Pathways of introduction of alien species in Norway: analyses of an exhaustive dataset to prioritise management efforts

1. Alien species constitute one of the major threats to global biodiversity. Stopping alien species at an early stage, preferably before establishment, is crucial for the effectiveness of management actions. To enable early detection and prevent future introductions, knowledge of pathways of introduction and their absolute and relative importance is crucial. 2. Based on an exhaustive impact assessment of alien species in Norway (all multicellular neobiota), the relations of taxonomy, lifestyle and ecological impact of alien species to their pathways of introduction are investigated. This taxonomically and ecologically unbiased dataset contains 2267 unique pathways of 1180 alien species. 3. Ecological and taxonomic patterns indicate that terrestrial organisms were predominantly introduced by means of escape (mainly perennial plants escaped from gardens), parasites as contaminants (mainly fungi and insects parasitising plants), freshwater organisms by release (mainly vertebrates) and marine organisms as stowaways (mainly invertebrates and algae). Unaided introductions were most common among insects and marine organisms. 4. Alien species with high ecological impact were mainly introduced along the same pathways as other alien species. In relative terms, high-impact species were overrepresented among released species, even though this pathway was subordinate in absolute terms. The number of pathways and the overall introduction pressure were important predictors of ecological impact, especially of the species' invasion potential, and area of occupancy. 5. Introduction rates of novel alien species have seen recent increases in all taxa and along almost all pathways. This acceleration was especially pronounced for insects and fungi introduced as contaminants and for marine organisms introduced as stowaways. In absolute terms, introduction rates were highest for plant escapes, reaching more than five novel species per year. 6. Synthesis and applications. Introductions of new alien species cannot be prevented by closing one or two introduction pathways, since none can be singled out as the main pathway of high-impact alien species. Yet each pathways closedmakes a difference, as this reduces the overall introduction pressure. The highest priorities for management are the pathways that are easiest to address, such as release, and those with the highest volumes, such as plant trade. ecological impact, escape, introduction pathway, invasive species, spread, stowawaypublishedVersio

Contributions to the lichen flora of Norway, primarily from the central and northern counties

New distributional data are given on 52 lichen species from Norway. Anisomeridium nyssaegenum, Lecideasphaerella, Sarcosagium campestre, Scoliciosporum perpusillum and Strangospora pinicola are new to Norway. 30 species are new to central Norway. A chemotype of Lecanora cadubriae with virensic acid is reported for the first time and a PD-negative chemotype of Lobaria scrobiculata is new to Europe. Maps on the distribution in Norway are provided for Bacidia subincompta, Cliostomum griffithii, Lecanora cadubriae, Micarea cinerea and Opegrapha rufescens. A map is provided concerning the European distribution of Cladonia metacorallifera var. reagens

Lobaria_raw data file for Dryad

This file present the results of genetic analyses of Lobaria pulmonaria sampled in three different localities in boreal rainforests of central Norway

Pathways of introduction of alien species in Norway: analyses of an exhaustive dataset to prioritise management efforts

1. Alien species constitute one of the major threats to global biodiversity. Stopping alien species at an early stage, preferably before establishment, is crucial for the effectiveness of management actions. To enable early detection and prevent future introductions, knowledge of pathways of introduction and their absolute and relative importance is crucial. 2. Based on an exhaustive impact assessment of alien species in Norway (all multicellular neobiota), the relations of taxonomy, lifestyle and ecological impact of alien species to their pathways of introduction are investigated. This taxonomically and ecologically unbiased dataset contains 2267 unique pathways of 1180 alien species. 3. Ecological and taxonomic patterns indicate that terrestrial organisms were predominantly introduced by means of escape (mainly perennial plants escaped from gardens), parasites as contaminants (mainly fungi and insects parasitising plants), freshwater organisms by release (mainly vertebrates) and marine organisms as stowaways (mainly invertebrates and algae). Unaided introductions were most common among insects and marine organisms. 4. Alien species with high ecological impact were mainly introduced along the same pathways as other alien species. In relative terms, high-impact species were overrepresented among released species, even though this pathway was subordinate in absolute terms. The number of pathways and the overall introduction pressure were important predictors of ecological impact, especially of the species' invasion potential, and area of occupancy. 5. Introduction rates of novel alien species have seen recent increases in all taxa and along almost all pathways. This acceleration was especially pronounced for insects and fungi introduced as contaminants and for marine organisms introduced as stowaways. In absolute terms, introduction rates were highest for plant escapes, reaching more than five novel species per year. 6. Synthesis and applications. Introductions of new alien species cannot be prevented by closing one or two introduction pathways, since none can be singled out as the main pathway of high-impact alien species. Yet each pathways closedmakes a difference, as this reduces the overall introduction pressure. The highest priorities for management are the pathways that are easiest to address, such as release, and those with the highest volumes, such as plant trade. ecological impact, escape, introduction pathway, invasive species, spread, stowawa

