Study: World Still Has Many Unknown Trees
2022-02-07
LRC
TXT
大字
小字
滚动
全页
1From Peru to Australia, Madagascar to California, the world has many wonderful tree species.
2How many? A new study suggests there are about 73,000 kinds of trees, many of them still undiscovered.
3Such information reminds us of how much more we can learn about the Earth, experts say.
4Researchers recently revealed the world's largest forest database, one that is made up of more than 44 million trees at more than 100,000 locations in 90 countries.
5Researchers used the data to estimate that Earth has about 73,300 tree species.
6That number is about 14 percent higher than earlier estimates.
7Of that total, about 9,200 are estimated to exist based on mathematical predictions but have not yet been identified by science.
8Many of these trees grow in South America, the researchers said.
9South America, home to the Amazon rainforest and Andean forests, was found to have 43 percent of the planet's tree species and the largest number of rare species, at about 8,200.
10Roberto Cazzolla Gatti of the University of Bologna in Italy was the lead writer of the study that appeared recently in the publication Proceedings of the National Academy of Sciences.
11Trees and forests are much more than just oxygen producers, Gatti said, explaining that they play an important part in the health of the environment.
12He added, "Our society often considers forests as just pieces of wood and trees as natural resources... From trees and forests humanity gets inspiration, relaxation, spirituality and essentially the meaning of life."
13The research team estimated that South America has about 27,000 known tree species and 4,000 yet to be identified.
14The team also had estimates for other areas of the world.
15Europe and Asia have about 14,000 known species and 2,000 unknown species.
16Africa has 10,000 known species and 1,000 unknown; North America including Central America has 9,000 known and 2,000 unknown; while Oceania including Australia has 7,000 known and 2,000 unknown.
17Study co-writer Peter Reich of the University of Michigan and University of Minnesota said that by measuring the number of trees "our study can contribute to tree and forest conservation efforts."
18Conservation is a term that means the protection of plants, animals, and the natural environment.
19Reich believes that "tree species diversity is key to maintaining healthy, productive forests, and important to the global economy and to nature."
20He added that the information in the study "is important because tree species are going extinct due to deforestation and climate change, and understanding the value of that diversity requires us to know what is there in the first place before we lose it."
21This study did not estimate the total number of individual trees globally.
22But 2015 research led by one of the co-authors put that number at about 3 trillion.
23The new study identified global tree diversity hot spots in the tropics and subtropics in South America, Central America, Africa, Asia and Oceania.
24It also determined that about a third of known species can be classified as rare.
25The researchers used methods developed by mathematicians to estimate the number of unknown species by using the numbers of known species.
26Tropical and subtropical areas in South America may have 40 percent of these yet-to-be-identified species, they said.
27Jingjing Liang of Purdue University in Indiana was a co-writer of the study.
28"This study reminds us how little we know about our own planet ....there is so much more we need to learn about the Earth so that we can better protect it and conserve natural resources for future generations," Liang said.
29I'm John Russell.
1From Peru to Australia, Madagascar to California, the world has many wonderful tree species. How many? A new study suggests there are about 73,000 kinds of trees, many of them still undiscovered. Such information reminds us of how much more we can learn about the Earth, experts say. 2Largest forest database 3Researchers recently revealed the world's largest forest database, one that is made up of more than 44 million trees at more than 100,000 locations in 90 countries. 4Researchers used the data to estimate that Earth has about 73,300 tree species. 5That number is about 14 percent higher than earlier estimates. Of that total, about 9,200 are estimated to exist based on mathematical predictions but have not yet been identified by science. Many of these trees grow in South America, the researchers said. 6South America, home to the Amazon rainforest and Andean forests, was found to have 43 percent of the planet's tree species and the largest number of rare species, at about 8,200. 7Roberto Cazzolla Gatti of the University of Bologna in Italy was the lead writer of the study that appeared recently in the publication Proceedings of the National Academy of Sciences. 8Trees and forests are much more than just oxygen producers, Gatti said, explaining that they play an important part in the health of the environment. 9He added, "Our society often considers forests as just pieces of wood and trees as natural resources... From trees and forests humanity gets inspiration, relaxation, spirituality and essentially the meaning of life." 10The research team estimated that South America has about 27,000 known tree species and 4,000 yet to be identified. 11The team also had estimates for other areas of the world. 12Europe and Asia have about 14,000 known species and 2,000 unknown species. 13Africa has 10,000 known species and 1,000 unknown; North America including Central America has 9,000 known and 2,000 unknown; while Oceania including Australia has 7,000 known and 2,000 unknown. 14Importance of the study 15Study co-writer Peter Reich of the University of Michigan and University of Minnesota said that by measuring the number of trees "our study can contribute to tree and forest conservation efforts." 16Conservation is a term that means the protection of plants, animals, and the natural environment. 17Reich believes that "tree species diversity is key to maintaining healthy, productive forests, and important to the global economy and to nature." 18He added that the information in the study "is important because tree species are going extinct due to deforestation and climate change, and understanding the value of that diversity requires us to know what is there in the first place before we lose it." 19This study did not estimate the total number of individual trees globally. But 2015 research led by one of the co-authors put that number at about 3 trillion. 20The new study identified global tree diversity hot spots in the tropics and subtropics in South America, Central America, Africa, Asia and Oceania. It also determined that about a third of known species can be classified as rare. 21The researchers used methods developed by mathematicians to estimate the number of unknown species by using the numbers of known species. Tropical and subtropical areas in South America may have 40 percent of these yet-to-be-identified species, they said. 22Jingjing Liang of Purdue University in Indiana was a co-writer of the study. 23"This study reminds us how little we know about our own planet ....there is so much more we need to learn about the Earth so that we can better protect it and conserve natural resources for future generations," Liang said. 24I'm John Russell. 25Will Dunham reported on this story for Reuters. John Russell adapted it for Learning English. 26____________________________________________________________ 27Words in This Story 28species - n. biology : a group of animals or plants that are similar and can produce young animals or plants : a group of related animals or plants that is smaller than a genus 29inspiration-n. something that makes someone want to do something or that gives someone an idea about what to do or create : a force or influence that inspires someone 30relaxation - n. a way to rest and enjoy yourself 31deforestation -- n. the act or result of cutting down or burning all the trees in an area