New Maps of Plant Diversity

New Maps of Plant Diversity



March 2007 - A new global set 
of maps of plant diversity offers clues to the likely impact 
of climate change on the services plants provide to humans. 
With several hundred thousand plant species plotted, the 
scientists who created the maps say they are the most 
extensive to date. 
Dr. Walter Jetz of the University of California-San Diego and 
Holger Kreft of the University of Bonn sought in their mapping 
study to determine how well the diversity, or the "richness," 
of plant species could be predicted from environmental 
conditions alone. 
The maps depict the species richness patterns of plants in 
1,032 geographic regions worldwide. 
"Climate change may drive to extinction plants that hold 
important cures before we find them," says Kreft, a biologist 
at the Nees Institute for Biodiversity of Plants at the 
University of Bonn. 
Maps of plant richness produced by Walter Jetz and Holger 
Kreft. The kriging noted on the maps is a geostatistical 
approach to modeling. 
"Ecological research like ours that captures complex diversity 
- environment relationships on a global scale may assist in a 
small, but important way so that such a fatal potential 
failure can be averted," said Kreft. 
"Given that we are far off from knowing the individual 
distributions of the world's 300,000 odd plant species," says 
Jetz. "Holger Kreft and I investigated how well the richness 
of plants can be predicted from environmental conditions 
alone." 
The maps, which accompany the study, "Global patterns and 
determinants of vascular plant diversity" published in this 
week's early online issue of the journal "Proceedings of the 
National Academy of Sciences," highlight areas where 
conservation efforts are especially important. 
Kreft said, "The global map of estimated plant species 
richness highlights areas of particular concern for 
conservation and provides much needed assistance in gauging 
the likely impact of climate change on the services plants 
provide to humans." 
Dr. Walter Jetz earned his PhD in zoology from Oxford 
University. 
Combining field-survey based species counts from over a 
thousand regions worldwide with high-resolution environmental 
data, the scientists were able to capture the factors that 
promote high species richness of plants. 
"This allowed us to estimate the richness of yet unsurveyed 
parts of the world," says Jetz, an assistant professor of 
biology at UCSD and the senior author of the paper. 
The scientists expect the maps to help pinpoint areas that 
deserve further attention for the discovery of plants or drugs 
that are as yet unknown to humanity. 
"Plants provide important services to humans - such as 
ornaments, structure, food and bio-molecules that can be used 
for the development of drugs or alternative fuels - that 
increase in value with their richness," says Jetz. 
Common across temperate latitudes, feverfew, Tanacetum 
parthenium, was known to medieval herbalists as a remedy for 
headache and fever. How many plants still unidentified could 
cure stubborn diseases? 
"Tropical countries such as Ecuador or Colombia harbor by a 
factor 10 to 100 higher plant species richness than most parts 
of the United States or Europe. The question is, Why?" 
An enthusiastic field ornithologist, Jetz has also 
participated in similar studies of the richness of bird 
distribution, and also that of terrestrial mammals and 
amphibians. 
"I am interested in the way environment, evolutionary history 
and chance affect ecological patterns at the level of the 
individual, population and community," he said, "and how these 
then combine to form patterns at the scale of continents or 
the whole globe." 





 

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