Community size and disturbance history jointly explain the interplay between stochastic and deterministic community variation in benthic invertebrates

Community ecology has so far struggled to integrate both deterministic and stochastic processes into a global model of community variation. To address this issue, we aimed to characterise the ecological conditions that determine the relative importance of deterministic and stochastic community variation in benthic macroinvertebrates. We sampled macroinvertebrate and algal periphyton communities, and microhabitat conditions at monthly intervals over a 5 year period in two sampling sites in the regulated Durance River and one site in the Asse River (a natural tributary of the Durance). The relative importance of stochastic and deterministic processes was estimated over time as functional and taxonomic spatial β-deviation (i.e. β-diversityobs – mean β-diversitynull / SD β-diversitynull) for each sampling date and site. We additionally quantified deterministic variation as the trait-environment relationship and predicted a positive correlation with β-deviation metrics. We found evidence of ..., Hydrological conditions
We obtained hourly hydrological data (Q m3s-1) for the period of December 2012 to August 2018. Hydrological data for the two Durance sites was obtained from the Escale hydroelectrical dam (28.3km & 34.7km upstream of the Dur-1 and Dur-2 sites, respectively). We also obtained hydrological data for the Bléone River (906 km² drainage basin) as both Durance sites were situated downstream from its confluence with the Durance (Figure 1). The Bléone River is also regulated by a dam but as discharge measurements were not available. We obtained simulated discharge values inferred from reservoir water levels for the sample period from the French electrical company (EDF). These simulated discharge values were then added to the Durance hydrograph. For the Asse site, we obtained hydrological data from the Clue Chambrières limnology station (14.7km upstream from the Asse study site). We also added the input of the Asse to the Dur-2 hydrograph, as Dur-2 is located downstrea..., , # Data from: Community size and disturbance history jointly explain the interplay between stochastic and deterministic community variation in benthic invertebrates

[https://doi.org/10.5061/dryad.brv15dvkb](https://doi.org/10.5061/dryad.brv15dvkb)

## Description of the data and file structure

## Files and variables

#### File: FunctionalTraits.xlsx

**Description:** Functional trait database adapted from Tachet et al. 2010

##### Variables

**FunTraits excel sheet:**

*  **Final_assignment**: Final taxonomic assignment of macroinvertebrate taxa.
* **FinalFun**: Final taxonomic assignment for functional traits. This is a tradeoff between the resolution of the Tachet et al. functional trait database and the final taxonomic assignment (Final_assignment). When final assignment is more precise than the functional trait database, taxa were homogenised to the next best taxonomic level. For example, *Baetis* spp. were homogenised to the genus level.
* **TaxLevel**: The taxonomic resolution aq...