Yngve Rekdal
Seniorrådgiver (pensjonistavtale)
(+47) 959 33 520
yngve.rekdal@nibio.no
Sted
Ås - Bygg O43
Besøksadresse
Oluf Thesens vei 43, 1433 Ås (Varelevering: Elizabeth Stephansens vei 23)
Forfattere
Ari Hietala Wilson Lara Henao A. Kolsgaard Simon Seljegard Nina Elisabeth Nagy Isabella Børja Tor Arne Justad Yngve Rekdal Even Bergseng Halvor SolheimSammendrag
Forest grazing by free-roaming livestock is a common practice in many countries. The forestry sector sees the practice as unfortunate owing to several reasons, such as damages inflicted by grazing in young plantations. Concerning Norway spruce forests, a tree species known to develop wood decay with high frequency followed from stem bark damage, there is a strong perception among foresters that the trampling damage caused by livestock on the superficial root system of this tree leads to decay. Because of the very limited scientific documentation available on this topic, we pursued a clarification by investigating three 38- to 56-year-old Norway spruce forests used for silvopasture. Two types of injuries were observed on exposed roots: bark cracks characterized by resin exudation, and injuries involving localized bark peeling and exposure of the underlying wood. These injuries occurred up to 250 cm away from the root collar, with the sector 50–150 cm away from the root collar showing the highest incidence of injuries. In two of the forest stands, wood within the injured root areas was primarily colonized by the wound parasite Corinectria fuckeliana or species of the order Helotiales, fungi that do not cause wood decay. Wood colonization of injured roots by Heterobasidion species, the most frequent wood decay fungi of Norway spruce, was common in the third stand, but only in a few cases it was possible to deduce that the colonization had probably initiated via trampling injuries on roots. In a few cases, an injury was located at stem base at the root collar height along paths used by animals, and in such cases, it was obvious that stem colonization by Heterobasidion species had initiated via the wound. The relatively small amount of data warrants caution when drawing conclusions. Considering the high establishment frequency of decay via stem bark wounds of Norway spruce observed in previous studies, our data would suggest that roots are generally better equipped to defend themselves upon infliction of superficial wounds than stem of this tree species. The likelihood of trampling injuries leading to decay may vary considerably between different stands, this presumably depending on the level of local propagule pressure by pathogenic wood decay fungi and the frequency of damages close to root collar.
Sammendrag
Nord-Noreg har dei største utmarksbeiteressursane i landet både i kvalitet og mengde. Men bruken av ressursen er liten og har ei negativ utvikling. Dette går fram av ein rapport frå NIBIO som for første gong gjev ei samla oversikt over utmarksbeite for husdyr i heile landet og for kvart fylke.
Sammendrag
Norsk institutt for bioøkonomi utførte somrane 2022 og 2023 vegetasjonskartlegging av området Oppheimsdalen og Brekkedalen i Voss herad. Samla areal er 104 km². Kartlegginga er gjort etter instruks for kartlegging i målestokk 1:20 000 - 50 000 (VK25). Det er laga vegetasjonskart og to avleia temakart for beite for sau og storfe. Denne rapporten beskriv metode for kartlegging, registrerte vegetasjonstypar og deira fordeling i området. Det er gjeve ein omtale av beitekvalitet og beitekapasitet, samt nokre råd kring skjøtsel av kulturlandskap og beite.
