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Sammendrag

Large-scale replacements of native birch with spruce have been carried out in Western Norway for economic reasons. This tree species shift potentially affects biotic components such as the eucaryome, consisting of microscopic animals (Metazoa), protists and fungi, which are key players in the functioning of forest ecosystem. The impact on the belowground eukaryome and its interactions with vegetation and soil properties is not well assessed. We examined the impact of replacing native birch with Norway spruce plantations on the eukaryome of the boreal forest floor in Western Norway using 18S rDNA metabarcoding. The tree species shift from birch to spruce had significant impacts on the eukaryome at both taxonomic (Metazoa) and functional categories (phagotrophs, phototrophs, parasites and osmotrophs). The distinct differences in eukaryome communities were related to changes in understorey vegetation biomass and soil chemistry following the tree species shift. This had a negative effect on eukaryome richness, particularly affecting phagotrophs and parasites, while the opposite was observed for osmotroph richness. Our results indicated that the spruce plantations altered the eukaryome communities and their food-web patterns compared to what was found in the native birch forest soil. This information should be taken into consideration in forest management planning.

Sammendrag

Questions Observations in permanent forest vegetation plots in Norway and elsewhere indicate that complex changes have taken place over the period 1988–2020. These observations are summarised in the “climate-induced understorey change (CIUC)” hypothesis, i.e. that the understorey vegetation of old-growth boreal forests in Norway undergoes significant long-term changes and that these changes are consistent with the ongoing climate change as an important driver. Seven testable predictions were derived from the CIUC hypothesis. Location Norway. Methods Vegetation has been monitored in a total of 458 permanently marked plots, each 1 m2, in nine old-growth forest sites dominated by Picea abies at intervals of 5–8 years over the 32-year study period. For each of the 52 combinations of site and year, we obtained response variables for the abundance of single species, abundance and species density of taxonomic–ecological species groups and two size classes of cryptogams, and site species richness. All of these variables were subjected to linear regression modelling with site and year as predictors. Results Mean annual temperature, growing-season length and the number of days with precipitation were higher in the study period than in the preceding ca. 30-year period, resulting in increasingly favourable conditions for bryophyte growth. Site species richness decreased by 13% over the 32-year study period. On average, group abundance of vascular plants decreased by 24% (decrease in forbs: 38%). Patterns of group abundance change differed among cryptogam groups: although peat-moss abundance increased by 39%, the abundance of mosses, hepatics and lichens decreased by 13%, 49% and 67%, respectively. Group abundance of small cryptogams decreased by 61%, whereas a 13% increase was found for large cryptogams. Of 61 single species tested for abundance change, a significant decrease was found for 43 species, whereas a significant increase was found only for 6 species. Conclusions The major patterns of change in species richness, group species density and group abundance observed over the 32-year study period accord with most predictions from the CIUC hypothesis and are interpreted as direct and indirect responses to climate change, partly mediated through changes in the population dynamics of microtine rodents. The more favourable climate for bryophyte growth explains the observed increase for a few large bryophyte species, whereas the decrease observed for small mosses and hepatics is interpreted as an indirect amensalistic effect, brought about by shading and burial in mats of larger species and accelerated by reduced fine-scale disturbance by microtine rodents. Indirect effects of a thicker moss mat most likely drive the vascular plant decline although long-term effects of tree-stand dynamics and former logging cannot be completely ruled out. Our results suggest that the ongoing climate change has extensive, cascading effects on boreal forest ecosystems. The importance of long time-series of permanent vegetation plots for detecting and understanding the effects of climate change on boreal forests is emphasised.

Sammendrag

I norsk skog på mineraljord er det stort sett nitrogen (N) som gir positivt utslag på trærnes vekst. Men også andre næringsstoffer kan i visse tilfeller øke veksten, blant annet i bestand på høy bonitet. Treaske inneholder både fosfor og kalium i tillegg til andre næringsstoffer, og har en kalkvirkning. Asken kan derfor være en bærekraftig gjødselressurs. I 2012 ble det anlagt et forsøk i Hobøl, Viken, hvor en rik granskog ble gjødslet med N (15 kg per daa), treaske (300 kg per daa) og en kombinasjon. Vi studerte effektene på trær, vegetasjon og jordsmonn. Humuskjemien ble undersøkt før behandling og to år etter, og jordvannkjemien under vekstsesongen i samme periode. Trærnes tilvekst ble undersøkt etter fem og ti år, og effekter på vegetasjonen etter to og ni. Ren N-gjødsling ga en viss effekt på trærnes tilvekst. Etter ti år var det ikke lenger økt årringvekst etter N-gjødsling. Derimot var effekten av å tilføre aske sammen med N god. Effekten av ren aske var liten i starten, men stigende gjennom perioden. Resultatene bekrefter at asketilførsel på fastmark kan gi positive tilveksteffekter på felt med god bonitet, men særlig i kombinasjon med N. To år etter gjødsling fant vi små effekter på mangfold av karplanter, men redusert mangfold av moser og lav. Antall og dekning av urter hadde økt i alle gjødslingsbehandlingene etter ni år, mens artsmangfold av bladmoser og levermoser var ytterligere redusert. Dekningen av blåbær og store moser som etasjemose og furumose økte i alle behandlinger, og antyder at andre faktorer enn gjødslingen også bidro. Det ble ikke funnet signifikante effekter av å tilføre aske eller aske + N på karbon- eller N-innholdet i humusen. Plantetilgjengelig konsentrasjon av flere andre stoffer som aluminium, kobolt, jern, nikkel, bly og sink gikk ned etter asketilførsel. Jordvannet viste kortvarige økninger av nitrat, ammonium og ulike grunnstoffer, samt lavere pH, etter tilførsel av N. Askegjødsling ga ikke effekter på jordvannkjemien.

