated driver of biogeochemical cycles in forest catchments of this region., Defoliating insects disrupt nutrient cycling of boreal catchments by redistributing carbon and nitrogen from forests to lakes. The resulting shift in lake biogeochemistry exceeds broader between-year trends observed across the boreal and north temperate region.

Published
2021

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