Document Type
Article
Publication Date
1-1-2019
Department
Biological Sciences
Abstract
1. Well‐documented in terrestrial settings, priming effects describe stimulated heterotrophic microbial activity and decomposition of recalcitrant carbon by additions of labile carbon. In aquatic settings, algae produce labile exudates which may elicit priming during organic matter decomposition, yet the directions and mechanisms of aquatic priming effects remain poorly tested.
2. We tested algal‐induced priming during decomposition of two leaf species of contrasting recalcitrance, Liriodendron tulipifera and Quercus nigra, in experimental streams under light or dark conditions. We measured litter‐associated algal, bacterial, and fungal biomass and activity, stoichiometry, and litter decomposition rates over 43 days.
3. Light increased algal biomass and production rates, in turn increasing bacterial abundance 141%–733% and fungal production rates 20%–157%. Incubations with a photosynthesis inhibitor established that algal activity directly stimulated fungal production rates in the short term.
4. Algal‐stimulated fungal production rates on both leaf species were not coupled to long‐term increases in fungal biomass accrual or litter decomposition rates, which were 154%–157% and 164%–455% greater in the dark, respectively. The similar patterns on fast‐ vs. slow‐decomposing L. tulipifera and Q. nigra, respectively, indicated that substrate recalcitrance may not mediate priming strength or direction.
5. In this example of negative priming, periphytic algae decoupled fungal activity from decomposition, likely by providing labile carbon invested towards greater fungal growth and reproduction instead of recalcitrant carbon degradation. If common, algal‐induced negative priming could stimulate heterotrophy reliant on labile carbon yet suppress decomposition of recalcitrant carbon, modifying energy and nutrients available to upper trophic levels and enhancing organic carbon storage or export in well‐lit aquatic habitats.
Publication Title
Functional Ecology
Volume
33
Issue
1
First Page
188
Last Page
201
Recommended Citation
Halvorson, H. M.,
Barry, J. R.,
Lodato, M. B.,
Findlay, R. H.,
Francoeur, S. N.,
Kuehn, K. A.
(2019). Periphytic Algae Decouple Fungal Activity From Leaf Litter Decomposition Via Negative Priming. Functional Ecology, 33(1), 188-201.
Available at: https://aquila.usm.edu/fac_pubs/15741
Comments
This is the peer reviewed version of the following article: [Periphytic algae decouple fungal activity from leaf litter decomposition via negative priming. Functional Ecology 33, 1 p188-201 (2018)], which has been published in final form at https://doi.org/10.1111/1365-2435.13235. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions: https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html#3.