Andes of South America are world's biodiversity champion says news study

World’s biodiversity champion: the Andes of South America

Andes of South America are world’s biodiversity champion says news study

Rhett A. Butler, mongabay.com

August 18, 2005

Currently there are three “competitive” maps of the world’s biodiversity hotspots based on different criteria:

areas rich in species diversity in general;
threatened species specifically; and
endemic species, which have a limited habitat.

A new study, based on bird distribution and detailed below, found that these three maps share only 2.5% of their total area, thus adding confusion to what hotspots should be priorities for conservation efforts. The overlap all occurs in the Andean region of South America, implying that this area is the world’s biodiversity champion when it comes to birds. South America is home to more than 3400 of the world’s 10,000 bird species.

Biodiversity Hotspots.
Conservation International, a leading conservation organization, sponsors a web site on Global biodiversity hotspots, the richest and most threatened reservoirs of plant and animal life on Earth.

New global bird map suggests ‘hotspots’ not a simple key to conservation

Imperial College London release

The first full map of where the world’s birds live reveals their
diversity ‘hotspots’ and will help to focus conservation efforts,
according to research published in Nature today (18 August).

Summary

Using bird data, researchers compared areas designated as “biodiversity hotspots” under three different hotspot conventions as defined by the following criteria:

areas rich in species diversity in general;
threatened species specifically; and
endemic species, which have a limited habitat.

and found that there is little overlap between the three hotspot maps. The team reports that all three hotspot types (1,2,3) share just 2.5% of their total area, all of which is located in the Andes of South America. For threatened species (2) and endemic (3) species of birds share 6.8% of their combined area.

The implications from the study are unclear. Many conservationists would argue that all three types of hotspots require preservation.

The findings are drawn from the most complete and detailed picture of
bird diversity yet made, based on a new global database of all living
bird species.

The map also shows that the pattern of bird diversity is much more
complicated than previously thought.

The researchers conclude that different types of ‘hotspot’ – the most
bird-rich locations on the planet — do not share the same geographic
distribution, a finding with deep implications in both ecology and
conservation.

For birds, hotspots of species richness are the mountains of South
America and Africa, whereas hotspots of extinction risk are on the
islands of Madagascar, New Zealand and the Philippines.

“In the past people thought that all types of biodiversity showed the
same sort of pattern, but that was based on small-scale analyses,” says
senior author Professor Ian Owens of Imperial College London. “Our new
global analyses show that different sorts of diversity occur in very
different places.”

Biodiversity hotspots have a high profile in conservation, but are
controversial as their underlying assumptions remain untested. The key
assumption is that areas ‘hot’ for one aspect of diversity will also be
hot for other aspects.

Their analyses now show that surprisingly, this is not the case –
different types of hotspot are in fact located in different areas.

“Different types of diversity don’t map in the same way,” Prof Owens
says. “There is no single explanation for the patterns. Different
mechanisms are therefore responsible for different aspects of
biodiversity, and this points to the need to base conservation strategy
on the use of more than one measure of biodiversity.”

The team mapped three different measures of diversity for the study:
species richness, threatened species richness (as assessed by their
extinction risk), and endemic species richness (birds with a small
breeding range). Only the Andes in South America contains bird hotspots
under all three measures.

To understand the mechanisms behind large scale biodiversity patterns,
the researchers first had to construct global maps before delving into
them.

Biodiversity hotspots

According to Conservation International, the world’s biodiversity hotspots hold especially high numbers of endemic species despite their limited extent: combined, the total area of remaining habitat covers only 2.3 percent of the Earth’s land surface. Each hotspot faces extreme threats and has already lost at least 70 percent of its original natural vegetation. Over 50 percent of the world’s plant species and 42 percent of all terrestrial vertebrate species are endemic to the 34 biodiversity hotspots.

source: Conservation International

“The prior bits of work were horribly dispersed: in paper maps on
expert’s desks, or in very old books and the heads of aging experts who
had originally surveyed the areas,” said Professor Owens.

It took five person years to get the data into a digital mapping format
known as a ‘GIS system’. This database was then used to score the
presence or absence of each of the nearly 10,000 different bird species
in a grid covering the world’s land area. Each of the 20,000 cells in
the grid is 100 km squared and contains an area similar to that of
Cyprus.

“We hope that birds are a model for this type of work,” said Professor
Owens. “There is such a wealth of historical information about them.
They are also large, colourful and you can see them in the day time.
It’s very difficult to do at this scale for other organisms.”

Andean Condor (Vultur gryphus)

The study is the result of a new form of ecological funding – a Natural
Environment Research Council Consortium Grant. These grants encourage
large-scale work and this was the first to be awarded, shared between
Imperial College London, the Institute of Zoology, and the Universities
of Sheffield and Birmingham. The next stages of the consortium work,
following the mapping, are to develop ecological and evolutionary
explanations for the bird diversity.

Notes to Editors:

This research is published in Nature (18 August 2005).

Title: Global hotspots of species richness are not congruent with
endemism or threat

Authors: C. David L. Orme1, Richard G. Davies3, Malcolm Burgess1, Felix
Eigenbrod1, Nicola Pickup1, Valerie A. Olson4, Andrea J. Webster5,
Tzung-Su Ding6, Pamela C. Rasmussen7, Robert S. Ridgely8, Ali J.
Stattersfield9, Peter M. Bennett4, Tim M. Blackburn5, Kevin J. Gaston3
and Ian P. F. Owens1,2

1 Division of Biology

2 NERC Centre for Population Biology, Imperial College London, Silwood
Park, Ascot, Berkshire SL5 7PY, UK

3 Biodiversity and Macroecology Group, Department of Animal and Plant
Sciences, University of Sheffield, Sheffield S10 2TN, UK

4 Institute of Zoology, Zoological Society of London, Regent’s Park,
London NW1 4RY, UK

5 School of Biosciences, University of Birmingham, Edgbaston, Birmingham
B15 2TT, UK

6 School of Forestry and Resource Conservation, National Taiwan
University, 1, Sec 4, Roosevelt Road, Taipei 106, Taiwan

7 Michigan State University Museum and Department of Zoology, West
Circle
Drive, East Lansing, Michigan 48824-1045, USA

8 Academy of Natural Sciences, 1,900 Benjamin Franklin Parkway,
Philadelphia, Pennsylvania 19103, USA

9 BirdLife International, Wellbrook Court, Girton, Girton Road,
Cambridge, CB3 0NA, UK

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Original release