Ascospores of the parasitic fungus Kretzschmaria deusta as rainstorm indicators during a late Holocene beech-forest phase around lake Meerfelder Maar, Germany     

Bas van Geel  Stefan Engels  Celia Martin-Puertas  Achim Brauer 《Journal of Paleolimnology》2013,50(1):33-40

Discrete reddish-brown, predominantly minerogenic detrital layers along the Holocene, annually laminated sediment sequence of Lake Meerfelder Maar represent extreme runoff events. We conducted detailed microfacies analyses and a high-resolution palynological investigation, focusing on ten detrital layers throughout the Holocene. We studied triad samples taken directly under, in and above the detrital layer. Fagus sylvatica (beech) was a dominant species in the regional forest around Lake Meerfelder Maar after ca. 3,800 years ago. Three detrital layers occurring during the Fagus phase exhibit short-term maxima of ascospores of the parasitic fungus Kretzschmaria deusta. In contrast, the ascospore contents are low in the event layers deposited during the early and middle Holocene. Fagus is a vulnerable host species for Kretzschmaria deusta and the fungus is common on Fagus. Ascospores are formed on the trunk base, and under normal weather conditions, few spores appear outside the forest. We interpret the short peaks in abundance of K. deusta in the event layers as indicators for rainstorms during which material was transported from the forest floor into the lake by strong winds and stormwater runoff. The open beech forest facilitated wind transport of the ascospores. We recommend analysis of fungal spores in lake sediments because fungal records may help to identify extreme weather events, even when such events are not macroscopically visible in the sediment sequence.  相似文献   

Long cores from small lakes—recovering up to 100 m-long lake sediment sequences with a high-precision rod-operated piston corer (Usinger-corer)     

Jens Mingram  Jörg F. W. Negendank  Achim Brauer  Dieter Berger  Andreas Hendrich  Michael Köhler  Hartmut Usinger 《Journal of Paleolimnology》2007,37(4):517-528

We present a unique, versatile piston corer for recovering continuous lake and bog sediment sequences with superior accuracy and quality. The main components of the system and their function are described, with special focus on measures for obtaining long, continuous lake sediment sections up to a current maximum length of 95 m. Examples of lake sediment profiles obtained with this system from different climatic zones are presented.  相似文献