SYDNEY, Feb. 1 (Xinhua) -- An international team of conservation scientists, including researchers from Australia, believe they have finally unearthed the answer as to how many tree species there are in the world.
Details of their tally of about 73,000 species, published in the U.S. science journal PNAS and released to the public on Tuesday, reflect the efforts of almost 150 scientists.
Associate Professor Andy Marshall of the University of the Sunshine Coast (USC) said the "hugely exciting" global dataset of trees was a "significant piece of the puzzle in ecology and biodiversity."
"The better the information, the better we can inform national and international plans for conservation priorities and biodiversity targets and management," said Marshall, who is using the data to research cost-benefit analysis for governments to set priorities on native forest restoration.
"This publication also recognizes that identifying trees in the middle of nowhere can be really hard work, starting with collecting materials such as flowers that may only bloom briefly and seasonally, then following individual identification processes that can take years," he said.
Marshall speaks from hard-won experience, having started his research in 1998 by trekking through Tanzania in East Africa, then he went to Australia before spending five years analyzing his wealth of data.
Along the way, he made several discoveries including two new African tree species from the custard apple family.
"One of them, the Mischogyne iddi, is a flowering tree that grows up to 20 meters tall up in the mountains," Marshall said, adding that they named it after a Tanzanian botanist, who was delighted by the honor.
Overall, the international team has discovered about 9,000 unclassified species, which now await their own names and scientific descriptions.
Almost 6,700 known tree species and 1,500 previously undiscovered species were estimated to be in the Oceania region, with researchers saying the tropical and subtropical forests of northeast Australia and the Pacific islands were a "hot spot" for such discoveries.
Project leader, Roberto Cazzolla Gatti of Purdue University, said the findings highlighted the "vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and global tree richness".
Marshall, meanwhile, is continuing his research with USC doctoral students in Australia and Tanzania, as well as his charity, Reforest Africa.
He said they would be working on setting up new vegetation plots from Cape York in Australia's northernmost, and down the coast of Queensland, adding to research plots already established on the Cassowary Coast and the Atherton Tablelands. ■
