Hopp til hovedinnholdet

Publikasjoner

NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2024

Til dokument

Sammendrag

Stress on tree vitality is expected to increase due to climatic extremes in European forests. The decline in vitality of European beech (Fagus sylvatica L.) that has been reported recently, makes it necessary to rethink its future adaptive potential under ongoing climate change. Here we performed a pan European assessment of defoliation chronologies on 414 ICP Forests Level I beech plots, between 1995 and 2022. We investigated the temporal trends, spatial variation, tree-specific patterns as well as climate sensitivity of defoliation at plot level. Various trends emerged and we delineated the plots accordingly: 1) increasing defoliation trends indicating declining vitality (categorized as t1 plots); 2) no trends indicating stable crown condition (t2 plots); 3) decreasing defoliation trends indicating increase in vitality (t3 plots). Spatial variation was found among these plots but no regional grouping or clustering. Tree-specific patterns on 14 % plots were observed, characterized by an expressed population signal of < 0.85, indicating high inter-tree variability. Defoliation was found to be sensitive to climatic variables, mainly to temperature but also precipitation, albeit only for a small percentage of plots. Sensitivity was indicated by statistically significant (p<0.05) Pearson’s correlation coefficients. Moreover, this response depended on month of the year. Climate sensitivity of defoliation also varied across space and plots of different trend categories. It also differed along monthly water balance gradient, further indicating the role of site-specific water availability in mediating the responses to climatic variables. Our study provided basis for long-term defoliation studies, and is a crucial building block to assess beech vitality under potentially changing future climate. Furthermore, such studies will provide more insights into changes in sensitivity and adequate future sites for beech.

Til dokument

Sammendrag

Aim Ecological and anthropogenic factors shift the abundances of dominant and rare tree species within local forest communities, thus affecting species composition and ecosystem functioning. To inform forest and conservation management it is important to understand the drivers of dominance and rarity in local tree communities. We answer the following research questions: (1) What are the patterns of dominance and rarity in tree communities? (2) Which ecological and anthropogenic factors predict these patterns? And (3) what is the extinction risk of locally dominant and rare tree species? Location Global. Time period 1990–2017. Major taxa studied Trees. Methods We used 1.2 million forest plots and quantified local tree dominance as the relative plot basal area of the single most dominant species and local rarity as the percentage of species that contribute together to the least 10% of plot basal area. We mapped global community dominance and rarity using machine learning models and evaluated the ecological and anthropogenic predictors with linear models. Extinction risk, for example threatened status, of geographically widespread dominant and rare species was evaluated. Results Community dominance and rarity show contrasting latitudinal trends, with boreal forests having high levels of dominance and tropical forests having high levels of rarity. Increasing annual precipitation reduces community dominance, probably because precipitation is related to an increase in tree density and richness. Additionally, stand age is positively related to community dominance, due to stem diameter increase of the most dominant species. Surprisingly, we find that locally dominant and rare species, which are geographically widespread in our data, have an equally high rate of elevated extinction due to declining populations through large-scale land degradation. Main conclusions By linking patterns and predictors of community dominance and rarity to extinction risk, our results suggest that also widespread species should be considered in large-scale management and conservation practices.

Sammendrag

Driftsgranskingane er eit forvaltningsoppdrag som NIBIO utfører for Landbruks- og matdepartementet. Den årlege undersøkinga viser status og utvikling for økonomien i landbruket og får fram verknadene av politikk og rammevilkår. Ho er såleis eit viktig verktøy for forvaltninga. Analysar av granskingsmaterialet gir dessutan grunnlag for rådgiving, forsking og undervisning.

Til dokument

Sammendrag

1. 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. 2. 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. 3. The models were moderately good at predicting snags remaining standing or falling, with a correct classification rate ranging from 68% to 75% among species. 4. 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). 5. 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.

Sammendrag

Utmarksbeitende dyr er utsatt for angrep fra fredet rovvilt. I oppdrag fra rovviltnemnda i region 6 Midt-Norge undersøker vi i hvilken grad det kan oppdages kadaver av sau og rein i utmark med bruk av droner i åpen og spesifikk kategori sammenlignet med Norske kadaverhunders standard for finsøk. Vi undersøker om droner er egnet til å sjekke ut hvorvidt et dødsvarsel fra GPS-merket sau eller tamrein er ekte eller falsk alarm. Med bakgrunn i gjeldende regelverk diskuterer vi med hvilke metoder droner kan benyttes i skadefellingssituasjoner. Utredningen er basert på feltforsøk, erfaringer, personlig kommunikasjon og faglitteratur. Droner var mer effektive til å finne kadaver som ligger åpent i terrenget sammenlignet med Norske kadaverhunders standard, målt i suksessrate og tidsbruk. Søk BVLOS med GPS-posisjon har den høyeste suksessraten og er lite tidskrevende. Kamerateknologien til moderne droner er god nok til å identifisere skadeomfang av dyr på bakken og kan bidra til å dokumentere tapsårsaker og t.o.m. forbedre dyrevelferd på utmarksbeite. Per dags dato kan en forvente at drone brukes som hjelpemiddel i en skadefellingssituasjon til søk etter dyret (termisk spor, RGB kamera, spor i snø), ved å forstyrre dyret og evt. drive dyret mot fellingslaget og ved å bedøve dyret. Mens drone kan ikke brukes til jakt, kan Miljødirektoratet gi dispensasjon. Erfaringsverdier og et vitenskapelig kunnskapsgrunnlag mangler.