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1. Trophic basis of production of stream detritivores shifts with reduced forest inputs

   https://doi.org/10.1007/s10750-020-04317-8  

   Eggert, Susan L. ; Wallace, J. Bruce ; Meyer, Judy L. ; Webster, Jackson R. ( August 2020 , Hydrobiologia)

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2. Shifts in seawater chemistry disrupt trophic links within a simple shoreline food web

   https://doi.org/10.1007/s00442-019-04459-0  

   Jellison, Brittany M. ; Gaylord, Brian ( August 2019 , Oecologia)
3. Prey adaptation along a competition-defense tradeoff cryptically shifts trophic cascades from density- to trait-mediated

   https://doi.org/10.1007/s00442-020-04610-2  

   Wood, Zachary T. ; Fryxell, David C. ; Moffett, Emma R. ; Kinnison, Michael T. ; Simon, Kevin S. ; Palkovacs, Eric P. ( March 2020 , Oecologia)

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4. Temporal changes in diatom valve diameter indicate shifts in lake trophic status

   Siver, Peter A. ; Sibley, Joel ; Lott, Anne M. ; Marsicano, Larry ( January 2021 , Journal of paleopathology)

   null (Ed.)

   When diatoms undergo vegetative cell division the new siliceous wall components are slightly smaller than those of the parent because they are produced within the confines of the parent wall. Thus, with continued growth the mean size of cells in a population declines. Given this unique feature of diatom cell division, if the growth of a species in a lake increases (decreases) under more (less) favorable conditions, then the mean size of the resulting population will decline (increase). Numerous paleolimnological investigations rely on shifts in the relative abundances of diatom species over time to infer lake conditions. Although relative abundance data yield information about the dominance of species in the community, they do not necessarily provide evidence about growth of a given species. For instance, a species could have increased in growth, but simply to a lesser extent than other taxa, resulting in a decline in relative abundance. In a similar fashion, relative abundance values can be misleading when used to infer environmental change, such as trophic status change in lakes. We propose that including data on mean size of diatom valves can yield greater insight into changes in growth and improve observations and conclusions based on relative abundance data. To test this concept, we examined changes in the mean diameter of Aulacoseira ambigua (Grunow) Simonsen valves relative to known shifts in lake trophic status in a core from Bantam Lake, Connecticut, representing * 130 years of sediment accumulation. The mean valve diameter of A. ambigua declined from 9.7 to 7.6 lm, with the largest declines clearly tracking significant increases in trophic status. We conclude that changes in the mean size of diatom frustules over time can provide valuable information for understanding long-term environmental changes. 

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5. Shifts in trophic architecture and ecospace stability determining survivorship and extinction at the end-Cretaceous

   Chiarenza, Alfio Alessandro ; García-Girón, Jorge ; Alahuhta, Janne ; DeMar, D. G. ; Jani, Heino ; Mannion, P. D. ; Williamson, T. E. ; Wilson Mantilla, G. P. ; Brusatte, S. L. ( November 2022 , Journal of Vertebrate Paleontology)

   An explanation for why some species, such as non-avian dinosaurs, became extinct, whereas others, including mammals, survived the Cretaceous/Paleogene (K/Pg) mass extinction, 66 million years ago (Ma) is still debated. What were the mechanisms behind community restructuring and the emergence of new ecological opportunities after the K/Pg event, selectively driving extinction and survivorship patterns? Using Markov networks, ecological niche partitioning and Earth System models, we reconstructed disruptions in continental food web dynamics, simulating long-term trajectories in ecospace occupancy through the latest Cretaceous (83.6–66.0 Ma) and early Paleogene (66.0–61.6 Ma). This method uses partial correlation networks to represent how different trophic groups interact in a food web and builds on empirical spatial co-variations to explore dependencies between trophic groups. Our analyses are based on a spatiotemporally and taxonomically standardized dataset, comprising more than 1,600 fossil occurrences representing more than 470 genera of fish, salamanders, frogs, albanerpetontids, lizards, snakes, champsosaurs, turtles, crocodylians, dinosaurs (including birds), and mammals across the best sampled region for this interval, the Western Interior of North America. We explicitly tested whether: 1) shifts in food web architecture underwent major restructuring before and after the K/Pg transition, including whether some trophic guilds were more prone to these shifts than others; and 2) any of these changes were associated with fluctuations in the realized niche space, helping to explain survivorship and extinction patterns at the boundary. We find a shift in latest Cretaceous dinosaur faunas, as medium-sized species counterbalanced a loss of large herbivores, but that dinosaur niches were otherwise resilient and static until the K/Pg boundary. Smaller terrestrial vertebrates, including mammals, followed a consistent trajectory of increasing trophic impact and relaxation of ecological niche limits that began in the Cretaceous and continued after the extinction. Patterns of mammalian ecological radiation and niche restructuring indicate that these taxa did not simply proliferate after the extinction; rather, their earlier ecological diversification might have helped them survive the K/Pg event, whereas the static niche of dinosaurs might have contributed to their demise. 

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