Environment
July 04, 2012 |
Looking for Solutions in the Fight to Preserve Biodiversity
By Roger Cohn
At the Rio+20 conference this week, conservation biologist Thomas Lovejoy received the prestigious Blue Planet Prize. Before traveling to Brazil, Lovejoy talked with Yale Environment 360 about the loss of biodiversity and about whether it is too late for the world to do something about it.
For decades, conservation biologist Thomas Lovejoy has repeatedly warned — sometimes in dire terms — about the loss of biodiversity. But Lovejoy, who this week was awarded the prestigious Blue Planet Prize, remains an optimist.
“There is no point in being unduly pessimistic, because that just guarantees all the bad things will happen,” says Lovejoy, who received the international environmental prize at the Rio+20 summit. Currently a professor at George Mason University, Lovejoy has worked since 1965 in the Brazilian Amazon, where he has helped lead one of the world’s largest and longest-running field experiments, studying the impacts of habitat fragmentation. Credited with introducing the term “biological diversity” to the scientific community, Lovejoy has spent his career promoting it, with stints at the Smithsonian Institution and the World Wildlife Fund.
Before heading to Brazil for Rio+20, Lovejoy sat down with Yale Environment 360 editor Roger Cohn and talked about the multi-pronged threats to biodiversity, from habitat loss to climate change; the potential impact of major dam projects and other planned development on the Amazon; and why he supports market-based conservation schemes that provide benefits to local residents.
On the need for a global effort to promote biodiversity, Lovejoy says, “I go to sleep at night almost praying that there will be a bolt of awareness, and then we can move forward.”
Yale Environment 360: It has been 20 years since the first Rio summit, and now you’re heading back for another international environmental conference, Rio+20. How do you feel about the progress, or lack of progress, on the issue of biodiversity loss in the last 20 years?
Thomas Lovejoy: Anybody who just looks at the facts will know that basically the entire global effort combined has failed to reach the scale it should have. There were some initial goals set out at Rio+10 and at the last meeting of the Convention on Biological Diversity in Japan [in 2010]. But not a single nation has met their goal, and global extinction rates are probably a thousand times the norm. And we are beginning to see some really major things, like what climate change is doing to coral reefs...
Hopefully, the countries can really make a much bigger effort coming along. But it is not pretty.
e360: The U.S. was one of the few developed countries to not ratify that [1992 Rio] convention on biodiversity, right?
Lovejoy: This is correct. The United States signed, but did not ratify. And there were some strange politics that went on influencing the Senate in the first two years of the Clinton administration, which by the time it was sorted out, the control of the Congress had changed, and the U.S. has never found a way to go back to looking at formally ratifying. However, it does have to be said that U.S. policy is to behave as if the country had ratified [the convention]. So we are not a totally bad actor.
e360: But why isn’t the issue of biodiversity more front and center when it comes to talking about environmental issues in this country? It doesn’t seem to be. Do you agree that’s true?
Lovejoy: I think it is true. I think actually most environmental awareness has subsided in this country. And biodiversity is mostly seen as an endangered species issue, even though that is really just the tip of the iceberg, or the eco-iceberg [laughs]. And I think it also relates to a complacence in this country about the state of the environment and the de-validation of science as being important in the public debate and discourse. And so things like biodiversity just get shunted to the sidelines.
e360: You are actually credited with coining the word “biodiversity,” and now we find there are numerous threats to biodiversity from climate change to deforestation to habitat loss and more. What do you see, currently, as the greatest threat to biodiversity — if you had to pick one issue, one concern?
Lovejoy: That is a very hard question to answer because I don’t think we have great metrics on all of these things. Globally, habitat destruction is probably still number one. Invasive species is edging it out. Unknown is the impact of the tens of thousands of man-made chemicals that basically have created this chemical soup we are all living in whether we are a whale or a human being.
And climate change is coming up fast on the outside, as it were. I was out in Yosemite for Earth Day and it no longer snows down to 3,000 feet above sea level — it only goes to 4,500 — and the Ponderosa pine, which depends on that winter snow, is dying out in that belt. So the fingerprints of climate change can be seen biologically essentially all over the planet — and it is just the beginning.
e360: There are protected areas that were set aside for certain species, plant or animal, and now as the climate changes, in many cases recent research is showing that these places are no longer hospitable habitat for the species they were set aside for. Do you see this as a real, growing problem, and if so, how do we address it?
