Understanding Ecosystems: Biotope, Biocenosis, and Biosphere
Omnivores include wild boars, chimpanzees, pigs, and humans. Every living thing depends on others for sustenance. Herbivores depend on plants, and carnivores depend on herbivores. To express the power relations in a group of living beings, we use diagrams called food chains.
Ecosystem Studies
Ecosystem studies involve:
- The interaction between organisms (who eats whom)
- Types of feeding (what they eat, how they reproduce)
- Their relationship with the environment (what happens when it’s hot, when there’s no water, etc.)
- The flow of energy and materials and its relation to all systems in their environment
Biotope and Biocenosis
Biotope: A term that literally means “living environment” and applies to the physical space, natural and limited, in which a biocenosis lives. The biotope and biocenosis together form an ecosystem. The biotope concept can be applied to all levels of the ecosystem: one end can be considered the general biotope, such as the sea, formed by the plants, animals, and microorganisms within it. The other end can be considered a local biotope, such as a coral reef, with its characteristic vegetation and associated fauna. The biotope can be homogeneous from an ecological viewpoint, or it may comprise a set of distinct ecological residences, such as a river and its upper reaches, middle, and lower, where different animal and plant communities live in each of them.
Biocenosis: A term that encompasses the entire plant communities (phytocoenosis), animals (zoocenosis), and microorganisms (microbiocenosis) that develop in a particular biotope.
Some examples of biocenosis would be the coral reef and its accompanying fauna, or the Posidonia beds and species of bryozoans and crustaceans that live with them. Species that form a biocenosis display various forms of interaction, such as competition, parasitism (food exploitation of an organism by another), or predation. These relationships are complex; each organism plays a certain role in the food chain (producers, consumers, decomposers), and disruption of these relationships may cause a disturbance in balance.
Ecosphere or Biosphere
The thin mantle of life that covers the Earth. Different approaches are used to classify its regions.
Biomes
Major vegetation units are called biomes by North American ecologists and vegetation by European ecologists. The main difference between the two terms is that biomes include associated animal life. The major biomes, however, are named after the dominant forms of plant life. Under the influence of latitude, elevation, and moisture regimes, and associated temperature, terrestrial biomes vary geographically from the tropics to the Arctic. We will study various types of forests, grasslands, scrub, and desert biomes. These also include associated freshwater communities: streams, lakes, ponds, and wetlands. Some ecologists also consider marine environments as biomes, including the open ocean, littoral regions, benthic regions, rocky coasts, beaches, estuaries, and associated tidal flats.