Sammendrag

Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost og vind, eller indirekte ved at klimaet påvirker omfanget av soppsykdommer og insektangrep. Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge i nær framtid. I denne rapporten presenteres resultater fra skogskadeovervåkingen i Norge i 2021 og trender over tid for følgende temaer: (i) Landsrepresentativ skogovervåking; (ii) Skogøkologiske analyser og målinger av luftkjemi på de intensive overvåkingsflatene; (iii) Overvåking av bjørkemålere i Troms og Finnmark; (iv) Barkbilleovervåkingen 2021 og mulig overgang til to generasjoner; (v) Asiatisk askepraktbille – en dørstokkart? (vi) Overvåking av askeskuddsyke; (vii) Andre spesielle skogskader i 2021.

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Sammendrag

The replacement of native birch with Norway spruce has been initiated in Norway to increase long-term carbon storage in forests. However, there is limited knowledge on the impacts that aboveground changes will have on the belowground microbiota. We examined which effects a tree species shift from birch to spruce stands has on belowground microbial communities, soil fungal biomass and relationships with vegetation biomass and soil organic carbon (SOC). Replacement of birch with spruce negatively influenced soil bacterial and fungal richness and strongly altered microbial community composition in the forest floor layer, most strikingly for fungi. Tree species-mediated variation in soil properties was a major factor explaining variation in bacterial communities. For fungi, both soil chemistry and understorey vegetation were important community structuring factors, particularly for ectomycorrhizal fungi. The relative abundance of ectomycorrhizal fungi and the ectomycorrhizal : saprotrophic fungal ratio were higher in spruce compared to birch stands, particularly in the deeper mineral soil layers, and vice versa for saprotrophs. The positive relationship between ergosterol (fungal biomass) and SOC stock in the forest floor layer suggests higher carbon sequestration potential in spruce forest soil, alternatively, that the larger carbon stock leads to an increase in soil fungal biomass.

Sammendrag

In a fertiliser experiment in a Norway spruce forest in SE Norway, four treatments were applied in a block design with three replicates per treatment. Treatments included 3 t wood ash ha−1 (Ash), 150 kg nitrogen ha−1 (N), wood ash and nitrogen combined (Ash + N), and unfertilised control (Ctrl). Treatment effects on understory plant species numbers, single abundances of species and (summarised) cover of main species groups were studied. Two years after treatment there were no significant changes for species numbers or abundances of woody species, dwarf shrubs or pteridophytes, nor for Sphagnum spp. in the bottom layer. The cover of graminoids decreased in Ctrl plots. Herb cover increased significantly in Ash + N and N plots due to the increase of Melampyrum sylvaticum. In Ash + N plots, mosses decreased significantly in species number, while their cover increased. Moss cover also decreased significantly in N plots. The species number and cover of hepatics decreased significantly in Ash and Ash + N plots. Hepatics cover also decreased in Ctrl plots. Both the lichen number and cover decreased in Ash + N plots. Single species abundances decreased for many bryophytes in fertilised plots. To conclude, fertilisation had modest effects on vascular plants, while bryophytes were more strongly affected, especially by Ash + N.

Sammendrag

To increase the annual uptake of CO2 as well as the long-term storage of carbon (C) in forests, the Norwegian government consider large-scale replacements of native, deciduous forests with faster-growing species like Norway spruce. To assess the effects of tree species change on ecosystem C and nitrogen (N) stocks and soil chemistry, we used a paired plot approach including stands of native downy birch and planted 45 – 60-year-old Norway spruce. The birch stands were used as reference for the assessment of differences following the tree species change. We found significantly higher C and N stocks in living tree biomass in the spruce stands, whereas no significant differences were found for dead wood. The cover of understory species groups, and the C and N stocks of the aboveground understory vegetation was significantly higher in the birch stands. The tree species change did not affect the soil organic carbon (SOC) stock down to 1 m soil depth; however, the significantly higher stock in the forest floor of the spruce stands suggested a re-distribution of SOC within the profile. There was a significant positive correlation between the SOC stock down to 30 cm soil depth and the total ecosystem C stock for the birch stands, and a negative correlation for the spruce stands. Significant effects of tree species change were found for C and N concentrations, C/N, exchangeable acidity, base saturation, and exchangeable Ca, K, Mg, Na, S, and Fe in the organic horizon or the upper mineral soil layer. The total ecosystem C stock ranged between 197 and 277 Mg ha-1 for the birch stands, and 297 and 387 Mg ha-1 for the spruce stands. The ecosystem C accumulation varied between 32 and 142 Mg ha-1 over the past 45-60 years, whereas the net ecosystem C capture was considerably lower and potentially negative. Our results suggest that the potential to meet the governments’ targets to increase C sequestration depend on the C debt incurred from the removed birch stands, the rotation length, and potentially also the susceptibility of the different stand types to future risk factors related to climate change.

