Biografi

Fagtema

  • økosystemtjenester og multifunksjonalitet i urban grøntstruktur
  • økologisk restaurering etter inngrep i landskapet
  • spredning og økologiske effekter av invasive arter
  • urban grønn infrastruktur som grønne tak, vegeterte infiltrasjonssoner og regnbed
  • restaurering av biologisk mangfold og funksjoner
  • stressresponser, rotvekst og samspill med jordforhold i konstruerte systemer

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PREMISE OF THE STUDY: Genetic differentiation in plant species may result from adaptation to environmental conditions, but also from stochastic processes. The drivers selecting for local adaptation and the contribution of adaptation to genetic differentiation are often unknown. Restoration and succession studies have revealed different colonization patterns for Brachypodium retusum, a common Mediterranean grass. In order to understand these patterns, we tested population differentiation and adaptation to different environmental factors. METHODS: Structured sampling of 12 populations from six sites and two soil types within site was used to analyze the spatial and environmental structure of population differentiation. Sampling sites differ in grazing intensity and climate. We tested germination and growth in a common garden. In subsets, we analyzed the differential response to stone cover, grazing and soil moisture. KEY RESULTS: We found significant differences among populations. The site explained population differentiation better than soil, suggesting a dominant influence of climate and/or genetic drift. Stone cover had a positive influence on seedling establishment, and populations showed a differential response. However, this response was not related to environmental differences between collection sites. Regrowth after clipping was higher in populations from the more intensively grazed Red Mediterranean soils suggesting an adaptation to grazing. Final germination was generally high even under drought, but germination response to differences in soil moisture was similar across populations. CONCLUSIONS: Adaptive population differentiation in germination and early growth may have contributed to different colonization patterns. Thus, the provenance of B. retusum needs to be carefully considered in ecological restoration.

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I rapporten er tilstanden med hensyn til forekomst av fremmede skadelige karplanter (FSK) i naturtypene sanddynemark, åpen grunnlendt kalkmark, kulturmarkseng, kystlynghei og høstingsskog gått gjennom. Resultatene viser omfattende problemer i alle naturtypene, men først og fremst i tettbygd strøk og i Sør Norge. Mot nord avtar problemene, men det er trolig store mørketall i datasettet på grunn av mangelfull kartlegging og innrapportering av funn. Rapporten foreslår på grunnlag av gjennomgangen en rekke tiltak både i naturtypene og for jordbrukslandskapet på et generelt grunnlag. Rapporten går i mindre grad inn på tiltak innenfor bebyggelse og i tettbygd strøk.

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Grønne tak kan bidra med mange økosystemtjenester og funksjoner som å holde tilbake og fordrøye nedbør på tak, fremme biologisk mangfold, estetikk osv., inkludert nye trender som takhager og urbane uterom, dyrking av mat og kombinasjoner med solcellepaneler. I denne rapporten gir vi en oversikt over disse ulike funksjonene, presenterer nye norske data på nedbørshåndteringen og peker på noen sentrale kunnskapshull for å utvikle teknologien videre.

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Plenarealer kan inngå som en integre1t del av byenes lokale overvannsdisponering (LOD). I denne rappmten ser vi på kunnskapsgrunnlaget rundt infiltrasjon og diskuterer konsekvenser for skjøtsel og flerbruk av plenarealene. Vi fant at målte mettede infiltrasjonsrater for norske plenarealer på sandig ejosrtdim oagt elert fote rl esiarnatdtbear sJeig1tgee rm i agjsseenrn. oSmamsnmitet np åm reudn dtetr 1r0en cgmu/tfotimrme iin vgeekns tvsiel sdoen hgeynd rmaueldis vkees eengetlnigs khaøpyeenree til undergrunnsmassene og oppbygningen av vekstmassene bestemme kapasiteten for overvannshåndtering til plenarealene og evt. problemer med uønsket oppstuving. Målrettet oppbygning av massene gir et sto1t potensiale for infiltrasjon av overvann ved etablering av grøntområder, men fordeling av overvann på eksisterende plen kan også gi store bidrag til LOD. pBorureks tarvu kptluerneanr eoagle urn tnilg oå vteh1avtacnhn, sshoåmn dluteftriinngg ovgi lt okprepvder eesns imnge.r…………...