Biodiversitet i plantefelt med gran (Picea abies) og i plantefelt med sitkagran (P. sitchensis). En sammenlignende studie.

Kunnskapen om biodiversitet i plantefelt av introduserte bartre er generelt mangelfull. Hovedmålet med dette prosjektet har vært å få større kunnskap om hvilken betydning plantefelt med sitkagran (Picea sitchensis) kan ha for biodiversiteten, og om biodiversiteten i sitkagran-bestand er forskjellig fra plantefelt med gran (P. abies). Det ble valgt tre undersøkelsesområder, Halsa, Jonsvatnet og Kolvereid, for kartlegging av lav på greiner, moser på dødved, samt moser og karplanter i skogbunnen. Kartleggingen omfattet 18 plantefelt i alderen 45 – 55 år. Det ble valgt seks plantefelt i hvert område og feltene ble valgt parvis: ett plantefelt med gran og ett med sitkagran. I hvert plantefelt ble en rute på 200 m2 tilfeldig plassert for kartlegging av valgte organismegrupper. Fem greiner og fem liggende dødvedstokker ble valgt tilfeldig i hvert plantefelt, og for hver grein/stokk ble totalt antall arter og frekvensen av artene undersøkt. I Kolvereid ble det i tillegg gjort ruteanalyser av karplanter og moser i bunnsjiktet. Tretetthet, kronedekning (%) og antall liggende dødved ble registrert for hver 200 m2 rute, og for valgte trær og greiner ble stammeomkrets (cm), greinlengde (cm), greinomkrets (cm) og greinvitalitet (død eller levende) målt. For dødved ble stokkdiameter (cm), stokkens nedbrytingsgrad (femgrads skala) og mengde bark (%) notert. Effekten av treslag (gran versus sitkagran), område (Halsa, Jonsvatnet og Kolvereid) og registrerte miljøvariabler ble testet på antall og frekvens av arter ved bruk av lineære miksede modeller. Det ble totalt registrert 76 arter av epifyttisk lav og 49 mosearter på dødved. Frekvensen av lav på greinene var betydelig mindre i sitkagranfeltene (26,9 %) enn i feltene med gran (61,2 %). Det var lavere frekvens av store bladlav i sitkagranbestandene. Det ble også registrert en betydelig lavere frekvens av dødvedmoser i plantefelt med sitkagran, enn i plantefelt med gran. Det var særlig bladmosene som hadde en lav frekvens i sitkagranfeltene (3 %), sammenlignet med granplantefeltene (57 %). Det ble også funnet et lavere gjennomsnittlig antall arter av lav og dødvedmoser i plantefelt med sitkagran (henholdsvis 7,1 og 3,9 arter), enn i felt med gran (henholdsvis 9,9 og 6,1 arter), men de statistiske analysene viser at effekten av treslag her varierte med område: I Kolvereid var antall arter av både lav og moser mye mindre i sitkagranfeltene, enn i feltene med gran. Ved Jonsvatnet var derimot artsantallet relativt høyt i begge typer plantefelt. Generelt var artsmangfoldet høyere ved Jonsvatnet, enn i Halsa og Kolvereid. Ruteanalyser av bunnvegetasjonen i Kolvereid viste at dekningen av moser var signifikant mye høyere i plantefelt med gran (84,0 %), enn med sitkagran (5,7 %), mens forekomsten av karplanter var lav i begge typer plantefelt. Plantefelt, gran, sitkagran, lav, moser, karplanter, kronedekning, dødved, kartlegging, biodiversitet, Picea abies, Picea sitchensis, Plantations, Norway spruce, Sitka spruce, lichens, bryophytes, canopy cover, decaying logs, mapping, biodiversity, Picea abies, Picea sitchensi

