Research in peatlands
Sernitzmoor
Since the fall of 2013, the spring fen in the Sernitz Valley (Schorfheide-Chorin Biosphere Reserve), another fen that had been affected by drainage, was sampled for soil fauna.
As part of the EU-LIFE Lesser Spotted Eagle project (www.lifeschreiadler.de), carried out by the Brandenburg Landesamt für Umwelt, Gesundheit und Verbraucherschutz, this bog was subsequently recultivated by, e.g., mowing (2014, 2015) and topsoil removal (October 2015). The effects of these measures on the soil fauna (Oribatida, Collembola) are documented every six months. The investigations should show whether the measures can achieve the development of a peatland-specific species composition.
Bioindication in acidic Sphagnum bogs
Various peat moss-rich bogs (e.g. Müritz National Park, Harz National Park) are examined with regard to their oribatid fauna and various environmental parameters (pH, C/N, vegetation) are recorded in parallel in order to characterize this type of bog and to derive the indicator value of individual oribatid mite species. If possible, different levels of degradation are sampled in a small area to find indicators for the quality of a bog.
Dubringer Moor
At 1,700 ha, the Dubringer Moor nature reserve is the largest contiguous peatland complex in Saxony and was already extensively investigated (soil) zoologically and botanically between 1986 and 1989. The oribatids were also sampled and have since been stored in the museum collection, but not identified so far. By comparing the current species inventory (sampling in 2012: soil samples, pitfall traps; Oribatida, Araneae, Myriapoda, Carabidae) with the inventory 25 years ago, the effects of increasing (drainage-related) desiccation were worked out. The results showed a clear decline in typical peatland species. The abundance of peatland-specific species still present is significantly reduced. However, in the event of prompt renaturation, the remaining species would presumably enable rapid regeneration of the peatland community (Lehmitz 2014).
The differences between the soil animal communities of a birch bog forest created by natural succession and a spruce forest created by afforestation were also investigated. Although the spruce forest grows on bog soil/peat, no peatland-specific oribatid mite species were found (Lehmitz 2014).
Small-scale heterogeneity of the isotopic signature (δ13C, δ15N) of Sphagnum and oribatids
The ratios of stable isotopes in Sphagnum sp. and the oribatids extracted from it were measured sample-specific to a) determine the trophic levels of tyrphophilous moss mite species and b) find out whether small-scale heterogeneity of a food resource transfers to potential consumers. It has been shown that oribatids in Sphagnum bogs cover three trophic levels and that the small-scale heterogeneity of δ15N in Sphagnum is transferred to all trophic levels (Lehmitz & Maraun 2016)
Dispersal of Oribatida
In various field experiments at the edge of the Nochten open-cast coal mine, the ways in which oribatid mites migrate into young soils were investigated. Wind dispersal was examined more closely as an immigration route by exposing sticky traps at different altitudes and examining them for oribatid mites. The transport of oribatid mites by the wind was demonstrated at an altitude of up to 160 m (Lehmitz et al. 2011). In addition, 12 circular plots were installed in an experimental area in which the top 30 cm of the meadow soil was replaced with moss mite-free substrate from the open-cast mine. Here, the active and passive epigeic (minibarber traps) and endogeic (minicontainer traps) immigration of moss mites was investigated over two years (Lehmitz et al. 2012).
As part of Meike Schuppenhauer’s dissertation, the dispersal of oribatid mites via watercourses was investigated. It was shown that streams and rivers can transport oribatid mites and other soil animals over long distances and thus play an important role in population dynamics and the colonization of new habitats (e.g. recolonization of peatlands after renaturation). In laboratory experiments, a considerable survival time of oribatid mites under water was demonstrated, as well as the ability to be transported on the surface of running water for many hours, although the results differed significantly from species to species (Schuppenhauer et al. 2019).
Molecular detection of oribatid mites
Soil is a highly diverse and individual-rich habitat. In order to morphologically examine its mostly tiny inhabitants, high-quality microscopes, many years of taxonomic expertise and a lot of time are required. For this reason, even in Germany, soil biodiversity has only been insufficiently studied and long-term studies that would allow conclusions about population trends only exist for earthworms at most. However, soil organisms are essential for many ecosystem functions and so the development of faster, but taxonomically correct, recording methods is necessary. Various collaborative projects (GBOL, MetaInvert) have therefore contributed to the development of molecular methods for recording soil animal communities (Schmidt et al. 2022) and, above all, the development of reference libraries with correctly identified species markers (Lehmitz & Decker 2017; Collins et al. 2023).
Participation in cross-section projects
Finalized research topics
Red list of earthworms (Lumbricidae et Criodrilidae) of Germany
The FU Berlin was commissioned by the BfN to carry out the project ” Erstellung der Roten Listen 2020 – Vorbereitungsphase (FKZ 3511 861100)”. The aim of the project was to optimize the methods used to compile Red Lists. As there was no Red List of lumbricids in Germany so far and the number of earthworm species seemed manageable, the first German Red List of earthworms was compiled using and testing the methodology and tools of the BfN (Lehmitz et al. 2016).
In collaboration with Germany’s lumbricid experts, a checklist of German lumbricid species was first compiled (Lehmitz et al. 2014), as it was not previously known exactly how many earthworm species there are in Germany. In addition, as much data as possible on earthworm records from the last 100 years was compiled and evaluated from literature and collections as well as from institutions and private persons, primarily using the Edaphobase soil animal data warehouse. The risk assessment was then carried out on the basis of the current population situation, the population trend and possible risk factors. The Red List also included an analysis of Germany’s responsibility for the individual species.