intertidal mussels as ecosystem engineers: maintenance of invertebrate assemblages amid intertidal stress gradients

In this study, we measured univariate and multivarite metrics of mobile invertebrate assemblages along the midlittoral vertical range of four replicate rocky shores, aiming a control habitat (barnacle cover) and a facilitated habitat (barnacle cover plus a secondary mussel cover). At any given shore height, differences between assemblages would indicate realized facilitation. Temperature and desiccation potential increase from the bottom to the top of this range, and increased facilitation higher on the shore would support the stress-gradient hypothesis. Along with invertebrate data, we provide key environmental data at study sites that could underlie any spatial structure on top of local vertical trends., Environmental parameters at study sites were estimated following standard techniques in intertidal ecology (i.e. shore characteristics). A  compass was used to estimate shore orientation. A digital clinometer measured shore inclination. Measuring tapes, water hoses and rulers were used to measure shore inclination, shore height and mussel bed cross-shore size. A digital thermometers coupled to a pointed probe was used to measure interstitial temperature.
In the lab, mobile invertebrates were sorted out from samples through washing and sieving and counted/identified under a dissecting microscope., , # Intertidal mussels as ecosystem engineers: maintenance of invertebrate assemblages amid intertidal stress gradients

The file contains different folders describing sampling sites and containing data on environmental characteristics of sites, mussel beds, and invertebrate identifications and counts.

## Description of the data and file structure

The five sheets of the file organize the data in the different aspects of the study.

1\) Metadata – informs the sampling period, site names and abbreviations, distance between sites (km) and coordinates in decimals.

2\) Main – includes invertebrate counts and identifications for all samples. ‘Site’ stands for the sampled rocky shores (Guaecá, Feiticeira, Itassucê and São Pedro); ‘Date’ for the sampling date; ‘Treatment’ for sampled habitat [control vs facilitated (= bed)]; ‘Level’ for the height within the mussel-bed vertical range (low, mid and high); ‘Replicate’ for each replicate sample (n = 5) within all combinations of site*treatment*...