Lärchenminiermotte (Coleophora laricella) und Vogelschutz/Vogelforschung im Emsland : Bilanz eines Langzeit-Freilandversuches : Synopsis of a long-term study

Alfeld

2005

S. 279-283

4 Abb., 15 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200124697

In the Emsland-area/NW Germany large scale afforestations of moorland with Scots pine (Pinus sylvestris) and Japanese larch (Larix leptolepis) were done in the 1950s. First attemps to control the Larch casebearer (Coleophora laricella) by means of insectivorous birds settled in ariticial nestboxes were started as early as 1965 in special study plots. Since 1974 until now the box-nesting birds were used also in favour of an intense avian research project in which bird-ringing plays an important part. The Larch casebearer was under surveillance from 1971 until 1994 by a threefold annual spot check. The moth's population dynamics presents itself as a cyclic fluctuation influecned by delayed density dependent factors to be found presumably in the reaction of the hosttree with defoliation. A. regulatory (density dependent) bird-effect on C. laricella, however, could not be shown. The pattern of Larch case-bearer infestation is rather due to local variations affecting the predisposition of larches to insect attack. The ornithological investigations developed into basis research especially on population dynamics (e.g. long-term increase in Coal tits Parus ater and Pied Flycatchers Ficedula hypoleuca), and on reproductive biology. Some species showed a significant long-term trend towards earlier breeding, which is proposed to ba causally involved with climatic warming in the course of the past three decades. Recently - in cooperation with the Insittute for Evolutionary Biologgy and Ecology, University of Bonn, - also molecular genetic techniques (DNA-fingerprinting) are used to investigate e.g. the occurance of extra-pair matings in Pied flycatcher and Coal tits together with resulting fitness consequences.