Strong temporal variation of consumer δ13C value in an oligotrophic reservoir is related to water level fluctuation
Laen...
Kuupäev
2023
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Nature Portfolio
Abstrakt
Using stable carbon and nitrogen isotope analysis (δ 13 C and δ 15 N) to assess trophic interactions in
freshwater ecosystems is a well established method, providing insight into ecosystem functioning.
However, the spatial and temporal variability of isotope values, driven by environmental fluctuation
is poorly understood and can complicate interpretations. We investigated how the temporal variation
of stable isotopes in consumers (fish, crayfish and macrozoobenthos) of a canyon-shaped oligotrophic
reservoir is associated with environmental factors such as water temperature, transparency, flooded
area, and water quality measures. Consumers and their putative food sources were sampled and
analyzed for carbon and nitrogen stable isotopes annually, and environmental parameters were
measured monthly from 2014 to 2016. Results revealed significant differences in δ 13 C and δ 15 N
values in each consumer among studied years. Over the years, fish and crayfish expressed differences
in δ 13 C between 3 and 5‰, whereas in zoobenthos differences were 12‰. Variability in δ 15 N was
similar across all consumers (2–4‰). Moreover, results suggest that the flooded area of the reservoir
was a major driver of δ 13 C stable isotope values variation in consumers, while variation in δ 15 N was
not linked to any of the studied environmental factors. Bayesian mixing models further showed
significant changes in the origin of detritivorous zoobenthos carbon sources (reversal shift from
terrestrial detritus to algae origin) between years with low water level to years with the standard
water level. Other species showed only slight differences in food source utilization among years. Our
study highlights the importance of environmental factors as sources of variation in consumer’s stable
isotope values which should be considered especially when studied ecosystem strongly fluctuate in
some environmental factor.
This study was supported by the Ministry of Education, Youth, and Sports of the Czech Republic (project CENAKVA II – LO1205 under the NPU I Programme) and by the Estonian University of Life Sciences (research project P190254PKKH to FE). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 951963. We thank Mikko Kiljunen for his valuable comments. Additionally, we thank Jan Kubec and Martin Fořt for their help with the field sampling. In addition, we thank three anonymous reviewers for their valuable and constructive comments.
This study was supported by the Ministry of Education, Youth, and Sports of the Czech Republic (project CENAKVA II – LO1205 under the NPU I Programme) and by the Estonian University of Life Sciences (research project P190254PKKH to FE). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 951963. We thank Mikko Kiljunen for his valuable comments. Additionally, we thank Jan Kubec and Martin Fořt for their help with the field sampling. In addition, we thank three anonymous reviewers for their valuable and constructive comments.
Kirjeldus
Märksõnad
reservoir, isotope analysis, water level, articles