Environmental Engineering Reference
In-Depth Information
Ecosystem A system comprising the organisms, the physical environment, and
the interactions among them within a specified volume of the Earth.
Ecosystems may be of any size, depending on the research questions
of interest, and are open to material and energetic flows with adjacent
systems. Although this definition encompasses human ecosystems,
for completeness it is considered that human ecosystems include
biological components, the physical environment of air, water, soil,
energy, the social and human institutions, and the built environment.
Suburb
This term has two meanings, depending on whether an Old World or a
New World context is intended. In the New World, a suburb is a
component of a broadly recognized urban area, a primarily residential
land cover in which single or multiple household dwellings are
interspersed with the open spaces of lawns and generous street land-
scaping. New World suburbs are often a locus of wealth and power.
Modest commercial nodes, mostly as service rather than
manufacturing or warehousing, may be included in such suburbs. In
contrast, Old World suburbs may be less green and more densely built
than New World suburbs, and in many cases may host concentrations
of lower income, less empowered persons. In the expanding cities of
the global south, shanty towns and informal settlements may consti-
tute much of the suburban realm.
Urban
Definition 1 refers to all components of densely settled and built up
areas, and contrasts with rural, agricultural, or wild lands. An alter-
native terminology for this inclusive definition is city-suburban-exur-
ban (CSE) system. Definition 2 refers to dense commercial,
industrial, and residential lands in contrast to suburbs and exurbs.
Definition of the Subject
Within the science of ecology, urban ecology is defined as the study of structure,
dynamics, and processes in urban ecological systems. Urban ecology is the study of
the relationships of human and nonhuman organisms in urban areas, the interactions
of these organisms with the native and built physical environment, and the effects of
these relationships on the fluxes of energy, materials, and information within
individual urban systems and between urban and nonurban systems. Urban ecology
applies the methods and concepts of the biological science of ecology to urban
areas, but requires and integrates with the concerns, concepts, and approaches of
social sciences to produce a hybrid discipline. Urban ecological systems include
individual organisms, populations, communities, and landscapes, as well as
buildings and infrastructure. Urban ecology further recognizes specific urban
ecosystems as a part of the global biogeochemical, economic, and human demo-
graphic system.
