Periodic Reporting for period 1 - Spor-oikos (The role of aquatic hyphomycete spores in headwater stream food webs: a food quality approach.)
Berichtszeitraum: 2017-09-01 bis 2019-08-31
Why is it important for the society: This project brings new information on the relation between an anthropogenic constraint (nutrient loads) and the integrity (biotic and functional) of an essential component responsible of the mineralization of huge quantities of terrestrial carbon. Understanding how our activities are affecting natural nutrient cycles, and the responsible of these cycles contribute towards European policy objectives (biodiversity) and strategies (conservation).
Overall objectives:
1. Investigate the chemical factors controlling aquatic hyphomycetes' sporulation and deduce if global changes could modulate the sporulation process and the intrinsic quality of spores.
2. Study the role of aquatic hyphomycete spores as a resource for consumers in headwater streams by characterizing their elemental (C, N and P) and biochemical (FA and sterols) composition.
Conclusions of the action (achievements):
(1) Production of fungal mycelia without exposing it directly to the medium. (2) Demonstration that fungal mycelia produce spores differing in size when exposed to different nutrient ratios. This new finding has important implications in a global warming context where natural nutrient ratios are affected by anthropogenic activities. (3) Demonstration that certain stoichiometric ratios affect spores of mycelia exposed to different nutrient ratios. (4) Demonstration that the chemical complexity of essential nutrients (C, N and P) needs to be considered when studying the effect on biological traits. We showed that phosphorus chemical complexity can increase fungal spores biovolume, and the essential ratios CN and CP. This can have consequences in their potential trophic quality.
1. Obtention of fungal traits from several parts of the world and harvesting fungal spores without fungal mycelia (especial microcosm).
2. Experiments to elucidate if the investment of fungal mycelia on asexual spores could be affected by the quantity and the quality of the nutrients (i.e. treatment 1, 2, 3, 4 and 5 of phosphorus designed recalcitrant (PRec) and treatment 1, 2, 3, 4 and 5 of phosphorus designed labile (PLab)).
I tested two hypotheses (1) the mycelia exposed to nutrients would invest the energy in the production of spores as the conditions were favorable, increasing the chances of dispersion and colonization. (2) Fungal mycelia exposed to nutrients would invest on its biomass, maximizing the opportunity of having access to nutrients. In parallel we sampled spores of 4 oligotrophic and 4 eutrophic streams.Rationale: (a) The laboratory experiments investigated whether if it was possible to manipulate the elemental composition of the spores by exposing the mycelia to different nutrient ratios. (b) The field study aimed to investigate the elemental composition of spores coming from natural ecosystems.
3. Main scientific achievements and innovation output
(1) Production of fungal mycelium without exposing it directly to the medium. (2) Demosntration that fungal mycelium produce spores differing in size when exposed to different nutrient ratios. (3) Demonstrations that certain stoichiometric ratios could be affected in the spores of mycelia exposed to different nutrient ratios. (3) demonstration that essential nutrients (C, N and P) need to be considered when studying the effect on biological traits.