On the mismatch in the strength of competition among fossil and modern species of planktonic Foraminifera

• Published in: Global Ecology and Biogeography
• Main Authors: Rillo, Marina C., Sugawara, Mauro T. C., Cabella, Brenno, Jonkers, Lukas, Baranowski, Ulrike K., Kučera, Michal, Ezard, Thomas H. G.
• Other Authors: Universidade Estadual Paulista (UNESP)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: community ecology; community phylogenetics; diversity dependent diversification; interspecific competition; macroevolution; microfossils; time-series analysis; zooplankton; Planktonic foraminifera
• Online Access: http://hdl.handle.net/11449/228736; https://doi.org/10.1111/geb.13000

German Academic Exchange Service London Natural Environment Research Council German Academic Exchange Service London: DAAD 2016/17 57210260 Natural Environment Research Council: NE/J018163/1 Natural Environment Research Council: NE/P019269/1 Aim: Many clades display the macroevolutionary pattern of a negative relationship between standing diversity and diversification rates. Competition among species has been proposed as the main mechanism that explains this pattern. However, we currently lack empirical insight into how the effects of individual-level ecological interactions scale up to affect species diversification. Here, we investigate a clade that shows evidence for negative diversity-dependent diversification in the fossil record and test whether the clade's modern communities show a corresponding signal of interspecific competition. Location: World's oceans. Time period: Holocene. Major taxa studied: Planktonic Foraminifera (Rhizaria). Methods: We explore spatial and temporal ecological patterns expected under interspecific competition. Firstly, we use a community phylogenetics approach to test for signs of local competitive exclusion among ecologically similar species (defined as closely related or of similar shell sizes) by combining species relative abundances in seafloor sediments. Secondly, we analyse whether population abundances of co-occurring species covary negatively through time using sediment trap time-series spanning 1–12 years. Results: The great majority of the assemblages are indistinguishable from randomly assembled communities, showing no significant spatial co-occurrence patterns regarding phylogeny or size similarity. Through time, most species pairs correlated positively, indicating synchronous rather than compensatory population dynamics. Main conclusions: We found no detectable evidence for interspecific competition structuring extant planktonic Foraminifera communities. Species co-occurrences and population dynamics are likely regulated by the abiotic environment and/or ...