TY  - JOUR
A1  - Rusak, James A.
A1  - Tanentzap, Andrew J.
A1  - Klug, Jennifer L.
A1  - Rose, Kevin C.
A1  - Hendricks, Susan P.
A1  - Jennings, Eleanor
A1  - Laas, Alo
A1  - Pierson, Donald C.
A1  - Ryder, Elizabeth
A1  - Smyth, Robyn L.
A1  - White, D. S.
A1  - Winslow, Luke A.
A1  - Adrian, Rita
A1  - Arvola, Lauri
A1  - de Eyto, Elvira
A1  - Feuchtmayr, Heidrun
A1  - Honti, Mark
A1  - Istvanovics, Vera
A1  - Jones, Ian D.
A1  - McBride, Chris G.
A1  - Schmidt, Silke Regina
A1  - Seekell, David
A1  - Staehr, Peter A.
A1  - Guangwei, Zhu
T1  - Wind and trophic status explain within and among-lake variability of algal biomass
JF  - Limnology and oceanography letters / ASLO, Association for the Sciences of Limnology and Oceanography
N2  - Phytoplankton biomass and production regulates key aspects of freshwater ecosystems yet its variability and subsequent predictability is poorly understood. We estimated within-lake variation in biomass using high-frequency chlorophyll fluorescence data from 18 globally distributed lakes. We tested how variation in fluorescence at monthly, daily, and hourly scales was related to high-frequency variability of wind, water temperature, and radiation within lakes as well as productivity and physical attributes among lakes. Within lakes, monthly variation dominated, but combined daily and hourly variation were equivalent to that expressed monthly. Among lakes, biomass variability increased with trophic status while, within-lake biomass variation increased with increasing variability in wind speed. Our results highlight the benefits of high-frequency chlorophyll monitoring and suggest that predicted changes associated with climate, as well as ongoing cultural eutrophication, are likely to substantially increase the temporal variability of algal biomass and thus the predictability of the services it provides.
Y1  - 2018
U6  - https://doi.org/10.1002/lol2.10093
SN  - 2378-2242
VL  - 3
IS  - 6
SP  - 409
EP  - 418
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Giling, Darren P.
A1  - Staehr, Peter A.
A1  - Grossart, Hans-Peter
A1  - Andersen, Mikkel Rene
A1  - Boehrer, Bertram
A1  - Escot, Carmelo
A1  - Evrendilek, Fatih
A1  - Gomez-Gener, Lluis
A1  - Honti, Mark
A1  - Jones, Ian D.
A1  - Karakaya, Nusret
A1  - Laas, Alo
A1  - Moreno-Ostos, Enrique
A1  - Rinke, Karsten
A1  - Scharfenberger, Ulrike
A1  - Schmidt, Silke R.
A1  - Weber, Michael
A1  - Woolway, R. Iestyn
A1  - Zwart, Jacob A.
A1  - Obrador, Biel
T1  - Delving deeper: Metabolic processes in the metalimnion of stratified lakes
JF  - Limnology and oceanography
N2  - Many lakes exhibit seasonal stratification, during which they develop strong thermal and chemical gradients. An expansion of depth-integrated monitoring programs has provided insight into the importance of organic carbon processing that occurs below the upper mixed layer. However, the chemical and physical drivers of metabolism and metabolic coupling remain unresolved, especially in the metalimnion. In this depth zone, sharp gradients in key resources such as light and temperature co-occur with dynamic physical conditions that influence metabolic processes directly and simultaneously hamper the accurate tracing of biological activity. We evaluated the drivers of metalimnetic metabolism and its associated uncertainty across 10 stratified lakes in Europe and North America. We hypothesized that the metalimnion would contribute highly to whole-lake functioning in clear oligotrophic lakes, and that metabolic rates would be highly variable in unstable polymictic lakes. Depth-integrated rates of gross primary production (GPP) and ecosystem respiration (ER) were modelled from diel dissolved oxygen curves using a Bayesian approach. Metabolic estimates were more uncertain below the epilimnion, but uncertainty was not consistently related to lake morphology or mixing regime. Metalimnetic rates exhibited high day-to-day variability in all trophic states, with the metalimnetic contribution to daily whole-lake GPP and ER ranging from 0% to 87% and < 1% to 92%, respectively. Nonetheless, the metalimnion of low-nutrient lakes contributed strongly to whole-lake metabolism on average, driven by a collinear combination of highlight, low surface-water phosphorous concentration and high metalimnetic volume. Consequently, a single-sensor approach does not necessarily reflect whole-ecosystem carbon dynamics in stratified lakes.
Y1  - 2017
U6  - https://doi.org/10.1002/lno.10504
SN  - 0024-3590
SN  - 1939-5590
VL  - 62
SP  - 1288
EP  - 1306
PB  - Wiley
CY  - Hoboken
ER  -