Sammendrag

Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost og vind, eller indirekte ved at klimaet påvirker omfanget av soppsykdommer og insektangrep. Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge i nær framtid. I denne rapporten presenteres resultater fra skogskadeovervåkingen i Norge i 2020 og trender over tid. I den landsrepresentative skogovervåkingen har kronetettheten hos gran og furu holdt seg stabil i 2020 sammenlignet med tidligere år. Det ble registrert lite misfarging hos bartrærne. Skadenivået hos både bartrær, bjørk og andre løvtrær var lavere enn i 2019. Abiotiske faktorer med snø, vind og tørke som de viktigste årsakene dominerte skadebildet hos alle treslag. Kjemiske analyser av luft og nedbør i den intensive skogovervåkingen viser at det fortsatt er høyest verdier av antropogene svovel- og nitrogenforbindelser på den sørligste overvåkingsflata i Birkenes grunnet langtransportert forurensing. Den høyeste konsentrasjonen av nitrogendioksid i luft ble målt på stasjonen i Hurdal i 2020, noe som skyldes utslipp fra veitrafikken i regionen. Det var lave nivåer av bakkenært ozon i Norge i 2020 og ingen overskridelser av UNECEs grenseverdi på 5000 ppb-timer for skog. Vegetasjonsanalysene fra Hurdal har påvist en endring i bunn-vegetasjonens artssammensetning grunnet økt lystilgang og mye barnålstrø. Både hogst utenfor overvåkingsflata og flere skrantende, råteangrepne og døde grantrær i flata har bidratt til økt lystilgang og til større strømengde på bakken. Mange grantrær på flata i Hurdal er sterkt preget av råte med lav kronetetthet og mye misfarging. Flere trær på flata har dødd de seinere årene som følge av råteskader, ofte i kombinasjon med andre faktorer som vindfelling og skader etter tørken i 2018 med påfølgende barkbilleangrep. Overvåking av bjørkemålere har vist at fjellbjørkeskogen både i Nord-Norge og fjellregionene i sørlige halvdel av landet har vært utsatt for betydelige utbrudd av bjørkemålere i løpet av perioden 2012–2018. Overvåkingsdata fra 2019 og 2020 tyder imidlertid på at målerbestandene nå er lave eller i sterk tilbakegang i det meste av landet. I Troms har målerbestandene allerede nådd et bunnpunkt, og bestandene er nedadgående også i fjellet i Sør-Norge. Vi forventer derfor at skogen i mesteparten av Norge vil bli mindre utsatt for angrep av bjørkemålere de neste par årene. De fleste fylkene hadde en økning i fangstverdiene i barkbilleovervåkingen i 2020-sesongen. Alle fangstverdiene var imidlertid under 10 000 biller per felle, mens de høyeste verdiene ved slutten av utbruddet på 1970-tallet var rundt 25 000 biller per felle. Fylkene rundt Oslofjorden hadde noen lokale tilfeller av tørke- og barkbilleskader. Det ble ikke funnet noen tydelig økning av fellefangstene i tiden for en annen generasjon, men modellberegninger viser at stor granbarkbille har nok døgngrader til å gjennomføre to generasjoner før overvintring. I august 2020 ble soppen Diplodia sapinea funnet på sterkt skadet vrifuru i Ås kommune. Tidligere har det blitt gjort noen få funn av soppen på andre bartrearter i det samme området. D. sapinea er vanlig i varmere strøk på flere kontinenter, spesielt på furuarter. De pågående klima-endringene har trolig bidratt til at soppen har kunnet spre og etablere seg mot nord, men vi kan heller ikke utelukke innførsel av soppen via plantemateriale til bruk i grøntanlegg eller skog. D. sapinea er trolig bare i etableringsfasen i Norge, og har til dags dato gjort liten skade på våre stedegne bartrær.....

Sammendrag

Det årlige netto opptaket i skogen i Norge økte frem til 2009 (over 35 mill. tonn), og har etter det vist en avtakende trend. I 2018 var det et netto opptak på i underkant av 28 millioner tonn CO2- ekvivalenter. Størrelsen på opptaket påvirkes av forvaltningen av skogarealene, både gjennom endringer i totalarealet (avskoging og påskoging), og forvaltningen av de eksisterende skogarealene. I en første rapport til Klimakur 2030 – skrevet på oppdrag fra Miljødirektorat og Landbruksdirektoratet - ble det presentert en første vurdering av syv klimatiltak som ikke tidligere var utredet, samt en kunnskapsoppdatering for noen tidligere utredede klimatiltak. I denne rapporten presenteres ytterligere vurderinger av fire av disse tiltakene; ungskogpleie, grøfterensk, stubbebehandling mot råte og gjødsling med treaske. Rapporten er skrevet på bestilling fra Landbruks- og matdepartementet (LMD) og Klima- og miljødepartementet (KLD), og det er departementene som har gjort utvalget av tiltak som skulle vurderes videre...

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Sammendrag

Grunneier vil nydyrke 83 daa på Lundbergvegen 89 (gnr 163 / bnr 5) i Nes kommune. Dette er en Konsekvensutredningen med de fagtema fastsatt av Nes Landbrukskontor; Landskapsbilde, Friluftsliv, Støy, Kulturminner og kulturmiljø, Naturmiljø, Vannmiljø, Naturressurser og Geoteknikk. Det er nylig nydyrket 49 daa på samme tiltaksområde, så konsekvensutredningen behandler et areal på 132 daa. Tiltaksområdet består av 2 mindre ravinedaler. Vest for område er det bakkeplanert på 1960-tallet. Tiltaksområdet vil planeres med stedegne masser. Tiltaksområdet består av flom-, hav- og fjordavsetninger med sand, silt, og lettleire. Matjordlaget må etter ferdig planering legges tilbake med beltegående gravemaskin for å hindre komprimeringsskader på jorda. Det anbefales å legge ut matjord med gravemaskin og stubbranker fra skogavvirkningen bør kvernes opp og blandes i matjordlaget Bekkedragene i bunn av ravinedalene er ikke helårsbekker, men det må lages et hydroteknisk anlegg som ivaretar vanntransporten...

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Sammendrag

Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost og vind, eller indirekte ved at klimaet påvirker omfanget av soppsykdommer og insektangrep. Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge i nær framtid. I denne rapporten presenteres resultater fra skogskadeovervåkingen i Norge i 2018 og trender over tid for følgende temaer: (i) Landsrepresentativ skogovervåking; (ii) Skogøkologiske analyser og målinger av luftkjemi på de intensive overvåkingsflatene; (iii) Overvåking av bjørkemålere i Troms og Finnmark; (iv) Granbarkbilleovervåking – utvikling av barkbillepopulasjonene i 2018; (v) Ny barkbille på vei – vil den like klimaet?; (vi) Phytophthora i importert jord på prydplanter og faren det utgjør for skog; (vii) Overvåking av askeskuddsyke; (viii) Skog- og utmarksbranner i 2018; (ix) Andre spesielle skogskader i 2018...….

