Unit 2.1.(45 min) 2.1 Ecosystems: What they are, how they ... Ecosystems what they are.pdf · Where did the concept come from? Sir Arthur Tansley, a Renaissance man coined the concept

Subodh Sharma Dr.nat.tech.; Aquatic Ecology Centre, P.O. Box: 6250, [email protected].

Unit 2.1.(45 min) 2.1 Ecosystems: What they are, how they Work, and how they Change?

PG diploma in Environment Education program


Ecosystem – What They Are

Where did the concept come from?

Sir Arthur Tansley, a Renaissance man coined the concept in 1935

~ Karl Mobius (1877)

~ S. A. Forbes (1887)


EcosystemsEugene Odum

~ Took concept of Ecosystem and brought it to the attention of the “ecological community” and made it a fundamental idea in society


EcosystemsEugene Odum con’t

~1953 published classic “Fundamentals of Ecology”



~ Figure 2.1 mixes biological systems with physical components



~ Faced criticism and developed Figure 2.2



~ Advocated using the idea of ecosystem beyond simply biology to the social sciences--New Ecology


ECOLOGY :

interdisciplinary

science


It overlaps with many elements of physical and

biological sciences

ECOLOGY

HYDROLOGYGENETICS

ATMOSPHERICSTUDIES

GEOLOGY

BEHAVIOR

BIOCHEMISTRY

PHYSIOLOGY


EcosystemsTHE RULES OF ECOLOGYF. A. BAZZAZ:

1. Everything is connected to everything else.

2. Everything must go somewhere.

3. There is no such thing as a free lunch.


ECO + SYSTEM

Part of word relates to the environment

Collection of related parts that function as a unit


ECOSYSTEM DEFINITIONS


‘Any area of nature that includes living organisms and non-living substances that interact to produce an exchange of materials between the living and non-living parts is an ecological system or ecosystem.’

(E. P. Odum(1959) Fundamentals of Ecology W. B. Sanders, Philadelephia.)


Due to that definition


2 basic ECOSYSTEMcomponents are :

LIVING - components ( biotic )

PHYSICAL- components ( abiotic )


Britannica def :

the complex of living organisms, their physical environment, and all their interrelationships in a particular unit of space


Examples of ecosystems


also called Lotic Ecosystem, any spring, stream, or river viewed as an ecological unit of the biotic community and the physiochemical environment, within which mass and energy are exchanged. The waters are usually flowing (lotic) and exhibit a longitudinal gradation in temperatures, concentration of dissolved material, turbidity, and atmospheric gases, from the source to the mouth.

riverine ecosystems


boundary ecosystemcomplex of living organisms in areas where

one body of water meets another, e.g.,estuaries and lagoons, or where a body of water meets the land, e.g., marshes. The latter are often called wetlands.


marine ecosystem :complex of living organisms in the ocean environment


Lacustrine - Pertaining to lakes — includes wetlands and deepwater habitats that may be tidal or non-tidal but ocean derived salinity is less than one part per thousand (1 ppt). 1 ppt is the equivalent of one gram of sodium chloride (salt) per liter of water.

lacustrine ecosystem


polar ecosystem : complex of living organisms in polar regions such as polar barrens and tundra


SummaryThe ecosystem is the central theme.It is man the geological agent, not so much as man the animal, ……….Nature with our intelligent help, can cope with man’s physiological needs and wastes, but she has no homeostatic mechanisms to cope with bulldozers, concrete, and the kind of agro-industrial air, water, and soil pollution that will be hard to contain as long s the human population itself remains out of control.

(Odum, 1971 page 36 First edition)

Documents

Unit 2.1.(45 min) 2.1 Ecosystems: What they are, how they ... Ecosystems what they are.pdf · Where did the concept come from? Sir Arthur Tansley, a Renaissance man coined the concept