Lovejoy: Well, certainly we are going to have to think about protected areas differently. It doesn’t mean they don’t have value, but basically nature is on the move wherever we look. You know, the Joshua trees are moving outside of Joshua Tree National Park because of climate change — they are just tracking their conditions. And that is just the beginning.
So we are going to have to think very differently about protected areas in the biologically dynamic landscape. We need to think about how to put natural connections back in the landscape and move more toward a matrix in which human aspiration is pursued within a natural matrix, as opposed to the other way around, and thereby make it easier for plants and animals and microorganisms to actually adjust to the changing natural conditions. Hopefully, most of them can make it through.
e360: The bulk of your work, back to your doctorate days, has been in the Amazon. I believe you have a long-running project down there on fragmented forests in the Amazon. Can you explain what the goal of that project was and is, and what you have learned from it?
Lovejoy: The initial purpose of this project was to generate data to answer and resolve a huge controversy in the ecological literature of the ‘70s, which was: What was better, a single large reserve, or several small reserves adding up to the same total area? I was asked, with Brazilian colleagues, to set up this giant experiment, I think it is the largest in landscape ecology, looking at habitat fragmentation. And now we are in year 33, and in 2003 we published the paper that makes it very clear that large is the answer. But we have learned a whole lot of other things in the process, including important things about secondary succession, which can play into the plants that are reforesting the Amazon and things of that sort.
e360: There now are a series of major dam projects either underway or planned in the Amazon, along with other major development. Are you concerned about the impacts of these projects, both individually and cumulatively?
Lovejoy: The plans for hydroelectric in the Amazon are both impressive and frightening. And it is not just within the Brazilian Amazon — the Brazilian energy authority has made these plans to build dams in other countries, like Peru, and then transmit the energy back to Brazil. And all of those kinds of plans are being developed independently of the plans looking at roads and other infrastructure, which is planned independently of agricultural policy, which is planned independently of conservation policy.
What really needs to be done is to develop an integrated plan to manage the entire Amazon as a system. If you don’t do that, it will eventually undercut its hydrological cycle, which is what keeps the Amazon in rainforest but also provides rainfall south of Brazil for agroindustry. So it is actually hugely important in the continental climate system.
e360: I’ve read articles that you’ve written in the past that have proposed looking at market-based conservation schemes, and one of the ones that has been most talked about and tried to move along in the last decade has been REDD [Reducing Emissions from Deforestation and Forest Degradation], and yet it has had its problems and has not really gotten as far along as people hoped it would at this point. What do you see as the advantages and values of a market-based approach to conservation versus a government or NGO-based approach to conservation? And, in the case of REDD, why do you think it has been so long and such a hard road to really get it moving?
Lovejoy: The advantage to having some globally-blessed market scheme like REDD, is that it can operate at a global scale. It will also provide some return, some recognition of the value of what forests are contributing to how the world works and bring, if it is done right, some income to the landholders. It actually advanced quite well in climate change talks, but failing an overall agreement about climate, it is just sitting there waiting to get started. Some nations want to resist it — they see it as an invasion of sovereignty. But you don’t have to do anything unless you want to, so there is much less reason for concern there. And what is particularly interesting is if you talk to the governors of a lot of these states in the Amazon and even some in Indonesia, they are quite interested in moving that forward.
e360: Why? What benefits beyond conservation do they see for their regions?
Lovejoy: Enough of the Amazon governors recognized the importance of the forest to the future of their states. They saw that if you could find a way to reward people who were living in the Amazon for pursuing their aspirations in ways that did not destroy the forest that you could actually move toward this whole idea of managing the Amazon as a system.
e360: And the Brazilian government supported that going into [the 2009 international climate talks in] Copenhagen?
Lovejoy: The Brazilian government supported the Amazon governors. Almost all the Amazon governors went there and had a memorable afternoon event, in which even some of the less environmentally oriented ones spoke in favor of this.
e360: Were you surprised by the lack of action on REDD at Copenhagen and do you see the chance of anything like that really emerging now?
Lovejoy: At the moment, the conventional wisdom about the UN Conference of the Parties on climate change is that getting something going globally is unlikely in the near future because of the absence of the United States playing an important role in the entire process, and that we will probably have to, in the interim, try and build a mosaic which can approximate but not achieve what a global agreement would.
e360: And do you see the U.S. position ever changing?
Lovejoy: Well, I see the U.S. position as possibly changing. But it will require much better public awareness and concern to create the political space to make it happen.
e360: If you had five minutes with Barack Obama to talk to him about an environmental issue, what would you say to him?
