The Ecology Book

185

See also: Field experiments 54–55 ■ Animal ecology 106–113 ■ Island

biogeog raphy 14 4 –149 ■ Big ecology 153 ■ Endangered habitats 236–239

S

cientists seeking faster

ways to analyze and counter

the many threats to plant

and animal populations increasingly

turn to macroecology. The term,

coined by American ecologists

James Brown and Brian Maurer

in 1989, describes studies that

examine relationships between

organisms and their environment

across large areas to explain

patterns of abundance, diversity,

distribution, and change.

Brown had tried and tested this

methodology in the 1970s while

studying the potential effects of

global warming on species in cool,

moist forest and meadow habitats

on 19 isolated ridges of the Great

Basin, in California and Utah. He

realized it would take years of fresh

fieldwork to collect enough data.

Instead, he used existing findings

to draw new conclusions. First, he

predicted how much shrinkage

would occur in the area of ridge-top

habitat with an assumed increase

in temperature. Using known data

on the minimum area required to

support a population of each small

mammal species, Brown was able

to work out the extinction risk on

each ridge as temperatures rose,

and suggest conservation priorities.

Enhancing fieldwork

Macroecology often supplements

fieldwork and can lead to surprising

discoveries. In Madagascar,

satellite data was used to develop

models for chameleon species and

predict them in areas beyond

their known ranges. As a result,

scientists investigating these areas

found several new sister species. ■

ORGANISMS IN A CHANGING ENVIRONMENT

IN CONTEXT

KEY FIGURE

James H. Brown (1942–)

BEFORE

1920 Swedish ecologist

Olof Arrhenius produces

a mathematical formula for

the relationship between

area and species diversity.

1964 British entomologist

C.B. Williams documents

patterns of species abundance,

distribution, and diversity in

his book Patterns in the

Balance of Nature.

AFTER

2002 British ecologists Tim

Blackburn and Kevin Gaston

argue—contrary to some—

that macroecology should be

treated as a discipline distinct

from biogeography.

2018 A team of scientists uses

practical macroecological

methods to show that bird

species living on islands have

relatively larger brains than

their mainland relatives.

By comparing community studies

made in deserts around the world,

macroecologists can determine the

greatest threats to a desert species

such as this banner-tailed kangaroo rat.

TO VISUALIZE

THE BIG PICTURE,

TAKE A DISTANT VIEW

MACROECOLOGY

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