Workpackages

In this proposal we aim at studying the effects of global change, and particularly some of the consequences of climate change, mainly changes in temperature and hydroperiod (and its predictability), using Mediterranean inland standing waters ecosystems, their communities, and specific organisms that inhabit them as model systems. We will explore the structural and/or functional effects of these changing factors at multiple ecological levels (populations, communities, ecosystems), and try to determine how these effects can be transmitted within different levels of this ecological hierarchy (Rowe, 1992). Furthermore, we will study evolutionary processes that may affect key species and may have consequences on upper organizational levels (Fussman et al. 2007; Mathews et al. 2011), such as bet-hedging as an adaptation to local unpredictability. We will also deal with specific aspects related to the consequences of the predicted changes of the studied factors at the different levels, such as reduced clonal diversity in the metapopulation (Pauls et al. 2012) and the metacommunity (Leibold & Chase, 2018), invasiveness of native aquatic communities (Davis, 2009), the expected changes in the incidence of pathogens following the One Health concept (WHO, 2023b) and, at the ecosystem level, the functioning of the main activities of the carbon cycle and the carbon exchanges, both by measuring fluxes as well as by using omics to detect the potential (metagenomics) and actual (metatranscriptomics) activities. Finally, the results of the project on the effect of the main ecological factors affecting the different levels of organization of standing waters systems, their biological communities, and populations (here based on model organisms) will be combined to assess the suitability of measures and make recommendations for climate change adaptation (UNEP-UICN, 2021).

The proposal is structured in several work packages (WP), that are interconnected with different intensity. For instance, the selection of the study sites (WP1) and the overall design of the field sampling campaigns (WP2) is common to different WPs, whereas certain tasks of some WPs are less connected to those of other WPs.

 

• WP1. Selection of study systems
• WP2. Sampling campaign
• WP3. Population level
• WP4. Community level
• WP5. Ecosystem (functional) level
• WP6. Climate change adaptation in mediterranean wetlands and their biological comunities, and transfer ti the society

 

Contingency plan

The main contingency that the project can face is linked to the innate meteorological variability of the Mediterranean climate. For example, some years may be extremely dry and some waterbodies, especially the small, ephemeral ones may not hold water long enough to sustain a well-developed biological community or for the sampling team to visit it in time. By sampling on three consecutive years (WP2) we will have the opportunity to choose the most appropriate period to carry on the multi-level analyses.
The evolution experiment (WP3) compares two treatments (control and reduced genetic variability) under one regime of extreme unpredictability (random length of the growing season and 50% probabilities of false starts). Differences may be too subtle. Being that the case (absence of differences in the response) there is the possibility of comparing our treatment against other regimes of unpredictability being simultaneously tested. Selection on diapause-related traits will be performed for seven cycles, which has been reported to be time enough as to observe divergent evolutionary trajectories in previous experiments with similar traits (Tarazona et al., 2017). Notwithstanding, our approach allows getting measurements of the studied traits immediately after each growing cycle. Thus, additional cycles may be run if necessary. Experimental populations are replicates in the sense that they are genetically identical. However, the particular sequence of different growing cycle lengths and the distribution of false starts along the sequence of growing cycles is different for each replicate. The idea behind this pseudoreplication is testing for the effect of any unpredictable fluctuation in the growing cycle length, and not for a particular fluctuation pattern. Bottlenecks in the diapausing egg bank may occur after cycles with zero recruitment to the egg bank at the end of the growing season, which may generate biases across treatments due to genetic drift. Nevertheless, our genomic approach will allow to estimate the impact of genetic drift in the experimental populations, as they will be compared with the origin population.

Most analyses at the community (WP4) and functional levels (WP5) strongly depend on sampling campaigns in WP2. As already mentioned, the working plan of sampling three consecutive years will allow, in the case one of these is too dry for some of the selected temporary water bodies to be filled, to focus our analyses on the effects of the hydroperiod gradient on the samples from the other two years. However, it would then not be possible to evaluate the interannual variability of community response for those temporary sites for three years, but only for two years. We have a long experience of sampling all the components of aquatic ecosystems and storing samples, so we expect no major problems. Nevertheless, it may be possible that one day some equipment would not work or some accident may happen. For instance, birds may not be captured in a windy day, a sampling net could be lost or broken or an oxygen meter may not calibrate in the field. We have taken this into account in the number of days planned for sampling, so that there is about 10% of surplus time that could be used to go back to a sampling site a few days later if necessary.