If asked to define a freshwater habitat, we would almost immediately think of water and fishes. While it is true that those two components usually dominate- they are most evident there- a freshwater habitat is in fact a community of not just plants and animals, but of microorganisms as well. Also, not forgetting in the mix the non-living, biotic and components like soil, climate and water. Include all of that along with the complex interrelationships among the organisms and the environment, and we are closer to an actual understanding of this ecosystem. Here we will be studying the biotic and abiotic components of two major freshwater ecosystems we’ve visited- the Ampang lake and the Gombak river.
Biotic factors consist of the living things that shape an ecosystem (Library.thinkquest.org). After examining the lake and river ecosystems, we only found two similar biotic components, which are the stonefly larvae (Plecoptera) and fish. In Ampang, we collected our biotic specimens through sampling macrophytes found in the littoral zone of the lake and over there we found abundant Bladderworts (Utricularia vulgaris), phytoplanktons and leaf litter from riparian vegetations- all of which weren’t found in the Gombak river. The only producers we found in the river were the biofilms (algae) layered on rocks. Other than that, the invertebrate predators found in both ecosystems also differ. We found plenty of water bugs (Hemiptera) and crayfish in the river and dragonflies and leeches in the lake. One vertebrate predator we found only at the river site and none at the lake was a tiny frog.
These organisms found in both ecosystems are divided into producers and consumers. The first step in the chain invovles the producers, or autotrophs like the phytoplankton. These producers convert sunlight into organic compounds through photosynthesis. The herbivorous consumers such as the beetle larvae (invertebrate grazers) feed on the algae and will be later consumed by...
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