Full-text - Norsk entomologisk forening

KallvellsjeaenStroplsjeaenKongsvoll Biological StationVest:be+.t,rI:~IQie" I'1/'ClrN!2 kmFig. 1. Location of Kongsvoll in Norway, and amap of the area sampled. The sites of the Malaisetraps are also indicated.laise traps along streams and pools and lakesare thus not the best possible for collectingNeuropteridea. In spite of that, the materialgive interesting data from montane areas. Onthe other hand, Malaise traps give good informationduring periods of bad weatherwhen nets are difficult to use efficiently.STUDY AREA AND METHODSThe study area was the surroundings ofKongsvoll Biological Station (62° ITN, 09°59'E) between the elevations 900 and 1452 m(Fig. 1). The two large geological regions inthe southern Scandinavian Caledonian meetin the sampling area, and the border roughlyfollows the River Driva. On the eastern sideis the Trondheim region, which containsmainly medium-grade mica schists and greenstonesof the cambro-silurian age. The westernside is mainly a basal gneiss region buildup of high-grade gneisses and schists of precambrianage. The differences in the geologybetween the eastern and the western side ofthe valley are most conspicuous when plantspecies are considered. The eastern side has amuch higher diversity of plant species thanthe western one. The sampling sites Stropla,Kaldvella and Gluptjern (Tab. 2) are on thewestern side and the remaining sites on theeastern side. The streams and lakes in theStroplsj0 area have pH in the range 6.0-6.5,and the lake Kallvellsj0en is about pH 6.8.The River Driva and the lakes and thestreams on the eastern side have pH in therange 7.3-7.9 (Bretten unpub!. data).The climate of the area is mainly continental,with a yearly precipitation of 473 mm atKongsvol!. The yearly mean temperature atHjerkinn (955 m a.s,!.) 10 km south ofKongsvoll, is -O.l°C, and only 19 days ayear have daily mean temperature abovelOoC (Nordhagen 1943).Malaise trap samples from 11 sites alongstreams and at pools and lakes have been usedfor this presentation. According to the definitionof biotic zones in mountainous areas58