TY  - JOUR
A1  - Giling, Darren P.
A1  - Nejstgaard, Jens C.
A1  - Berger, Stella A.
A1  - Grossart, Hans-Peter
A1  - Kirillin, Georgiy
A1  - Penske, Armin
A1  - Lentz, Maren
A1  - Casper, Peter
A1  - Sareyka, Joerg
A1  - Gessner, Mark O.
T1  - Thermocline deepening boosts ecosystem metabolism: evidence from a large-scale lake enclosure experiment simulating a summer storm
JF  - Global change biology
N2  - Extreme weather events can pervasively influence ecosystems. Observations in lakes indicate that severe storms in particular can have pronounced ecosystem-scale consequences, but the underlying mechanisms have not been rigorously assessed in experiments. One major effect of storms on lakes is the redistribution of mineral resources and plankton communities as a result of abrupt thermocline deepening. We aimed at elucidating the importance of this effect by mimicking in replicated large enclosures (each 9 m in diameter, ca. 20 m deep, ca. 1300 m 3 in volume) a mixing event caused by a severe natural storm that was previously observed in a deep clear-water lake. Metabolic rates were derived from diel changes in vertical profiles of dissolved oxygen concentrations using a Bayesian modelling approach, based on high-frequency measurements. Experimental thermocline deepening stimulated daily gross primary production (GPP) in surface waters by an average of 63% for > 4 weeks even though thermal stratification re-established within 5 days. Ecosystem respiration (ER) was tightly coupled to GPP, exceeding that in control enclosures by 53% over the same period. As GPP responded more strongly than ER, net ecosystem productivity (NEP) of the entire water column was also increased. These protracted increases in ecosystem metabolism and autotrophy were driven by a proliferation of inedible filamentous cyanobacteria released from light and nutrient limitation after they were entrained from below the thermocline into the surface water. Thus, thermocline deepening by a single severe storm can induce prolonged responses of lake ecosystem metabolism independent of other storm-induced effects, such as inputs of terrestrial materials by increased catchment run-off. This highlights that future shifts in frequency, severity or timing of storms are an important component of climate change, whose impacts on lake thermal structure will superimpose upon climate trends to influence algal dynamics and organic matter cycling in clear-water lakes. Keywords: climate variability, ecosystem productivity, extreme events, gross primary production, mesocosm, respiration stratified lakes
KW  - climate variability
KW  - ecosystem productivity
KW  - extreme events
KW  - gross primary production
KW  - mesocosm
KW  - respiration stratified lakes
Y1  - 2017
U6  - https://doi.org/10.1111/gcb.13512
SN  - 1354-1013
SN  - 1365-2486
VL  - 23
SP  - 1448
EP  - 1462
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Darwall, William
A1  - Bremerich, Vanessa
A1  - De Wever, Aaike
A1  - Dell, Anthony I.
A1  - Freyhof, Joerg
A1  - Gessner, Mark O.
A1  - Grossart, Hans-Peter
A1  - Harrison, Ian
A1  - Irvine, Ken
A1  - Jähnig, Sonja C.
A1  - Jeschke, Jonathan M.
A1  - Lee, Jessica J.
A1  - Lu, Cai
A1  - Lewandowska, Aleksandra M.
A1  - Monaghan, Michael T.
A1  - Nejstgaard, Jens C.
A1  - Patricio, Harmony
A1  - Schmidt-Kloiber, Astrid
A1  - Stuart, Simon N.
A1  - Thieme, Michele
A1  - Tockner, Klement
A1  - Turak, Eren
A1  - Weyl, Olaf
T1  - The alliance for freshwater life
BT  - a global call to unite efforts for freshwater biodiversity science and conservation
JF  - Aquatic Conservation: Marine and Freshwater Ecosystems
N2  - 1. Global pressures on freshwater ecosystems are high and rising. Viewed primarily as a resource for humans, current practices of water use have led to catastrophic declines in freshwater species and the degradation of freshwater ecosystems, including their genetic and functional diversity. Approximately three-quarters of the world's inland wetlands have been lost, one-third of the 28 000 freshwater species assessed for the International Union for Conservation of Nature (IUCN) Red List are threatened with extinction, and freshwater vertebrate populations are undergoing declines that are more rapid than those of terrestrial and marine species. This global loss continues unchecked, despite the importance of freshwater ecosystems as a source of clean water, food, livelihoods, recreation, and inspiration.

