Scientists have long puzzled over a seemingly straightforward question: How many species live on Earth?
And now, after nearly three centuries, they have come up with a seemingly straightforward answer: 8.7 million.
But experts say we have identified just a fraction – only 10 per cent – of these species, and that the vast majority are still waiting to be discovered.
Still, the number, according to a new study in PLoS Biology, a journal published by the Public Library of Science, is the most precise estimated total of species in the world. Until now, scientists pegged the figure at three to 100 million – a large range because there was no way to confirm the estimate.
Breaking down the number, 6.5 million species are on land, and 2.2 million are in the ocean. But of those species, 86 per cent of land-inhabitants and 91 per cent of ocean-dwellers have not yet been discovered, described or catalogued, the study reports.
Why it matters?
Lead author Camilo Mora says pinning down the number of species on Earth is a “massive discovery,” emphasizing its importance to animal conservation.
“We’re losing species,” he said, citing climate change, habitat loss and pollution as culprits. “We can only appreciate the magnitude of this loss when we have a reference on how many species are there.”
The discovery is also a boon to humans, as well. “The food we eat, the water we drink and the air we breathe – all these things [are] afforded to us by species,” Dr. Mora said. “Imagine the possibilities when you know that there are 90 per cent of the species out there that remain to be discovered!”
The estimated 600,000 species of fungi (there are currently 40,000 known species), such as moulds and mushrooms, are a particularly noteworthy finding because they are “very important” for humans, he added, citing fungi’s use for things like penicillin and yeast for bread.
How’d they do it?
“We have been working on this for 260 years since the first species was described,” Dr. Mora said, referencing Swedish scientist Carl Linnaeus, whose system for classifying organisms launched modern taxonomy in the mid-1700s.
“Unfortunately, the question proved to be so hard, that despite all of this time and all of this work, we haven’t been able to provide a number to that basic question of how many species are there. So now for the first time, we have a statistical method that gives a number to it.”
He and his colleagues at Dalhousie University refined the estimated total by “identifying numerical patterns” within the taxonomic system, which categorizes life forms in a pyramid-like hierarchy (ranked from the most-specific “species” level up to the most-general “domain” level ).
Researchers found that by using numbers from higher-ranked taxonomic groups, they could accurately predict the number of species.
The future of taxonomy
Dr. Mora has hopes that the new estimate will also bolster interest in the dying field of taxonomy. He recounts the story of an ecologist who suspected a fish he collected in Panama was a new species, but could not verify his hunch due to a lack of resources. It was only 30 years later that a geneticist conducted DNA analysis on the fish, confirming that it was indeed a new species.
“You cannot really have any understanding of the ecology – the role – that a species has [unless] you have a name to them,” Dr. Mora said, adding there is a risk that scientists may discover a species that is critical to a functioning ecosystem only after it disappears.
Based on current costs and requirements, classifying all remaining species using traditional methods would cost more than $364-billion (U.S.), with more than 300,000 taxonomists working for 1,200 years, the study suggests. But DNA analysis would reduce the time and money involved in identifying new species.
Countries in Europe and North America invest the most in taxonomy, but the majority of species do not live in these places. Most undiscovered life is below the ocean’s surface, in tropical forests or coral reefs.
“How can it be possible that we don’t know 90 per cent of the species on this planet?” Dr. Mora said. “Today, we have the technology to go out in space … yet we don’t have the technology to go down nine, 10 thousand metres down the ocean’s surface to find out what is really down there.”
He compares an undiscovered species to a missing engine part, which could cause the engine – the Earth’s ecosystem – to stop working. The number illuminates the “magnitude of our lack of understanding or lack of knowledge of planet earth,” a deficiency that taxonomy seeks to address, Dr. Mora said.
Among the list of thousands of new species found every year that challenge assumptions about Earth is halicephalobus mephisto, a worm-like species found more than three kilometres into the Earth’s crust, which the study says challenged the notion that this “harsh” environment is unique to single-cell organisms. There is also the kiwa hirsuta, a white, fuzzy crustacean-like decapod found 1,500 kilometres south of Easter Island at a depth of 2,200 metres; scientists said it formed a new biological family called kiwaidae.
Globe and Mail, Tuesday, Aug. 23, 2011
25 de agosto de 2011
22 de agosto de 2011
National Park Service and International Union for the Conservation of Nature Join Together to Support Parks and Protected Areas around the World
WASHINGTON – The National Park Service (NPS) and the International Union for the Conservation of Nature (IUCN) have joined together to support protected areas and national parks around the world. The first partnership action is sending David Reynolds, the NPS Northeast Region Chief of Natural Resources and Science on a 40-month project to help develop globally recognized professional standards for park rangers, managers and park system executives.
“David’s work will help build capacity for the IUCN Global Programme on Protected Areas,” said National Park Service Director Jonathan B. Jarvis. “He will rely on his 33 years with the National Park Service and connections within the international community to write standards so that park and protected area staff will be true and effective professionals with the capacity to do their jobs under often difficult circumstances.”
Over the next few years, the relevance of protected areas will be a significant subject of discussion through IUCN’s World Conservation Congress in 2012, the IUCN World Parks Congress in 2014 and ongoing discussions in the Convention on Biological Diversity. Reynolds will conduct his work from Medford, N.J., with occasional travel to parks and protected areas and training centers around the world.
“We are absolutely delighted with this support from one of our IUCN member organizations”, said Trevor Sandwith, Director of IUCN’s Global Programme on Protected Areas. "Capacity development is one of the key requirements for national governments to manage their protected area systems effectively. David will take responsibility for working across IUCN’s regions, themes and commissions to build competent protected area professionals and institutions. We hope this will lead to a globally recognized professional qualification in protected area management and ultimately to protected area systems themselves as being certified as being managed at the highest professional levels.”
The new post is a return to his earliest days in the international work, Reynolds said. “I worked in parks in West and Central Africa in the Peace Corps in the mid 1970’s, began my NPS career in the National Park Service’s International Affairs Office back in 1978 and have kept involved with international assignments over the years, so I’m in a familiar environment.”
Reynolds said, “I have to come up with tools to measure results. Many of these countries don’t have the financial resources of the United States and Canada; some don’t even have the computers most of us find as a basic tool in our jobs. So the trick to this project will be to develop something that is flexible enough to meet the needs of individual employees working in parks and protected areas in different countries and still set high professional standards so that training centers around the world can develop their own curricula.”
In addition to this pioneering work on capacity development for management effectiveness, IUCN’s Global Programme on Protected Areas is focusing on a core set of priorities that includes climate change, the role of equitable governance and benefit-sharing, sustainable finance and investment, and above all, communicating at global and local levels that protected areas really do work.
IUCN is the world’s oldest and largest global environmental network - a democratic membership union with more than 1,000 government and NGO member organizations, and almost 11,000 volunteer scientists in more than 160 countries. More information is available at http://www.iucn.org/
About the National Park Service. More than 20,000 National Park Service employees care for America's 394 national parks and work with communities across the nation to help preserve local history and create close-to-home recreational opportunities. Learn more at www.nps.gov.
Postado por Parques e Áreas Protegidas às 16:11