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Sammendrag

Atmospheric nitrogen (N) pollution is considered responsible for a substantial decline in plant species richness and for altered community structures in terrestrial habitats worldwide. Nitrogen affects habitats through direct toxicity, soil acidification, and in particular by favoring fast-growing species. Pressure from N pollution is decreasing in some areas. In Europe (EU28), overall emissions of NO x declined by more than 50% while NH3 declined by less than 30% between the years 1990 and 2015, and further decreases may be achieved. The timescale over which these improvements will affect ecosystems is uncertain. Here we use 23 European forest research sites with high quality long-term data on deposition, climate, soil recovery, and understory vegetation to assess benefits of currently legislated N deposition reductions in forest understory vegetation. A dynamic soil model coupled to a statistical plant species niche model was applied with site-based climate and deposition. We use indicators of N deposition and climate warming effects such as the change in the occurrence of oligophilic, acidophilic, and cold-tolerant plant species to compare the present with projections for 2030 and 2050. The decrease in N deposition under current legislation emission (CLE) reduction targets until 2030 is not expected to result in a release from eutrophication. Albeit the model predictions show considerable uncertainty when compared with observations, they indicate that oligophilic forest understory plant species will further decrease. This result is partially due to confounding processes related to climate effects and to major decreases in sulphur deposition and consequent recovery from soil acidification, but shows that decreases in N deposition under CLE will most likely be insufficient to allow recovery from eutrophication.

Sammendrag

Short-term (three to four years) effects of forest harvesting on soil solution chemistry were investigated at two Norway spruce sites in southern Norway, differing in precipitation amount and topography. Experimental plots were either harvested conventionally (stem-only harvesting, SOH) or whole trees, including crowns, twigs and branches were removed (whole-tree harvesting, WTH), leaving residue piles on the ground for some months before removal. The WTH treatment had two sub-treatments: WTH-pile where there had been piles and WTH-removal, from where residues had been removed to make piles. Increased soil solution concentrations of NO3–N, total N, Ca, Mg and K at 30 cm depth, shown by peaks in concentrations in the years after harvesting, were found at the drier, less steep site in eastern Norway after SOH and WTH-pile, but less so after WTH-removal. At the wetter, steeper site in western Norway, peaks were often observed also at WTH-removal plots, which might reflect within-site differences in water pathways due largely to site topography.

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Sammendrag

Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost og vind, eller indirekte ved at klimaet påvirker omfanget av soppsykdommer og insektangrep. Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge som følge av økt handel og import. Eksempler på begge er omtalt i denne rapporten som presenterer resultater fra skogskadeovervåkingen i Norge i 2016........

Sammendrag

NIBIO har på oppdrag fra Miljødirektoratet testet en ny metodikk utviklet for kartlegging og verdisetting av naturtyper av nasjonal forvaltningsinteresse (NNF). 39 ruter a 500x500 meter ble kartlagt sommeren 2017 og 33 naturtyper ble registrert fordelt på 130 lokaliteter. Evaluering av metodikken er basert på resultater fra denne kartleggingen. Metodikken er evaluert generelt og for hvert hovedøkosystem (naturlige åpne områder i lavlandet, semi-naturlig mark, skog og våtmark) og naturtype.

Sammendrag

Effects of clear-cut harvesting on ground vegetation plant species diversity and their cover are investigated at two Norway spruce sites in southern Norway, differing in climate and topography. Experimental plots at these two sites were either harvested conventionally (stem-only harvesting) or whole trees including crowns, twigs and branches were removed (whole-tree harvesting), leaving residue piles on the ground for some months. We compare the number of plant species in different groups and their cover sums before and after harvesting, and between the different treatments, using non-parametric statistical tests. An overall loss of ground vegetation biodiversity is induced by harvesting and there is a shift in cover of dominant species, with negative effects for bryophytes and dwarf shrubs and an increase of graminoid cover. Differences between the two harvesting methods at both sites were mainly due to the residue piles assembled during whole-tree harvesting and the physical damage made during the harvesting of residues in these piles. The presence of the residue piles had a clear negative impact on both species numbers and cover. Pile residue harvesting on unfrozen and snow-free soil caused more damage to the forest floor in the steep terrain at the western site compared to the eastern site.

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Sammendrag

Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost og vind, eller indirekte ved at klimaet påvirker omfanget av soppsykdommer og insektangrep. Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge i framtida. Eksempler på begge er omtalt i foreliggende rapport. I denne rapporten presenteres resultater fra skogskadeovervåkingen i Norge i 2015: (i) Overvåking av skogens helsetilstand på de landsrepresentative flatene. (ii) Skogøkologiske analyser og målinger av luftkjemi på de intensive overvåkingsflatene. (iii) Barkbilleovervåking og analyse av klimaeffekter. (iv) Import skadegjørere og analyse av invasjonspotensialet til fremmede billearter. (v) Overvåking av askeskuddsyke. (vi) Andre skaderegistreringer fra Skogskader.no og befaringer i 2015. Skogovervåkingen på de landsrepresentative flater viser at gran- og furuskogens generelle helsetilstand var god i 2015, selv om det ble registrert uvanlig mange skader på gran og kronetettheten hos furu hadde sunket i forhold til året før. Siden 2007 har kronetettheten likevel økt hos begge treslagene mens trenden har vært motsatt i ICP Forests’ nettverk. Det var lite misfarging på gran og furu og få skader på furu i 2015, mens bjørk, som tidligere, hadde flest skader av alle undersøkte treslag. Det ble ellers registrert få spesielle skader på skog i 2015. Konsentrasjon og atmosfærisk avsetning av både svovel og nitrogen var generelt veldig lave i 2015. Konsentrasjonen av uorganiske nitrogenforbindelser i jordvann og nivået av bakkenært ozon var også lave i Norge i 2015. Ozonnivåene er i stor grad styrt av værforholdene og vil derfor kunne oppvise store årlige variasjoner. Kjemiske analyser på de intensive skogovervåkings-flatene i Norge har dokumentert en betydelig reduksjon over tid i nivåer av svovelkomponenter både i luft, nedbør og jordvann som følge av store utslippsreduksjoner i Europa. Overvåkingsflata på Sørlandet, som er mest utsatt for langtransporterte forurensinger, hadde som i tidligere år de høyeste nitrogen- og svovelverdier i barnålene i 2015. Verdiene hadde økt i forhold til 2013 og var på det høyeste nivået siden hhv. 1995 og 1999, til tross for at både tilførselen og deposisjonen av disse elementene har avtatt sterkt siden 1990. På de to andre flatene var nitrogenverdiene vesentlig lavere, og i Osen var det dessuten for lite nitrogen i forhold til de andre næringsstoffene. Nitrogenmangel er imidlertid normalt i boreale barskoger. Vegetasjonsanalyser på den intensive skogovervåkingsflata i Hurdal viser at dekningen av etasjehusmose og to vmoser har økt siden 1999, mens flere andr mosearter har gått tilbake. Økt vekst av store bladmoser som etasjehusmose er også dokumentert av andre norske studier og har blitt forklart som et resultat av at mange milde og nedbørrike høster har gjort vekstsesongen lengre. Resultatene fra granbarkbilleovervåkingen i 2015 viste en moderat økning av populasjonene for landet sett under ett. Analyser av tidsserier for klimaeffekter og utviklingen i granbarkbillebestanden indikerer en trend mot økende barkbillemengder i Trøndelag og Nordland, som har mye hogstmoden gran. Denne økningen er mest markert i tørre og varme år. Tidligere modellberegninger har predikert at den forventete temperaturøkningen kan føre til at granbarkbillen får to generasjoner per sommer i stedet for én så langt nord som Trøndelag, noe som kan gi en markert økning i antall angrep på stående trær...

