Ecology and environment

BARC 0903 Ecology and environment credit 1

Introduction • Meaning and scope of ecology; evolution of ecology; man, environment and ecosystem; components of 

nature and basis concepts and processes of ecology; flow of material water energy, invasion, succession, predation, regulatory forces, adaptation, trophic levels, food chain, food web, ecological pyramids; Environmental zones. 

Ecosystem and its Relevance to Environment • Resources and human settlements impact of advanced agricultural methods, urbanization and 

industrialization on nature; urban ecosystem approach evolution and significance; soil, water, land, vegetation and solar, biomas, wind, hydro energy resources; settlement planning and energy conservation; development and management 

Quantitative Ecology • Introduction to quantitative ecology, identification of ecological parameters for planning at different 

levels; site planning, settlement planning and regional planning; data needs and format for data collection; types of analysis required to evolve ecological parameters. Planning for environmentally sensitive areas. 

Environmental Impact Studies • EIA ‐meaning, significance and framework; Methodologies ‐ checklist, matrices, network and social cost‐

benefit analysis; sources and acquisition of environmental information; Environmental land use classification; Environment impact studies of development projects. 

Environmental Policies • Global and national policies on environment; Five year plans in relation to environmental aspects; Legal 

measure for protection of environment; Environmental awareness and education in India; Agencies involved in environment protection; Public participation; Role of planners in shaping the future environment 

Sem

July –Dec 2011

Sem

Jan–

June

 2011

Others

Exercise plan 

• Exercise 1: Visit to an ecologically sensitive area, mapping of ecological parameters and understanding of various concepts of ecology with them. Eg derivation of food webs, energy pyramids in the given site.

• Exercise 2: Exercise on ecological planning process for particular area.• Exercise 3: Case study of a bioremediation technique.• Exercise 4: To understand work done by various agencies involved in 

environment protection PETA, WWF, CSE, BNHS

Sem

July –Dec 2011

Sem

Jan–

June

 2011

Others

Ecosystems: Basic Concepts

• What is meant by an ecosystem• The biotic and abiotic community• Food chains, trophic levels, ecological pyramid• Water and carbon cycles • Benefits from ecosystem services

Some definitions

• Ecosystem: Defined area in which a community lives with interactions taking place among the organisms between the community and its non‐living physical environment.

• An ecosystem is formed by the interactions between all living and non‐living things 

• How do living and non‐living things interact in an environment?

What is an ecosystem?• System = regularly interacting and interdependent components forming a unified whole

• Ecosystem = an ecological system;= a community and its physical environment treated together as a functional system

Ecosystem Services• The human economy depends upon the services performed 

for free by ecosystems. • The ecosystem services supplied annually are worth many 

trillions of dollars. • Economic development that destroys habitats and impairs 

services can create costs to humanity over the long term that may greatly exceed the short‐term economic benefits of the development.

• These costs are generally hidden from traditional economic accounting, but are nonetheless real and are usually borne by society at large.– http://www.epa.gov/watertrain/pdf/issue2.pdf

Ecosystems:Fundamental Characteristics

• Structure:– Living (biotic)– Nonliving (abiotic)

• Process:– Energy flow– Cycling of matter (chemicals)

• Change:– Dynamic (not static)– Succession, etc.

Abiotic components:• ABIOTIC components:• Are non living physical and chemical factors in the 

environment which affect the ecosystems.• Eg radiation, temperature, water, pressure sometimes 

even sound waves.• Solar energy provides practically all the energy for 

ecosystems.• Inorganic substances, e.g., sulfur, boron, tend to cycle 

through ecosystems.• Organic compounds, such as proteins, carbohydrates, 

lipids, and other complex molecules, form a link between biotic and abiotic components of the system. 

BIOTIC components• Biotic is a living component of a  communtiy.• The biotic components of an ecosystem can be classified according to their mode of energy acquisition.

• In this type of classification, there are:• Autotrophs and Heterotrophs• Organisms that produce their own food from an energy source, such as the sun, and inorganic compounds.

• Organisms that consume other organisms as a food source.

Modified from: General Ecology, by David T. Krome

Trophic level: the position an organism occupies in a food chain. All the organisms that are the same number of food-chain steps from the primary source of energy

Trophic Levels• A trophic level is the position occupied by an organism in a 

food chain.• Trophic levels can be analyzed on an energy pyramid.• Producers are found at the base of the pyramid and 

compromise the first trophic level. • Primary consumersmake up the second trophic level.• Secondary consumers make up the third trophic level.• Finally tertiary consumersmake up the top trophic level.