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Background and aims Layered profiles of designed soils may provide long-term benefits for green roofs, provided the vegetation can exploit resources in the different layers. We aimed to quantify Sedum root foraging for water and nutrients in designed soils of different texture and layering. Methods In a controlled pot experiment we quantified the root foraging ability of the species Sedum album (L.) and S. rupestre (L.) in response to substrate structure (fine, coarse, layered or mixed), vertical fertiliser placement (top or bottom half of pot) and watering (5, 10 or 20 mm week−1 ). Results Water availability was the main driver of plant growth, followed by substrate structure, while fertiliser placement only had marginal effects on plant growth. Root foraging ability was low to moderate, as also reflected in the low proportion of biomass allocated to roots (5–13%). Increased watering reduced the proportion of root length and root biomass in deeper layers. Conclusions Both S. album and S. rupestre had a low ability to exploit water and nutrients by precise root foraging in substrates of different texture and layering. Allocation of biomass to roots was low and showed limited flexibility even under water-deficient conditions.

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Extensive green roofs have become a frequently used option for stormwater retention across manydifferent climates including cold and wet regions. Despite the extensive documentation of green rooftechnology for stormwater management, the knowledge about their function and potential use in wetand cold regions is deficient. Using historic data on daily temperature and precipitation in a green roofwater balance model coupled with the Oudin model of evapotranspiration (ET), we evaluated the effects ofmaximum green roof storage capacities (Smax) and ET on stormwater retention along climatic gradientsin Northern Europe. Large differences in potential annual stormwater retention were found betweenlocations, driven by differences in temperature and precipitation amounts. Highest retention in abso-lute values was found for the wettest locations, while the warmest and driest locations showed highestretention in percentage of annual precipitation (up to 58% compared to 17% for the lower range). Alllocations showed a considerable retention of stormwater during summer, ranging from 52% to 91%. Stor-age capacities accepting drought conditions once every 3.3–3.9 year were found to be about 25 mm inthe cold and wet locations increasing to 40–50 mm in the warmer and drier locations. Correspondingstorage capacities to prevent wilting of non-succulent vegetation was on average a factor of 1.5 larger(not including Sheffield and Malmö). Annual retention increased both with an increase in plant wateruse (specific crop factors, Kc) and with an increase in Smax, but was found to be more sensitive to changesin Kcthan to changes in Smax. Hence, ET was the limiting factor for green roof retention capacity in thecold and wet locations, but relatively large changes in evapotranspiration would be needed to have animpact on retention. The potential to use vegetation with higher water use to better restore the storagecapacity between storm-events in these regions was however limited by the risk of permanent wilting ofnon-succulent vegetation, even on the wettest locations. A considerable increase in roof storage capacityand substrate thickness would be required to reduce this risk; still the increase in stormwater retentionwould be marginal.

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To predict how the function of urban vegetation and the provision of ecosystem services respond to combinations of natural and anthropogenic drivers, a better understanding of multiple stress interactions is required. This study tested combined effects of moderate levels of drought, soil salinity and exposure to diesel exhaust on parameters of physiology, metabolism, morphology and growth of Pinus sylvestris L. saplings. We found that plant responses were primarily dominated by single stressors and a few two-way interactions. Stressor combinations did not have considerable additional negative effects on plant performance compared to single stressors. Hence, synergistic and antagonistic interactions were rare and additive effects frequent. Drought cycles caused most negative effects, from chlorophyll a fluorescence and epicuticular wax content to growth responses, while soil salinity caused fewer negative effects but contributed to reduction in fine root growth and fluorescence parameters at low air contamination. Interestingly, the air contamination alone had only marginal effects on plant morphology and growth, but contributed an antagonistic effect, dampening the negative effect of drought and salinity on the maximum quantum efficiency of PSII photochemistry (Fv/Fm) and fine root biomass. Although, these effects were moderate, it appears that exhaust exposure had a cross-acclimation effect on plant responses to drought and salinity. We also found that salinity had a negative effect on the accumulation of particulate matter on shoots, illustrating that the plant stress situation can affect the provisioning of certain ecosystem services like pollution attenuation. These findings have implications for the understanding of the complex natural and anthropogenic stress situation of urban, and how to maintain the ecological functions and delivery of ecosystem services.

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Nitrogen-limited ecosystems are threatened by extensive spread of broom (Cytisus scoparius (L.) Link), a European leguminous shrub that is invasive in several countries. The establishment of invading species may, however, be suppressed by competition from native vegetation. The neighbor impact of the grass Festuca rubra subsp. commutata Gaudin on the performance of C. scoparius was studied in a greenhouse experiment with different arrival order, under low and high nitrogen supply, and with or without inoculation of nitrogen-fixing bacteria. Aboveground biomass of both species was measured after a six-months establishment period, and after a five-months regrowth period. In both periods, presence of F. rubra reduced the performance of C. scoparius as indicated by negative neighbor-effect intensity indices (NIntA). During the establishment period the competitive impact of F. rubra was highest, when planted before C. scoparius, followed by synchronous and late planting. Inoculation with rhizobia and low fertilization decreased the competitive impact of F. rubra. After cutting and regrowth priority effects of F. rubra were still visible. Interaction between the two study species was not affected anymore by inoculation, but strongly by fertilization, with highest competitive impact of F. rubra on C. scoparius under high nitrogen fertilization. In both study periods biomass of C. scoparius was negatively correlated with biomass of F. rubra. Our study provides knowledge about competition processes, which help to improve conservation and restoration measures regarding the spread of C. scoparius. Early sowing of a native grass can help to suppress the invasive species at an early stage. Competitive impact of the grass might be strengthened by high nitrogen availability.