Sammendrag

Whole-tree harvest (WTH), i.e. harvesting of forest residues (twigs, branches and crown tops) in addition to stems, for bioenergy purposes may lead to biodiversity loss and changes in species composition in forest ground vegetation, which in turn also will affect soil properties. Effects of clear-cut harvesting on ground vegetation have been investigated at two Norway spruce sites in southern east and western Norway, respectively, differing in climate and topography. Experimental plots at these two sites were either harvested conventionally (stem-only harvest, SOH), leaving harvest residues spread on the site,or WTH was carried out, with the residues collected into piles at the site for six - nine months prior to removal. Vegetation plots in the eastern site were established and analysed before WTH and SOH in 2008 and reanalysed after harvesting in 2010, 2012 and 2014. In the western site vegetation plots were established before WTH and SOH in 2010 and reanalysed after harvesting in 2012 and 2014 (and planned for 2016). All vegetation plots are permanently marked. Pre-as well as post-harvesting species abundances of all species in each vegetation plot were each time recorded as percentage cover (vertical projection) and subplot frequency. Environmental variables (topographical, soil physical, soil chemical, and tree variables) were recorded only once; before WTH and SOH. Effec ts of WTH and SOH on ground vegetation biodiversity and cover are presented.

Sammendrag

Tree harvest and different harvesting methods may affect the soil carbon (C) pool in forest ecosystems. In con- ventional stem-only timber harvesting (SOH), branches and tops that are left in the forests may contribute to the build-up of the soil carbon pool. In whole-tree harvesting (WTH), inputs of organic matter from branches and tops are strongly reduced. We established field experiments at Gaupen, SE and Vindberg, SW Norway, to study the short-term effects of SOH and WTH on processes affecting the accumulation and loss of soil C. Logging residues on the WTH plots were collected in piles that were removed after 6 months, rendering two sub treatments (WTH- pile and WTH-removal areas). We weighed selected trees and logging residues, surveyed understorey biomass production, quantified pre-harvest soil C and nutrient pools down to 30 cm. Soil respiration was measured and soil water sampled monthly during the growing season, while temperature and moisture were measured continuously. Organic and mineral horizons were incubated at different temperatures to estimate potential C and N mineraliza- tion, and deep sequencing of the ITS2 barcode region of fungal DNA was performed on the samples. Litterbags were deployed in the SOH plots. The logging residues amounted to 2.2-2.4 kg C m-2 At Gaupen, the mean in situ soil respiration rates increased following harvest with all treatments, but were significantly higher in WTH-pile and SOH relative to the WTH- removal areas in the first year as well as the fourth year of treatment. The former rates included aboveground decomposing needles and twigs but excluded coarser branches. The observed increase in the WTH-removal areas may be related to decomposing roots, as well as to increased C mineralization partly due to the higher soil tem- peratures following harvest. Soil temperature was the single most important factor explaining the variability in soil respiration rates over all treatments. At Vindberg, a decrease in soil respiration was observed with all treatments in the second and third years following harvest. At both sites, decomposition of logging residues from needles was more rapid relative to twigs and fine roots. The decomposing residues released a substantial amount of nitrogen which was gradually reflected in the soil water at 30 cm soil depth. A considerable increase in the NO3-N concen- tration also in the WTH-removal areas in the second year following harvest suggests an increase in N availability from decomposing fine roots and/or soil organic matter. The increased N availability in the WTH-removal areas was supported by results from short term lab incubations of undisturbed soil from the forest floor. The changes in the WTH-removal areas were also reflected in the soil fungal diversity: saprophytic ascomycetes on decaying plant material showed a striking increase in all treatments. For the WTH-removal areas, this may, again, be related to the increased input of root litter; however, the decrease in mycorrhizal basidiomycete species and the vigorous increase of ascomycetes following harvest may also affect the C mineralization of soil organic matter.

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Sammendrag

Peat bogs have accumulated more atmospheric carbon (C) than any other terrestrial ecosystem today. Most of this C is associated with peat moss (Sphagnum) litter. Atmospheric nitrogen (N) deposition can decrease Sphagnum production, compromising the C sequestration capacity of peat bogs. The mechanisms underlying the reduced production are uncertain, necessitating multifactorial experiments.•We investigated whether glasshouse experiments are reliable proxies for field experiments for assessing interactions between N deposition and environment as controls on Sphagnum N concentration and production. We performed a meta-analysis over 115 glasshouse experiments and 107 field experiments.•We found that glasshouse and field experiments gave similar qualitative and quantitative estimates of changes in Sphagnum N concentration in response to N application. However, glasshouse-based estimates of changes in production – even qualitative assessments – diverged from field experiments owing to a stronger N effect on production response in absence of vascular plants in the glasshouse, and a weaker N effect on production response in presence of vascular plants compared to field experiments.•Thus, although we need glasshouse experiments to study how interacting environmental factors affect the response of Sphagnum to increased N deposition, we need field experiments to properly quantify these effects.

