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Temperature effects on periphyton, epiphyton and epipelon under a nitrogen pulse in low-nutrient experimental freshwater lakes

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The ongoing global climate change involves not only increased temperatures but may also produce more frequent extreme events, such as severe rainfall that could trigger a pulse of nutrients to lakes. In shallow lakes, this may affect primary producers through a number of direct and indirect mechanisms. We conducted a six-month mesocosm experiment to elucidate how periphyton (on inert substrata), epiphyton and epipelon biomass responded to a nitrogen (N) pulse, an approximately tenfold enrichment of the NO3-pool, under three contrasting warming scenarios: ambient temperature and ca. +3°C and ca. +4.5°C elevated temperatures (hereafter T1, T2 and T3). After the N pulse, we found a higher periphyton biomass at elevated than at ambient temperatures but no change in epiphyton biomass. Epipelon biomass was lower in T3 than in T1. Both periphyton and epiphyton biomasses correlated negatively with snail biomass, while epiphyton biomass correlated positively with light. Different responses to higher temperatures under short-term extreme nutrient loading conditions may be attributed to differences in the access to nutrient sources and light. Our data suggest that the biomass of periphyton in oligotrophic clear-water lakes will increase significantly under conditions exhibiting short-term extreme nutrient loading in a warmer climate.
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PRIMARY RESEARCH PAPER
Temperature effects on periphyton, epiphyton and epipelon
under a nitrogen pulse in low-nutrient experimental
freshwater lakes
Yu Cao .Saara Olsen .Marı
´a Florencia Gutierrez .Sandra Brucet .
Thomas A. Davidson .Wei Li .Torben L. Lauridsen .
Martin Søndergaard .Erik Jeppesen
Received: 21 May 2016 / Revised: 19 January 2017 / Accepted: 21 February 2017 / Published online: 7 March 2017
ÓSpringer International Publishing Switzerland 2017
Abstract The ongoing global climate change
involves not only increased temperatures but may also
produce more frequent extreme events, such as severe
rainfall that could trigger a pulse of nutrients to lakes. In
shallow lakes, this may affect primary producers
through a number of direct and indirect mechanisms.
We conducted a six-month mesocosm experiment to
elucidate how periphyton (on inert substrata), epiphyton
and epipelon biomass responded to a nitrogen (N) pulse,
an approximately tenfold enrichment of the NO
3
-pool,
under three contrasting warming scenarios: ambient
temperature and ca. ?3°C and ca. ?4.5°C elevated
temperatures (hereafter T1, T2 and T3). After the N
pulse, we found a higher periphyton biomass at elevated
than at ambienttemperatures but no changein epiphyton
biomass. Epipelon biomass was lower in T3 than in T1.
Both periphyton and epiphyton biomasses correlated
negatively with snail biomass, while epiphytonbiomass
correlated positively with light. Different responses to
higher temperatures under short-term extreme nutrient
loading conditions may be attributed to differences in
the access to nutrient sources and light. Our data suggest
that the biomass of periphyton in oligotrophic clear-
water lakes will increase significantly under conditions
exhibiting short-term extreme nutrient loading in a
warmer climate.
Handling editor: Zhengwen Liu
Y. Cao (&)
Key Laboratory of Aquatic Botany and Watershed
Ecology, Wuhan Botanical Garden, Chinese Academy of
Sciences, Wuhan 430074, China
e-mail: caoyu1413@126.com
Y. Cao W. Li
Hubei Key Laboratory of Wetland Evolution &
Ecological Restoration, Wuhan Botanical Garden,
Chinese Academy of Sciences, Wuhan 430074, China
Y. Cao S. Olsen S. Brucet T. A. Davidson
T. L. Lauridsen M. Søndergaard E. Jeppesen
Lake Ecology Section, Department of Bioscience, Aarhus
University, 8600 Silkeborg, Denmark
S. Olsen W. Li T. L. Lauridsen E. Jeppesen
Sino-Danish Centre for Education and Research (SDC),
Beijing, China
M. F. Gutierrez
Instituto Nacional de Limnologı
´a (CONICET-UNL),
Ciudad Universitaria, 3000 Santa Fe, Argentina
S. Brucet
Aquatic Ecology Group, University of Vic - Central
University of Catalonia, Vic, Spain
S. Brucet
ICREA, Catalan Institution for Research and Advanced
Studies, Barcelona, Spain
123
Hydrobiologia (2017) 795:267–279
DOI 10.1007/s10750-017-3140-4
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... both the water and the sediment, and to harvest light as close to the water surface as possible, whereas phytoplankton have first access to light, but rely on nutrients from the water column (Hansson 1988). If nutrient concentrations in the water increases, phytoplankton, as well as filamentous algae, generally become more abundant (Cao et al. 2017), reducing light penetration through the water column and subsequently primary production at the sediment surface becomes light-limited (Hansson 1988(Hansson , 1989. Hence, there is an ever-ongoing competition among different life-forms of primary producers which to a large extent determines water clarity (Scheffer 1990;Moss 2012). ...
... As climate on Earth is rapidly changing (IPCC 2013), a major challenge is to understand and predict how interactions among primary producers will change and thereby shape future lakes and ponds. Temperature is a major factor affecting biomass development of primary producers (Mckee et al. 2002;Hansson et al. 2013;Cao et al. 2014Cao et al. , 2017Urrutia-Cordero et al. 2016;Li et al. 2017;Velthuis et al. 2017), although most studies have focused on a single group of primary producers and fail to provide knowledge on the overall, long-term outcome of the interactions among macrophytes, filamentous, and planktonic algae. Moreover, a major knowledge gap is that despite many studies address increases in the mean temperature, few have focused on how effects of heat waves (Cao et al. 2015(Cao et al. , 2017Bertani et al. 2016;Li et al. 2017), that is, a higher mean temperature delivered as stronger amplitudes in temperature than at present (IPCC 2013), may affect the biomass distribution and competitive interactions among primary producers. ...
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