Betesmönster hos älg (Alces alces) vintertid i fjällnära skog : En studie av födoval i relation till trädslagssammansättning och habitat

• Main Author: Hambeson, Ella
• Format: Bachelor Thesis
• Language: Swedish
• Published: Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013) 2023
• Subjects: Food choice; Alces alces; forested mountainous terrain; winter diet; selection; Betesval; fjällnära skog; vinterföda; selektion; Zoology; Zoologi; Forest Science; Skogsvetenskap; Norway; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-94380

Browsing patterns in large herbivorous mammals are complex and decisions regarding food items occur at different levels depending on internal or external factors such as energy requirements and available food sources. A broader understanding of the behavior of animals living in habitats of economic interests for humans enables human exploitation with as little impact as possible on the animals' habitats. In this study, individual moose (Alces alces) tracks in the snow were surveyed in a mountainous environment with spruce-dominated forest, to map out what was browsed in relation to what was available in forests of two age classes: young and older. The following hypotheses were made: (1) every potential tree a moose passes will not be browsed and the browsed trees will be browsed to different degrees, and (2) the amount of available forage and the amount of used forage will differ between young and older forest. The moose tracks were followed on skis or on foot and all trees within browsing distance along a transect of 50 meters were counted and signs of browsing were recorded. Control transects (without fresh tracks) were also surveyed in the same forest areas where moose tracks were found. The data showed a higher proportion of available trees in young forest (60%) compared to older forest (40%) (all trees along the track transects), and a higher proportion of browsed trees in young forest (26%) compared to older forest (17%) (excluding Norway spruce, Picea abies). Downy birch (Betula pubescens) was the most abundant tree (56%) and Scots pine (Pinus silvestris) the least abundant (<1%). Only 20% of all available trees along the track transects were freshly browsed to some extent, and even among the more selected species no more than around 50% of all available trees were freshly browsed. In young forest, Eurasian aspen (Populus tremula), rowan (Sorbus aucuparia) and willow (Salix spp.) were the most selected by moose, while common juniper (Juniperus communis) was the least selected. In older forest, however, ...