The presentation helps to understand urban ecology.

1. What is URBAN ECOLOGY ?
Shreeram Ghimire (Nature Conservation and Sustainable Development Society)
Kathmandu, Nepal

2. • Definition
Urban ecology is defined as sub discipline of biology and ecology.
Urban influences more focus on human influences to plant and
animal populations in urban settlements and their impacts.
The ecological functions of urban ecosystems and habitats to
human population is another subject of discussion under this
subdiscipline.
Urban Ecology also constitutes the phenomenon of interaction
between biophysical forces and socio-economic aspect of cities.
It is the study of relationship between living and nonliving parts of
man-made environments, and the quantification of flows of energy,
materials and nutrients, etc. required to sustain urban systems.

3. Historical Background of Urbanization
• The first city was created in a fertile crescent known as Mesopotamia.
• The capital city of Nepal, Kathmandu is another example. Kathmandu is
regarded as city of temple, which is so fertile and had been regarded as
center of civilization.
• The region between the Tigris and Euphrates rivers, called Mesopotamia in
Greek, Al Jazirah in Arabic, and Iraq today, is regarded as first settled
around 10,000 BCE.
• The largest city in 3100 BCE was Memphis, Egypt, with over 30,000 people.
• Over the centuries, people have been drawn to cities as centers of
civilization including governing, trade, culture, learning, and
entertainment. City is the space where the history of hunter-gatherer
converted to human settlement in one place and engage in other pursuits
besides getting food.

4. Basic Idea of Ecology
• Oekologie comes from the Greek word Oikos, the hearth or home and
logia, the study. Ernest Haeckel in 1866 coined the term ecology. AS Tansley
in 1935 coined the term ecosystem. E.P. Odum defines ecology as the study
of the relationships between structure and function in nature.
• The definition of ecology by Odum provides strong rationale for applying
the science of ecology to the study of cities as well, including how human
behavior as studied by social scientists and ecosystem behavior as studied
by natural scientists are linked and, together, comprise the urban
ecosystem.
• Urban ecological structure is the ‘nouns’ of the environment, the number,
size, composition, and nature of the components, and is comprised of
abiotic and biotic components. Urban ecological function is the ‘verbs’ and
includes how species have adapted to or evolved in the urban
environment.

5. • Scope of Urban Ecology as Academic Domain
• Urban Environmental Quality as problems of most of the mega cities in
both developing and developed world
• Growing size of Urban slums in African and Asian continents
• Natural Disaster in Urban areas
• Chemical pollution by synthetic but unregulated chemicals in every
aspects of daily life of cities
• Future challenges and solutions: Climate Change and Global Warming
• Common platform for planners, educators and decision makers
• Next science to introduce Human as part of ecology
• The science to integrate biophysical systems with socioeconomic science

6. Principle Subsystems of Urban Ecosystem
• Hydrological System
• Climate System
• Atmospheric System
• Energy System
• Nutrient Cycling System
• Material Cycling System
• Biological System
• Economic System
• Sociological System

7. Systems Ecology in Urban Ecosystem
• Urban ecosystem is now studies as “coupled human/nature systems”.
• In this approach, human is included as part of nature, the same as
other animals and quantified human position same as other.
• Social and natural sciences are linked to assess fully the human role in
ecosystem, and is critical for this approach.
• Through this approach, the past practice of studying urban systems as
domain of social scientists has been translated to interdisciplinary
science and cross-cutting issue.
• Systems ecology prevail the fact of socio-ecological research to
understand the modern complex urban systems. Socio-ecological
metabolism, land use and landscapes, governance, and
communication are major issues related to socio-ecological research.

8. Socio-Ecological Metabolism
• Activities in cities associate with the flow and transfer of energy, that
energy uses metabolism, which is composed of production, capture or
generation of energy, and respiration or consumption. So, the city itself is
collection of thermodynamic processes.
• Metabolism of a city is closely associated with social perspective. Typical
example is relation between capital and energy flow. In the USA in 2015,
about 6mJ of energy were required for each dollar of economic activity.
• Several ancient cities died due to lack of sustainable source of resources
like energy supply. With the invention of fossil fuels, cities created in
modern era of human history are functioning as fossil fuel has largely
covered energy need of the cities. The energy required for city metabolism
is derived from these fossil fuels. The price of these fuels will rise and cities
will feel shortage in future due to limited availability. So, to maintain socio-
ecological metabolism of cities, green infrastructure is being promoted as
part of climate/energy policy.

9. Environment Gradient Analysis
• In urban ecology, study of behavior of living organisms in different
environmental situations other than wild habitat is essential. Concentration
od nutrients in stream water, percent of canopy cover on an urban block are
typical examples of gradients.
• Soils, streams, vegetation and the animal diversity in the urban areas change
dramatically along the different environment gradients. Soil organic matter,
soil bulk density, soil nutrient availability etc. are example of important
gradient to be studied in cities which are informative and important to urban
sustainability.
• Urban forests that provide cooling and aesthetic relief to urban inhabitants,
are useful in making city free from air conditioning, which reduces energy
consumption and helps for city’s sustainability.

10. Correlation Analysis
• This tool is very useful in studying relation between various factors and urban
ecosystem. Temperature, Soil pH, number of vehicles, value of clean energy
production per capita etc. are such factors which can be used to measure the
status of city’s ecological life.
• Statistical parameters like multivariate stepwise regression analysis can be
used to set the standard of various parameters related to ecosystem of the
cities. Air, water, soil and biodiversity can be monitored by using recorded
values of factors associated with the samples collected in the cities.

11. Footprint Analysis
• Modern cities are centers of consumption. The city consumes the products
that produced by several times bigger landscapes. In 2006, Vancouver BC
needed the area 36 times its size to support city’s metabolism.
• The energy and material that is extracted/produced to support the lifestyle
of a city is referred to as ecological footprint
• Largest portion of such ecological footprint goes to food and energy.
• Analysis of ecological footprint of a city is very essential for sustainability of
that city.

12. Systems Flow Diagramming
• This diagrammatic model was developed by H.T. Odum to track the changes
in storages and flows of energy in an ecosystem.
• By determining the inputs, transformations, and outputs of energy or
materials of the city, changes in ecosystem stocks and flows can be calculated
using computerized models.
• Zucchetto developed first urban systems flow diagrams for the city of Miami,
Florida. He calculated flows and storages of energy, land, and materials.

13. Energy Return on Investment (EROI) Analysis
• Per Unit energy on unit of energy invested is termed as energy return on
investment. EROI is useful to calculate energy need of each city for running
lifestyle.
• Hall and others evaluated the energy costs and benefits of three strategies:
tree plantation, rooftop solar thermal and urban food production. They
found that solar thermal would yield an EROI twice that of urban food
production and over three times that of an urban forest.
• People around the globe are advocating about green fuels, green
infrastructure and green jobs. The benefits of this strategies have been
investigated, the trade-offs between them have not.

14. Emergy Analysis
• The amount of embodied energy in each material good used by society
including both industrial energy (e.g., fossil fuels) and natural energies
(including sunlight, rain etc.) and how that is transformed through use is
called emergy analysis.
• The energetic cost of extraction of raw materials, the energetic cost of the
transformation of those materials into some usable product, and the
transportation energy cost of moving the product to market can be defined
as embodies energy.

15. • In the age of degradation of both natural systems and natural
habitats, urban ecology can help to identify gaps and solutions both
to our understanding and behaviors.
• To preserve both social and environmental quality of life in cities, the
science that help to evaluate trade-offs between alternative choices is
urban ecology.
The presentation is developed during the study of Springer publication named “Understanding Urban Ecology”.