in vents, seeps, deep-sea sediments, reefs, open ocean and coastal waters, the deep-sea, and species
 
5. Microbially dominated ecosystems

5.1 Defining microbial ecosystems
  • Ecosystems consist of habitats, conditions and organisms. Habitats separated by physically defined boundaries. Conditions are defined by chemical and physical determinants changing in time and space. Organisms, present as communities (= multitude of populations) can change conditions and migrate across boundaries. Cross-boundary transmitting agents: Arthropods, Chordates, Annelids, Protozoa; transport vehicles: water, aerosols, food; transport mechanisms: ingestion, inhalation, surface contact.
  • Niches: physiologically defined ecosystem functions changing through the presence and the evolution of organims.
  • Barriers are limitations for microbial migration and functioning. Physical barriers: temperature, radiation, pressure, pore size, adhesion attraction; chemical barriers: pH, salinity, oxidant, denaturant, surfactant, toxicity; biological barriers: immune response, trophic competition, predator-prey, viral attack, resistance, surface protection.
  • The role of microbes in ecosystem functioning.
  • Linking structures with functions in microbial ecosystems.

5.2 Biodiversity in functionally stabilized ecosystems and in spreading vectors (an overview)
  • Diversity of archaea, bacteria, protists and viruses in aquatic ecosystems in gradients and transients: nival zone, alpine, subalpine, highland, lowland, riverine, estuarine, littoral, reefs, shelf, continental slope, open oceans, abyssal sediments.
  • Freshwater vs. marine habitats.
  • Lakes and reservoirs in temperate and tropic climatic zones.
  • Oxic and anoxic sediments of lakes and oceans.
  • Subsurface aquifers: oligotrophy and bioremediation.
  • Microbial mats and biofilms.
  • Hot spring cyanobacterial mats.
  • Marine hydrothermal vents and cold seeps.
  • Cryoenvironments in snow and ice.
  • Endolithic and rock surface environments (e.g. lichens).
  • Rock - a dry hostile environment.
  • Commensal and syntrophic microbiota associated with metazoan (surfaces, gastro-intestinal tracts, microniches in gut habitats).
  • Microbes living on and in minerals.
  • Atmospheric dust and droplet clouds as vectors for the dissemination of microorganisms.
 
  microeco