theme one lectures 1 to 3 geography

BIOGEOGRAPHY

Theme 1:

THE RELATIONSHIP BETWEEN GEOGRAPHY,

BIOGEOGRAPHY AND ENVIRONMENTAL

MANAGEMENT

Lecture 1

What is Biogeography?

Biogeography: the large-scale geographic

pattern in the distribution of species, and the

causes and history of this distribution. Zoogeography

Phytogeography

Lecture 2

Environmental Science: the study of the complex

interactions of human populations with matter and

energy resources; it incorporates aspects of the

natural and social sciences, business, law,

technology, and other fields.

Lecture 3

Vicariance biogeography:

The distribution of organisms depends on their

normal means of dispersal; e.g., disjunctions are

explicable in terms of new barriers (rivers, rises in

sea-level, etc.) having split formerly continuous

ranges, rather than in terms of the organisms hopping

over already existing barriers.

The Gaia Principle

First described by James Lovelock in 1979, the Gaia Principle describes the

Earth as a single, living organism, with all its biological, geological,

chemical and hydrological processes acting in concert, to regulate the planet

and ensure its survival through an exquisite array of feedback loops.

An example of a Gaia feedback loop is the relationship between plants and

carbon dioxide. When carbon dioxide levels rise in the atmosphere, plants

are able to grow better and extract more carbon dioxide – thereby

“balancing” the Earth as a complex system.

But some scientists criticise the Gaia Principle because it can’t be tested.

They say it is impossible for “stabilising” feedback loops to evolve as

described by Lovelock, and argue that the Earth is ever-changing