Trophic Levels Found on an Energy Pyramid

• The greatest amount of energy is found at the base of the pyramid.

• The least amount of energy is found at top of the pyramid.

Source: corpuschristiisd.org/user_files/91702/Ecosystem.ppt 

Trophic Structure Reminder

• Eltonian pyramids• Number of individuals per species• Is this pyramid stable?

Biomass

• Energy is sometimes considered in terms of biomass, the mass of all the organisms and organic material in an area.

• There is more biomass at the trophic level of producers and fewer at the trophic level of tertiary consumers. (There are more plants on Earth than there are animals.)

• Bio=life             Mass=weight• Bio + Mass = Weight of living things within an ecosystem.

Trophic Structure Reminder

•Express trophic structure as energy transfer

•Energy pyramids can never be inverted

•Is there room for anyone else

at the top of this food chain?

Food Chains

• The producers, consumers, and decomposers of each ecosystem make up a food chain.

• There are many food chains in an ecosystem.• Food chains show where energy is transferred and not who eats who.

Example of a Food Chain

Food Webs• All the food chains in an area make up the food web of the area.

© 2003 John Wiley and Sons Publishers

Food web of a hot spring

© 2003 John Wiley and Sons Publishers

Fig 6.5  Food web of the harp seal.

Ecology is

The study of the distribution and abundance of organisms,

ANDthe flows of energy and materials

between abiotic and biotic components of ecosystems.

Urban EcologyAn interdisciplinary study of the urban 

ecosystem

Origin of Cities

• Through most of history, the human population has lived a rural lifestyle.

• Settled communities of people became possible with the advent of agriculture (10,000 to 4,000 BC).

City YearBecame #1 Population Information

Memphis, Egypt 3100 BCE Well over 30,000Akkad, Babylonia (Iraq) 2240Lagash, Babylonia (Iraq) 2075

Ur, Babylonia (Iraq) 2030 65,000

Thebes, Egypt 1980Babylon, Babylonia (Iraq) 1770

Avaris, Egypt 1670

Memphis, Egypt 1557

Thebes, Egypt 1400

Nineveh, Assyria (Iraq) 668Babylon, Babylonia (Iraq) 612 First above 200,000

Understanding how urban ecosystems function is integral to mitigating their negative effects on ecosystem services, assessing their impact on neighboring environments, and considering them in decision-making dialogue.

Institute for Ecosystem Studieshttp://www.ecostudies.org/IES_urban_ecology.html

Engaging urban dwellers is critical; their activities directly impact the way urban ecosystems function and they have a vested interest in maintaining the environmental integrity of the area they live in.

What is “Urbanization?”

• Often related to industrialization• Up until very recently -- about 200 years

ago -- the proportion of the world’s urban population was limited to about 5%

Speed of Urbanization

• In 18003%• By 190014 %• In 1950 30%• In 2000 47 % (about 2.8 billion)

Human Numbers Through Time

Name Population

1 London, United Kingdom 6,480,0002 New York, United States 4,242,0003 Paris, France 3,330,0004 Berlin, Germany 2,707,0005 Chicago, United States 1,717,0006 Vienna, Austria 1,698,0007 Tokyo, Japan 1,497,0008 St. Petersburg, Russia 1,439,0009 Manchester, United Kingdom 1,435,00010 Philadelphia, United States 1,418,000

http://geography.about.com/library/weekly/aa011201f.htm

Ten Largest Cities of 1900

Name Population

1 Shanghai, China 13,278,5002 Mumbai (Bombay), India 12,622,5003 Buenos Aires, Argentina 11,928,4004 Moscow, Russia 11,273,4005 Karachi, Pakistan 10,889,1006 Delhi, India 10,400,9007 Manila, Phillipines 10,330,1008 São Paolo, Brazil 10,260,1009 Seoul, South Korea 10,165,40010 Istanbul, Turkey 9,631,700

Source: © Stefan Helders, World Gazetteer, 2004. Reprinted with permission. Web: www.world-gazetteer.com .

Ten Largest Cities of 2004

Global Urbanization Trends (cont’d)

Size of Urban Population in the World

(Source: United Nations, World Urbanization Prospects, The 1999 Revision)

Global Urbanization Trends (cont’d)

(Source: United Nations, World Urbanization Prospects, The 1999 Revision)

Comparison of Urban Population in Developed Countries and Developing Countries

Impacts of Urbanization

By concentrating humans and the resources they consume, metropolitan areas alter 

• soil drainage, • water flow, and • light availability. Furthermore they concentrate:• waste• energy demand 

Consequences of Urbanization:

Food Import Trends in Puerto Rico