| Popis: |
In the context of accelerating changes and the massive challenges those changes represent for the ecosystems, temporal ecology has emerged. Some work already exists that describes the importance of temporalities from the point of view of communities (i.g., describing temporal dynamics of communities, the timing of biological events in phenology, co-occurrence and coupling study of synchrony). How- ever, investigating the role of temporal dynamics of environmental drivers’ importance for biological responses remains scarce. The dy- namic of the temporal driver is the temporal context of the temporal- ity of communities, and it defines their time environment. Chapter 1 classifies the varieties of the temporality of drivers, shows how those temporalities are relevant, and proposes a systematic framework for their study. One particular aspect of the temporal dynamics of environmental drivers we focused on is the rate of change. This particular aspect has received growing attention in the last five years as it has been pointed out that it could be determinant in the passing of thresholds between stable states. We conducted a review and synthesis of the existing ex- perimental and theoretical work on rates of change of environmental drivers across levels of complexity in biology (i.e. organism, popula- tion, community, ecosystem). We did not limit ourselves to ecology because we believe a reductionist approach is needed to understand how the rate of change impacts the ecosystem since the response orig- inates at the individual level. Chapter 2 results from our work: rate of change matters for a variety of driver effects and shows no homoge- nous effects between magnitude for one diver, between drivers, and across levels of organizational complexity. Finally, we put into practice the framework we develop in chap- ter 2 to study the rate of change in a series of three experiments. We wanted to demonstrate that rates of temperature change affect growth and show in practice how to study this effect. We used a fungal com- munity collection of 30 strains. The rate of temperature affected fun- gal growth for moderate heat stress but did not affect thermal limits; hence, the temperature rate of change has a non-uniform effect on our tested system. We also showed a non-uniform effect across the strains, indicating strain-specific diversity in responses to temperature rate of changes. Finally, we showed that the rate of temperature change im- pacts competition outcomes. Our work demonstrates how the rate of change can be relevant in ecology and shows how it can be studied. |
