Spatial heterogeneity strongly affects estimates of ecosystem metabolism in two north temperate lakes

To characterize the spatial variability of metabolism estimates (gross primary production [GPP], respiration [R], and net ecosystem production [NEP]) in two Northern Wisconsin lakes, we collected data from 27 and 35 dissolved oxygen sensors placed in a two‐dimensional array throughout the upper mixed layers over a period of 10 d per lake in midsummer. Averaged over the deployment, aerial metabolism estimates among sensor locations varied 1–2 orders of magnitude and were largely unrelated to physical habitat within the lake. For all sites and days, 76–90% of the explainable variance in GPP and R was attributable to location in the lake rather than day of the deployment. NEP, on the other hand, was less affected by location, with 79–93% of the explained variance attributable to the day of the deployment. Single‐location estimates can yield errors of more than an order of magnitude in estimates of daily GPP and R and can mischaracterize the trophic status of the lake. Using a rarefaction approach, we found that using four randomly placed sensors increased the precision of the resulting daily metabolism estimates fourfold over single‐location measures in both lakes.

[1]  S. MacIntyre,et al.  Spatial and Temporal Variability in the Ecosystem Metabolism of a High-elevation Lake: Integrating Benthic and Pelagic Habitats , 2011, Ecosystems.

[2]  M. Pace,et al.  Difficulty in Discerning Drivers of Lake Ecosystem Metabolism with High-Frequency Data , 2011, Ecosystems.

[3]  S. Thackeray,et al.  Spatial heterogeneity in a small, temperate lake during archetypal weak forcing conditions , 2011 .

[4]  Jonathan J. Cole,et al.  Lake metabolism and the diel oxygen technique: State of the science , 2010 .

[5]  W. G. Sprules,et al.  Evaluating the effect of wind‐driven patchiness on trophic interactions between zooplankton and phytoplankton , 2010 .

[6]  Stephen R. Carpenter,et al.  Estimates of phosphorus entrainment in Lake Mendota: a comparison of one‐dimensional and three‐dimensional approaches , 2009 .

[7]  Mark H. Hansen,et al.  Macro‐ to fine‐scale spatial and temporal distributions and dynamics of phytoplankton and their environmental driving forces in a small montane lake in southern California, USA , 2008 .

[8]  S. Carpenter,et al.  Assessing pelagic and benthic metabolism using free water measurements , 2007 .

[9]  P. Diggle,et al.  Model‐based geostatistics , 2007 .

[10]  T. Serra,et al.  The role of surface vertical mixing in phytoplankton distribution in a stratified reservoir , 2007 .

[11]  J. Downing,et al.  Plumbing the Global Carbon Cycle: Integrating Inland Waters into the Terrestrial Carbon Budget , 2007, Ecosystems.

[12]  K. Sand‐Jensen,et al.  Temporal dynamics and regulation of lake metabolism , 2007 .

[13]  E. Jeppesen,et al.  Substratum as a driver of variation in periphyton chlorophyll and productivity in lakes , 2006, Journal of the North American Benthological Society.

[14]  Paul C. Hanson,et al.  Gross primary production and respiration differences among littoral and pelagic habitats in northern Wisconsin lakes , 2006 .

[15]  Aaron M. Ellison,et al.  A Primer of Ecological Statistics , 2004 .

[16]  S. Carpenter,et al.  Lake metabolism: Relationships with dissolved organic carbon and phosphorus , 2003 .

[17]  N. Caraco,et al.  Contrasting impacts of a native and alien macrophyte on dissolved oxygen in a large river , 2002 .

[18]  Stephen R. Carpenter,et al.  Persistence of net heterotrophy in lakes during nutrient addition and food web manipulations , 2000 .

[19]  D. Lodge,et al.  Periphyton production on wood and sediment: substratum-specific response to laboratory and whole-lake nutrient manipulations , 2000, Journal of the North American Benthological Society.

[20]  Jonathan J. Cole,et al.  Atmospheric exchange of carbon dioxide in a low‐wind oligotrophic lake measured by the addition of SF6 , 1998 .

[21]  S. MacIntyre,et al.  Vertical and Horizontal Transport in Lakes: Linking Littoral, Benthic, and Pelagic Habitats , 1995, Journal of the North American Benthological Society.

[22]  R. Wetzel.  Death, detritus, and energy flow in aquatic ecosystems , 1995 .

[23]  R. Wanninkhof.  Relationship between wind speed and gas exchange over the ocean , 1992 .

[24]  D. Pont,et al.  Spatial distribution patterns in freshwater macrozooplankton: variation with scale , 1991 .

[25]  Stephen G. Monismith,et al.  Convective motions in the sidearm of a small reservoir , 1990 .

[26]  B. Jähne,et al.  On the parameters influencing air‐water gas exchange , 1987 .

[27]  S. V. Smith.  Physical, chemical and biological characteristics* of CO2 gas flux across the air‐water interface , 1985 .

[28]  G. Belle,et al.  Explicit Calculation of the Rarefaction Diversity Measurement and the Determination of Sufficient Sample Size , 1975 .

[29]  Gene E. Likens,et al.  Energy Flow in Bear Brook, New Hampshire: An Integrative Approach to Stream Ecosystem Metabolism , 1973 .

[30]  Daniel Simberloff,et al.  Properties of the Rarefaction Diversity Measurement , 1972, The American Naturalist.

[31]  H. Odum.  Primary Production Measurements in Eleven Florida Springs and a Marine Turtle-Grass Community1 , 1957 .

[32]  Howard T. Odum,et al.  Trophic Structure and Productivity of Silver Springs, Florida , 1957 .

[33]  H. Odum.  Primary Production in Flowing Waters1 , 1956 .

[34]  Raymond L. Lindeman.  The trophic-dynamic aspect of ecology , 1942 .

[35]  R Core Team,et al.  R: A language and environment for statistical computing. , 2014 .

[36]  D. Lodge,et al.  Putting the Lake Back Together: Reintegrating Benthic Pathways into Lake Food Web Models , 2002 .