2.  The causes of these declines include hydrological alterations, habitat degradation and loss, overexploitation, invasive species, pollution, and the multiple impacts of climate change. Although there are policy initiatives that aim to protect freshwater life, these are rarely implemented with sufficient conviction and enforcement. Policies that focus on the development and management of fresh waters as a resource for people almost universally neglect the biodiversity that they contain.

3. Here we introduce the Alliance for Freshwater Life, a global initiative, uniting specialists in research, data synthesis, conservation, education and outreach, and policymaking. This expert network aims to provide the critical mass required for the effective representation of freshwater biodiversity at policy meetings, to develop solutions balancing the needs of development and conservation, and to better convey the important role freshwater ecosystems play in human well-being. Through this united effort we hope to reverse this tide of loss and decline in freshwater biodiversity. We introduce several short- and medium-term actions as examples for making positive change, and invite individuals, organizations, authorities, and governments to join the Alliance for Freshwater Life.
KW  - biodiversity
KW  - conservation evaluation
KW  - endangered species
KW  - fish
KW  - invertebrates
KW  - macrophytes
Y1  - 2018
U6  - https://doi.org/10.1002/aqc.2958
SN  - 1052-7613
SN  - 1099-0755
VL  - 28
IS  - 4
SP  - 1015
EP  - 1022
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Bizic, Mina
A1  - Ionescu, Danny
A1  - Karnatak, Rajat
A1  - Musseau, Camille L.
A1  - Onandia, Gabriela
A1  - Berger, Stella A.
A1  - Nejstgaard, Jens C.
A1  - Lischeid, Gunnar
A1  - Gessner, Mark O.
A1  - Wollrab, Sabine
A1  - Grossart, Hans-Peter
T1  - Land-use type temporarily affects active pond community structure but not gene expression patterns
JF  - Molecular ecology
N2  - Changes in land use and agricultural intensification threaten biodiversity and ecosystem functioning of small water bodies. We studied 67 kettle holes (KH) in an agricultural landscape in northeastern Germany using landscape-scale metatranscriptomics to understand the responses of active bacterial, archaeal and eukaryotic communities to land-use type. These KH are proxies of the millions of small standing water bodies of glacial origin spread across the northern hemisphere. Like other landscapes in Europe, the study area has been used for intensive agriculture since the 1950s. In contrast to a parallel environmental DNA study that suggests the homogenization of biodiversity across KH, conceivably resulting from long-lasting intensive agriculture, land-use type affected the structure of the active KH communities during spring crop fertilization, but not a month later. This effect was more pronounced for eukaryotes than for bacteria. In contrast, gene expression patterns did not differ between months or across land-use types, suggesting a high degree of functional redundancy across the KH communities. Variability in gene expression was best explained by active bacterial and eukaryotic community structures, suggesting that these changes in functioning are primarily driven by interactions between organisms. Our results indicate that influences of the surrounding landscape result in temporary changes in the activity of different community members. Thus, even in KH where biodiversity has been homogenized, communities continue to respond to land management. This potential needs to be considered when developing sustainable management options for restoration purposes and for successful mitigation of further biodiversity loss in agricultural landscapes.
KW  - agriculture
KW  - eRNA
KW  - land use
KW  - metacommunity
KW  - transcriptomics
Y1  - 2022
U6  - https://doi.org/10.1111/mec.16348
SN  - 0962-1083
SN  - 1365-294X
VL  - 31
IS  - 6
SP  - 1716
EP  - 1734
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Kayler, Zachary E.
A1  - Premke, Katrin
A1  - Gessler, Arthur
A1  - Gessner, Mark O.
