Periodic Reporting for period 1 - RECODYN (Ecosystem recovery dynamics and their response to climate change and habitat fragmentation)
Periodo di rendicontazione: 2023-01-01 al 2025-06-30
The goal of RECODYN is to determine the recovery rates and trajectories of biodiversity, community structure and ecosystem functioning in complex multitrophic communities, and how climate change and habitat fragmentation – two of the largest threats to biodiversity and ecosystems in terrestrial systems – influence those dynamics. To achieve this, I will use an integrative approach that combines the development of new theory on metacommunities and temperature-dependent food web dynamics in close dialogue with a unique long-term terrestrial mesocosm experiment. RECODYN is articulated around three objectives. First, I will investigate differences between natural assembly and recovery dynamics. Then, I will determine the effects of global change – i.e. climate change and fragmentation – on biodiversity, community structure, spatial and temporal stability, and key ecosystem functions of recovering ecosystems. Finally, I will provide creative solutions to restore ecosystems in a warmer and more fragmented world.
RECODYN proposes an ambitious integrative and innovative research program that will provide a much-needed new perspective on ecological restoration in an era of global change. It will greatly contribute to bridging the gap between theoretical and empirical ecology, and to move restoration from an idiosyncratic discipline to a more predictive science. RECODYN will foster links with environmental policy by providing new restoration measures that derive from our theoretical and empirical findings.
Experimental setup (WP1 [T3-4]; WP2 [T8]):
- Application of the experimental design described in the project proposal (24 cages, 4 replicates of paired cages, 3 treatments) (WP1 [T3-4]; WP2 [T8])
- Preparation of labs in France (sorting laboratory, greenhouse) (WP1 [T3-4]; WP2 [T8])
- Application of experimental perturbation (plant biomass removal and tilling) in 8 of the experimental cages (WP1 [T3-4]; WP2 [T8])
- Application of thermal manipulation (shutter system) and dispersal limitation in global change treatments (WP2 [T8])
Data collection (WP1 [T3-4]; WP2 [T8]):
- Initial training sampling of plant species, useful for identification throughout the project (WP1 [T3-4]; WP2 [T8])
- Continuous sampling of plant species. Data collected (ongoing): species richness, species abundance and biomass (species level and community level) (WP1 [T3-4]; WP2 [T8])
- Continuous sampling of insect species. Data collected (ongoing): species richness, species estimated abundances, plant feeding damage (this will help establish interactions between plants and animals, and herbivory pressure) (WP1 [T3-4]; WP2 [T8])
- Frequent sampling of soil respiration with EGM-5 device (WP1 [T3-4]; WP2 [T8])
Model construction (WP1 [T1-2]; WP2 [T5-7]):
- We have started to build the basic theoretical model to investigate ecosystem recovery dynamics under global change scenarios (WP1 [T1-2]; WP2 [T5-7])
MAIN ACHIEVEMENTS.
Despite the experimental sampling is still in process, we have already completed 13 samplings (3 in 2023, 10 in 2024). Each has information on plant species (richness, abundance and biomass), some have additional information on insect species (richness, abundance, feeding damage / herbivory pressure), soil respiration or functional traits. Preliminary results suggest that, at the level of grassland plants, functional recovery is fast (i.e. plant biomass) yet species richness and composition are not similar to control sites. This potentially affects the relationship between diversity and function in disturbed systems.
Regarding the theoretical side of the project, we have started to develop quantitative models of seed - plant - insect communities. These models use differential equations and have natural, seasonal environmental fluctuations to which different types of perturbations are added.
1) The experimental data shows that plant species richness, plant composition, and plant biomass have different recovery rates. Whereas the number of species recovers relatively quickly after the induced perturbation, species composition and biomass show slower recovery rates. Additionally, functional recovery (i.e. plant biomass) is faster than compositional recovery. More data is needed to make further conclusions; yet, these results suggest that restoration studies that focus on single variables may be under- and/or overestimating actual community recovery. In sum, a more complete, holistic perspective of community recovery is fundamental to assess restoration outcomes.
2) Global change factors (i.e. temperature change and dispersal limitation) reduce functional recovery (i.e. plant biomass) of ecological communities. This result suggests that the potential of plant communities to recover after a perturbation will be lower with higher temperatures, at least in terms of biomass. If confirmed by more data and other variables, this result provides evidence of an explicit effect of global change on ecosystem recovery dynamics.
There is a lot of information collected at the experiment that is still being analysed. Also, the theoretical models are in process and have not yet definitive results. More information will be included at the end of the project.