DOI: 10.5061/dryad.xgxd254p9
title: Data from: Macroinvertebrate community responses to disturbance in a fragmented river with contrasting legacies of alteration

description: 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 is impaired by reduced flow, sedimentation, and hypoxia,
 were comprised of smaller-bodied and pollution-tolerant taxa with lower
 α-diversity. Unlike the upper segment, communities were patchily
 distributed among sites (higher spatial turnover), which made it more
 difficult to detect system-wide temporal variation in composition
 throughout the study. Our study underscores the benefit of including
 measures of connectivity and spatial heterogeneity when assessing the
 ecological integrity of lotic systems. Understanding system-wide response
 to disturbances across longer time frames can help better predict and
 mitigate the impacts of climate change on ecosystem integrity in degraded
 rivers.
description: 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<sup>-2</sup> 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 quantification data to
 convert estimates m<sup>-2</sup> wood to
 m<sup>-2</sup> channel bottom. Metrics of
 integrity: Diversity was calculated using the diversity() function in the
 vegan package in R v4.2.1 using abundance data and the Shannon Diversity
 Index. To calculate total biomass (mg AFDM), we summed the biomass of all
 taxa for each site and sampling event. Body size (mg AFDM) was calculated
 by dividing total biomass (mg AFDM) by total abundance (number of
 individuals) per m<sup>2</sup> channel bottom. EPT biomass (mg
 AFDM m<sup>-2</sup> channel bottom) was calculated by summing
 the biomass values for all invertebrates within the orders Ephemeroptera,
 Plecoptera, and Trichoptera. We calculated Hilsenhoff Biotic Index (HBI)
 using published tolerance values. For voltinism analysis, we assigned taxa
 a voltinism category (semivoltine, univoltine, and bi/multivoltine) from
 the US EPA Freshwater Biological Traits Database based on geographic
 proximity when possible and calculated percent multivoltine taxa as a
 proportion of total abundance. Environmental
 parameters: UCR discharge data were obtained from the USGS gage station at
 Foreman, IL. We measured LCR discharge during February-May 2013 and
 combined these with measurements by Illinois Department of Natural
 Resources personnel from May 2011 and January-May 2013. We then
 established a correlation between measured LCR discharge events and daily
 UCR discharge from USGS, performed using Spearman rank correlation in R
 and extrapolated to estimate LCR discharge for 2011-2013. Using these
 discharge measurements, we calculated two discharge-related parameters:
 mean monthly discharge (m<sup>3</sup>
 s<sup>-1</sup>) (hereby referred to as Qmo) and coefficient of
 variation of mean daily discharge (QCV) for each month, calculated as the
 standard deviation divided by the mean. We measured dissolved oxygen (DO)
 every 15 minutes for 24 hours once per month using a Hydrolab mini-sonde 5
 (OTT Hydromet, Loveland, CO), ~0.4 m below the water surface at one site
 each in the UCR and LCR and calculated three DO parameters: mean (DOmean),
 minimum (DOmin), and maximum (DOmax) values (mg
 L<sup>-1</sup>) for the 24-hour period measured each month. We
 recorded hourly water temperature (ºC) with HOBO® data loggers at four of
 the eight study sites and calculated two temperature-related parameters:
 mean monthly temperature (Temp) and cumulative degree days (above 0ºC) as
 of each sampling date starting January 1 of each year (DegDays). For
 chlorophyll, we collected benthic algae samples monthly from three snag
 habitats at each study site by delineating and scrubbing a
 4-cm<sup>2</sup> area using a plastic template and steel
 brush. We also collected three sestonic algae samples monthly from the
 water column. Benthic slurries and sestonic samples were filtered through
 0.7-μm glass fiber filters and extracted in 90% buffered acetone overnight
 in the dark and on ice, and the chlorophyll-<em>a</em>
 concentration was determined using fluorometry following EPA method 445.0.
