042 FAGRAPPORTFAGRAPPORT Provisional list of rare and potentially threatened spiders (Arachnida: Araneae) in Norway including their proposed Red List status Kjetil Aakra Erling Hauge NINA Norsk institutt for naturforskning nina fagrapport 042 Norwegian Institute for Nature Reseach Aakra, K. & Hauge, E. 2000. Provisional list of rare and potential- ly threatened spiders (Arachnida: Araneae) in Norway including (NINA) and Norwegian Institute for their proposed Red List status. - NINA Fagrapport 42: 1-38. Cultural Heritage Research (NIKU) Trondheim, July 2000 issue the following publications: ISSN 0805-469X NINA Scientific Reports (Fagrapport) ISBN 82-426-1151-3 NIKU Scientific Reports (Fagrapport) These series present the results of NINAs and NIKUs own rese- Management field: arch work, overviews of problems, existing knowledge within Conservation of biodiversity a topic, literature reviews and material gathered from outside sources. The reports are issued as an alternative or a supliment Copyright ©: to international publication when timing, the nature of the Foundation for Nature Research and material or the sector targeted, call for it. Cultural Heritage Research (NINA•NIKU) NINA Assignment Report (Oppdragsmelding) The report may be quoted when the source is NIKU Assignment Report (Oppdragsmelding) mentioned by name. This is the minimum report supplied by NINA/NIKU when ex- ternal research or investigative assignments have been com- pleted. The number of copies are limited. NINA Topic Report (Temahefte) NIKU Topic Report (Temahefte) These series present special topics. The series is targeted at the general public or specific groups in the community, e.g. the Editor: agricultural sector, environmental departments, tourism and Bjørn Åge Tømmerås outdoor recreation, organizations etc. It is therefore more po- Norwegian Institute for Nature Research, pular in its presentation form, with more illustrations than the Trondheim previously mentioned series. Layout and design Most of the publications mentioned above are in Norwegian, Eva Marie Schjetne but will also have an English abstracts and legends of figures NINA•NIKU Graphic Office and tables in English. Illustration on front page, Arctosa cinerea: NINA Fact Sheet (Fakta-ark) Kjetil Aakra These doble-pages sheets give (in Norwegian) a popular sum- mary of other publications to make the results of NINAs and Prints: Norservice NIKUs work available to the general public (the media, societi- es and organisations, various levels of nature management, Stock: 250 politicians and interested individuals). Contact address: NINAs and NIKUs staff also publish their research results in NINA international scientific journals, popular scientific periodicals, Tungasletta 2 and newspapers. 7485 Trondheim Tlf: + 47 73 80 14 00 NINA•NIKU homepage: http://ninaniku.no/ Fax:+ 47 73 80 14 01 Accessibility: Open Contracting sponsor: Liable signature: Norwegian Institute for Nature Research 2 nina fagrapport 042 Referat Abstract Aakra, K. & Hauge, E. 2000. Midlertidig liste over sjeldne og po- Aakra, K. & Hauge, E. 2000. Provisional list of rare and potential- tensielt truede edderkopper (Arachnida: Araneae) i Norge inklu- ly threatened spiders (Arachnida: Araneae) in Norway including dert deres foreslåtte Rød Liste status. - NINA Fagrapport 42: 1-38. their proposed Red List status. - NINA Fagrapport 42: 1-38. Alle edderkopper registrert i Norge har vært gjenstand for en All Norwegian spider species known to occur in Norway have gjennomgåelse med tanke på deres truethet og verne status. been surveyed and their conservation status assessed. Altogether Totalt 91 arter eller 16.4 % av de 555 kjente norske edderkop- 91 species or 16.4 % of the 555 species known to occur in parter er inkludert i dette Rødlisteforslaget. For hver art er utbre- Norway have been included in the current Red List proposal. delse både i Norge og resten av verdne oppgitt, sammen med Distribution in both Norway and the rest of the world, habitat trusselfaktorer, habitatkrav og taksonomiske spørsmål hvor det preferences, threat factors, worldwide conservation status and ta- er nødvendig. xonomy, where necessary, are detailed for each species. Tyve arter er gitt statusen “Utdødd”, en er “Direkte Truet”, en Twenty species have been assigned to the “Extinct?” Category, er “Sårbar”, 21 er “Hensynskrevende”, 25 er “Usikker” og 23 er one is considered “Endangered”, one is “Vulnerable”, 21 are “Utilstrekkelig Kjent”. Størstedelen av artene hører til i østlige “Declining, care demanding”, 25 are “Indeterminate” and 23 are (31.8 %) eller sørøstlige (44 %) deler av Norge. “Insufficiently Known”. The majority of the species occur in the eastern (31.8 %) or the southeastern parts (44 %) of Norway. Flest arter hører hjemme i skogen (31 %) eller i åpne habitatty- per (22 %). Av den siste gruppen er 15 % varmekjære, inkludert The largest number of species are forest inhabitants (31 %) or in- flere arter i de strengeste rødlistekategoriene. Arter som lever i habitants of open biotopes (22 %). Of the latter group 15 % are urtevegetatsjon, busker og små trær utgjør 19 % av totalen. thermophilous, including several species in the strictest Red List Edderkopper i andre habitattyper, som myrer, våtmarker, elve- categories. Species living in herbaceous vegetation, bushes and on bredder og strandsonen er relativt færre, men flere av de mest low branches of trees represent 19 % of the total. Spiders living in interessante og sjeldne artene hører til i disse biotopene. Av de other habitats, including wetlands and peatlands, river banks and ulike taxa står hjulspinner familien Araneidae i en særstilling, seashores are fewer in numbers but some of our most vulnerable hele 35 % av alle antatt utdødde arter hører til denne familien. and rarest species are found in these biotopes. Of the taxonomic Årsaken er trolig å finne i flere forhold; innsamlingsteknikker groups the orb-weaver family Araneidae has a disproportionally som favoriserer andre grupper, en rêell tilbakegang i antall og large number of species in the “Extinct?” category (35 % of all in vanskelig tilgang til disse artenes habitater. the category). This is probably caused by a combination of collecti- on bias, genuine decline and lack of suitable sampling methods in Generelle trusselfaktorer er gitt for artene med hensyn på deres what is often inaccessible habitats. habitater. Åpenmarksarter er sårbare for gjenngroing som følge av at kulturmarker ikke lenger skjøttes og for enkelte jordbruk- General threat assessment is provided for the species in respect to spraksiser, skogsarter er svært sårbare ovenfor moderne skog- their habitat. Open habitats are vulnerable to regrowth and agri- bruksmetoder, spesielt hogst av urskog og gammel kontinuitets- cultural practices, forest species are sensitive to modern forestry skog, våtmarks og myrarter er sensitive ovenfor drenering og an- methods, particularily the removal of old-growth stands, peatland nen forandring i hydrologi, ripare og kystarter er sårbare for and wetland species are vulnerable to changes in hydrology, coas- tråkkeffekter, forurensing, jordbruks og anleggsvirksomhet mens tal and riparian species are vulnerable to trampling effects, polluti- alpine høyfjellsarter er sårbare ovenfor alle faktorer som fører til on, agricultural and construction activities while alpine species are forandringer i deres mikrohabitater. Generelle forslag til vern og sensitive to changes in their microhabitats. General suggestions skjøtsel av disse artene er gitt, best vern av edderkopper oppnåes regarding the conservation of these rare spiders are given, as with ved varig fredning og beskyttelse av deres habitater. most invertebrates preservation are best facilitated through pro- tection and monitoring of their habitats. Norske ansvarslister er gitt for myr/våtmark-, skogs- og åpen- marksarter basert på rødlister fra andre land i Europa. Norwegian Responsibillity Lists are presented for peatland/wet- land species, high-altitude alpine species and forest, grassland Kjetil Aakra and open land species, based on comparison with Red Lists of Museum of Natural History and Archaeology, other countries in Europe. Department of Natural History, NTNU, N-7491 Trondheim, Norway Email: [email protected] Kjetil Aakra Museum of Natural History and Archaeology, Erling Hauge Department of Natural History, NTNU, N-7491 Trondheim, Norway Zoological Museum, Email: [email protected] University of Bergen, N-5007, Bergen, Norway Email: [email protected] Erling Hauge Zoological Museum, University of Bergen, N-5007, Bergen, Norway Email: [email protected] 3 nina fagrapport 042 Preface Contents The official Norwegian Red Lists are based on proposals in re- Referat....................................................................................3 ports and publications by specialists which are considered, ap- Abstract ..................................................................................3 proved and published by Direktoratet for naturforvaltning (DN). Preface....................................................................................4 Red Lists are increasingly used in Norway today when planning 1 Introduction.......................................................................5 the management and conservation of biological resources. The 2 Methods and material........................................................5 first Norwegian Red Lists dealt solely with vertebrates but from 3 Present state of knowledge................................................7