The Ecology Book

135

This idea had been developing

long before Arthur Tansley

published his influential paper

on the subject in 1935. As early

as 1864, conservationist George

Perkins Marsh, in his book Man

and Nature, had identified “the

woods,” “the waters,” and “the

sands” as different types of habitat.

He examined how the relationship

between them and the animals and

plants that lived in them could be

upset by human activity.

Interconnected systems

By the 20th century, the idea had

taken hold that these and other

environments could be understood

as discrete entities, with distinctive

interactions between the living

and inert elements within them. In

1916, American ecologist Frederic

Clements built on this idea in his

work on plant succession, referring

to a “community” of vegetation as

ECOSYSTEMS

Tropical coral reefs are some of the

most diverse ecosystems of all, full of

fish, sea turtles, crustaceans, mollusks,

and sponges, as well as corals.

See also: Animal ecology 106–113 ■ The food chain 132–133 ■ Energy flow through ecosystems 138–139 ■ The biosphere

204–205 ■ The Gaia hypothesis 214–217 ■ Environmental feedback loops 224–225 ■ Ecosystem services 328–329

a single unit, and using the term

“biome” to describe the whole

complex of organisms inhabiting

a given region.

Tansley envisaged ecosystems

as being made up of biotic (living)

elements and abiotic (nonliving)

elements such as energy, water,

nitrogen, and soil minerals, which

are essential to the functioning of

the systems as a whole. The biotic

components within an ecosystem

not only interact with one another,

but also with the abiotic parts.

Thus, within any given ecosystem,

the organisms adapt to both the ❯❯

Arthur G. Tansley A free-thinking Fabian socialist

and atheist, Arthur Tansley was

one of the most influential

ecologists of the 20th century.

Born in London in 1871, he studied

biology at University College

London, where he later taught.

In 1902, he founded the journal

New Phytologist and he later

established the British Ecological

Society, becoming founding editor

of its Journal of Ecology. In 1923,

he took a break from teaching to

study psychology with Sigmund

Freud in Vienna. He was later

Sherardian Professor of Botany

at the University of Oxford.

He retired in 1937, but

maintained a special interest

in conservation. Tansley was

appointed the first Chairman of

the UK’s Nature Conservancy in

1950, five years before his death.

Key works

1922 Types of British Vegetation

1922 Elements of Plant Ecology

1923 Practical Plant Ecology

1935 “The use and abuse of

vegetational terms and

concepts,” Ecology

1939 The British Islands and

Their Vegetation

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