Description
Plankton communities play an important role in the transition from winter to spring conditions by fuelling the ecosystem’s primary production. Global climate change with pronounced warming during the winter is likely to affect this dynamic. Mixotrophic protists, capable of supplementing photosynthesis by heterotrophic nutrition either through uptake of dissolved organic matter(DOM) or via ingestion of other microbes, contribute signifcantly to the plankton and can be common under ice in temperate lakes, Arctic and Subarctic fjords and various Antarctic regions. Despite a vast number of feld and laboratory studies, mainly under summer conditions, there are still many open questions concerning their quantitative role within biogeochemical models of aquatic food webs, and the abiotic and biotic factors enhancing/inhibiting their occurrence,
diversity and activity.
The spring bloom in subarctic ecosystems is triggered by increasing light availability and elevated DOM levels. Both factors likely affect grazing by mixotrophic protists. Hence, resolving their role in the trophic transfer in winter and early spring will be critical for predicting the response of plankton communities to a changing climate.
By manipulating water temperature, ice cover and addition of different types of DOM in experimental mesocosms, the Umeå-experiment provides the ideal setting for us to study the relative importance of mixotrophy under environmental conditions that represent future climate scenarios. Further, the experimental design at Umeå reduces logistical barriers to studies of plankton communities under winter conditions. We will combine this with a comparison of
different methods available for the study of bacterivory by mixotrophic protists.
| Period | 1 Mar 2022 → 31 Jul 2031 |
|---|---|
| Held at | Aquacosm |
| Degree of Recognition | International |