History of Ecology
The Botanical
Geography
Alexander von
Humboldt
father of ecology
He was the first to take on the
study of the relationships between
organisms and their environment.
He exposed the existing
relationships between observed
plant species and climate, and the
described vegetation zones using
latitude and altitude, a discipline
now known as geobotany.
Idea for Plant Geography one
of Humboldts famous works.
The notion of Biocoenosis
Charles Darwin and Alfred Wallace (18231913)
Alfred Russel Wallace, contemporary and
colleague of Darwin, was first to propose a
"geography" of animal species.
Several authors recognized at the time that
species were not independent of each other,
and grouped them into plant species, animal
species, and later into communities of living
beings or biocoenosis.
The first use of this term is usually attributed
to Karl Mbius in 1877
The Biosphere
Eduard Suess and Vladimir Vernadsky
After observing the fact that life developed only
within strict limits of each compartment that
makes up the atmosphere, hydrosphere, and
lithosphere.
The Austrian geologist Eduard Suess proposed
the term biosphere in 1875. Suess proposed the
name biosphere for the conditions promoting life,
such as those found on Earth, which includes
flora, fauna, minerals, matter cycles, etc.
.
In the 1920s Vladimir I. Vernadsky, a Russian
geologist who had defected to France,
detailed the idea of the biosphere in his work
"The biosphere" (1926), and described the
fundamental principles of the biogeochemical
cycles. He thus redefined the biosphere as
the sum of all ecosystems.
First ecological damages were reported in the
18th century, as the multiplication of colonies
caused deforestation. Since the 19th century,
with the industrial revolution, more and more
pressing concerns have grown about the
impact of human activity on the environment.
The term ecologist has been in use since the
end of the 19th century
The Ecosystem
Over the 19th century, botanical geography and
zoogeography combined to form the basis of biogeography.
This science, which deals with habitats of species, seeks to
explain the reasons for the presence of certain species in a
given location.
It was in 1935 that Arthur Tansley, the British ecologist,
coined the term ecosystem, the interactive system
established between the biocoenosis (the group of living
creatures), and their biotope, the environment in which
they live. Ecology thus became the science of ecosystems.
Tansley's concept of the ecosystem was adopted by the
energetic and influential biology educator Eugene Odum.
Along with his brother, Howard T. Odum, Eugene P. Odum
wrote a textbook which (starting in 1953) educated more
than one generation of biologists and ecologists in North
America.
Ecological Succession
At the turn of the 20th century, Henry
Chandler Cowles was one of the founders of
the emerging study of "dynamic ecology",
through his study of ecological succession at
the Indiana Dunes, sand dunes at the
southern end of Lake Michigan. Here Cowles
found evidence of ecological succession in
the vegetation and the soil with relation to
age.
Ecological succession is the process by which
a natural community moves from simpler
level of organization to a more complex
community
Human ecology
Human ecology began in the 1920s, through the
study of changes in vegetation succession in the city
of Chicago. It became a distinct field of study in the
1970s.
This marked the first recognition that humans, who
had colonized all of the Earth's continents, were a
major ecological factor.
Humans greatly modify the environment through the
development of the habitat (in particular urban
planning), by intensive exploitation activities such as
logging and fishing, and as side effects of
agriculture, mining, and industry. Besides ecology
and biology, this discipline involved many other
natural and social sciences, such as anthropology
and ethnology, economics, demography, architecture
and urban planning, medicine and psychology, and
many more.
The development of human ecology led to the
increasing role of ecological science in the design
and management of cities.
In recent years human ecology has been a topic that
has interested organizational researchers. Hannan
and Freeman (Population Ecology of Organizations
(1977), American Journal of Sociology) argue that
organizations do not only adapt to an environment.
Instead it is also the environment that selects or
rejects populations of organizations. In any given
environment (in equilibrium) there will only be one
form of organization (isomorphism). Organizational
ecology has been a prominent theory in accounting
for diversities of organizations and their changing
composition over time.
James Lovelock and
the Gaia hypothesis
The Gaia theory, proposed by James Lovelock,
in his work Gaia: A New Look at Life on Earth,
advanced the view that the Earth should be
regarded as a single living macro-organism.
In particular, it argued that the ensemble of
living organisms has jointly evolved an ability
to control the global environment by
influencing major physical parameters as the
composition of the atmosphere, the
evaporation rate, the chemistry of soils and
oceans so as to maintain conditions
favorable to life.
This vision was largely a sign of the
times, in particular the growing
perception after the Second World War
that human activities such as nuclear
energy, industrialization, pollution, and
overexploitation of natural resources,
fueled by exponential population
growth, were threatening to create
catastrophes on a planetary scale.
Thus lovelocks Gaia hypothesis was
embraced by many environmental
movements as an inspiring view : their
Earth-mother, Gaia was becoming sick
from humans and their activities.
Thank you !
Presented by:
Ana Rose D. Villaruel