Data from: Genetic structure in a fragmented Northern Hemisphere rainforest: large effective sizes and high connectivity among populations of the epiphytic lichen Lobaria pulmonaria

An extraordinary diversity of epiphytic lichens is found in the boreal rainforest of central Norway, the highest-latitude rainforest in the world. These rainforest relicts are located in ravine systems, and clear cutting has increased the distance between remaining patches. We hypothesized that the relatively small lichen populations in the remaining forest stands have suffered a depletion of genetic diversity through bottlenecks and founder events. In order to test this hypothesis we assessed genetic diversity and structure in populations of the tripartite lichen Lobaria pulmonaria using eight SSR loci. We sampled thalli growing on Picea abies branches and propagules deposited in snow at three localities. Contrary to expectations, we found high genetic diversity in lichen and snow samples, and high effective sizes of the studied populations. Also, limited genetic differentiation between populations, high historical migration rates, and a high proportion of first generation immigrants were estimated, implying high connectivity across distances <30 km. Almost all genetic variation was due to variation within sites; spatial genetic structures within populations were absent or appeared on small scales (5–10 m). The high genetic diversity in the remaining old boreal rainforests shows that even relict forest patches might be suitable for conservation of genetic diversity

Spredningsveier for fremmede arter i Norge. Kunnskapsstatus per 2019.

