170 Ecosystem
In the late 1920s Tansley conducted a massive plant inventory of England for the Ecological Society. During this study, Tansley began to focus not just on the list of plants he set
out to create, but on the relationships between this vast list of plants. Which grasses were
found with which others? With which bushes and weeds? Which grasses populated lowland
meadows? Which were found on craggy mountainsides? And so forth.
By 1930 Tansley had realized that he couldn’t fully analyze the relationships between
plants without considering the effects of animals. He began to inventory and map the many
browsers—animals that ate grasses. Soon he realized that any study of these browser animals was woefully incomplete unless he included an inventory of the carnivores that
controlled browser populations.
Then he realized that he had to include recyclers and decomposers (organisms that
broke down decaying plant and animal matter into the basic chemical nutrients for plants).
Finally he added the physical (inorganic) environment (water, precipitation, climate, etc.).
Tansley had realized by 1935 that each area he studied represented an integrated, enclosed local system that acted as a single unit and included all organisms in that given area
and their relationship to the local inorganic environment. It was a breathtakingly grand concept. Each species was linked to all others. What happened to one affected all others.
Water, sunlight, and some inorganic chemicals entered the system from the outside.
All living organisms inside the closed ecological system fed off each other, passing food up
and then back down the food web.
Tansley shortened the name from ecological system to ecosystem. That term and that
concept, however, did not gain popularity until 1953 when American scientist Eugene
Odum published Fundamentals of Ecology, a book that explained the concept of, and used
the term, ecosystem.
Fun Facts: An important ecosystem service that most people don’t think
about is pollination. Ninety percent of the world’s food crops would not
exist without pollinators like bees, bats, and wasps.
More to Explore
Anker, Peder. Imperial Ecology: Environmental Order in the British Empire,
1845–1945. Cambridge, MA: Harvard University Press, 2002.
Ball, Jackie. Ecology. New York: Gareth Stevens, 2003.
Dorling Kindersley Staff. Ecology: Eyewitness. New York: DK Publishing, 2000.
Lane, Brian. Ecology. New York: DK Publishing, 2005.
Stone, Lynn. Forests. Vero Beach, FL: Rourke Publishing, 2004.