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Area-efficient constructed systems for stormwater management and bioretention may involve large fluc-tuations in subsurface water levels. Such fluctuations challenge vegetation by forcing roots to exploredeeper layers to access water during dry periods. In a controlled experiment, we studied growth pat-terns and the ability of Phragmites australis roots to track subsurface water level fluctuations of differingamplitude and frequency in substrates with contrasting water-holding capacity. We found that P. aus-tralis was able to adjust its rooting pattern to considerable subsurface water level fluctuations (to wellbelow 120 cm), but that substrate characteristics can restrict its ability to adjust to larger fluctuations.Fluctuation amplitude was the driving factor for plant growth and biomass allocation responses, whilesubstrate characteristics and fluctuation frequency were less important. When not exposed to large waterlevel fluctuations, P. australis grew larger shoots and only explored intermediate rooting depths. Therewas a negative relationship between root and rhizome biomass, showing a resource-based trade-off andshort-term costs of adjusting rooting patterns to large water level fluctuations. These results indicatethat P. australis is suited for systems with considerable subsurface water fluctuations, but constraints onits flexibility need to be investigated.

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Grønne tak demper og fordrøyer avrenning etter nedbør og er etablert som et tiltak for lokal overvannsdisponering. I prosjektet Fremtidens Byer, ble det i 2014 etablert forsøkstak med utprøving av ulike tekniske løsninger og vegetasjon i flere norske byer. I denne rapporten følger vi opp utviklingen på disse takene med analyser og vurderinger av vegetasjonen 4 vekstsesonger etter oppstart......

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Grønne tak demper og fordrøyer avrenning etter nedbør og er etablert som et tiltak for lokal overvannsdisponering. I prosjektet Fremtidens Byer, ble det i 2014 etablert forsøkstak med utprøving av ulike tekniske løsninger og vegetasjon i flere norske byer. I denne rapporten følger vi opp utviklingen på disse takene med analyser og vurderinger av vegetasjonen 3 vekstsesonger etter oppstart. Undersøkelsene viser at det er stor forskjell i kvalitet på vegetasjonen på de ulike takene. Noen få har høy og akseptabel kvalitet, men mange har middels til lav og ikke akseptabel kvalitet. Det er et stort problem at en ikke klarer å opprettholde kvaliteten på takene over tid. Noen av problemene skriver seg fra oppstartsfasen, mens andre er resultat av episoder med krevende værforhold som har gitt stor utgang av vegetasjon. Noen er også et resultat av lokale miljøforhold. Takene på Kalvøya, Bærum er et godt eksempel på det, der en nå har godt dokumentert negative effekter av skygge og le på bergknappvegetasjonen. I tillegg til de store utfordringene med kvalitet, er det en dynamikk i utvikling av vegetasjonen som kan få konsekvenser på sikt. Matter med de høyvokste Phedimus og Hylotelephium artene gir stort sett godt og tett vegetasjonsdekke, men utkonkurrerer de lave artene og dominerer fullstendig på flere av takene. Det ser også ut til å være en utfordring å få til gode løsninger basert på lave stedegne arter. Arbeidet med å finne bedre løsninger basert på stedegne arter bør intensiveres. For å kunne dra nytte av disse takene i flere år framover, er det behov for tekniske justeringer og oppfølging på flere av takene som reparasjon av skader, gjødsling og luking av ugras. Disse justeringene bør skje i 2017.

