This topic covers material that falls into two important spheres of geographical study: biogeography and conservation science. These topics form major components of many undergraduate geography courses, and may also be part of your A-Level syllabus.

The topic includes several reading resources, including two research articles from the journal Science, and some conservation organisation websites which contain lots of useful information and case studies. You will need to read these resources as you work through the task. Questions for consideration and discussion are included.
Some additional suggestions for reading and discussion are also included: these are not essential for this task but will help you to find more about biogeography and conservation.

Much of this material is still being hotly debated, and the aim of this task is getting you to engage critically with the material. What are your opinions and your interpretations of the evidence?

Global Patterns of Biodiversity

How does biodiversity vary spatially across the globe? Where is biodiversity highest and lowest?

Read first: Gaston, K.J. 2000, Global patterns in biodiversity, Nature, 405, 220-227

The paper by Gaston (2000) is an excellent place to start researching the spatial patterns of biodiversity, and some of the theories proposed to explain these patterns. The first two and a half pages are particularly good; after this the discussion become a little technical, but you should still be able to draw some useful understanding from it – just don’t worry too much if you don’t understand all of it! Concentrate on the latitudinal gradient of biodiversity – the most obvious and important spatial pattern of biodiversity.

HINT: In these scientific journal papers, you will sometimes come across terms that you may not be familiar with (“endemic species”, for example). It is important that you look these terms up. A geography-specific dictionary is particularly useful for this. Another excellent resource is the Encyclopaedia of Life Sciences.

Most of the discussion in the Gaston (2000) paper is based on terrestrial patterns of biodiversity. But what about spatial patterns in the oceans?

Why are there more species at the equator than the poles?

Gaston includes discussion of lots of theories that have been proposed by biogeographers and ecologists to explain the latitudinal gradient of biodiversity.

When confronted with many possible explanations, it can be tempting to try to decide which of the theories is best (and therefore perhaps the correct theory). However, many of these explanations are complementary, and some are strongly related. They also apply differently to different groups of species. For example, birds are very mobile, and therefore have the potential to colonise new areas very quickly. Therefore, the theory that the high latitudes have low biodiversity because they are still recovering from local extinction during the last Ice Age is unlikely to be relevant to the pattern of diversity in birds. However, for other less mobile groups of species, this slow colonisation may be more important in explaining their low diversity in the high latitudes.

A good way to consider the different theories is to think about a particular example or case study – as you will see in the activity on Madagascar.

Resource activities

Case Study: Madagascar

Madagascar has incredibly high biodiversity, and the number of species discovered on the island is still rising. Using the Gaston paper, think about why biodiversity is so high in Madagascar. 


Links between geographical knowledge and conservation science

This section assumes that you already know something about what has been described as the current “biodiversity crisis" and explores how human activities may threaten biodiversity.


Taking it further

If this topic has interested you, here's a few more resources to take your understanding further.


Reflective questions

To answer and record these questions you will need to have an account and be logged in.

Task 1

What are the key arguments, concepts, points contained within it?

Task 2

What are you struggling to understand?

What could you do to improve your understanding of these concepts/terminology etc.?

Task 3

What further questions has this resource raised for you?

What else are you keen to discover about this topic and how could you go about learning more?

Can you make any links between this topic and your prior knowledge or school studies?

Help us evaluate this resource

Your feedback is very important to us. Please complete a short questionnaire.


Further reading

  • Biodiversity on The Guardian

    The Guardian biodiversity website contains lots of interesting articles, and regular news updates on stories relevant to biodiversity.