A1  - Griebler, Christian
A1  - Hilt, Sabine
A1  - Klemedtsson, Leif
A1  - Kuzyakov, Yakov
A1  - Reichstein, Markus
A1  - Siemens, Jan
A1  - Totsche, Kai-Uwe
A1  - Tranvik, Lars
A1  - Wagner, Annekatrin
A1  - Weitere, Markus
A1  - Grossart, Hans-Peter
T1  - Integrating Aquatic and Terrestrial Perspectives to Improve Insights Into Organic Matter Cycling at the Landscape Scale
JF  - Frontiers in Earth Science
N2  - Across a landscape, aquatic-terrestrial interfaces within and between ecosystems are hotspots of organic matter (OM) mineralization. These interfaces are characterized by sharp spatio-temporal changes in environmental conditions, which affect OM properties and thus control OM mineralization and other transformation processes. Consequently, the extent of OM movement at and across aquatic-terrestrial interfaces is crucial in determining OM turnover and carbon (C) cycling at the landscape scale. Here, we propose expanding current concepts in aquatic and terrestrial ecosystem sciences to comprehensively evaluate OM turnover at the landscape scale. We focus on three main concepts toward explaining OM turnover at the landscape scale: the landscape spatiotemporal context, OM turnover described by priming and ecological stoichiometry, and anthropogenic effects as a disruptor of natural OM transfer magnitudes and pathways. A conceptual framework is introduced that allows for discussing the disparities in spatial and temporal scales of OM transfer, changes in environmental conditions, ecosystem connectivity, and microbial-substrate interactions. The potential relevance of priming effects in both terrestrial and aquatic systems is addressed. For terrestrial systems, we hypothesize that the interplay between the influx of OM, its corresponding elemental composition, and the elemental demand of the microbial communities may alleviate spatial and metabolic thresholds. In comparison, substrate level OM dynamics may be substantially different in aquatic systems due to matrix effects that accentuate the role of abiotic conditions, substrate quality, and microbial community dynamics. We highlight the disproportionate impact anthropogenic activities can have on OM cycling across the landscape. This includes reversing natural OM flows through the landscape, disrupting ecosystem connectivity, and nutrient additions that cascade across the landscape. This knowledge is crucial for a better understanding of OM cycling in a landscape context, in particular since terrestrial and aquatic compartments may respond differently to the ongoing changes in climate, land use, and other anthropogenic interferences.
KW  - landscape connectivity
KW  - organic matter mineralization
KW  - priming effects
KW  - ecological stoichiometry
KW  - aquatic-terrestrial interfaces
KW  - anthropogenic interferences
Y1  - 2019
U6  - https://doi.org/10.3389/feart.2019.00127
SN  - 2296-6463
VL  - 7
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Tiegs, Scott D.
A1  - Costello, David M.
A1  - Isken, Mark W.
A1  - Woodward, Guy
A1  - McIntyre, Peter B.
A1  - Gessner, Mark O.
A1  - Chauvet, Eric
A1  - Griffiths, Natalie A.
A1  - Flecker, Alex S.
A1  - Acuna, Vicenc
A1  - Albarino, Ricardo
A1  - Allen, Daniel C.
A1  - Alonso, Cecilia
A1  - Andino, Patricio
A1  - Arango, Clay
A1  - Aroviita, Jukka
A1  - Barbosa, Marcus V. M.
A1  - Barmuta, Leon A.
A1  - Baxter, Colden V.
A1  - Bell, Thomas D. C.
A1  - Bellinger, Brent
A1  - Boyero, Luz
A1  - Brown, Lee E.
A1  - Bruder, Andreas
A1  - Bruesewitz, Denise A.
A1  - Burdon, Francis J.
A1  - Callisto, Marcos
A1  - Canhoto, Cristina
A1  - Capps, Krista A.
A1  - Castillo, Maria M.
A1  - Clapcott, Joanne
A1  - Colas, Fanny
A1  - Colon-Gaud, Checo
A1  - Cornut, Julien
A1  - Crespo-Perez, Veronica
A1  - Cross, Wyatt F.
A1  - Culp, Joseph M.
A1  - Danger, Michael
A1  - Dangles, Olivier
A1  - de Eyto, Elvira
A1  - Derry, Alison M.
A1  - Diaz Villanueva, Veronica
A1  - Douglas, Michael M.
A1  - Elosegi, Arturo
A1  - Encalada, Andrea C.
A1  - Entrekin, Sally
A1  - Espinosa, Rodrigo
A1  - Ethaiya, Diana
A1  - Ferreira, Veronica
A1  - Ferriol, Carmen
A1  - Flanagan, Kyla M.
A1  - Fleituch, Tadeusz
A1  - Shah, Jennifer J. Follstad
A1  - Frainer, Andre
A1  - Friberg, Nikolai
A1  - Frost, Paul C.
A1  - Garcia, Erica A.
A1  - Lago, Liliana Garcia
A1  - Garcia Soto, Pavel Ernesto
A1  - Ghate, Sudeep
A1  - Giling, Darren P.
A1  - Gilmer, Alan
A1  - Goncalves, Jose Francisco
A1  - Gonzales, Rosario Karina
A1  - Graca, Manuel A. S.
A1  - Grace, Mike
A1  - Grossart, Hans-Peter
A1  - Guerold, Francois
A1  - Gulis, Vlad
A1  - Hepp, Luiz U.
A1  - Higgins, Scott
A1  - Hishi, Takuo
A1  - Huddart, Joseph
A1  - Hudson, John
A1  - Imberger, Samantha
A1  - Iniguez-Armijos, Carlos
A1  - Iwata, Tomoya
A1  - Janetski, David J.
A1  - Jennings, Eleanor
A1  - Kirkwood, Andrea E.
A1  - Koning, Aaron A.
A1  - Kosten, Sarian
A1  - Kuehn, Kevin A.
A1  - Laudon, Hjalmar
A1  - Leavitt, Peter R.
A1  - Lemes da Silva, Aurea L.
A1  - Leroux, Shawn J.
A1  - Leroy, Carri J.
A1  - Lisi, Peter J.
A1  - MacKenzie, Richard
A1  - Marcarelli, Amy M.
A1  - Masese, Frank O.
A1  - Mckie, Brendan G.
A1  - Oliveira Medeiros, Adriana
A1  - Meissner, Kristian
A1  - Milisa, Marko
A1  - Mishra, Shailendra
A1  - Miyake, Yo
A1  - Moerke, Ashley
A1  - Mombrikotb, Shorok
A1  - Mooney, Rob
A1  - Moulton, Tim
A1  - Muotka, Timo
A1  - Negishi, Junjiro N.
A1  - Neres-Lima, Vinicius
A1  - Nieminen, Mika L.
A1  - Nimptsch, Jorge
A1  - Ondruch, Jakub
A1  - Paavola, Riku
A1  - Pardo, Isabel
A1  - Patrick, Christopher J.
A1  - Peeters, Edwin T. H. M.
A1  - Pozo, Jesus
A1  - Pringle, Catherine
A1  - Prussian, Aaron
A1  - Quenta, Estefania
A1  - Quesada, Antonio
A1  - Reid, Brian
A1  - Richardson, John S.
A1  - Rigosi, Anna
A1  - Rincon, Jose
A1  - Risnoveanu, Geta
A1  - Robinson, Christopher T.
A1  - Rodriguez-Gallego, Lorena
A1  - Royer, Todd V.
A1  - Rusak, James A.
A1  - Santamans, Anna C.
A1  - Selmeczy, Geza B.
A1  - Simiyu, Gelas
A1  - Skuja, Agnija
A1  - Smykla, Jerzy
A1  - Sridhar, Kandikere R.
A1  - Sponseller, Ryan
A1  - Stoler, Aaron
A1  - Swan, Christopher M.
A1  - Szlag, David
A1  - Teixeira-de Mello, Franco
A1  - Tonkin, Jonathan D.
