@article{EhrlichKathGaedke2020,
  author    = {Ehrlich, Elias and Kath, Nadja Jeanette and Gaedke, Ursula},
  title     = {The shape of a defense-growth trade-off governs seasonal trait dynamics in natural phytoplankton},
  series = {The ISME journal},
  volume    = {14},
  journal   = {The ISME journal},
  number    = {6},
  publisher = {Nature Publishing Group},
  address   = {London},
  issn      = {1751-7362},
  doi       = {10.1038/s41396-020-0619-1},
  pages     = {1451 -- 1462},
  year      = {2020},
  abstract  = {Theory predicts that trade-offs, quantifying costs of functional trait adjustments, crucially affect community trait adaptation to altered environmental conditions, but empirical verification is scarce. We evaluated trait dynamics (antipredator defense, maximum growth rate, and phosphate affinity) of a lake phytoplankton community in a seasonally changing environment, using literature trait data and 21 years of species-resolved high-frequency biomass measurements. The trait data indicated a concave defense-growth trade-off, promoting fast-growing species with intermediate defense. With seasonally increasing grazing pressure, the community shifted toward higher defense levels at the cost of lower growth rates along the trade-off curve, while phosphate affinity explained some deviations from it. We discuss how low fitness differences of species, inferred from model simulations, in concert with stabilizing mechanisms, e.g., arising from further trait dimensions, may lead to the observed phytoplankton diversity. In conclusion, quantifying trade-offs is key for predictions of community trait adaptation and biodiversity under environmental change.},
  language  = {en}
}
@article{EhrlichGaedke2020,
  author    = {Ehrlich, Elias and Gaedke, Ursula},
  title     = {Coupled changes in traits and biomasses cascading through a tritrophic plankton food web},
  series = {Limnology and oceanography},
  volume    = {65},
  journal   = {Limnology and oceanography},
  number    = {10},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0024-3590},
  doi       = {10.1002/lno.11466},
  pages     = {2502 -- 2514},
  year      = {2020},
  abstract  = {Trait-based approaches have broadened our understanding of how the composition of ecological communities responds to environmental drivers. This research has mainly focussed on abiotic factors and competition determining the community trait distribution, while effects of trophic interactions on trait dynamics, if considered at all, have been studied for two trophic levels at maximum. However, natural food webs are typically at least tritrophic. This enables indirect interactions of traits and biomasses among multiple trophic levels leading to underexplored effects on food web dynamics. Here, we demonstrate the occurrence of mutual trait adjustment among three trophic levels in a natural plankton food web (Lake Constance) and in a corresponding mathematical model. We found highly recurrent seasonal biomass and trait dynamics, where herbivorous zooplankton increased its size, and thus its ability to counter phytoplankton defense, before phytoplankton defense actually increased. This is contrary to predictions from bitrophic systems where counter-defense of the consumer is a reaction to prey defense. In contrast, counter-defense of carnivores by size adjustment followed the defense of herbivores as expected. By combining observations and model simulations, we show how the reversed trait dynamics at the two lower trophic levels result from a "trophic biomass-trait cascade" driven by the carnivores. Trait adjustment between two trophic levels can therefore be altered by biomass or trait changes of adjacent trophic levels. Hence, analyses of only pairwise trait adjustment can be misleading in natural food webs, while multitrophic trait-based approaches capture indirect biomass-trait interactions among multiple trophic levels.},
  language  = {en}
}
@article{WurzbacherWarthmannBourneetal.2016,
  author    = {Wurzbacher, Christian and Warthmann, Norman and Bourne, Elizabeth Charlotte and Attermeyer, Katrin and Allgaier, Martin and Powell, Jeff R. and Detering, Harald and Mbedi, Susan and Großart, Hans-Peter and Monaghan, Michael T.},
  title     = {High habitat-specificity in fungal communities in oligo-mesotrophic, temperate Lake Stechlin (North-East Germany)},
  series = {MycoKeys},
  volume    = {41},
  journal   = {MycoKeys},
  publisher = {Pensoft Publ.},
  address   = {Sofia},
  issn      = {1314-4057},
  doi       = {10.3897/mycokeys.16.9646},
  pages     = {17 -- 44},
  year      = {2016},
