DOI: 10.5061/dryad.zcrjdfnjm
title: Data for: Horizontal viewsheds of large herbivores as a function of woodland structure

description: This dataset contains values of tree stem density per hectare of different
 size classes (Sapling: &gt; 0.3m, &lt; 1.3m height, Small stem:
 &gt;=1.3m height, &lt; 10cm DBH, Medium stem: 10-20cm DBH, Large:
 21-30cm DBH, Very large: &gt;=31cm DBH), Viewshed Coefficient values
 (vc), Leaf Area Index (LAI) values for 0.75 - 1.5m above the ground and
 average percentage cover of bramble (Rubus frutocisus agg.). These data
 have come from 71 circular 15m-radius sampling plots (four-character codes
 in plotID column across ten woodland sites (three-character codes in site
 column).  The "raw_data" tab contains the
 untransformed, unscaled raw data. The "transformed_scaled_data"
 tab contains the transformed, scaled data that were used in the modelling
 approach in the associated manuscript.
description: The tree stem density data were collected through manual stem
 counts and measurements using a Diameter at Breast Height (DBH) tape. The
 units of these stem density columns are "stem density per
 hectare". The Viewshed Coefficient (vc) values
 were produced from 3D pointcloud datasets collected with a hand-held
 mobile terrestrial laser scanner (GeoSLAM ZEB Revo). The pointclouds were
 processed in R (version 4.0.3) following methodology in the associated
 manuscript using the <em>viewshed3d</em> (Lecigne &
 Eitel, 2022) and <em>lidR</em> (Roussel et al., 2020)
 packages. The vc values were calculated using the h_visibility function in
 the viewshed3d package. The Leaf Area Index (LAI) data
 were also extracted from the 3D pointcloud data following methodology in
 the associated manuscript by generating Leaf Area Density (LAD) profiles
 using the LAD function in the<em> lidR </em>package, then
 calculating LAI values from these profiles using the<em> lai
 </em>function in the <em>leafR</em> (de Almedia et al,
 2021) package. The
 "average.bramble.perc.cover" column contains values of average
 percentage bramble (<em>Rubus frutocisus agg.</em>) cover for
 each plot. Bramble cover was measured following methodology in the
 associated manuscript using randomly placed 0.25m^2 quadrats.
 In the "transformed.scaled.data" tab, the columns
 containing ".log" in the title have been log transformed. In
 addition, all values accept those in the "vc" column have been
 scaled through z-scoring. 
description: # Data for: Horizontal viewsheds of large herbivores as a function of
 woodland structure *** Raw and transformed data from tree stem surveys and
 mobile hand-held terrestrial laser scanner surveys of temperate woodlands
 in North Wales for the purpose of assessing the effect of woodland
 structure on viewsheds for herbivores living in the woodland understory.
 Analysis in the associated publication found a significant negative effect
 of small stem density on the viewshed coefficient (vc), meaning higher
 densities of small stems resulted in lower visibility for herbivores. ##
 Description of the data and file structure This dataset contains values of
 tree stem density per hectare of different size classes (Sapling: &gt;
 0.3m, &lt; 1.3m height, Small stem: &gt;=1.3m height, &lt;
 10cm DBH, Medium stem: 10-20cm DBH, Large: 21-30cm DBH, Very large:
 &gt;=31cm DBH), Viewshed Coefficient values (vc), and Leaf Area Index
 (LAI) values for 0.75 - 1.5m above the ground. These data have come from
 71 circular 15m-radius sampling plots (four-character codes in plotID
 column across ten woodland sites (three-character codes in site column).
 The tree stem density data were collected through manual stem counts and
 measurements using a Diameter at Breast Height (DBH) tape. The units of
 these stem density columns are "stem density per hectare". The
 Viewshed Coefficient (vc) values were produced from 3D pointcloud datasets
 collected with a hand-held mobile GeoSLAM (Nottingham) ZEB Revo
 terrestrial laser scanner. The pointclouds were processed in R version
 4.0.3 (R Core Team, 2021) following methodology in the associated
 manuscript using the viewshed3d (Lecigne & Eitel, 2022) and lidR
 (Roussel et al., 2020) packages. The vc values were calculated using the
 h\_visibility function in the viewshed3d package. The Leaf Area Index
 (LAI) data were also extracted from the 3D pointcloud data following
 methodology in the associated manuscript by generating Leaf Area Density
 (LAD) profiles using the LAD function in the lidR package, then
 calculating LAI values from these profiles using the lai function in the
 leafR (de Almedia et al, 2021) package. The
 "average.bramble.perc.cover" column contains values of average
 percentage bramble (Rubus frutocisus agg.) cover for each plot. Bramble
 cover was measured following methodology in the associated manuscript
 using randomly placed 0.25m^2 quadrats. The "raw\_data" tab
 contains the untransformed, unscaled raw data. The
 "transformed\_scaled\_data" tab contains the transformed, scaled
 data that were used in the modelling approach in the associated
 manuscript. In the "transformed\_scaled\_data" tab, the columns
 containing ".log" in the title have been log transformed. In
 addition, all values accept those in the "vc" column have been
 scaled through z-scoring. ## Sharing/Access information Any questions or
 trouble with access, please email the corresponding author: Amy Gresham
 amygresham48@gmail.com ## Code/Software All pointcloud processing that
 generated these data was conducted in R version 4.0.3 using the lidR
 (Roussel et al., 2020), viewshed3d (Lecigne & Eitel, 2022) and
 leafR (de Almedia et al, 2021) packages. Please email the corresponding
 author for any enquiries: Amy Gresham amygresham48@gmail.com