1. Basic Ecological Concepts and Principles

7/30/2019 1. Basic Ecological Concepts and Principles

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Basic Ecological Principles

Environmental Science


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Introduction Plants and animals that live in a particular place

share the same physical environment. No livingorganisms exist in isolation from otherorganisms.

The organisms in the environment live together

either in harmony or by feeding on others.

Environment includes the ABIOTIC (non-livingthings) such as air, water, climate, the soil typeand the BIOTIC (living things) conditions at a

particular location.


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Themes in Ecology ECOLOGY is the scientific study of the

relationship between organisms and theirenvironment.

The term ecology came from a Greek wordOIKOS, meaning home or a place to live in and

LOGUS, meaning study. The main concern of ecology is the

environment and the relationship of the physicaland the biological components in theenvironment.


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Themes in Ecology The living components of the environment that

includes the plants, animals, and themicroorganisms are called BIOTA.

The region of the earth where there is life iscalled BIOSPHERE. It extends high into the

atmosphere, to the bottom of the ocean, anddeep down into the caves.


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Themes in Ecology The basic unit of study in ecology is the

ECOSYSTEM.

Ecosystem is a more or less independent part ofthe biosphere. It can also be natural, artificial ormanaged.

Ecosystem may also differ in composition,species diversity, abundance and variation inborders of habitat, but all these ecosystemshave the same ecological processes such as

NUTRIENT CYCLING and FEEDING RELATIONSHIPS.


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Themes in Ecology A HABITAT is a place in which you find animals

and plants.

The kinds of animals and plants that can live ina habitat depend upon what the habitat is likeand on the climatic and edaphic factors.

Different animals and plants will affect eachother by competition, predation, grazing,sheltering and so on.


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Hierarchy in an Ecosystem An ORGANISM is any living thing, whether it is a

human being, a germ, a rose bush, or a pandabear.

A group of organisms of the same kind is aPOPULATION. A population can be defined as a

group of interbreeding organisms living in thesame area

A COMMUNITY is the next largest level oforganization. A community includes all the

organisms, sometimes hundreds of different types,in a given area.


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Hierarchy in an Ecosystem An ECOSYSTEM includes all organisms in a

defined area and their nonliving environment. A BIOME is one of several major types of

ecosystems found on the planet. Each biome ischaracterized by a particular type of

vegetation. The biomes together with the aquatic

ecosystem of the world comprise theBIOSPHERE.


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Hierarchy in an EcosystemOrganism

Populat ion

Communi ty

Ecosystem

Biome

Biosphere


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The GAIA Hypothesis The GAIA HYPOTHESIS, also known as GAIA

THEORY or GAIA PRINCIPLE, proposes that allorganisms and their inorganic surroundings onearth are closely integrated to form a single andself-regulating complex system, maintaining the

conditions for life on the planet. The Gaia Hypothesis is a view of a SELF-

SUSTAINING BIOSPHERE, in which everyorganism is linked to one another.


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Structure of an Ecosystem An ecosystem possesses both living components

or BIOTIC FACTORS and nonliving or ABIOTICFACTORS.

ABIOTIC FACTORS are physical and chemicalcharacteristics of the environment. They include

solar energy (amount of sun light), oxygen, CO2,water, temperature, humidity, ph, and availabilityof nitrogen.

BIOTIC FACTORS include all the living things that

affect an organism. Biotic Components are oftencategorized as PRODUCERS, CONSUMERS, andDECOMPOSERS.


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The End

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1. Basic Ecological Concepts and Principles