The greed and need of human being has modified and changed the natural ecosystems
greatly. The main reasons for the modification of natural ecosystems are,
1) Increasing human population,
2) Increasing human needs, and
3) Changing life styles. In this lesson you will learn about different types of human
modified ecosystems, the modifications brought about for their optimum utilization.
Characteristics of human modified ecosystems
a) Highly simplified.
b) Species diversity is very low.
c) Food chains are simple and small.
d) Depend on human (anthropogenic) support for survival; need for fossil fuel energy.
Fertilizers, irrigation etc.
e) Attract large number of weeds.
f) More susceptible to epidemic diseases.
g) Suffer from soil erosion.
h) Highly unstable.
Human modified ecosystems may or may not depend on solar energy e.g. in an industry
energy is provided in the form of fossil fuel or electricity or both. Some examples of human
modified ecosystems are:
(1) Agro-ecosystems
(2) Plantation forests
(3) Urban ecosystems
(4) Rural ecosystems
(5) Aquaculture
(6) Industrial areas
(7) Laboratory cultures
AGRO-ECOSYSTEMS
Agro-ecosystems are large areas where commercial crops are cultivated. Crop plants are
sown and harvested by humans for economic purposes. They are also known as crop
ecosystems and mostly cultivated as monoculture (growing only one type of crop) on the
entire field or sometimes growing two or more crop species in the same field at the same
time. Characteristics of agro-ecosystems
(1)They are highly simplified ecosystems supporting monoculture of a crop species.
(2) Species diversity is lowest
(3) Highly unstable and not self sustaining.
(4) Attract weeds and susceptible to plant diseases.
(5) Soil are poor, deficient in nutrients, require supplement of chemical or fertilizers.
(6) Need artificial irrigation and water management.
(7) Dependent on human care and management.