Botanists Release More Comprehensive Data Set of New World Plants

Botanists have compiled the most complete data set of rare plants in North and South America, revealing where unique species are found and what factors play into whether a plant species is common or rare in a region.

A research team from Aarhus Universty compiled the data, with bioscience professor Jens-Christian Svenning leading the group with support from doctoral candidate Naia Morueta-Holme.

The researchers are calling their work the most comprehensive botanical data set to date.The record already contains 20 million entries of approximately 250,000 species, with more to come.The project, which has been going on for more than five years, is called Botanical Information and Ecology Network (BIEN). The research published in the journal Ecology Letters is the first study to be published as a result of the project.

Morueta-Holme explained: "We've finally got a place where we can gather all the records and create an overview of where New World plant species are located. This unique data set provides us with an opportunity to fundamentally understand what determines the current diversity and distribution of plants. We're now better able to predict how species, vegetation and even agricultural crops will react to environmental change. This improves our chances of taking the necessary management measures to avoid negative consequences."

"The study shows that especially California, Mexico, the Caribbean islands, parts of the Andes, the south of South America, and the region around Rio de Janeiro are dominated by rare species. This came as a surprise to us, because the regions are very different in terms of climate and vegetation type. They include habitats such as wet tropical rainforests, dry subtropical regions, and even deserts, tropical mountains, and cool temperate grasslands and forests," Svenning said.

There does, however, seem to be consistent processes at play driving the plant distribution.

"There are two factors in particular that are important for the distribution of the rare species. Firstly, a stable climate with relatively small seasonal differences, where the climate has remained much the same for tens of thousands of years. Secondly, only small areas of habitat are involved. The species are unable to spread, but the stability nevertheless enables them to survive for long periods of time, and to develop and specialize in the same place," Morueta-Holme explained.

In North America, distinctly regional climates over the eras have played into plant distribution.

"Even though we're expecting less climate change in the areas dominated by rare species than in North America, for example, it could well be that future changes may be beyond what the species can tolerate. Our results show that climate change will no doubt have serious consequences for some of the most biodiverse areas in the world, which are also threatened by increasing land-use changes of natural areas," said Morueta-Holme.