Oligotrophic Ecosystem

Oligotrophic Ecosystem

Subject: Environment

Section: Ecosystem

Context- Cave ecosystems are understudied in India. Caves have a microclimate of their own. The cave-dwelling fauna could be more sensitive to minor changes and climate change could exacerbate local extinctions, according to scientists.

Concept-

What are Oligotrophic Ecosystems:

• Oligotrophic environments are those that offer little to sustain life.
• These environments include deep oceanic sediments, caves, glacial and polar ice, deep subsurface soil, aquifers, ocean waters, and leached soils.
• An oligotroph is an organism that can live in an environment that offers very low levels of nutrients.

Caves as Oligotrophic Ecosystem:

• Caves form an Oligotrophic ecosystem, which has no direct energy source – there is no sunlight or vegetation.
• Their primary source of energy comes in through either a bird’s or bat’s guano or droppings.
• Invertebrates in the cave were exclusively dependent on the swiftlet guano or droppings.
• With caves having a microclimate of their own, he states that the cave-dwelling fauna could be even more sensitive to minor changes and climate change could exacerbate local extinctions.
• Oligotrophic caves are characterized by very limited sources of organic material and simplified trophic structure due to their predominant isolation from surface ecosystems.
• In nutrient-poor caves heterotrophic bacteria dominate accompanied by a number of chemoautotrophs that gain energy from inorganic chemicals through chemosynthesis and fix inorganic carbon.
• Phosphorus is usually considered to be the most limiting nutrient in temperate oligotrophic ecosystems.
• The majority of aquatic ecosystems in regions sensitive to acidification are oligotrophic, since their watersheds are on thin soils with granitic or gneiss bedrock.

Difference between Oligotrophic & Eutrophic Lakes: