ORGANIZATION OF BIOSPHERE

 ORGANIZATION OF BIOSPHERE  

BIOSPHERE

·       The Biosphere (also known as the Ecosphere), is the worldwide sum of all Ecosystems.

·       The Biosphere is made up of the parts of Earth where life exists.

·       Scientists describe the Earth in terms of Spheres.

a)     Lithosphere or Geosphere - The solid surface layer of the Earth.

b)     Atmosphere - The layer of air that stretches above the Lithosphere.

c)     Hydrosphere - The earth’s water, on the surface, in the ground, and in the air.

d)     Cryosphere – The portions of Earth's surface where water is in solid form, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps, ice sheets, and frozen ground. Thus, there is a wide overlap with the Hydrosphere.  

·       Since life exists on the ground, in the air, and in the water, the biosphere overlaps all these spheres. Although the biosphere measures about 20 kilometers from top to bottom, almost all life exists between about 500 meters below the ocean’s surface to about 6 kilometers above sea level.

·       Biosphere maintains or creates the conditions of temperature, light, gases, moisture, and minerals required for life processes.

·       Biosphere can be naturally sub-divided into Terrestrial and Aquatic biosphere.

i) Terrestrial biosphere

·       The Terrestrial biosphere is usually distributed into particular climatic regions called Biomes, each of which is characterized by a dominant plant form, altitude, and latitude.

·       Particular biomes include grassland, desert, mountain, and tropical rain forest.

ii) Aquatic biosphere

·       The Aquatic biosphere is generally divisible into freshwater and marine realms.

COMMON TERMINOLOGIES IN MICROBIAL ECOLOGY

Ecology

·       The study of the interactions among organisms and between organisms and their environment.

Microbial Ecology

·       A subset of ecology focusing on microbes.

Biogeography

·       Patterns in the distribution of organisms over space.

Microbial Biogeography

·       A subset of biogeography focusing on microbes.

Community

·       A group of different kinds of organisms (at least two) that occupy the same space at the same time that interact and share the same environment.

·       Mixture of different Population is called Community.

Populations

·       Similar organisms produce a Population (all the members of a single species) through reproduction.

·       For organisms with Sexual reproduction, this level is the “Species”. In contrast, Prokaryotes are classified using taxonomic units such as “Strain”.

Microbiome

·       A community of microbes that occupy a specific space or collection of spaces is called Microbiome. 

·       The “Human microbiome” refers generally to the communities of microbes found in and on humans.

·       The “Built environment microbiome” refers to the communities of microbes found in and on entities that have been built by humans.

Ecosystem

·       A community of organisms and their environment that operate as a system.

Habitat

·       The habitat is the physical location in the environment to which an organism has adapted.

·       In the case of microorganisms, the habitat is frequently a microenvironment, where particular qualities of oxygen, light, or nutrient content are somewhat stable.

Niche

·       The Niche is the overall role that a species (or population) serves in a community. This includes such activities as

ü  Nutritional intake (what it eats)

ü  Position in the community structure (what is eating it)

ü  Rate of population growth.

A Niche can be broad (such as scavengers that feed on nearly any organic food source) or narrow (microbes that decompose cellulose in forest litter or that fix nitrogen).