Klövviltets besöksfrekvens och bete i sydsvenska poppelplanteringar

Abstract: Energy is an essential part of the society and for a sustainable future we need to use the energy resources in a sustainable way. The forest is Sweden’s most important resource for renewable energy and a higher production combined with shorter rotation periods (time from planting to clear cutting) can increase the access to energy. The tree genus poplar (Populus spp.) is interesting as energy resource as it has both high production and short rotation period. But browsing ungulates are a major threat to the establishment of poplar plants and therefore the poplar plantations need to be fenced in today. To use fences is expensive and time consuming; this makes it interesting to find more cost-effective solutions where there is no need to fence. The aim with this study was to look at the ungulates’ occupation rate and browsing pressure in poplar plantations without fence. Occupation rate was estimated as the amount of individuals of each species that was caught on a picture compared to the total amount of pictures the camera could take per day. Browsing pressure is here defined as the percentage browsed plants (fresh bites) per plot and week. I wanted to see which ungulate species that was most frequent and how the occupation rate at different plots varied with time. The correlation between occupation rate and browsing pressure was also analysed and the effect of supplementary feeding was added to this analysis. To reach the goal with this study pictures from camera traps and field inventories were used. The study was carried out during the summer (during twelve weeks) at 19 sampling plots with camera traps, at the research stations Asa, Småland and Tönnersjöheden, Halland. At each sampling plot one-year old poplar clones were planted; four species, four hybrids and hybrid aspen. Supplementary feed (silage) was provided at six of the plots. The browsing pressure was highest at Tönnersjöheden and increased towards the end of the summer. Because of a similar distribution between moose and roe deer at the two research stations the composition of the game population is probably not a reason for the observed difference in browsing pressure. Climate, alternative fodder and ground vegetation can have been influencing both occupation rate and browsing pressure. Results showed that occupation rate was highest in the middle and the end of the study period. At each plot where field observation indicated browsed plants there was at least one picture of moose or roe deer. However, no significant relationship could be seen between the units of occupation rate and browsing pressure used in the study. Browsing pressure was lower at plots where silage was provided. One reason for this can be that there was a lower occupation rate there as well. Earlier studies have shown that moose and roe deer have been missing at plots where wild boar has been observed. Wild boars were observed at plots with silage and it would be interesting to do a further study on how wild boars are affecting other ungulates.