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Sammendrag

Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain. •Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data. •We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increasedannual precipitation intensified the negative effects of N. The temperature effect was comparable to an experimental application of almost 4 g N m−2 yr−1 for each 1°C increase. •Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation.

Sammendrag

Rapporten presenterer sammendrag av resultatene for 2010 fra tre overvåkingsprogrammer: “Overvåking av langtrans­portert forurenset luft og nedbør”, ”Overvåkingsprogram for skogskader” (OPS) og “Program for terrestrisk naturovervåking” (TOV). The report presents results for 2010 from three national monitoring programmes on long-range transboundary air pollution.

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Sammendrag

The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them in ensuring a sustainable environment. Weak economies and lack of expertise in environmental sciences were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. Activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. […]

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Sammendrag

The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them in ensuring a sustainable environment. Weak economies and lack of expertise in environmental sciences were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. Activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. The forestry sectors in the Kyrgyz Republic and neighbouring countries in Central Asia, surrounding the Fergana Valley, are closely linked to the environmental and emergency planning sectors. Overgrazing and overharvesting have contributed to a dramatic decline in forest cover. The TEMP-CA project contributes to a better understanding of environmental problems and sustainable forestry in Central Asia. The TEMP-CA project has promoted institutional co-operation between Norway and the Central Asian countries as well as between different institutions both within and between the countries of Central Asia. Increased expertise for scientists, fieldworkers, laboratory staff and staff in different forest departments as well as institutional development in general are important outputs from the TEMP-CA project. The Umalak monitoring site in Tashkent region, the Republic of Uzbekistan, was the tenth of ten monitoring sites established in forests in Central Asia: 1: ”Kara-Koi” in the Osch oblast, the Kyrgyz Republic. 2: ”Sogot in the Jalal-Abad oblast, the Kyrgyz Republic. 3: “Dugoba” in Batken oblast, the Kyrgyz Republic. 4: “Besh-Tash” Talas oblast, the Kyrgyz Republic. 5: “Sary-Chelek”, in Jalal-Abad oblast, the Kyrgyz Republic. 6: “Navobod” in Sogdi oblast, the Republic of Tajikistan. 7: “Gauyan” in Batken oblast, the Kyrgyz Republic. 8: “Zaamin” in Djizak region, the Republic of Uzbekistan. 9: “Urumbash” in Jalal-Abad oblast, the Kyrgyz Republic. 10: “Umalak Teppa”, Tashkent region, the Republic of Uzbekistan. […]

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Sammendrag

The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them in ensuring a sustainable environment. Weak economies and lack of expertise in environmental sciences were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. Activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. The forestry sectors in the Kyrgyz Republic and neighbouring countries in Central Asia, surrounding the Fergana Valley, are closely linked to the environmental and emergency planning sectors. Overgrazing and overharvesting have contributed to a dramatic decline in forest cover. The TEMP-CA project contributes to a better understanding of environmental problems and sustainable forestry in Central Asia. The TEMP-CA project has promoted institutional co-operation between Norway and the Central Asian countries as well as between different institutions both within and between the countries of Central Asia. Increased expertise for scientists, fieldworkers, laboratory staff and staff in different forest departments as well as institutional development in general are important outputs from the TEMP-CA project. […]

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Sammendrag

The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them in ensuring a sustainable environment. Weak economies and lack of expertise in environmental sciences were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. Activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. The forestry sectors in the Kyrgyz Republic and neighbouring countries in Central Asia, surrounding the Fergana Valley, are closely linked to the environmental and emergency planning sectors. Overgrazing and overharvesting have contributed to a dramatic decline in forest cover. The TEMP-CA project contributes to a better understanding of environmental problems and sustainable forestry in Central Asia.The TEMP-CA project has promoted institutional co-operation between Norway and the Central Asian countries as well as between different institutions both within and between the countries of Central Asia. Increased expertise for scientists, fieldworkers, laboratory staff and staff in different forest departments as well as institutional development in general are important outputs from the TEMP-CA project.

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Sammendrag

The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them in ensuring a sustainable environment. Weak economies and lack of expertise in environmental sciences were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. Activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. The forestry sectors in the Republic of Tajikistan and neighbouring countries in Central Asia, surrounding the Fergana Valley, are closely linked to the environmental and emergency planning sectors. Overgrazing and overharvesting have contributed to a dramatic decline in forest cover. The TEMP-CA project contributes to a better understanding of environmental problems and sustainable forestry in Central Asia. The TEMP-CA project has promoted institutional co-operation between Norway and the Central Asian countries as well as between different institutions both within and between the countries of Central Asia. Increased expertise for scientists, fieldworkers, laboratory staff and staff in different forest departments as well as institutional development in general are important outputs from the TEMP-CA project.

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Sammendrag

The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them in ensuring a sustainable environment. Weak economies and lack of expertise in environmental sciences were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. Activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. The forestry sectors in the Kyrgyz Republic and neighbouring countries in Central Asia, surrounding the Fergana Valley, are closely linked to the environmental and emergency planning sectors. Overgrazing and overharvesting have contributed to a dramatic decline in forest cover. The TEMP-CA project contributes to a better understanding of environmental problems and sustainable forestry in Central Asia. The TEMP-CA project has promoted institutional co-operation between Norway and the Central Asian countries as well as between different institutions both within and between the countries of Central Asia. Increased expertise for scientists, fieldworkers, laboratory staff and staff in different forest departments as well as institutional development in general are important outputs from the TEMP-CA project. The Gauyan monitoring site in Batken oblast in the Kyrgyz Republic was the seventh of ten monitoring sites established in forests in Central Asia: 1: ”Kara-Koi” in the Osch oblast, the Kyrgyz Republic. 2: ”Sogot in the Jalal-Abad oblast, the Kyrgyz Republic. 3: “Dugoba” in Batken oblast, the Kyrgyz Republic. 4: “Besh-Tash” Talas oblast, the Kyrgyz Republic. 5: “Sary-Chelek”, in Jalal-Abad oblast, the Kyrgyz Republic. 6: “Navobod” in Sogdi oblast, the Republic of Tajikistan. 7: “Gauyan” in Batken oblast, the Kyrgyz Republic. 8: “Zaamin” in Djizak region, the Republic of Uzbekistan. 9: “Urumbash” in Jalal-Abad oblast, the Kyrgyz Republic. 10: “Umalak Teppa”, Tashkent region, the Republic of Uzbekistan.

