1. Ecology of terrestrial
ecosystems
To control ecological processes
in the field, a thorough analysis of the spatial and temporal variability
of key biotic and abiotic factors involved is required. Considering the
great diversity of habitats and organisms, this would be an infinite undertaking.
Therefore, our approaches are
- Study of extreme habitats
(e.g., deserts, contaminated sites), in order to mark corner stones
in the functioning of terrestrial ecosystems
- Study of typical sites
of the North German region with varying degrees of human impact (meadows,
forests, dunes)
- Improvement and development
of generalising theoretical concepts
- Modelling of selected processes,
population dynamics and interactions
- Scaling up (study of model
systems with increasing complexity and similarity to outdoor conditions:
batch experiments, microcosms, greenhouse studies, field manipulations;
modelling)
- Desert
ecology
Hartmut
Koehler : SUK/REK, Andrea Ruf,
Broder Breckling: SCALEUP
Selected references
- Albrecht, H.,
Kühn, N., Filser, J., 2001: Investigations in an agricultural catchment
of Southern Germany: Site effects on plant and animal distribution within
an Agricul-tural Landscape. - Ecological Studies (Springer, Berlin)
147: 209-227
- Goralczyk,K.(1998):
Nematodes in a coastal dune succession: Indicators of soil properties?.-
Applied Soil Ecology 9: 465-469
- Koehler, H., K.
Mathes, B. Breckling (eds.), 1999: Bodenökologie interdisziplinär. Springer,
Berlin, etc., XII+241. Verhoeven R (2001)
- Ciliates in coastal
dune soils of different stage of development. Europ J Soil Biol, in
press
2.
Soil animals and ecosystem functioning
Soil animals directly interact
with the soil matrix, dead organic matter and soil microorganisms, thus
having a large potential to influence soil structure, organic matter decomposition,
mineralisation and plant growth. A number of studies both in the field
and mainly in the laboratory have convincingly demonstrated this for several
groups of soil animals, however, surprisingly little is known about the
significance of soil biological diversity or of keystone species for these
processes. Also the impact of soil animals on plant growth has hardly
been studied. In laboratory and field studies, we focus on the impact
of presumed keystone species (i.e. dominant in number or biomass, sensitive
or tolerant towards disturbance) on plant growth and selected other processes.
Juliane
Filser, Detlev Handelmann
Selected references
- Mebes, K.-H.,
Filser, J., 1998: Does the species composition of Collembola affect
nitrogen turnover? - Applied Soil Ecology 9, 241-247
- Mommertz, S.,
Jell, B., Winter, K., Filser, J., 1998: How to quantify the contribution
of microflora and microfauna to nitrogen mineralisation in agricultural
soils? - Some remarks. In: Pizl, V., Tajovsky, K. (eds): Soil zoological
problems in Central Europe. Proceedings of the 4th Central European
Works-hop on Soil Zoology, Ceske Budejovice, April 23-24, 1997. ISB
ASCR, Ceske Budejovice, ISBN 80-902020-4-7, 145-150
3.
Anthropogenic impact on ecosystems, especially on soils
Nowadays there are no more
ecosystems not affected by human activities, the only differentiation
that can be made is the strength of the impact. Soil is a crucial basis
for human use, for nutrition, raw material production, building and recreation
activities. A sustainable use of the resource soil is indispensable. In
order to achieve this, we need:
- Evaluation of effects of
human activities:
Terrestrial ecosystems
are largely influenced by human activities such as industrial production,
traffic or farming, including the introduction of genetically modified
organisms. All these activities directly or indirectly affect soils
and their crucial functions. Due to the complexity of both the soil
compartment and the variety of impacts, it is not possible to judge
how human influences affect the soil as a living space and as a "bio-reactor"
(nutrient mineralisation, decomposition of harmful substances, filtering)
by measuring abiotic factors (e.g., bulk density, toxicant concentration)
only. Soil animals have diverse generation times, are mobile and closely
interact with biotic and abiotic soil components, including living
plants. Thus they can serve as indicators integrating over space and
time, a variety of chemical, physical and biological parameters and
related processes.
Andrea
Ruf, Hartmut Koehler,
Broder Breckling.
