Biology Tutorials > Freshwater Ecology > Running Water Freshwater Community Factors

Running Water Freshwater Community Factors

running freshwater community

Physical and chemical factors on a running water ecosystem

This tutorial continues from the previous one, which introduced lotic (running water) communities. Here, some of the physical and chemical factors that provide the framework of a running water community in which organisms in their favored ecological niches occupy are presented.

  • Temperature – The difference between running water and still water temperature is that running water communities’ temperature varies more rapidly but over a smaller range. In Summer, water from the source of the river is usually colder than the water found at the delta because it has not been exposed to the warm air heated by the sun. The reverse occurs in Winter where water is warmer until exposed to the colder air.
  • Light – On the whole, less light penetrates a running water body due to ripples in the water, debris blocking out sunlight to lower layers as well as overhanging shrubs that perhaps are taking advantage of a tributary water source. These are all examples of how the intensity of light reaching the lotic community can be affected, and in turn, directly affects the rate of photosynthesis done by plants in the community.
  • Chemical Composition – Many factors can alter the chemical composition of the freshwater environment, including precipitation, the percolation of water via vegetation and sea spray to name a few. All in all, various elements and compounds are required by organisms in their daily activities and fluctuations or even an absence of such elements and compounds results in a direct effect on the lives of such organisms.
  • Organic Matter – Organic matter previous external to the running water environment can also play a part in altering the ecosystem. This mostly occurs due to overhanging vegetation, although organic matter can be drawn into the ecosystem by the various sources mentioned in the previous tutorial.

Such factors all play a part in the lives of animals and plants occupying the lotic environment. The next tutorials, e.g. Lotic Communities & Algae, look at how plants and animals exist in such an ecosystem.

 

Credit: USGS

Quiz

Choose the best answer.

1. The river temperature tends to be colder than the water at the delta at winter.
2. In general, less light penetrates a running body of water.
3. Ripples in the water promotes better light penetration in rivers.
4. Light intensity is one of the factors affecting lotic community.
5. Chemical composition of the freshwater environment has an effect on the biotic components of a lotic ecosystem.

Send Your Results (Optional)

Your Name
To Email
Biology Tutorials > Freshwater Ecology > Running Water Freshwater Community Factors

You will also like...

An artistic depiction of Dunkleosteus fish
Fish

The sea was teeming with life. Eventually, through reproduction and continued variation, fish came about. There are over..

Young plant growing from the soil.
Soils

Nutrients in the soil are essential to the proper growth of a land plant. This tutorial deals with the properties of soi..

Kidneys
Kidneys and Regulation of Water and Inorganic Ions

The kidneys are responsible for the regulation of water and inorganic ions. Read this tutorial to learn about the differ..

Schematic diagram of bacterial lactose operon
Gene Action – Operon Hypothesis

Learn how the way genes control and determine every aspect of the body. This lesson uses lac operon as an example. ..

..

kinesin motor proteins transporting molecules across microtubules
Movement of Molecules Across Cell Membranes

Molecules move within the cell or from one cell to another through different strategies. Transport may be in the form of..

A chart depicting Mendel's Law of Dominance
Mendel’s Law & Mendelian Genetics

One of Mendel’s law of inheritance is the “law of dominance”. Read this tutorial to know more about this form of i..