Ken Olaf Storaunet
Seniorforsker
(+47) 902 32 668
ken.olaf.storaunet@nibio.no
Sted
Ås - Bygg H8
Besøksadresse
Høgskoleveien 8, 1433 Ås
Sammendrag
Persistence of standing dead trees (snags) is an important determinant for their role for biodiversity and dead wood associated carbon fluxes. How fast snags fall varies widely among species and regions and is further influenced by a variety of stand- and tree-level factors. However, our understanding of this variation is fragmentary at best, partly due to lack of empirical data. Here, we took advantage of the accruing time series of snag observations in the Finnish, Norwegian and Swedish National Forest Inventories that have been followed in these programs since the mid-1990s. We first harmonized observations from slightly different inventory protocols and then, using this harmonized dataset of ca. 43,000 observations that had a consistent 5-year census interval, we modelled the probability of snags of the main boreal tree species Pinus sylvestris, Picea abies and Betula spp. falling, as a function of tree- and stand-level variables, using Bayesian logistic regression modelling. The models were moderately good at predicting snags remaining standing or falling, with a correct classification rate ranging from 68% to 75% among species. In general, snag persistence increased with tree size and climatic wetness, and decreased with temperature sum, advancing stage of decay, site productivity and disturbance intensity (mainly harvesting). Synthesis and applications: The effect of harvesting demonstrates that an efficient avenue to increase the amount of snags in managed forests is protecting them during silvicultural operations. In the warmer future, negative relationship between snag persistence and temperature suggests decreasing the time snags remain standing and hence decreasing habitat availability for associated species. As decomposition rates generally increase after fall, decreasing snag persistence also implies substantially faster release of carbon from dead wood.
Forfattere
Aksel Granhus Clara Antón-Fernández Heleen de Wit Kjersti Holt Hanssen Fride Høistad Schei Rannveig Margrete Vigdisdatter Jacobsen Ulrika Jansson Heikki Korpunen Christian Wilhelm Mohr Jenni Nordén Jørund Rolstad Ignacio Sevillano Svein Solberg Ken Olaf Storaunet Marta VergarecheaSammendrag
Miljødirektoratet har gitt NIBIO, NINA og NIVA i oppdrag å vurdere hvilken effekt økt bruk av lukkede hogstformer kan ha for karbonlagring i skog, biodiversitet, økologisk tilstand, vannkvalitet og skognæring. Oppdraget er utført ved hjelp av gjennomgang av relevant litteratur, data fra Landsskogtakseringen, modellbaserte simuleringer og ekspertvurderinger.
Forfattere
Ken Olaf StoraunetSammendrag
Det er ikke registrert sammendrag