Lecture 3
Ecosystem
SUMMER 2023
GED 2283 ENVIRONMENTAL SCIENCE
SECTION 1
Md. Emon Rahman
RESEARCH ASSOCIATE CUM LECTURER, CENTER FOR SUSTAINABLE DEVELOPMENT
Email: emon.rahman@ulab.edu.bd
ECOSYSTEM
Structure and Function of Ecosystem
How do organisms respond to environmental change?
All living things must be able to respond to what's
going on around them. Anything that causes
an organism to react or respond is called
a stimulus (plural: stimuli). Stimuli can
be
external
(outside
the
organism)
or internal (inside the organism).
How do organisms respond to environmental
change?
 Disperse, adjust through phenotypic plasticity, or adapt through genetic
changes
 Phenotypic plasticity describes the tendency of a particular genotype to
produce different phenotypes under altered environmental conditions
 As a reflection of their behavioral flexibility, urban species often exhibit
innovative behaviors
 More innovative species are better at learning and solving problems, which
are important traits for adjusting to city living
 Changes to the environment can sometimes cause a mismatch between the
actual quality of a habitat and the cues used by individuals to assess that
quality, resulting in an “ecological trap”
Description: https://youtu.be/gAjF1mWdhKk
Forest Ecosystem
Forest Producers
Forest Consumers
Forest Decomposers
Interdependence and Symbiosis:
Foundations of Forest Ecology
Components of a Forest Ecosystem
1. Productivity
The basic requirement for any ecosystem to function and sustain is the constant input of solar
energy. Plants are also the producers in a forest ecosystem.
2. Decomposition
Decomposition is an extremely oxygen-requiring process. In the process of decomposition,
decomposers convert the complex organic compounds of detritus into inorganic substances such as
carbon dioxide, water and nutrients.
3. Energy flow
Energy flows in a single direction. Firstly, plants capture solar energy and then, transfer the food to
decomposers. Organisms of different trophic levels are connected to each other for food or energy
relationship and thus form a food chain.
4. Nutrient Cycling
Nutrient cycling refers to the storage and movement of nutrient elements through the various
components of the ecosystem. There are two types of Nutrient cycling, gaseous and sedimentary.
Please follow this link to gather more informationhttps://www.environmentbuddy.com/plants-and-trees/forest-ecosystem-components-types-examples/
Forest in Bangladesh
Forest in Bangladesh
Forest in Bangladesh
Swamp Forests
These are also called Wetland forests. The other name of these forests is Littoral
forests.
Tropical Thorn forests
They are found in the area with very little rainfall (as little as 50cm). Arid
regions of Rajasthan, Gujarat, Rajasthan, Uttar Pradesh are example of tropical
thorn forests.
Montane Forest
Montane Forest refer to any forest found in hilly/ mountain
areas. Dense forests are common in areas of moderate
elevations. The montane ecosystems are highly affected by
the climate which gets colder as the elevation increases.
Tropical Rain Forests
These are also called equatorial rainforests. Rainforests
are those forests which are characterized by heavy rainfall
between 1750 mm and 2000 mm. These forests incur
heavy showers of 100-600 cm a year, so they are named
so. Coffee, bananas, and chocolates come from tropical
rainforests.
THANK YOU
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