Macroinvertebrate community responses to disturbance in a fragmented river with contrasting legacies of alteration

Flow is a critical factor determining riverine ecosystem structure and function. Widespread hydrologic alteration, however, has impacted the ecological integrity of rivers in ways that are not well understood, including responses of biological communities to increasingly frequent and severe climatic disturbances. Our study compared responses of invertebrate communities on woody debris to large flooding and extreme drought in two highly contrasting segments of an impaired low-gradient river. The upstream segment, which according to previous research has higher α-diversity and production of large-bodied and sensitive invertebrates, maintained higher flows and longitudinal connectivity throughout the four-year study. Communities in this upper segment resembled one another among sites (lower spatial turnover), but experienced greater temporal shifts in composition associated with hydrological disturbances. Conversely, invertebrate communities in the highly altered downstream segment, which ..., These data sets contain macroinvertebrate community structure and environmental data from the Cache River in southern Illinois, USA, from Jun-Aug of 2010-2013.
Macroinvertebrates: We sampled eight sites (100-m reaches), four each upstream (UCR) and downstream (LCR) of the Post Creek Cutoff. We collected three macroinvertebrate samples at each site from large woody debris (snags) using a 250-μm mesh net, scrubbing the snag in a bucket of stream water, and preserving in ~8% formalin. We measured the length of the snag and the circumference in three places to estimate surface area. Preserved invertebrates were enumerated and identified using a dissecting microscope. Lengths were measured to the nearest mm and used to estimate biomass using published length-mass relationships. We estimated abundance and biomass m-2 of wood using the surface area of the snags collected and averaged three samples per site for each sample date at each study site. We then used site-specific wood habitat quantif..., , # Data from: Macroinvertebrate community responses to disturbance in a fragmented river with contrasting legacies of alteration

[https://doi.org/10.5061/dryad.xgxd254p9](https://doi.org/10.5061/dryad.xgxd254p9)

## Description and file structure

The files described below contain data used for statistical analyses and visualizations in the article “Macroinvertebrate community responses to disturbance in a fragmented river with contrasting legacies of alteration” in River Research and Applications. Data are provided in .CSV format. Each description below is for a separate file.

### Abundance (samples averaged): Cache\_NMDS\_N.csv

The contents of the columns in Cache_NMDS_N.csv are as follows:
year: when samples were collected (2010, 2011, 2012, or 2013).
month: when samples were collected (June, July, or August).
segment: river segment where samples were collected; UCR = Upper Cache River or LCR = Lower Cache River.
site: site number (1-8) where the samples were collected.
sitedate: a...