Transcript PowerPoint Presentation - History of Ecology and Agriculture

History of Ecology, the
Environmental Movement and
Agriculture
Martha Rosemeyer
IES
January 6, 2003
Outline
 I. History of Ecology (Martha)
 II. The Environmental Movement (Lin)
 III. The intersection of ecology, the
environmental movement and agriculture
(Martha)
Ecology is the science that underpins
the environmental movement,
especially ecosystem ecology
 Ecology is the study of the interactions
between living organisms and their
environment
 Ecosystem is a community of organisms
(biotic components) and their environment
(abiotic components) interacting as an
ecological unit
Ecosystems
Dynamic systems through time with
characteristic patterns of:
A. energy flow
B. nutrient cycling
C. succession
Food web concept important in
bioaccumulation
 As one organism ingests another then the
toxins accumulate, particularly those that
are fat soluable
Nutrient Cycles
Guo and Bradshaw 1993
Succession
Sucession
History of Ecology
 Herodotus 480 BC “balance of
nature” concept
 Ernst Haeckel (1869) coined term “ecology”

German biologist = “economy of nature”
 Ellen Swallow (Richards) called “the woman
who founded ecology” (1892)
She used “ecology” to mean broad,
interdisciplinary field. She particularly focused
on industrial pollutants and air and water quality
F. (and E.) Clements 1900
 Vegetational communities as an
organism that is born reaches climax
state through succession
 Contested by other scientists whose data
does not support this, e.g. Cowles, Cooper

plants and animals do not act as one
assemblage-- much variability in their range
 Another idea that influenced agriculture:
weeds are indicators of soil properties
 Ideas are still around in various forms

Gaia concept, Lovelock and Margulis
Cowles
Tansley
 Tansley (British) 1935 concept
of the ecosystem
 “The elegance of the[Tansley’s] idea of the
ecosystem is that it is comprehensive,
including within itself all those elements
physical, chemical and biological, which
could conceivably affect the organisms
being studied.” (Evans 1976)
 Note that still focussed on the organism
 However, the ecosystem idea was also
shared by a number of other scientists
Photo: Chicago Daily News
Eugene Odum, Introduction to
Ecology text 1953
 Defined ecology as the structure
and function of ecosystems
 Influenced by others developing ideas of
energy flow and nutrient cycles, which he
systematized and explained well
 Heavily influenced by brother, Howard, an
Electrical Engineer
Drawings of energy flow diagrams used
electrical engineering symbols
Guo and Bradshaw 1993
History of nutrient cycling
 von Leibig, German chemist 1840


plants assimilate nutrients from soil
basic nutrient cycles, e.g. nitrogen
 Sukachev 1945 (Russian)



“biogeocoenosis” = biogeochemical cycling
“One of the teachings of dialectical materialism
is that in nature all phenomena and objects are
interrelated.”
“It is a major task of natural science to deepen
its knowledge of existing relationships to
discover the underlying patterns with a view to
controlling them on behalf of man.” Sukachev
1960
II. Environmental movement
 Where did the environmental movement
begin?


time
site specificity or name specificity
III. The intersection of ecology,
the environmental movement and
agriculture
 Agriculture starts about 12,000 years agotraditional systems
 ...
 US until 1940-50 most holding small, ie
what a family could farm



some mechanization
inputs, like fertilizer, low
hybrid corn 1930s
Green revolution 1950,
post WW II, “conventional” ag
 Appeared to be
imminent famine in
China and India
 Green Revolution
means:
Adoption of high
yielding varieties,
dependent upon
irrigation, fertilizers
and pesticides
 Wartime capability turned to produce
peacetime inputs for war on famine

pesticides (defined as a substance which kills
weeds, insects or bacteria, fungi (diseasecausing organisms)
 Successful in terms of absolute increase in
food production
 1960s and 1970s, social impact of green
revolution was reported

in Punjab, India, small farmers loose their land,
credit becomes an issue
1960-1970s Rachel Carson
publishes Silent Spring 1962
 Environmental impacts of agriculture come
forward
 Environmentalists view agriculture “bad”
because it is humanly managed vs. the
“pristine” natural world
 Environmental groups don’t actively
support organic agriculture
1980s Rise of agroecology as a
response to conventional ag:
interdisciplinary field- five major
contributors




Ecology
Environmentalism
Agriculture
Indigenous agriculture, especially
traditional tropical systems
 Social sciences
Agroecology
 AE is the study of the interactions between
living organisms and their environment in
agricultural systems

takes a “systems approach”
 Latin America contributed ideas ahead of
US

Altieri, Gliessman, Vandermeer, Carroll
 Varying social emphasis, e.g. in Latin
America the social aspects are much more
emphasized vs. in US where agroecology is
heavily weighted toward the ecological
“Hot” topics in agroecology
 Pesticides and bioaccumulation
 Pesticide effects on biodiversity
Diverse Peruvian
potatoes
 Mixtures of pesticides and effects on organisms
 Endocrine disrupting effects of pesticides and
industrial chemicals
 Genetic engineering and “genetic pollution” in
environment
“Hot” topics in agroecology, cont.




Soil food web- function of diversity
Predator/prey interactions and biocontrol
Nutrient cycles
Industrial waste--toxic waste and
application to land of heavy metals and
dioxin in fertilizers
Environmental groups now are
embracing sustainable agriculture
 Greenpeace- anti-genetic engineering
campaign
 Sierra Club/Friends of the Earth run articles
on sustainable agriculture often
 Redefining Progress hosts sustainable
agriculture conference
Major underlying philosophical
themes in agroecology and the
environmental movement
 Are humans separate from or part of nature?
 Are their aspects of nature that act as a
supra-organism?
 Is a reductionist or holistic approach more
useful and accurate, or do they each give
different information?