Responsible: Søren Christensen.
Aim: The course aims at giving a general overview of ecosystems of the world and will focus on sensitive processes of interest in a Global change context. The course will also give an introduction for non-specialists to investigation of key-processes and tools to analyse biodiversity with emphasis on soil organisms.
Teachers: Søren Christensen, Sven Jonasson, Anders Michelsen, Annelise Kjøller, Sten Struwe and invited specialists
Form and duration of course: residential, one week, August 2001
Evaluation: Group report
The course describes major terrestrial biomes of the world, the climatic
background for their existence and variability due to soil structure and
composition, and vegetation. Focus will be on an axis covering the arctic,
boreal tundra and forest, temperate forest and agriculture, and tropical
forest, savannah, and agriculture.
With a contrasting approach the life of soil microbes and their grazers,
detritivores and carnivores is dealt with from an ecophysiological point of
view. Interaction within and among these groups of organisms is discussed
based on ecosystem functions considered important such as primary
production, decomposition, and trace gas exchange soil-atmosphere.
Decomposition involves a vast number of soil organisms organised in trophic
and information networks of varying interaction strength. In contrast,
primary production is mainly governed by a single organism (the plant) in
close interaction with specific beneficial and harmful micro-organisms and
invertebrates, and more casual interaction with selected decomposer
organisms. Main trace gases of the atmosphere (CH4 and N2O) are produced
and consumed by soil organisms, which are also members of the decomposer
system. Under this heading tools to trace specific organisms and processes
of importance are described.
Broad scale approaches are presented that describe the structure and
function of the soil decomposer community and possibly the associations
involved in primary production. By focussing such descriptions on
measurable community functions like decomposition and on the resistance and
resilience of decomposition to well defined disturbances one of the aims is
to discuss the importance of single species for ecosystem function in a way
that may be experimentally verified. Ultimately this community approach
will help bridging the gap between the above-mentioned biome approach and
ecophysiological approach that is based upon research disciplines within
different branches of natural science.
The interactions of human activities with ecosystem processes are
discussed in a land-use framework whereby manageable aspects will be in
focus. Change from forest to agriculture in the temperate or tropic zone,
and drainage of humid soils in the boreal zone are land use changes that
affect biotic processes within the system. These changes will eventually
results in altered outputs of CO2 and trace gases to the atmosphere and of
inorganic ions such as NO3- to subsurface aquifers.
Topics: Soil description, pedology, structure and composition. Water,
movement and availability.
Primary production in different biomes, energy, water, nutrients,
Decomposition, microorganisms (bacteria and fungi) diversity and activity,
Trace gases, microbial production and consumption, experimental
approaches, upscaling of results from plot to landscape to region
Intervention strategies, managed ecosystems, dealing with pollutants as
Courses Main page