Three Main Ecological Questions - Where Do Organisms Live?
- Why?
- How Many?
Abiotic Factors are nonliving components that affect the environment and living organisms. They also influence distribution. Some examples include bodies of water, temperature, light, and nutrients.
- Climate-the prevailing weather conditions in a particular area.
Examples Of Abiotic Factors :
The dead organic material can be considered as a component of the soil, since it is not living, even thou gh organic in origin. Soil may be considered thus as a complex variety of mineral particles plus the dead organic matter. It is also important to consider the voids within soil as a property of the soil, since the packing density and shape of soil particles affect the resulting characteristics of water and plant root penetration, as well as the hosting of organisms from micro-organisms to large animal burrows. Technically soils can be as impermeable as solid non-porous rock, or as highly pervious as coarse sand. The granularity of soils is generally merely a function of the geologic time weathering of the local earth crust as well as the depositional history of fluvial, marine and aeolian processes. The resulting soil permeability plays an important role in determining the plant palette that can adapt to a given habitat. Loosely packed or highly pervious soils generally are poor in near surface water retention, but effective in encouraging downward percolation of water, with the result of enhancing local groundwater basins and thus sustaining water supply in the wider basin. Such loose soils are also hospitable to root penetration and thus plant growth, provided that rainfall or runoff is sufficient to supply the needs of the plants in an environment of marginal surface soil water retention. The coarsest such soils are gravels, which may be quite ineffective in supporting plant growth, if there no intervening finer soil particles. Temperature can strongly influence the functioning of an ecosystem. It's included in Meteorological factors. The chief meteorological parameters that comprise abiotic factors of ecosystems are temperature, sunlight, wind velocity,barometric pressure, humidity, etc Meteorological abiotic factors may be simply the prevailing climatic features that define an ecosystem's atmospheric abiotic features; in some cases, the meteorologic factors may be episodic or even catastrophic events that define major transformations of an ecosystem. Examples of such abiotic upheavals are windrow from hurricanes and tornadoes; torrential floods that scour and uproot large amounts of vegetative cover; prolonged drought which may alter the plant association and animal ecology.As important as water availability is the quality of water within a habitat. This topic embraces not only concentrations of chemicals present in natural water systems, but also to human introduced chemicals. Significant naturally occurring constituents include nutrients and trace minerals used in organism metabolism; among nutrients, nitrate, phosphate and potassium are some of the most fundamental ions taken up by plants and animals. With regard to man-produced pollutants, some of the chief components are petroleum hydrocarbons,pesticides, herbicides and heavy metals. Trace minerals that are often important to metabolic function include zinc, magnesium and iron; each trace mineral that is beneficial to organisms can be classed as a pollutant if human produced discharges to the environment accumulate to a high level. In many cases heavy metals and complex organic materials may accumulate in plant and animal tissue, subsequent to uptake from the environment. Light energy (sunlight) is the primary source of energy in nearly all ecosystems. It is the energy that is used by green plants (which contain chlorophyll) during the process of photosynthesis; a process during which plants manufacture organic substances by combining inorganic substances. Visible light is of the greatest importance to plants because it is necessary for photosynthesis. Factors such as quality of light, intensity of light and the length of the light period (day length) play an important part in an ecosystem.Quality of light (wavelength or color):
Plants absorb blue and red light during photosynthesis. In terrestrial ecosystems the quality of light does not change much. In aquatic ecosystems, the quality of light can be a limiting factor. Both blue and red light are absorbed and as a result do not penetrate deeply into the water. To compensate for this, some algae have additional pigments which are able to absorb other colors as well.Light intensity ("strength" of light)
The intensity of the light that reaches the earth varies according to the latitude and season of the year. The southern hemisphere receives less than 12 hours of sunlight during the period between the 21st March and the 23rd of September, but receives more than 12 hours of sunlight during the following six months.
Day length (length of the light period):
Certain plants flower only during certain times of the year. One of the reasons for this is that these plants are able to "measure" the length of the night (dark periods). However, it was thought that it is the day length (light periods) to which plants reacted and this phenomenon was termed photoperiodism. Photoperiodism can be defined as the relative lengths of daylight and darkness that effect the physiology and behavior of an organism.
Winds or air currents arise on a world-wide scale as a result of a complex interaction between hot air expanding and rising (convection) in the mid latitudes. This has various effects on the rotation of the earth and results in a centrifugal force which tends to lift the air at the equator. This force is known as the Coriolis force and tends to deflect winds to their left of the southern hemisphere and to the right in the northern hemisphere. Winds carry water vapor which may condense and fall in the form of rain, snow or hail. Wind plays a role in pollination and seed dispersal of some plants, as well as the dispersal of some animals, such as insects. Wind erosion can remove and redistribute topsoil, especially where vegetation has been reduced. Warm berg winds results in desiccation which creates a fire hazard. If plants are exposed to strong prevailing winds are they usually smaller than those in less windy conditions.
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