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Sammendrag

The collapse of the Soviet Union in the Central Asian countries has led to enormous challenges for them in ensuring a sustainable environment. Weak economies and lack of expertise in environmental sciences were important reasons for the Norwegian support to the environmental sector in this region. The State Forest Service of the Kyrgyz Republic and the Norwegian Forestry Group initiated the TEMP project, later renamed TEMP-CA, in the Kyrgyz Republic in 2004. Activities in the Republic of Tajikistan were included in 2007 and in the Republic of Uzbekistan from 2008. The forestry sectors in the Kyrgyz Republic and neighbouring countries in Central Asia, surrounding the Fergana Valley, are closely linked to the environmental and emergency planning sectors. Overgrazing and overharvesting have contributed to a dramatic decline in forest cover. The TEMP-CA project contributes to a better understanding of environmental problems and sustainable forestry in Central Asia. The TEMP-CA project has promoted institutional co-operation between Norway and the Central Asian countries as well as between different institutions both within and between the countries of Central Asia. Increased expertise for scientists, fieldworkers, laboratory staff and staff in different forest departments as well as institutional development in general are important outputs from the TEMP-CA project. [...]

Sammendrag

Vegetasjonsovervåkingen i granskog ble etablert ved Norsk institutt for jord- og skogkartlegging (fra 2006: Norsk institutt for skog og landskap) i 1988 (T. Økland 1990, 1996). Samme år ble det også etablert tilsvarende overvåking i Solhomfjell-området (Gjerstad, Aust-Agder i regi av Universitetet i Oslo/Miljøverndepartementet (R. Økland & Eilertsen 1993). I regi av Norsk institutt for jord- og skogkartlegging ble det etablert og analysert to områder pr år fra 1988 til 1992, til sammen 10 områder. Flatene i Paulen ble første gang analysert i 1990. Etter 2004 har Direktoratet for naturforvaltning finansiert vegetasjonsovervåkingen i granskog gjennom TOV-programmet, men i noe redusert omfang (ett område pr år). Metodene for overvåkingen av markvegetasjon ble i 1988 utviklet for å overvåke effekter av langtransportert luftforurensing, men har også vist seg godt egnet til å fange opp effekter av klimaendringer på markvegetasjonen (se for eksempel T. Økland et al. 2001, 2004a,b, 2007, 2008, 2009b, Nordbakken et al. 2010). De permanente vegetasjonsflatene i Paulen har tidligere vært analysert i 1990, 1995, 2000, og 2005. Reanalyseringen i 2010 var således 5. gangs analyse av disse flatene.

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Sammendrag

Semi-natural grasslands and their species and populations are declining rapidly throughout Europe, bringing about a need for successful vegetation recreation methods. To maintain biodiversity and ecological services of semi-natural grasslands, we need more knowledge on the relative performance of different recreation methods. In a replicated experiment in western Norway, we evaluated two hay transfer methods (hard or light raking of local hay), sowing of local seeds and natural regeneration for recreating semi-natural grassland in a road verge. We compared treated trial plots with their respective donor plots (where hay and seeds were harvested) for three successive years by evaluating vegetation cover, species richness and species transfer rates, and vegetation dynamics analysed by Bray-Curtis compositional dissimilarity (BC) and GNMDS (Global Non-Metric Multidimensional Scaling) ordination. Vegetation cover at the trial site exceeded that of donor sites in three years. Transfer rates of common species were high for seed sowing and both hay transfer procedures. Species composition in trial plots for all three treatments became significantly more similar to donor plots, but was still relatively dissimilar after three years. Natural regeneration showed a different temporal pattern and also had a higher successional rate. The species composition of the other treatments followed the same trajectory toward the donor sites as revealed by GNMDS. We found relatively small differences between the two hay transfer methods and seed sowing. Transfer of local hay therefore appears to be a successful method of establishing local species when recreating semi-natural grasslands, and is generally cheaper than using commercial local seed mixtures.

Sammendrag

Seminatural grasslands and their species and populations are declining rapidly throughout Europe, bringing about a need for successful vegetation recreation methods. To maintain biodiversity and ecological services of seminatural grasslands, we need more nowledge on the relative performance of different recreation methods. In a replicated experiment in western Norway, we evaluated two hay transfer methods (hard or light raking of local hay), sowing of local seeds and natural regeneration for recreating seminatural grassland in a road verge. We compared treated trial plots with their respective donor plots (where hay and seeds were harvested) for three successive years by evaluating vegetation cover, species richness and species transfer rates, and vegetation dynamics analysed by Bray–Curtis compositional dissimilarity (BC) and GNMDS (Global NonMetric Multidimensional Scaling) ordination. Vegetation cover at the trial site exceeded that of donor sites in three years. Transfer rates of common species were high for seed sowing and both hay transfer procedures. Species composition in trial plots for all three treatments became significantly more similar to donor plots, but was still relatively dissimilar after three years. Natural regeneration showed a different temporal pattern and also had a higher successional rate. The species composition of the other treatments followed the same trajectory toward the donor sites as revealed by GNMDS. We found relatively small differences between the two hay transfer methods and seed sowing. Transfer of local hay therefore appears to be a successful method of establishing local species when recreating seminatural grasslands, and is generally cheaper than using commercial local seed mixtures.

