Oligotrophic Ecosystem
- April 4, 2022
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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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:
Oligotrophic | Eutrophic |
These are lakes with fewer nutrients, low productivity, and clear water | These are lakes with high nutrients, high productivity, and dark water |
Biological oxygen demand is quite low | Biological oxygen demand is comparatively high |
Sunlight penetration is high | Sunlight penetration is low |
Less eutophication process | High eutrophication process |
Less phosphate and nitrates | High level of phosphate and nitrates |
They have no odour. | Presence of odour due to high decomposition rate. |