- Control of biotic soil processes
Soils are the crucial basis
for most of the human food production and act as filters and catalysts,
protecting ground and surface waters from eutrophication and input
of harmful substances. The experiences of the past decades have shown
that human use is often accompanied by soil degradation (e.g. erosion,
desertification, salinisation). Facing the increasing global population
it is of uttermost importance to maintain the present soil resources
and possibly to re-activate degraded soils. Soil organisms affect
physical stability and hydraulic properties of soils and are responsible
for organic matter transformation and finally mineralisation. The
equilibrium maintained by them is affected by land-use and other human
activities. To guarantee sustainable use of soils and to direct their
functions it is necessary to understand to what extent (a-)biotic
processes are influenced by e.g. management. Appropriate manipulation
experiments both in the laboratory and in the field and subsequent
modelling help in developing management recommendations and guidelines
for the sustainable use of soils.
FAM
/ Juliane Filser
Selected references
- Filser, J., Dette,
A., Fromm, H., Lang, A., Mebes, K.H., Munch, J.C., Nagel, R., Winter,
K., Beese, F., 1999: Reactions of soil organisms to site-specific management:
the first long-term study at the landscape scale. - In: Windhorst, W.,
Enckell, P.H. (eds.): Proceedings of the conference "Sustainable Landuse
Management - The Challenge of Ecosystem Protection", 28.9.-1.10.99,
Salzau Federal Cultural Center, Organizers: University of Kiel/European
Ecological Federation. Ecosys Suppl. Bd. 28, 139-147
- Filser, J., Lang,
A., Mebes, K.-H., Mommertz, S., Palojärvi, A., Winter, K., 1996: The
effect of land-use change on soil organisms - an experimental approach.
- Verh. d. Ges. f. Ökologie 26, 671-679
- Koehler, H., 2000:
Natural regeneration and succession: results from a 13 yrs study with
reference to mesofauna and vegetation, and implications for management.
Landscape and Urban Planning 52: 123-130.
- Mathes K., J.
Ranke (1999): Erfassung des Gefahrenpotentials von Chemikalien: Ein
alternativer Ansatz aus ökologischer Sicht. Zeitschrift für Angewandte
Umweltforschung, Sonderheft 10/1999, 97-104.
- Menzel G., K.
Mathes (1999): Risikobewertung und Monitoring der Umwelteffekte gentechnisch
veränderter Nutzpflanzen - Untersuchungen zum vertikalen Gentransfer
bei Brassica napus L. (Raps). Zeitschrift für Ökologie und Naturschutz
8: 157-162.
- Paulus R., J.
Römbke, A. Ruf, L. Beck (1999): A comparison of the litterbag-, minicontainer-
and bait lamina-method in an ecotoxicological field experiment with
diflubenzuron and btk. Pedobiologia 43:120-133.
- Ruf, A. (1998):
A maturity index" for predatory soil mites (Mesostigmata: Gamasina)
as an indicator of environmenatal impacts on forest soils. - Appl. Soil
Ecol. 9:447-452
4. Biology
and diversity of soil animals
Soils probably inhere an incredible
diversity of organisms ("The soil ecosystem is the poor man's tropical
rain forest" - M.B. Usher, 1982). Soil biology still is a relatively young
field of research, and the majority of species is still not described.
In some groups and geographical regions taxonomy is quite well developed
whereas in others astronomic estimates of numbers of unknown species -
especially in microorganisms - demonstrate the poverty of our present
knowledge. Facing this enormous diversity, classical (morphological-physiological)
taxonomy is quickly approaching its limits. Molecular methods (both DNA
and protein based) are a powerful tool in supporting identification and
classification of soil organisms, and recent developments such as chip
biotechnology give promising perspectives.
MOLART
FSP
IV
On the other hand, the vast
number of taxa badly needs to be aggregated in functional groups - for
which an understanding of the biology is required. The majority of managed
soils are dominated by relatively few species of animals, and only after
disturbance other taxa become more important. Members of both groups can
be termed as keystone species since they are either very successful in
a relatively stable system or they are able to cope with major disturbance.
Due to their direct and indirect relations with soil states and processes
it is of uttermost importance to study the biology of keystone species
in soils. Understanding their requirements and susceptibilities will help
i) in developing a consistent hierarchy of functional groups of soil animals
and ii) in directing soil processes by management.
