Ársrit Ræktunarfélags Norðurlands - 01.01.1976, Qupperneq 28

In 1973, however, only two maxima were encountered for the arthro-
pods (graph 2), and the spring maximum was then much higher
than the maximum in autumn, probably due to a wet june and a
following drought. The different families of Collembola and Oribatei
seem to behave in a similar way in general.
Some vertical migration to deeper layers in autumn may be noticed
from the tables.
HEIMfLDASKRÁ
Brauns, A. 1968: Praktische Bodenbiologie. Stuttgart.
Helgi Hallgrímsson. 1969: Lífið í jarðveginum. Arsr. Rf.Nl. 66: 31—69.
Helgi Hallgrimsson. 1975: Um lífið í jarðveginum IV. Smádýralíf jarðvegsins
í ýmsum gróðurlendum. Ársr. Rf.Nl. 72: 28—44.
Helgi Hallgrímsson og Jóhannes Sigvaldason. 1974: Um lífið í jarðveginum
III. Athuganir á rannsóknareitum á Víkurbakka sumarið 1969. Ársr.
Rf.Nl. 71: 36-55.
Jackson, R. M. 1966: Life in the soil. Stuclies in biology no. 2. Institute oí
Biology. New York. (60 bls.)
Jóhannes Sigvaldason, 1973: Um lífið í jarðveginum II. Nokkrar athuganir á
dýralífi í tilraunareitum á Akureyri Ársr. Rf. Nl., 70: 51—62.
Kevan, D. K. McE. (ritstjóri) 1955: Soil Zoology. Proceedings of the Univ.
of Nottingham, Second Easter Scool in Agricultural Science, 1955.
(Safn fyrirlestra um jarðvegslífið).
Maynard, E. A. 1951: A monograph of the Collembola or Springtail Insects
of New York State. New York.
Michael, A. D. 1898: Oribatidae. í Das Tierreicli, 3. Lief. Acarina. Berlin.
Ljósprentað 1965 í Weinheim.
Richards, B. N. 1974: Introduction to the soil ecosystem. Longman.
Sellnick, M., 1940: Die Milbenfauna Islands. Göteb. Kungl. Vetensk. — och
Vitterh. — Samh. Handl. Femte följden. Ser. B. Bd. 6, nr. 14. (Göteborg.)
Trolldenier, G., 1971: Bodenbiologie. Die Bodenorganismen im Haushalt
der Natur. Kosmos. Stuttgart. (150 bls.)
Weis-Fogh, T. 1948: Ecological Investigations on Mites and Collemboles in
the soil. Natura Jutlandica. Bd. 1. Aarhus.
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