DOI: 10.4231/0r47-4f65
title: Connecticut River Watershed Riparian Canopy Data

description: &lt;p&gt;To understand how riparian (stream side) tree canopy cover controls light availability in river networks, we collected hemispherical photographs of tree canopy cover of rivers and streams through the Connecticut River watershed. Data collection occurred primarily in the Farmington River watershed in Connecticut and the Passumpsic River watershed in Vermont, two 5&lt;sup&gt;th&lt;/sup&gt; order tributaries of the Connecticut River. These results have been used in a published study of the response to the Connecticut River to drought conditions by Hosen et al. (&lt;a aria-label="Digital Object Identifier" class="epub-doi" href="https://doi.org/10.1002/lno.11127"&gt;https://doi.org/10.1002/lno.11127&lt;/a&gt;) with additional publications pending.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Methods&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;em&gt;Field Methods&lt;/em&gt;&lt;/p&gt;

&lt;p&gt;Leaf-on data was collected from June 2016 through September 2016. We used a Kodak PixPro SP360 camera to capture hemispherical images of riparian canopy for each site (Figure 1).&lt;/p&gt;

&lt;p&gt;Once we arrived at a site, we used a random number generator to determine our sampling location within a 100-meter range upstream or downstream of the stream point of access. For forested and agricultural sites, a 10-meter buffer was mandated, at minimum, to ensure that areas cleared for roads or trails did not impact light penetration results.&lt;/p&gt;

&lt;p&gt;When the sampling site was identified, we transected the stream. Three images were taken per sampling site&mdash;one per bank, and one in the due center of streamflow. The camera was consistently balanced 15 to 45 centimeters above the water for each image, with a 30- to 45- centimeter range for most sites. An identifying mark on the camera mount was oriented due south in each photo for replicability.&lt;/p&gt;

&lt;p&gt;A subset of leaf-off data was collected from December 2016 through April 2017 (n=20). Twelve sites located were in the Farmington River watershed and eight in the Passumpsic.&lt;/p&gt;

&lt;p&gt;&lt;em&gt;Photo Preparation and Canopy Cover Estimation&lt;/em&gt;&lt;/p&gt;

&lt;p&gt;Photos were processed using SideLook 1.1.01 with automatic threshold detection (Nobis and Hunziker 2005). White pixels indicated light penetration and black pixels indicated canopy cover, riparian structures, or ground cover. When visual assessment indicated that automatic threshold results did not correctly sort pixels, we used the &ldquo;set frame&rdquo; feature to manually correct the image.&lt;/p&gt;

&lt;p&gt;After processing, photos were analyzed using standard protocols for CIMES canopy cover analysis software (Gonsamo et al. 2011).&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Four files are included in this dataset:&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;1) Extracted Canopy Cover Values.csv&lt;/strong&gt;&lt;br /&gt;
This file contains extracted canopy cover values from rivers and streams of the Connecticut River watershed. The following attributes are included in this file:&lt;br /&gt;
&lt;strong&gt;Photo:&lt;/strong&gt; The name of the photo file used (all photos are included in the repository).&lt;br /&gt;
&lt;strong&gt;gap_percent:&lt;/strong&gt; Percent of canopy that are gaps in foliage, computed following Gonsamo et al. (2011; doi:10.1016/j.compag.2011.10.001)&lt;br /&gt;
&lt;strong&gt;crown_gap_percent:&lt;/strong&gt; Percent of canopy that are gaps in the crown of foliage. Here&#39;s crown gaps are defined as gaps in the canopy that occur more than 30&deg; above level.&lt;br /&gt;
&lt;strong&gt;Watershed:&lt;/strong&gt; the watershed in which samples were taken (either Passumpsic River or Farmington Rivers).&lt;br /&gt;
&lt;strong&gt;Photo.Site.Name:&lt;/strong&gt; Site name where photo was taken. Metadata about each site is available in the file named &quot;Site Metadata.csv&quot;.&lt;br /&gt;
&lt;strong&gt;Photo Number:&lt;/strong&gt; Replicate photos were taken at each site and are numbered.&lt;br /&gt;
Season: Photographs were taken in Summer (June - September 2016) or Winter (December 2016 - April 2017).&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;2) Site Metadata.csv&lt;/strong&gt;&lt;br /&gt;
&lt;strong&gt;Watershed:&lt;/strong&gt; the watershed in which samples were taken (either Passumpsic River or Farmington Rivers).&lt;br /&gt;
&lt;strong&gt;Site Name:&lt;/strong&gt; Name of the site where photos were taken.&lt;br /&gt;
&lt;strong&gt;Site Cover Type:&lt;/strong&gt; Categorical description of riparian zone. FF = fully forested: both left and right banks were forested, PF = partially forested: either the left or right bank was not forested due to anthropogenic activity.&lt;br /&gt;
&lt;strong&gt;Stream Order:&lt;/strong&gt; Stream order as defined by NHDPlus.&lt;br /&gt;
&lt;strong&gt;Stream Width:&lt;/strong&gt; Stream width in meters as measured on the day of sampling.&lt;br /&gt;
&lt;strong&gt;Site Latitude:&lt;/strong&gt; Latitude of the sampling site.&lt;br /&gt;
&lt;strong&gt;Site Longitude:&lt;/strong&gt; Longitude of the sampling site.&lt;br /&gt;
&lt;strong&gt;Drainage Area (km2):&lt;/strong&gt; Drainage area in square kilometers as determined using USGS StreamStats.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;3) Original JPG Images.zip&lt;/strong&gt;&lt;br /&gt;
A file containing a subset of the original images before conversion to monochrome with SideLook.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;4) Sidelook Processed Images.zip&lt;/strong&gt;&lt;br /&gt;
A file containing the canopy images after processing using SideLook 1.1.01 (Nobis and Hunziker 2005; doi:10.1016/j.agrformet.2004.10.002).&lt;/p&gt;
description: Canopy cover values were extracted from hemispherical camera images from the Connecticut River watershed. Images were collected from June 2016 through April 2017.