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Quantitative Investigations On Bird Communities In Different Habitats In The Orkhon-Selenge-Valley In Northern Mongolia, Tobias Stenzel, Michael Stubbe, Ravčigijn Samjaa, Sundev Gombobaatar

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

In the breeding seasons 2001 to 2003, the avifauna of a study area of about 80 km² in the Selenge Aymag was studied.

The area is characterized by loose groves of elms (Ulmus pumila) and pine trees (Pinus sylvestris), and a chain of barchan dunes which separate the Orkhon valley from the up to 70 m higher situated forest steppe. Steppe species (Stipa spp.) dominate in the south; the northern steppe part is characterized by Caragana bushes (Caragana microphylla, locally C. stenophylla). Between Orkhon Gol and the eastern dunes, dry steppe …

Reproductive Ecology Of Two Common Woody Species, Juniperus Sabina And Artemisia Santolinifolia, In Mountain Steppes Of Southern Mongolia, Katrin Ronnenberg

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The present study describes the reproductive ecology of the prostrate shrub Juniperus sabina and the dwarf shrub Artemisia santolinifolia in dry mountain steppes of southern Mongolia. Whereas stands of the juniper are located at the drought limit of the genus’ distributional range, the genus Artemisia is typical of central Asian drylands. Both species produce large numbers of reproductive organs. For Juniperus sabina, however, only 2.5% of the morphologically intact seeds were found to be viable. Correspondingly, neither seedlings nor saplings were found in the field, and recruitment by reseeding happens at most rarely under the present climatic conditions.

Instead, …

Die Parasitierung Der Luzerne-Blattschneiderbiene, Megachile Rotundata (Hymenoptera: Megachilidae), Durch Physocephala Pusilla (Diptera: Conopidae) In Der Mongolei = Parasitization Of The Alfalfa Leaf-Cutter Bee, Megachile Rotundata (Hymenoptera: Megachilidae), By Physocephala Pusilla (Diptera: Conopidae) In Mongolia, Karsten Seidelmann

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Physocephala pusilla Meigen (Diptera: Conopidae) was found to be a dangerous endoparasitoid of the alfalfa leafcutter bee Megachile rotundata F. (Hymenoptera: Megachilidae) in Mongolia. The conopid fly parasitizes adults and causes their early death. In 1989 and 1990, 16% and 15% respectively of the M. rotundata females were found dead in front of the bee shelter. However, the number of bees (females and males) dying in the field is unknown. These bees cause a contamination of the alfalfa fields due to an increase of the conopid population. Therefore, Ph. pusilla becomes a serious problem for the management of M. rotundata …