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Invasive nitrogen-fixing plants drive vegetation dynamics and may cause irreversible changes in nutrient-limited ecosystems through increased soil resources. We studied how soil conditioning by the invasive alien Lupinus nootkatensis affected the seedling growth of co-occurring native plant species in coastal dunes, and whether responses to lupin-conditioned soil could be explained by fertilisation effects interacting with specific ecological strategies of the native dune species. Seedling performance of dune species was compared in a greenhouse experiment using field-collected soil from within or outside coastal lupin stands. In associated experiments, we quantified the response to nutrient supply of each species and tested how addition of specific nutrients affected growth of the native grass Festuca arundinacea in control and lupin-conditioned soil. We found that lupin-conditioned soil increased seedling biomass in 30 out of 32 native species; the conditioned soil also had a positive effect on seedling biomass of the invasive lupin itself. Increased phosphorus mobilisation by lupins was the major factor driving these positive seedling responses, based both on growth responses to addition of specific elements and analyses of plant available soil nutrients. There were large differences in growth responses to lupin-conditioned soil among species, but they were unrelated to selected autecological indicators or plant strategies. We conclude that Lupinus nootkatensis removes the phosphorus limitation for growth of native plants in coastal dunes, and that it increases cycling of other nutrients, promoting the growth of its own seedlings and a wide range of dune species. Finally, our study indicates that there are no negative soil legacies that prevent re-establishment of native plant species after removal of lupins.

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Rapporten presentere resultater fra et forprosjekt som svarer på problemstillinger knyttet til det biologiske grunnlaget for videre utvikling av birøkternæringen på Jæren og etablering av lokale merkevarer og honningtyper. Vi identifiserte de viktigste trekkplantene i landskapet gjennom sommeren og dokumenterte honningkvalitet for noen perioder. 2015 var et utypisk år med lave temperaturer og sein blomstring. Resultatene ga derfor ikke svar på alle aktuelle problemstillinger, men viste at tilnærmingen og metodikken er egnet til å løse disse. Biene samlet pollen fra minst 32 ulike arter, men platanlønn, bringebær, rogn og geitrams var som ventet de viktigste trekkplantene. Det var betydelige forskjeller i sukkerinnhold, syreinnhold og fenolprofiler mellom honning slynget til ulike tidspunkt og lokaliteter. Forprosjektet gir et grunnlag for å undersøke metoder for å øke tilgangen på pollen- og nektarressurser i landskapet, redusere variasjonen i ressurstilgang over tid og vurdere om forskjellene i honningkvalitet mellom ulike trekkplanter kan brukes til å utvikle sortshonning og lokale produkter.

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Grøntmiljø gir et mangfold av positive effekter, men det må framskaffes mer konkret kunnskap om betydningen av grøntmiljø i forskjellige områder og sammenhenger. Hovedutfordringen blir å knytte sammen effektene av mange små tiltak slik at de samlet gir et viktig bidrag til bærekraftig utvikling av urbane områder.

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Plant responses to elevated CO2 are governed by temperature, and at low temperatures the beneficial effects of CO2 may be lost. To document the responses of winter cereals grown under cold conditions at northern latitudes, autumn growth of winter wheat exposed to ambient and elevated levels of temperature (+2.5°C), CO2 (+150 µmol mol-1), and shade (-30%) was studied in open-top chambers under low light and at low temperatures. Throughout the experiment, temperature dominated plant responses, while the effects of CO2 were marginal, except for a positive effect on root biomass. Increased temperature resulted in increased leaf area, total biomass, total root biomass, total stem biomass, and number of tillers, but also a lower content of total sugars and a weaker tolerance to frost. The loss of frost tolerance was related to the larger size of plants grown at elevated temperature. The 30% light reduction under shading did not affect the growth, sugar content, or frost tolerance of winter wheat. At the low temperatures found at high latitudes during autumn, the atmospheric CO2 increase is unlikely to enhance autumn growth of winter wheat to any significant extent, while a temperature increase may have important and major effects on its development and growth.

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Med de ventede klimaendringene, vil vekstsesongen forskyves i forhold til innstråling. Høyere temperatur, sein høst og tidlig vår gjør at temperaturen vil være høy nok for vekst en større del av året enn i dag. Det er usikkert om innstråling er tilstrekkelig til at plantene kan utnytte den økte temperaturen og hvordan en forskyving av vekstavslutning påvirker herdeprosessene.

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I 2004 startet et relativt omfattende klimaforskningsprogram i Bioforsk med en total ramme på ca. 20 millioner kroner over 5 år. I løpet av de tre årene som har gått er det blitt gjennomført en lang rekke forsøk for å belyse hva som kan skje ved en framtidig klimaendring blant annet med høsthvete

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Twelve fertilizer/biostimulant products or product families were compared with mineral fertilizer in three two-year trials on USGA greens and sand-based football fields in southern Norway. Within each trial, all treatments were received the same amount of total nitrogen per year. Substitution of some of the mineral fertilizer with Gro-Power® improved turfgrass quality in one trial. Otherwise, the organic fertilizers and biostimulants producted results that were equal to or inferior to the control treatment. In conclusion, fertilization of sand-based golf greens and football fields ought to be based on light and frequent applications of mineral fertilizer throughout the growing season. Organic fertilizers and biostimulants can, at best, be supplements to such a fertilizer program.

