The Ecology Book

138

LIFE IS SUPPORTED

BY A VAST NETWORK

OF PROCESSES

ENERGY FLOW THROUGH ECOSYSTEMS

IN CONTEXT

KEY FIGURE

Raymond Lindeman

(1915 – 42)

BEFORE

1913 American zoologist

Victor Shelford produces the

first illustrated food webs.

1920 Frederic Clements

describes how groups of plant

species are associated in

communities.

1926 Russian geochemist

Vladimir Vernadsky sees that

chemicals are recycled between

living and nonliving things.

1935 Arthur Tansley develops

the concept of the ecosystem.

AFTER

1957 American ecologist

Eugene Odum uses radioactive

elements to map food chains.

1962 Rachel Carson draws

attention to the accumulation

of pesticides in food chains,

in her book Silent Spring.

I

n 1941, Raymond Lindeman

submitted the final chapter of

his Ph.D. thesis for publication

in the prestigious journal Ecology.

Titled “The Trophic-dynamic

Aspect of Ecology,” it was about

the relationship between food

chains and the changes over time

in a community of species.

Lindeman had spent five years

studying the life forms in an aging

lake at Cedar Creek Bog, Minnesota,

and was especially interested in

the changes in the lake as, year

by year, aquatic habitat gradually

gave way to land. He received

his Ph.D., but his paper was initially

rejected by Ecology, for being

too theoretical.

Lindeman had painstakingly

sampled everything in the lake,

from the aquatic plants and

microscopic algal plankton to the

worms, insects, crustaceans, and

fish that fed upon one another and

depended on each other for their

existence. He stressed that the

community of organisms could not

be properly understood on its own;

instead, it must be examined in the

context of its wider surroundings.

The living (biotic) organisms and

Producers (plants and

algae) depend on energy

gathered from the Sun and

nutrients from decomposed

organic matter.

Primary consumers

are dependent on an

abundance of plants

and algae to eat.

Secondary consumers

rely on an abundance of

primary consumers as

their food source.

Life is supported

by a vast network

of processes.

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