A1  - Uusheimo, Sari
A1  - Veach, Allison M.
A1  - Vilbaste, Sirje
A1  - Vought, Lena B. M.
A1  - Wang, Chiao-Ping
A1  - Webster, Jackson R.
A1  - Wilson, Paul B.
A1  - Woelfl, Stefan
A1  - Xenopoulos, Marguerite A.
A1  - Yates, Adam G.
A1  - Yoshimura, Chihiro
A1  - Yule, Catherine M.
A1  - Zhang, Yixin X.
A1  - Zwart, Jacob A.
T1  - Global patterns and drivers of ecosystem functioning in rivers and riparian zones
JF  - Science Advances
N2  - River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented “next-generation biomonitoring” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.
Y1  - 2019
U6  - https://doi.org/10.1126/sciadv.aav0486
SN  - 2375-2548
VL  - 5
IS  - 1
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Ionescu, Danny
A1  - Bizic, Mina
A1  - Karnatak, Rajat
A1  - Musseau, Camille L.
A1  - Onandia, Gabriela
A1  - Kasada, Minoru
A1  - Berger, Stella A.
A1  - Nejstgaard, Jens Christian
A1  - Ryo, Masahiro
A1  - Lischeid, Gunnar
A1  - Gessner, Mark O.
A1  - Wollrab, Sabine
A1  - Grossart, Hans-Peter
T1  - From microbes to mammals: Pond biodiversity homogenization across different land-use types in an agricultural landscape
JF  - Ecological monographs
N2  - Local biodiversity patterns are expected to strongly reflect variation in topography, land use, dispersal boundaries, nutrient supplies, contaminant spread, management practices, and other anthropogenic influences. Contrary to this expectation, studies focusing on specific taxa revealed a biodiversity homogenization effect in areas subjected to long-term intensive industrial agriculture. We investigated whether land use affects biodiversity levels and community composition (alpha- and beta-diversity) in 67 kettle holes (KH) representing small aquatic islands embedded in the patchwork matrix of a largely agricultural landscape comprising grassland, forest, and arable fields. These KH, similar to millions of standing water bodies of glacial origin, spread across northern Europe, Asia, and North America, are physico-chemically diverse and differ in the degree of coupling with their surroundings. We assessed aquatic and sediment biodiversity patterns of eukaryotes, Bacteria, and Archaea in relation to environmental features of the KH, using deep-amplicon-sequencing of environmental DNA (eDNA). First, we asked whether deep sequencing of eDNA provides a representative picture of KH aquatic biodiversity across the Bacteria, Archaea, and eukaryotes. Second, we investigated if and to what extent KH biodiversity is influenced by the surrounding land use. We hypothesized that richness and community composition will greatly differ in KH from agricultural land use compared with KH in grasslands and forests. Our data show that deep eDNA amplicon sequencing is useful for in-depth assessments of cross-domain biodiversity comprising both micro- and macro-organisms, but has limitations with respect to single-taxa conservation studies. Using this broad method, we show that sediment eDNA, integrating several years to decades, depicts the history of agricultural land-use intensification. Aquatic biodiversity was best explained by seasonality, whereas land-use type explained little of the variation. We concluded that, counter to our hypothesis, land use intensification coupled with landscape wide nutrient enrichment (including atmospheric deposition), groundwater connectivity between KH and organismal (active and passive) dispersal in the tight network of ponds, resulted in a biodiversity homogenization in the KH water, leveling off today's detectable differences in KH biodiversity between land-use types. These findings have profound implications for measures and management strategies to combat current biodiversity loss in agricultural landscapes worldwide.
KW  - biodiversity homogenization
KW  - eDNA
KW  - intensive agriculture
KW  - kettle hole;
KW  - land use
Y1  - 2022
U6  - https://doi.org/10.1002/ecm.1523
SN  - 0012-9615
SN  - 1557-7015
VL  - 92
IS  - 3
PB  - Wiley
CY  - Hoboken
ER  -