DOI: 10.5061/dryad.1ns1rn8st
title: Data for: Abundance and accessibility of forage for reindeer in forests of Northern Sweden: impacts of landscape and winter climate regime

description: The survival of reindeer during winter, their period of greatest food
 stress, is largely dependent upon the abundance and accessibility of food
 in their pastures. In Northern Sweden this realised availability of forage
 is notably affected by snow conditions and the impacts of forestry on
 understorey in these pastures. Whilst these factors have been examined to
 some extent in isolation, their combined effect on overall forage
 availability has, to the best of our knowledge to date, not been studied.
 In this study, vegetation surveys and analysis of snow conditions were
 undertaken in 16 forest stands at various stages of recovery from
 clear-cutting. The variation in abundance and growth of understorey
 species edible by reindeer, such as lichen, were noted as forest age
 increased. The barrier effect of ice lenses in snow during winter was also
 noted. Lichen biomass was significantly affected by a combination of stand
 age, understorey vegetation height, and lichen height. Soil disturbance
 from the processes of felling, and competition in the vegetation
 communities recovering from this disturbance were identified as key
 drivers of change in lichen biomass. Overall, clear-cut forests had some
 of the greatest prevalence of ice lenses in the snow column, and forage
 availability at these sites was up to 61 % less than in stands over 58
 years in age.
description: Tree age was measuring according to dendrochronological
 procedures, using a Mattson No. 4. Increment Borer (Sorbus International,
 Somerset, UK). Canopy cover was measured using a spherical densiometer
 (Spherical Crown Densiometer, Convex Model A, Forestry Suppliers,
 USA.). At each site vegetation surveys were undertaken
 in 10 replicates of 4 m<sup>2</sup> quadrats. Percentage cover
 of each species was visually estimated. Plant height was measured at five
 random points within each quadrat and averaged. In two of the 4
 m<sup>2</sup> quadrats at each site, five quadrants of
 0.01 m<sup>2</sup> were placed. Lichen cover, and height at
 three points, was noted. All lichen within the 0.01 m<sup>2
 </sup>quadrats was extracted, dried to a constant weight at
 105 <sup>o</sup>C, and immediately cooled and weighed
 (Satorius M-prove, Satorius AG, Goettingen, Germany). All data was nested
 by site. Snow pits were dug in November 2019, plus
 January and March 2020. Six pits were dug per site, each &gt; 10 m
 distance from one another, with three within 0.5 m of a tree and three in
 open areas between the trees. At clear-cut sites, the six snow pits were
 randomly distributed. In pits, snow depth was measured,
 alongside hardness of each layer within the snow column using the hand
 hardness test. All
 measurements were undertaken by the lead author. The thickness of each
 distinct layer was measured with a ruler. Snow of the hand hardness
 categories P, K and I (henceforth PKI) were regarded as impenetrable to
 reindeer. If greater than 1 % of the site showed signs of reindeer digging
 the site was classified as having cratering present, otherwise classified
 as cratering being absent. All data was nested by site.
 Daily temperature data at Jokkmokk flygplats weather station was
 used for winters starting 2006 until the winter of 2019/20, alongside
 daily snow depth data during the same period at Murjek D weather station.
 Winter was defined as 1<sup>st</sup> October to
 20<sup>th</sup> April corresponding to the period when
 reindeer are allowed to be present in their winter grazing
 grounds. Data were nested by site to avoid
 pseudoreplication.
description: Please refer to README file.