  abstract  = {Freshwater fungi are a poorly studied ecological group that includes a high taxonomic diversity. Most studies on aquatic fungal diversity have focused on single habitats, thus the linkage between habitat heterogeneity and fungal diversity remains largely unexplored. We took 216 samples from 54 locations representing eight different habitats in the meso-oligotrophic, temperate Lake Stechlin in North-East Germany. These included the pelagic and littoral water column, sediments, and biotic substrates. We performed high throughput sequencing using the Roche 454 platform, employing a universal eukaryotic marker region within the large ribosomal subunit (LSU) to compare fungal diversity, community structure, and species turnover among habitats. Our analysis recovered 1027 fungal OTUs (97\% sequence similarity). Richness estimates were highest in the sediment, biofilms, and benthic samples (189-231 OTUs), intermediate in water samples (42-85 OTUs), and lowest in plankton samples (8 OTUs). NMDS grouped the eight studied habitats into six clusters, indicating that community composition was strongly influenced by turnover among habitats. Fungal communities exhibited changes at the phylum and order levels along three different substrate categories from littoral to pelagic habitats. The large majority of OTUs (> 75\%) could not be classified below the order level due to the lack of aquatic fungal entries in public sequence databases. Our study provides a first estimate of lake-wide fungal diversity and highlights the important contribution of habitat heterogeneity to overall diversity and community composition. Habitat diversity should be considered in any sampling strategy aiming to assess the fungal diversity of a water body.},
  language  = {en}
}
@article{CeulemansGaedkeKlauschiesetal.2019,
  author    = {Ceulemans, Ruben and Gaedke, Ursula and Klauschies, Toni and Guill, Christian},
  title     = {The effects of functional diversity on biomass production, variability, and resilience of ecosystem functions in a tritrophic system},
  series = {Scientific Reports},
  volume    = {9},
  journal   = {Scientific Reports},
  publisher = {Macmillan Publishers Limited},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-019-43974-1},
  pages     = {16},
  year      = {2019},
  abstract  = {Diverse communities can adjust their trait composition to altered environmental conditions, which may strongly influence their dynamics. Previous studies of trait-based models mainly considered only one or two trophic levels, whereas most natural system are at least tritrophic. Therefore, we investigated how the addition of trait variation to each trophic level influences population and community dynamics in a tritrophic model. Examining the phase relationships between species of adjacent trophic levels informs about the strength of top-down or bottom-up control in non-steadystate situations. Phase relationships within a trophic level highlight compensatory dynamical patterns between functionally different species, which are responsible for dampening the community temporal variability. Furthermore, even without trait variation, our tritrophic model always exhibits regions with two alternative states with either weak or strong nutrient exploitation, and correspondingly low or high biomass production at the top level. However, adding trait variation increased the basin of attraction of the high-production state, and decreased the likelihood of a critical transition from the high- to the lowproduction state with no apparent early warning signals. Hence, our study shows that trait variation enhances resource use efficiency, production, stability, and resilience of entire food webs.},
  language  = {en}
}
@article{BoitMartinezWilliamsetal.2012,
  author    = {Boit, Alice and Martinez, Neo D. and Williams, Richard J. and Gaedke, Ursula},
  title     = {Mechanistic theory and modelling of complex food-web dynamics in Lake Constance},
  series = {Ecology letters},
  volume    = {15},
  journal   = {Ecology letters},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1461-023X},
  doi       = {10.1111/j.1461-0248.2012.01777.x},
  pages     = {594 -- 602},
  year      = {2012},
  abstract  = {Mechanistic understanding of consumer-resource dynamics is critical to predicting the effects of global change on ecosystem structure, function and services. Such understanding is severely limited by mechanistic models inability to reproduce the dynamics of multiple populations interacting in the field. We surpass this limitation here by extending general consumer-resource network theory to the complex dynamics of a specific ecosystem comprised by the seasonal biomass and production patterns in a pelagic food web of a large, well-studied lake. We parameterised our allometric trophic network model of 24 guilds and 107 feeding relationships using the lakes food web structure, initial spring biomasses and body-masses. Adding activity respiration, the detrital loop, minimal abiotic forcing, prey resistance and several empirically observed rates substantially increased the model's fit to the observed seasonal dynamics and the size-abundance distribution. This process illuminates a promising approach towards improving food-web theory and dynamic models of specific habitats.},
  language  = {en}
}