Hendrichsen, D.K., Sandvik, H., Töpper, J.P., Olsen, S.L., Hilmo, O., Magnussen, K., Navrud, S., Fleisje, E.M. 2020. Spredningsveier for fremmede arter i Norge. Kunnskapsstatus per 2019. NINA Rapport 1735. Norsk institutt for naturforskning. Fremmede arter utgjør en betydelig trussel mot verdens biologiske mangfold. I denne rapporten presenterer vi kunnskapsstatusen angående spredningsveier for fremmede arter til og i Norge, der «spredningsvei» omfatter alle tilsiktede eller utilsiktede mekanismer som kan føre til at en art kan spre seg fra et geografisk område til et annet. Vi gjennomgår først den internasjonale litteraturen og analyserer deretter dataene fra Fremmedartslista 2018, som en oppfølging og videreutvikling av en tidligere analyse basert på Norsk svarteliste 2012. Hovedfunnene er: De viktigste introduksjonsveier til Norge er rømning/forvilling, forurensning og blindpassasjerer. Det er også blant disse tre introduksjonsveier det kommer flest arter med høy eller svært høy økologisk risiko, selv om den prosentvise andelen av slike arter er høyest blant bevisste utsettinger. Karplanter utgjør majoriteten av artene langs alle introduksjonsveier unntatt egenspredning, men introduseres hovedsakelig via forvilling. Forurensning er den viktigste introduksjonsveien for insekter og sopper; blindpassasjerer for marine arter og øvrige terrestriske invertebrater; og utsettinger for virveldyr og limniske arter. Flest dørstokkarter forventes introdusert som forurensning og blindpassasjerer. Andelen og antallet av dørstokkarter med høy eller svært høy økologisk risiko er også størst langs disse to introduksjonsveiene. Utviklingstrenden i antall fremmede arter er økende, uten tegn til noen nedbremsing eller «metning». Nesten alle introduksjonsveier har hatt sin sterkeste økning i den siste 25-års-perioden. Antall nyregistreringer er positivt korrelert med bruttonasjonalproduktet (BNP). Den antatte utviklingen frem mot 2030 og 2050 er at antall fremmede arter vil øke. Siden antall introduserte arter per krone i BNP har vært synkende, er det imidlertid grunn til å anta at antall nye fremmede arter ikke vil vokse like mye som veksten i befolkning og BNP. Fastmarkssystemer blir kolonisert av flest fremmede arter, med hovedvekt på skogsmark og sterkt endret mark. Den viktigste spredningsveien er her rømning/forvilling, særlig av hageplanter. Dyr og sopper i disse systemene har fremfor alt kommet som forurensning og via egenspredning. I våtmarkssystemer spiller egenspredning en større rolle. De fremmede artene i saltvannsbunnsystemer og marine vannmasser er hovedsakelig dyr som har kommet som blindpassasjerer i forbindelse med skipstrafikk eller via egenspredning fra naboland. Ferskvannsbunnsystemene og limniske vannmasser koloniseres mest via egenspredning. Global oppvarming antas å øke invasjonspotensialet for fremmede arter og å endre deres effekter på stedegen natur. Det foreligger imidlertid hittil ingen systematisk sammenstilling av relevante data for å kunne teste disse forventningene for Norge.Hendrichsen, D.K., Sandvik, H., Töpper, J.P., Olsen, S.L., Hilmo, O., Magnussen, K., Navrud, S., Fleisje, E.M. 2020. Pathways of introduction of alien species in Norway: the state of knowledge in 2019. NINA Report 1735. Norwegian Institute for Nature Research. Alien species pose a significant threat to the world's biodiversity. In this report, we present the state of knowledge concerning pathways of introduction and spread of alien species to and in Norway; a "pathway" being any mechanism that can cause a species to spread from one geographical area to another. As a follow-up of a comparable analysis carried out in 2014, we analyse the data contained in the Norwegian 2018 alien species listing. Our main findings are: The most important pathways of introduction to Norway are escape, contamination and stowaways. In absolute numbers, most species with high or severe ecological impact are introduced along the same pathways, although the highest proportion of these is found among released species. Vascular plants constitute the majority of species along all pathways except unaided dispersal, but most plants have been introduced by escape. Insects and fungi have mainly been introduced as contaminants; marine species and other terrestrial animals mainly as stowaways; whereas freshwater species and vertebrates have mainly been introduced by release.Most door-knockers are expected to be introduced as contaminants and stowaways. The proportion and number of doorknockers with high or severe ecological impact is also largest along these two introductory pathways. The overall temporal trend in the number of alien species is increasing, without any signs of deceleration or saturation. Almost all pathways of introduction had their steepest increase during the past 25 years. The number of new species observations is positively correlated with the gross domestic project (GDP), although the number of species introduced per NOK in GDP has been declining. Therefore, the projected trend towards 2030 and 2050 is that the number of introductions of alien species will increase, albeit not as fast as human population size and GDP. Most alien species have been found to colonise non-wetland terrestrial systems, especially forests and heavily modified nature. The most important pathway of introduction is escape, mainly of garden plants. Animals and fungi occurring in these systems have been introduced as contamination and through unaided dispersal. In wetland systems, unaided dispersal plays a more important role. The alien species in marine systems are mainly animals that have been introduced as stowaways with ships or via unaided dispersal from neighbouring countries. Fresh-water systems are colonized mostly via unaided dispersal. Global warming is expected to increase the invasion potential of alien species and to alter their effects on native nature. So far, however, no systematic compilations of relevant data are available that would allow a test of these expectations for Norway

Generic Ecological Impact Assessment of Alien Species (GEIAA): the third generation of assessments in Norway

The Generic Ecological Impact Assessment of Alien Species (GEIAA) is described. It comprises a set of criteria and an assessment procedure. The set of criteria consists of three criteria that quantify invasion potential, and six criteria that capture the ecological effects of alien species. The threshold values for all criteria are numerically defined, rendering the set of criteria fully quantitative. Genericity is ensured by using criteria that are applicable to all taxonomic groups and in all habitats. In being generic, quantitative, ecological and normatively neutral, the criteria were inspired by the international Red List criteria. Capturing both invasion potential and effect, GEIAA can be regarded as a full ecological impact assessment. The assessment procedure contains guidelines on documentation, the collection of background information, the handling of uncertainty, and quality assurance. GEIAA represents the second revision, and thus the third generation, of assessment methodology in Norway. It has recently been used to carry out more than 2500 impact assessments of alien species in Norway and Sweden