Sammendrag

Several places in Sogn og Fjordane county, W Norway, old pollarded trees of elm Ulmus glabra stand out as characteristic elements in the cultural landscape. These pollarded trees, which serve as habitats for many groups of organisms and are important key species in the cultural landscape, are threatened due to changes in farming management during the last century. In order to obtain more knowledge about the bryophyte flora on older elm pollards in Sogn og Fjordane county we examined two trees from each of four locations along an east-west gradient, from a strong oceanic climate in coastal areas towards slightly continental conditions further inland. Epiphytic bryophytes were recorded in three different height zones (basal, middle, and top) on the north, east, south and west sides of the trees. We looked for differences in species number (i) between the four locations, (ii) between three height zones (basal, middle and top) of the stems, and (iii) between different expositions (N, S, E and W) of the stems. We found 31 bryophyte species on the eight examined trees. No relation between geographic position and species number was found. There were significantly more species in the basal zones than in the middle zones, while there were no significant differences between the middle zones and top zones, or between the basal zones and top zones. The species number on the northern side exposition was significantly higher than on the eastern and southern sides of the stem.

Sammendrag

This study focused on a suite of vascular plant species (six herbs and two grasses) common to traditionally managed, species-rich grasslands in Western Norway. We assessed the suitability of two species transfer methods (seed sowing and soil seed bank) for restoration of species-rich grassland on a newly established road verge. We compared the species\" frequencies one and three years after they were sown on a naked, newly created road verge with their frequencies in aboveground vegetation and soil seed banks of comparable, local grasslands. Species frequencies in the aboveground vegetation differed significantly from those in the seed banks. Moreover, the frequencies in the seed banks differed from those recorded one year after sowing, and the frequencies in the aboveground vegetation differed from those recorded three years after sowing. Avenula pubescens and Knautia arvensis, found in more than 25% of the aboveground grassland plots, did not germinate from any of the seed bank samples. Festuca rubra, Galium verum, Pimpinella saxifraga and Silene vulgaris were more frequent in the aboveground plots than in the seed bank samples. Pimpinella saxifraga, Galium verum and Lychnis viscaria emerged quite well both from sown seeds and from the seed bank. Avenula pubescens was frequent in the aboveground vegetation, but did not germinate from sown seeds. Six species established well from seeds, and most increased in frequency in the sown plots from the first to the third year. No species was found in the sown plots only, but three years after sowing, three species were more frequent in the sown plots than in the aboveground vegetation of donor grassland plots. Our fine-scale, point-to-point study demonstrates that different restoration methods produce widely differing species composition even when the donor material is identical. We propose that different substrates and a combination of establishment methods (sowing and hay transfer) are needed as supplements to seed banks to re-establish species-rich grassland.

Sammendrag

Vegetasjonsovervåkingen i granskog ble etablert ved Norsk institutt for jord- og skogkartlegging (fra 2006: Norsk institutt for skog og landskap) i 1988. Samme år ble det også etablert tilsvarende overvåking i Solhomfjell-området (Gjerstad, Aust-Agder) i regi av Universitetet i Oslo/Miljøverndepartementet. I regi av Norsk institutt for jord- og skogkartlegging ble det etablert og analysert to områder pr år fra 1988 til 1992, til sammen 10 områder. Prøveflatene i Gutulia ble første gang analysert i 1989. Etter 2004 har Direktoratet for naturforvaltning finansiert vegetasjonsovervåkingen i granskog gjennom TOV-programmet, men i noe redusert omfang. Metodene for overvåkingen av markvegetasjon ble i 1988 utviklet for å overvåke effekter av langtransportert luftforurensing, men har også vist seg godt egnet til å fange opp effekter av klimaendringer på markvegetasjonen. De permanente vegetasjonsflatene i Gutulia har tidligere vært analysert i 1989, 1994, 1999, og 2004 (femårig omløpstid). Reanalyseringen i 2009 var således 5. gangs analyse av disse prøveflatene....

Sammendrag

Helgeland er i foreliggende rapport definert som kommunene Hattfjelldal, Grane, Vefsn, Bindal, Brønnøy, Hemnes og Rana. Det er 38 utredningsområder som skal vurderes for vern, hvilket tilsvarer 119 090 ha eller 7 % av Helgelands totale areal. De 38 utredningsområder utgjør et brutto produktivt skogareal på 8 916 ha, hvorav omkring 46 % (4 130 ha) er fradrag. Det er fradrag for nøkkelbiotoper, samt buffer mot vann og myr, som utgjør forskjellen mellom brutto og netto produktivt skogareal. De 8 916 ha produktiv skog som berøres av utredningsområdene utgjør 4 % av den produktive skogen på Helgeland, og 1 % av den produktive skogen i Nordland. Det totale brutto virkesvolumet på statens grunn på Helgeland er 2 978 094 m3, hvorav 17 % er berørt av de 38 utredningsområdene. Dette tilsvarer et berørt volum som utgjør omkring 3,5 % av Helgelands totale volum, og 1,5 % av Nordlands totale volum. Innenfor de 38 utredningsområdene er 46 % av det produktive skogareal dekket av nøkkelbiotoper, samt buffer mot vann og myr. Dette illustrerer at utredningsområdene har en stor naturverdi (andel viktige habitater) i forhold til det generelle landskapet på Helgeland og i hele Nordland. 19 av områdene er vurdert å ha regionalt unike naturkvaliteter, mens 16 områder tillegges nasjonalt unike kvaliteter. Et meget stort innhold av signal- og rødlistearter er knyttet til 9 av utredningsområdene, men rødlistearter er funnet i (minst) 29 av områdene. Kunnskaper om de observerte rødlisteartenes populasjonsstørrelse og utvikling i de ulike utredningsområdene er svært begrenset, og forekomst av moser, insekter og fugl er generelt lite undersøkt i de fleste av utredningsområdene. Dette innebærer at det ikke er mulig å foreta en kvantifisering av effekter på rødlisteartene ved å ikke verne. […]