Download Scope of Ecology

Scope of Ecology
Ecology (from Greek word oikos “household” and
logos “study of”)
• Is the scientific study of the distribution,
abundance and relationship between organisms
and their environment
Environment
• Includes not only the physical but also the
biological conditions under which an organism
lives
Relationship
• Includes interactions with the physical world
and with members of other species and the
same species
The term ecology was coined by the German
zoologist Ernst Haeckel in 1866. He called it
Oecologie and defined its scope as the study of
the relationship of animals to their
environment.
Environmental Science
• an interdisciplinary academic field that integrates
physical and biological sciences (including physics,
chemistry, biology, soil science, geology, and
geography) to the study of the environment, and
the solution of environmental problems.
• Environmental science provides an integrated,
quantitative, and interdisciplinary approach to the
study of environmental systems
• Organisms interact Ecosystem
with their environment within the
context of the ecosystem.
• Eco – relates to the environment
• System – a collection of related parts that function as a
unit.
Ecosystem consists of two basic interacting components:
•biotic (living)
•abiotic (physical)
Ecosystem components form a
• All organisms of a given kind constitute a
hierarchy
species. Each species represents a particular
array of hereditary material called a gene pool,
which is distinct from the gene pools of other
species.
• Populations – groups of individual organisms of
the same species that interbreed and occupy
given areas at given times. Each organism and
population has a habitat, the place where it
lives.
• Community – populations of plant and animals
species living and interacting in a given area at a
given time.
• Ecosystem – community of living things that
interact with each other and with the physical
environment.
• Biosphere – combination of all ecosystems
The Organism and its Environment
Fundamental ways the organism relates to its
environment
• Environmental conditions vary both in time and
space
– All organisms live in a varying physical environment
of temperature, moisture, light, and nutrients.
•
Organisms need a fairly constant internal
environment
•
Homeostasis – the maintenance of conditions within the
range that the organism can tolerate
• Homeostasis is possible only within a limited
range of conditions
– Leibig’s law of the minimum (the performance of an
organism will be a function of the most limiting
environmental factor)
• An organism cannot do equally well in differing
environments
– The characteristics that enable an organism to do
well under one set of conditions limit its
performance under a different set of conditions.
• The distribution of organisms reflects environmental
variation
• Environmental components
– Affect the distribution and abundance of organisms
Kangaroos/km2
> 20
10–20
5–10
1–5
0.1–1
< 0.1
Limits of
distribution
Figure 50.2
Southern Australia has
cool, moist winters and
warm, dry summers.
Climate in northern Australia
is hot and wet, with seasonal
drought.
Red kangaroos
occur in most
semiarid and arid
regions of the
interior, where
precipitation is
relatively low and
variable from
year to year.
Southeastern Australia
has a wet, cool climate.
Tasmania
• An organism lives in a habitat
– The actual location or place where an organism lives
is called its habitat
• Constraints and trade-offs in habitat use define an
organism’s niche
• The basic role of an organism in the community – what it
does, its relationship to its food and enemies (species
occupation)
• Includes all the physical and biological variables that affect
an organism’s well-being