Study area
We conducted this study within nine different counties in Norway,
representing a gradient of landscape productivity and human influence
from Troms & Finnmark County in the north (68° N), to Agder County in
the south (58° N) (Figure 1). The southern areas are in general more
fragmented, with forested areas intermixed with agricultural fields and
scattered human settlements, whereas the northern areas are less
productive with boreal forests and alpine tundra. Forests are dominated
by conifers, mainly Scots pine (Pinus sylvestris ) and Norway
spruce (Picea abies ), intermixed with deciduous species such as
birch (Betula pubescens and B. pendula ), rowan
(Sorbus aucuparia ), aspen (Populus tremula ), gray alder
(Alnus incana ), and willow (Salix caprea ), which are more
abundant in the south. Mean annual temperatures decrease with latitude,
being milder in the south (annual mean temperature 7.8°C in
Kristiansand) than in the north (annual mean temperature -0.2°C in
Tromsø) (no.climate-data.org), and
winter severity (i.e. snow depth and low temperatures) increases with
latitude and altitude. Human population densities range from 1642.7
inhabitants per km2 in Oslo County to 3.4 inhabitants
per km2 in Troms & Finnmark
(www.ssb.no). Lynx can potentially be found
across the entire study area but in higher densities in the southernmost
areas. Wolves are restricted to the wolf management zone in southeastern
Norway (Figure 1). Wolf density outside the wolf management zone is
practically zero, as wolves outside the zone are culled as part of
management plans.