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During 2005 and 2006, 12 different fertilizer/biostimulant products or product families were evaluated on a new USGA green, a new sand-based football field, and/or a two to three year old USGA green at Bioforsk"s research units Landvik, Særheim and Apelsvoll in Southern Norway. Within each trial, all treatments were adjusted to the same total nitrogen rate per year (3.0/2.8, 2.5/1.7, and 1.75/1.75 kg N/100 m2 on the football field, new and established golf green in 2005/2006, respectively). Inputs of other nutrients varied among treatments. Application intervals varied among treatments in 2005, but most products were applied at biweekly intervals in 2006. Mineral fertilizers Arena® (small granules) and Fullgjødsel® were included as control treatments on golf greens and the football field, respectively. The mostly animal-based organic product families Suståne resulted in faster grow-in of the creeping bentgrass green at Landvik, while the products familiy ProGreen and ProGreen plus Activo had a similar effect on the football field established on straight sand at Særheim. When used as the only fertilizer source, neither these product families nor the animal-based product family Bio Kombi showed any advantage for maintenance of established turf The only product family resulting in a general improvement in turfgrass quality over the whole experimental period was Gro-Power®. This product family is based on humus, with all of its nitrogen in an easily available form. Unlike most other organic product families, it was tested in combination with mineral fertilizer Arena® as used in the control treatment. When used as the only fertilizer source, the seaweed product Golf Algin resulted in slower grow-in and more diseases in autumn than the control treatment. Used as maintenance fertilizer during summer, the visual ratings of Golf Algin plots were equal to or higher than the visual ratings of control plots. The liquid organic fertilizer Flex" resulted in slow establishment at Landvik and Særheim. In summer, the visual ratings of Flex" plots at these locations were mostly on level with or higher than control plots, but in autumn, the turf at Landvik became very light green, perhaps due to leaching losses. Like Golf Algin, Flex" seems to be a good maintenance fertilizer for the summer period. The seaweed product Maxicrop" had no effect on turf quality at Landvik. The biostimulant GoGreen improved turfgrass colour in autumn, but had no effect on winter diseases after almost five months of snow cover at Apelsvoll. By contrast, replacement of some of the Arena® fertilizer with ammoniumsulfate resulted in significantly better winter survival, root development and overall turfgrass quality in the same experiment. In conclusion, we recommend that fertilization of sand-based golf greens and football fields are primarily based on light and frequent applications of mineral fertilizer throughout the growing season. Organic fertilizers and biostimulants can never replace mineral fertilizer, but they are important supplements that warrant further research for optimal use.

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Ulike metoder for å stimulere deklorering av DDT i sedimenter er undersøkt; ex-situ behandling av oppgravde masser i biopiles (hauger), in-situ behandling for strandkantmaterialer (in-situ land) og under vann (in-situ vann). Behandlingene ble optimalisert for å oppnå reduserende forhold og for å stimulere reduktiv omdanning av DDT til DDD. Under behandlingsforhold i dette prosjektet, var 30 ukers behandlingstid for kort tid til å bekrefte omdanning av DDT, kun trender ble observert. Kombinasjonen innstråling og plastdekke viste at en kan opprettholde en temperatur på 25-30°C i store deler av ranken ved lufttemperaturer rundt 10°C. Disse temperaturene er funnet gunstige for nedbryting av DDT. Også ved synkende lufttemperatur opprettholdes en temperatur høy nok til å stimulere nedbrytning. Underlag med 5 cm isopor hadde god evne til å hindre reduksjon i jordtemperaturen i nedre lag av jordmassene i ranken. Ulike tilsetningsmaterialer for å skape anaerobe forhold ble sammenlignet. Kumøkk og potetrev (biprodukt fra potetindustrien) gav størst reduksjon i oksygennivå

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Forekomsten av ugras i IVAR sin hagekompsot fra Sele ble undersøkt ved spireforsøk. Det ble tatt ut prøver fra overflaten av siktet ranke og ranker til sikting i 2007 i juni og oktober. Prøver fra inne i ferdig siktet ranke ble tatt ut i juni. Det spirte noe ugras fra prøvene tatt ut i juni, men mengden ugras ble vurdert å være liten. Det tok lang tid før spiring startet, noe som tyder på spirehemming i komposten. Ugrassituasjonen i anlegget ble også vurdert og det anbefales å etablere et permanent vegetasjonsdekke på områdene rundt rankene.