Alternative site for the Global ecosystem typology with additional information for ecosystem profiles and indicative maps.
This site is maintained by jrfep
The Artificial subterranean freshwaters biome includes aquatic systems in underground canals, drains, sewers and water pipes constructed by humans. These are usually well connected to surface waters. The availability of resources is largely a function of source waters and the water regime, which varies from permanent to intermittent and low to high flow velocity. Sunlight is absent or, if it diffuses through vents and portals (as in some canals), it is generally too dim to support photosynthesis. Algae may nonetheless be transported through these systems, depending on the water of source. Although primary productivity is low and energy is supplied from allochthonous sources, secondary productivity by heterotrophic microbes in biofilms and in the water column may be quite high in sewers and drains where organic carbon, nutrients and dissolved oxygen are abundant. This may support several tiers of detritivores and predators including microspoic invertebrates, macro-invertebrates and small vertebrates including rodents and fish. Anaerobic bacteria may be important components of the trophic network where organic carbon and nutrients are abundant but dissolved oxygen is scarce, due to either low aeration or high microbial activity. In water supply pipes, however, low levels of organic carbon and nutrients, exacerbate constraints on productivity imposed by the absence of light. As a consequence the trophic webs within pipes are truncated and simple, and the mostly transitory biota reflects that of the source waters.