Glossary

Ecological factor a condition the medium in which living things respond adaptive reactions. Environmental factors determine the conditions for the existence of organisms. Distinguish abiotic, biotic, natural and man-made environmental factors.

Abiotic factors - nonliving components and effects, of inorganic nature, directly or indirectly affect living organisms: climate, soil and hydrographical factors. The main environmental factors are temperature, light, water, salinity, oxygen, the magnetic field of the earth, soil.

Biotic factors - factors of living environment, affecting the livelihoods of organisms. The action of biotic factors expressed in the form of influences on the livelihoods of some organisms and other organisms all together on the environment. Distinguish direct and indirect relationships between organisms.

Начало формы

A limiting factor or limiting resource is a factor that controls a process, such as organism growth or species population, size, or distribution. The availability of food, predation pressure, or availability of shelter are examples of factors that could be limiting for an organism. An example of a limiting factor is sunlight in the rainforest, where growth is limited to all plants in the understory unless more light becomes available.

A number of potential factors could influence a biological process, but importantly only one is limiting at any one place and time. This recognition that there is always a single limiting factor is vital in ecology; and the concept has parallels in numerous other processes. Some other limiting factors in biology are water availability, temperature, shelter, or predation

Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, refers to more or less predictable and orderly changes in the composition or structure of an ecological community. Succession may be initiated either by formation of new, unoccupied habitat (e.g., a lava flow or a severe landslide) or by some form of disturbance (e.g. fire, severe windthrow, logging) of an existing community. Succession that begins in areas where no soil is initially present is called primary succession, whereas succession that begins in areas where soil is already present is called secondary succession.

Types of succession Primary and secondary succession

If the development begins on an area that has not been previously occupied by a community, such as a newly exposed rock or sand surface, a lava flow, glacial tills, or a newly formed lake, the process is known as primary succession.

If the community development is proceeding in an area from which a community was removed it is called secondary succession. Secondary succession arises on sites where the vegetation cover has been disturbed by humans or other animals (an abandoned crop field or cut-over forest, or natural forces such as water, wind storms, and floods.) Secondary succession is usually more rapid as the colonizing area is rich in leftover soil, organic matter and seeds of the previous vegetation, whereas in primary succession the soil itself must be formed, and seeds and other living things must come from outside the area.