DOI: 10.5061/dryad.931zcrjx9
title: Data from: Within-reach temperature heterogeneity is limited in a southern Appalachian stream network, southeastern USA

description: Stream temperature monitoring networks, combined with geospatial data and
 statistical modeling, facilitate temperature mapping at the spatial
 resolution of inter-confluence stream reaches and at continental spatial
 extents. Comparatively few monitoring efforts quantify spatiotemporal
 temperature heterogeneity within inter-confluence stream reaches. We
 measured within-reach temperature heterogeneity for six study reaches in a
 southern Appalachian stream network, southeastern USA. Within each reach,
 we logged temperature at 27 monitoring points every 15 minutes for three
 days during early summer and three days during late summer of 2018.
 Analysis of variance indicated that daily minimum, mean, and maximum water
 temperature metrics vary more among reaches than within reaches. For
 example, the difference in daily mean temperature from the warmest to
 coldest reach was 8.7°C, whereas within-reach variation never exceeded
 2.3°C for any of the three daily temperature metrics. Mixed effects models
 indicated that most variation in the three daily water temperature metrics
 can be explained by reach-resolution covariates, including elevation,
 watershed area, and forest cover. The limited within-reach temperature
 heterogeneity was driven by longitudinal position along the reach but,
 surprisingly, not by riparian canopy gaps, vertical stratification, or
 other factors. Our findings verify that temperature mapping at the
 resolution of inter-confluence reaches effectively captures temperature
 gradients and indicate that thermally-sensitive organisms have limited
 access to fine-scale refuge in southern Appalachian streams. Generally,
 within-reach temperature heterogeneity should be quantified in more
 geographic and physiographic contexts to understand natural and
 anthropogenic drivers of this variation, validate reach-resolution
 temperature mapping, and forecast climate change refuges.
description: # Data from: Within-reach temperature heterogeneity is limited in a
 southern Appalachian stream network, southeastern USA Dataset DOI:
 [10.5061/dryad.931zcrjx9](10.5061/dryad.931zcrjx9) ## Description of the
 data and file structure These files include (1) stream temperature
 monitoring data from the Little River watershed (Blount County, Tennessee)
 and (2) associated geographic and environmental variables describing the
 monitoring locations. ### Files and variables #### File: ####
 site_env_v01.csv **Description:**  ##### Variables * COMID: Unique
 flowline ID from National Hydrography Dataset (NHD). * lon: Longitude in
 decimal degrees. * lat: Latitude in decimal degrees. * reach: One of six
 reach name abbreviations. * transect: One of nine transect numbers. *
 point: One of three point numbers, or alternative air temperature
 monitoring point. * period: Early or late summer monitoring period denoted
 1 or 2, respectively. * attach: Method of logger attachment in stream. *
 bank: Abbreviation for point on left or right bank. * azimuth_300m:
 Azimuth in units of degrees of transect. * lon_pos: Longitudinal distance
 of transect in meters from the upstream-most transect. * lat_pos_m:
 Lateral distance of point in meters from the streambank. * lat_pos:
 Lateral position of point defined as stream middle or edge. * vert_pos:
 Vertical position of point defined as surface or benthic. * vert_pos_cm:
 Vertical position of point in centimeters from water surface. *
 vert_strat: Type of monitoring point defined as surface, benthic, or
 neither. * S_depth: Water depth in centimeters on monitoring day 1. *
 E_depth: Water depth in centimeters on monitoring day 3. * canopy:
 Riparian canopy cover measured as percent covered. * Missing data:
 mentioned as NA #### File: #### dframe_temps15min.csv **Description:** 
 ##### Variables * reach: One of six reach name abbreviations. * transect:
 One of nine transect numbers. * point: One of three point numbers, or
 alternative air temperature monitoring point. * period: Early or late
 summer monitoring period denoted 1 or 2, respectively. * day: Monitoring
 day 1, 2, or 3. * date_time: Date and time of temperature measurement. *
 WT: Water temperature measured in degrees Celsius. * AT: Air temperature
 measured in degrees Celsius. ## Access information Other publicly
 accessible locations of the data: * n/a Data was derived from the
 following sources: * n/a