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ŠUMARSKI LIST 3-4/2017 str. 34     <-- 34 -->        PDF

highly popular game species (Apollonio et al. 2010, Csányi et al. 2014). On the other hand, it may cause severe damage in forestry (browsing, bark stripping and rubbing young trees), and agriculture (grazing on meadows and fields; Gill 1992, Reimoser and Gossow 1996, Verheyden et al. 2006, Mysterud et al. 2010, Marchiori et al. 2012).
The magnitude of red deer impacts on the environment and humans primarily depends on its local population density (Putman 1996, Palmer et al. 2007). The principal factor that determines population density is habitat suitability (Sinclair et al. 2005), which may be in numerous ways affected by humans, both intentionally and unintentionally. In wildlife management, for example, supplemental feeding and other measures are performed to improve environmental carrying capacity, which affects spatial distribution and fitness of red deer (Putman and Staines 2004, Rodriguez-Hidalgo et al. 2010, Jerina 2012). Forestry measures constantly transform forests and consequently (often unintentionally) affect their habitat suitability for red deer (Adamič 1991, Reimoser and Gossow 1996, Kramer et al. 2006, Kuijper et al. 2009). The full extent of anthropogenic factors is usually poorly understood (Weisberg and Bugmann 2003). Therefore it is difficult or almost impossible to properly address them in forest and wildlife management planning. To optimise and rationalise red deer management, it is important to know the impacts of a variety of factors, in particular of the anthropogenic kind, on habitat suitability.
Space use of red deer may be affected by a variety of natural and anthropogenic environmental as well as „historical” factors (events/management in the past). Key factors include topography (altitude, exposure, slope; Debeljak et al. 2001, Zweifel-Schielly et al. 2009, Baasch et al. 2010, Stewart et al. 2010, Alves et al. 2014) and climate (temperature, precipitation, wind; Schmidt 1993, Conradt et al. 2000, Luccarini et al. 2006). Numerous studies have also demonstrated the impact of different anthropogenic factors: a) forest characteristics, in particular proportion of forest in the landscape (Biro et al. 2006, Zweifel-Schielly et al. 2009, Heurich et al. 2015), fragmentation (Licoppe 2006, Baasch et al. 2010, Allen et al. 2014) and internal forest structure (e.g. proportion of individual age classes, conifer/broadleaf ratio; Debeljak et al. 2001, Licoppe 2006, Borkowski and Ukalska 2008, Alves et al. 2014); b) supplemental feeding sites (Putman and Staines 2004, Luccarini et al. 2006, Perez-Gonzalez et al. 2010, Jerina 2012, Reinecke et al. 2014), fields and meadows (Biro et al. 2006, Godvik et al. 2009, Zweifel-Schielly et al. 2009, Perez-Barberia et al. 2013, Lande et al. 2014); c) disturbance factors such as roads and hiking trails (Baasch et al. 2010, Jerina 2012, Meisingset et al. 2013). Among the „historical” factors, present-day space use is probably most strongly affected by past management of red deer, in particular drastic interventions such as eradication or reintroduction of species (Apollonio et al. 2010, Scandura et al. 2014).
Habitat studies of wild ungulates including red deer can generally be divided into small-scale and large-scale studies. Small-scale studies are commonly conducted on small areas (less than one to several 10 km2) and are based on detailed spatial data such as telemetry and pellet group counting (e.g. Luccarini et al. 2006, Lovari et al. 2007, Borkowski and Ukalska 2008, Heinze et al. 2011, Alves et al. 2014). They typically include only few environmental factors with narrow gradients of values (because usually environment does not change drastically over small distances). Therefore they are more locally relevant and should not be extrapolated. On the other hand, large-scale (e.g. regional level) studies are based on rough indicators of population density (e.g. culling), typically referring to large (up to several 10 km2) administrative units (hunting grounds, municipalities; e.g. Mysterud et al. 2002, Merli and Meriggi 2006, Cowled et al. 2009). The limitation of such studies is that they cannot reliably analyse environmental factors which vary at a smaller spatial scale (e.g. internal forest structure). There is, however, an absence of studies combining the benefits of both approaches.
The purpose of this study was to analyse the impacts of environmental and historical factors on spatial distribution and local population density of red deer on extensive area but at a fine spatial resolution, thus combining the advantage of both approaches. With the aim to improve both red deer and forest management, we focused on habitat factors affected by both disciplines.
The study area comprises the entire Slovenia (20,273 km2; 45°25’ – 46°53’ N, 13°23’ – 16°36’ E), which has very diverse geographical, climatic and landscape features. As such it is also a very diverse red deer habitat, which contributes to the robustness of the study. Average annual temperatures range from 0°C to 14°C and precipitation from 800 mm to 3 300 mm (Ogrin 1996). Altitude ranges from sea level to > 2 500 m high Alpine peaks; 59% of the land is covered in forest; forest cover varies locally from < 20% in predominantly agricultural and urban areas to > 90% in large massifs of Dinaric mountains and Pre-alps (Figure 1; Jakša 2012). Mixed forests are the most common forest type; however, the conifer/broadleaf ratio varies significantly. Common beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) are the most abundant tree species, representing 31% and 30% of the growing stock, respectively. They are followed by silver fir (Abies alba Mill.) with 7% and sessile oak (Quercus petraea (Matt.) Liebl.) with 6%; individual shares of other species are < 5%. Majority of forests