Lovejoy: I would make the point, one, that the planet works as a linked biological and physical system. Second, that two degrees of global warming is too much for ecosystems. Three, that planetary-scale restoration of ecosystems could actually pull a significant amount of CO2 out of the atmosphere. And four, that if we fail to do those kinds of things, it will just create environmental havoc for the U.S. as well as the rest of the world.
e360: Have you had those five minutes?
Lovejoy: I have not, as yet, had those five minutes.
e360: You have had some pretty, I don’t want to say dire, but uncomfortable, predictions over the years about biodiversity loss and, regrettably, I think many — if not most of them — have come true. Are you at all optimistic that we can stem the tide of biodiversity loss in a meaningful way, or can we just do the best we can against the tide?
Lovejoy: There are two ways I look at that. One is, that the fuse is very, very short, that we could see just a lot of environmental havoc and a growing inability of society to cope with it as the various problems erupt. On the other hand, I could also see a moment of awareness where globally countries will recognize that this is in fact the greatest challenge to society in its entire history and that we have a choice before us of entering into what, in a sense, could be the real dark ages. Or we could get our act together and rise to really deal with the problem... I go to sleep at night almost praying that there will suddenly be a bolt of awareness and then we can move forward.
e360: But when you wake up in the morning?
Lovejoy: When I wake up in the morning, you know, you have just got to try and make it all happen. There is no point in being unduly pessimistic, because that just guarantees all the bad things will happen.
Photo by Fernando Silva/flickr/Creative Commons
Reprinted with permission from Yale Environment 360
Ban on Fish Discards Is Approved by the European Union
The European Union has decided to end the controversial practice of allowing fishermen to select high-value species from their nets and then discard the remainder of dead fish, a practice that leads to the destruction of an estimated 1 million tons of edible fish a year in EU waters. The EU Council announced its intention to implement a discard ban, but did not set a firm date, saying discard bans for some species could be phased in as late as 2020. Although some environmental groups praised the ban, others said that allowing the practice of fish discards to continue for another eight years could be too late to save some severely overfished species, such as plaice and sole. EU officials hailed the long-sought ban, with the president of Denmark calling it “a very important step in the direction of a radical new fisheries policy — a sustainable fisheries policy.” Conservationists say the policy of allowing fishermen to meet their quotas by selecting only certain species and tossing away the rest is one of the main reasons for the precipitous decline in European fish stocks.
Photo by Tim Pearce/flickr/Creative Commons
Reprinted with permission from Yale Environment 360
Marine Reserves Replenish Commercial Fisheries, DNA Tests Show
DNA testing has shown that the creation of marine reserves where no fishing is allowed helps to replenish fish stocks outside the reserve boundaries. In a study conducted at Australia’s Great Barrier Reef, researchers collected tissue samples from two species of commercially popular fish — including 466 samples of adult coral trout and 1,154 samples from stripey snapper — located within three reserve areas. After collecting juveniles of both species in protected and unprotected areas over the next 15 months, the researchers found that about half of the juveniles were offspring of fish found in the reserve areas, even though the reserves accounted for just 28 percent of the study area. In other words, fish found in the reserves “punch above their weight in replenishing fishery stocks,” said Garry Russ, a researcher from James Cook University and one of the authors of the study, published online in the journal Current Biology.
Photo by 88rabbit/flickr/Creative Commons
Reprinted with permission from Yale Environment 360
The Clean Water Act at 40: There’s Still Much Left to Do
By Paul Greenberg
The Clean Water Act of 1972, one of the boldest environmental laws ever enacted, turns 40 this year, with an impressive record of cleaning up America's waterways. But from New York Harbor to Alaska’s Bristol Bay, key challenges remain.
When you turn 40, three questions inevitably arise:
- Who am I?
- What have I done?
- What else can I do?
Forty years ago, the U.S. Congress, in an uncharacteristically uncowardly move, overwhelmingly overrode President Nixon’s veto and passed the most powerful law for the protection of water in American (and perhaps world) history. Yes, this year the Clean Water Act officially enters its midlife crisis years.
Since it is a law, and not a person, we won’t expect it to buy a red sports car and hook up with another law half its age. But having aged and weathered and yet oftentimes stood firm against its adversaries even if its knees became not quite what they used to be, it is worth asking this much buffeted piece of legislation in its 40th year, the three essential questions of mid-life.
So, to begin with, Clean Water Act, who are you?
