Data from: Macroinvertebrate community responses to disturbance in a fragmented river with contrasting legacies of alteration
Data files
Aug 26, 2024 version files 266.32 KB
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Cache_NMDS_B.csv
50.73 KB
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Cache_NMDS_env_2.csv
10.22 KB
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Cache_NMDS_N.csv
50.93 KB
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invert_metrics2.csv
16.81 KB
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raw_invert_with_sitedate.csv
130.79 KB
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README.md
6.84 KB
Abstract
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.
README: Data from: Macroinvertebrate community responses to disturbance in a fragmented river with contrasting legacies of alteration
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.
Methods
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 quantification data to convert estimates m-2 wood to m-2 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 m2 channel bottom. EPT biomass (mg AFDM m-2 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 (m3 s-1) (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-1) 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-cm2 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-a concentration was determined using fluorometry following EPA method 445.0. We then calculated two chlorophyll parameters: mean benthic (BenChl) and sestonic (SesChl) chlorophyll-a concentrations (μg m-2) for each site per sampling date.