 We then calculated two chlorophyll parameters: mean benthic (BenChl) and
 sestonic (SesChl) chlorophyll-<em>a</em> concentrations (μg
 m<sup>-2</sup>) for each site per sampling date.
description: # 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 factor combining the site (e.g., UC1 = site 1 in the UCR) and month/year (e.g., June 2010) in which the samples were collected. segment_year: a factor combining the river segment (UCR or LCR) and year in which the samples were collected. Acerpenna …: the remaining columns are the abundance values (individuals per m^2 river channel) for each macroinvertebrate taxon found in three samples averaged together from that site/date. ### Biomass: Cache\_NMDS\_B.csv The contents of the columns in Cache_NMDS_B.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. wet/dry: a factor indicating whether the samples were collected in a “wet” year (2011 and 2013) or a “dry” year (2010 and 2012). sitedate: a factor combining the site (e.g., UC1 = site 1 in the UCR) and month/year (e.g., June 2010) in which the samples were collected. segment_year: a factor combining the river segment (UCR or LCR) and year in which the samples were collected. Acerpenna…: the remaining columns are the biomass values (mg AFDM per m^2 river channel) (AFDM = ash-free dry mass) for each macroinvertebrate taxon found in three samples averaged together from that site/date. Note: Cambaridae and Palaemonidae (both rare) were excluded to prevent their high individual biomass from skewing analyses. ### Environmental Parameters: Cache\_NMDS\_env\_2.csv The contents of the columns in Cache_NMDS_env_2.csv are as follows: sitedate: a factor combining the month/year (e.g., June 2010) and site (e.g., UC1 = site 1 in the UCR) in which the samples were collected. 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. Qmo: mean monthly discharge (m3/s). QCV: coefficient of variation of mean daily discharge. DOmean: mean dissolved oxygen (mg/L) over 24-h period. DOmin: minimum dissolved oxygen (mg/L) over 24-h period. DOmax: maximum dissolved oxygen (mg/L) over 24-h period. SesChl: sestonic chlorophyll-a concentration (μg/m^2). BenChl: benthic chlorophyll-a concentration (μg/m^2). Temp: mean monthly temperature (ºC). DegDays: cumulative degree days (above 0ºC). ### Metrics: invert\_metrics2.csv The contents of the columns in invert_metrics2.csv are as follows: date: when samples were collected (m/dd/yyyy). year: when samples were collected (2010, 2011, 2012, or 2013). month: 3-letter abbreviation of month when samples were collected. Month: number of month when samples were collected. day: day of month when samples were collected. 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 factor combining the month/year (e.g., June 2010) and site (e.g., UC1 = site 1 in the UCR) in which the samples were collected. TotalN: total macroinvertebrate abundance (individuals per m2 river channel) for all macroinvertebrate taxa found in three samples averaged together from that site/date. sqrtN: square root of total abundance TotalB: total macroinvertebrate biomass (mg AFDM per m2 river channel) for all macroinvertebrate taxa found in three samples averaged together from that site/date. sqrtB: square root of total biomass BodySize: average individual mass, calculated by dividing total biomass by total abundance sqrtBS: square root of BodySize HBI: Hilsenhoff Biotic Index (see equation 2 from Hilsenhoff WL 1977 Use of arthropods to evaluate water quality of streams. In Technical Bulletin No. 100.), calculated using tolerance values from a variety of published sources. EPT B: total biomass (mg AFDM per m2 river channel) of macroinvertebrates in the orders Ephemeroptera, Plecoptera, and Trichoptera. sqrtEPT: square root of EPT B. Richness: number of distinct taxa found. percent_multi: relative abundance of taxa with a multivoltine life history (two or more generations per year). percent_uni: relative abundance of taxa with a univoltine life history (one generation per year). percent_semi: relative abundance of taxa with a semivoltine life history (less than one generation per year). arcsinsqrtmulti: the arcsine-square root transformation of percent multivoltine. arcsinsqrtuni: the arcsine-square root transformation of percent univoltine. arcsinsqrtsemi: the arcsine-square root transformation of percent semivoltine. ### Abundance (individual samples): raw\_invert\_withsitedate.csv In contrast to the abundance file described above which averaged together three samples for each site-date, this file contains abundance values for each sample separately, used for alpha (Shannon) diversity calculations. The contents of the columns in raw_invert_withsitedate.csv are as follows: year: when sample was collected (2010, 2011, 2012, or 2013). month: when sample was collected (June, July, or August). reach: river segment where sample was collected; UC = Upper Cache River or LC = Lower Cache River. site: site number (1-8) where the sample was collected. sample: sample replicate number (e.g., s1 = sample 1.). date_R_s_rep: A factor combining the month, year, reach, site, and sample replicate number. sitedate: a factor combining the site (e.g., UC1 = site 1 in the UCR) and month/year (e.g., June 2010) in which the sample was collected. Acerpenna …: the remaining columns are the abundance values (individuals per m2 river channel) for each macroinvertebrate taxon found in each individual sample.