Juliane
Filser/ COLLEAGUES
Selected references
- Filser, J., Setälä,
H., 1999: Recent advances in decomposer food web ecology. In: Farina,
A. (Hrsg.): Perspectives in Ecology. A Glance from the VII International
Congress of Ecology (INTECOL). Florence, Italy, 19-25 July 1998. Backhuys,
Leiden, NL, 355-368
- Filser, J., Wittmann,
R., Lang, A., 2000: Response types in Collembola towards copper in the
microenvironment. - Environmental Pollution 107, 71-78
- Koehler, H., 1999:
Mesostigmatic mites. Agric., Ecosystems & Environment, 74: 395-410.
- Simonsen, V.,
Filser, J., Krogh, P.H., Fjellberg, A., 1999: Three species of Isotoma
(Collembola, Iso-tomidae) based on morphology, isozymes and ecology.
- Zoologica Scripta 28, 281-287
5. Development
of test systems
The composition of the decomposer
community is appropriate to indicate soil conditions, as has been shown
for many different taxa. However, the detailed analysis of soil communities
(or only selected taxa) is too laborous to be carried out as a standard
method. For evaluating soils of unknown quality or the effects of potentially
harmful substances or mechanical impacts on soils it is necessary to develop
appropriate representative test systems that are easy to handle. This
is definitely not possible by using one test organism only, rather it
is necessary to develop a test battery representing the most important
groups of taxa, and to modify such test batteries according to the specific
habitat types in question.
Maike
Schaefer
Selected references
- Frische, T. (2003).
Ecotoxicological evaluation of in situ bioremediation of soils contaminated
by the explosive 2,4,6-trinitrotoluene (TNT). Environmental Pollution
121, 103-113
- Schaefer M (2001):
Comparing different endpoints in earthworm toxicology;11th Annual Meeting
of SETAC Europe; Madrid, Spain, p. 135.
- Frische, T. (1999)
Zum ökotoxikologischen Gefahrenpotential von TNT für das System Boden
Wirkungsanalysen mit einem terrestrischen Multispezies-System. In: Markert,
B. u. Oehlmann, J. (Hrsg.) Ökotoxikologie - Ökosystemare Ansätze und
Methoden. ecomed, Landsberg, 106-116.
- Paulus R., J.
Römbke, A. Ruf, L. Beck (1999): A comparison of the litterbag-, minicontainer-
and bait lamina-method in an ecotoxicological field experiment with
diflubenzuron and btk. Pedobiologia 43:120-133
- Mommertz, S.,
Schauer, C., Kösters, N., Lang, A., Filser, J., (1996): A comparison
of D-Vac suction, fenced and unfenced pitfall trap sampling of epigeal
arthropods in agroecosystems. - Ann. Zool. Fennichi 33, 117-124
6.
Analysis of dispersal processes
Ecosystems are open systems,
influenced by both abiotic and biotic processes. Dispersal assembles such
diverse aspects as spreading of chemicals or microorganisms through the
soil matrix, active dispersal (growth of root or hyphae, walking animals)
or wind dispersal (substances, seeds, permanent stages of microorganisms).
A thorough analysis of the most relevant dispersal processes in ecosystems
is required for understanding population dynamics, effects of chemical
substances and all related processes, i.e. ecosystem functioning per se.
Hauke
Reuter, Broder Breckling,
Gertrud Menzel
Selected references
- Breckling, B.,
Reuter, H. Middelhoff, U., 1997: An Oject Oriented Modelling Strategy
to Depict Activity Pattern of Organisms in Heterogeneous Environments.
Environmental Modelling and Assessment 2:95-104.
- Kraß J.D., K.
Mathes (1999): Biologische Bodensanierung: Systemanalyse und numerische
Simulation. In: Koehler, H., K. Mathes, B. Breckling (eds.), Bodenökologie
interdisziplinär. Springer, Berlin, Heidelberg
- Mebes, K.-H.,
Filser, J., 1997: A method for estimating the significance of surface
dispersal for population fluctuations of Collembola in arable land.
- Pedobiologia 41, 115-122
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