The Federal Water Pollution Control Act of 1972, known as The Clean Water Act was not the first piece of federal legislation to protect water. But it was the first time that real power was invested with the federal government to make sure that water got clean and stayed clean. Its essential demand, that all waterways in the United States be “fishable and swimmable” by 1985 was remarkable in its forthrightness. It invested the Environmental Protection Agency with the power to prosecute “point source polluters,” i.e. commercial enterprises directly responsible for fouling the water. No longer was the onus on citizens to prove the value of clean water. Rather the burden was switched to industry. Industry had to prove that its actions did not impinge upon what became codified as an American right to fish and swim, safely, in public waterways.
Next, Clean Water Act, what have you done?
Are all public American waterways fishable and swimmable as they were mandated to be by 1985? They most assuredly are not. But the most egregious aspects of the abuse of water have stopped. Cleveland’s Cuyahoga River no longer catches fire, as it did regularly, throughout the 1950s and 60s. A corporation can no longer spill oil into the sea and expect to escape without a fine. Indeed, the billions of dollars British Petroleum will undoubtedly have to pay in the coming years as a result of the 2010 Gulf Spill are made possible by the instruments of the Clean Water Act.
And these gains extend from the broadly national to the intimately local. Because of the Clean Water Act, New York City now has more than a half-dozen public swimming events in New York Harbor, including a 28.5-mile loop of Manhattan that will take place this June. Because of the Clean Water Act, oysters placed on six test reefs in an experiment coordinated by the Hudson River Foundation in 2010 found enough dissolved oxygen to survive, raising the possibility that oysters could once again become an integral part of the Hudson River estuary. But there is still a lot of work to be done.
Which leads us to, Clean Water Act, what else can you do?
It is a remarkable achievement that point-source polluters can now be monitored and often controlled. But there still remain two vital areas of clean water protection that have yet to be brought in line. The first is the control of “nonpoint source” polluters — the diffuse negative impacts of humanity in general. While it is fairly straightforward to identify a pesticide manufacturer that is dumping its effluent into a waterway and sue it because of that violation, it is considerably more difficult to mitigate the effects of private citizens whose brazen acts of clean water abuse often consist simply of flushing their own toilets. Because of outdated and overloaded wastewater treatment plants, for example, raw sewage still pours into New York Harbor through “combined sewage overflows” whenever it rains more than a tenth of an inch. We need to figure this piece of the puzzle out, not only through large-scale modernization and expansion of sewer systems but also by establishing tax incentives for the implementation of innovative storm water sequestering technologies like green roofs.
The other trick the old dog might pull off in its middle years is to let its bite finally exceed its bark on a critical area of its jurisdiction. Section 404c of the Act allows the EPA to protect waterways that support shellfish beds, fish spawning grounds, wildlife zones, and recreational areas. As I write these words, proponents for the development of the gargantuan "Pebble Mine" copper and gold prospect in Alaska’s Bristol Bay are already denouncing a recently completed EPA “watershed assessment” of the region even before the public has gotten a chance to look at it. This assessment will almost certainly provide the scientific justification for a 404c action that will protect Bristol Bay — home to the largest concentration of wild salmon left on earth. EPA could effectively protect the area — and its half-billion dollar a year fishing industry — as a vast, commercially productive wild salmon reserve. The Clean Water Act might just have the teeth to do that; but this old guard dog must be loosed for the attack for the law to become all that it was meant to be.
A bold promise. A lot, but not enough, accomplished. Many interesting and important things still left to do. If I were turning 40 this year, I would find that summing up of my life-to-date cause for pride, anxiety and hope. Such a summing up might even make me feel a little bit young. There are many out there for whom 40 is just the start of the most meaningful part of their lives. As they say nowadays, 40 is the new 30.
Reprinted with permission from Yale Environment 360
Africa’s Ambitious Experiment to Preserve Threatened Wildlife
By Caroline Fraser
Five nations in southern Africa are joining together to create a huge conservation area that will extend across their borders and expand critical territory for elephants. But can these new protections reverse decades of decline for area wildlife while also benefiting the people who live there?
“They’re Angolan refugees returning home,” biologist Mike Chase tells reporters. He’s not talking about people. He’s talking about elephants, moving out of his native Botswana, step by ponderous step. On their backs are riding the hopes of one of the most ambitious ecological experiments on the planet, the Kavango Zambezi Transfrontier Conservation Area, or KAZA.
The largest such project in the world, at more than 170,000 square miles, KAZA is the size of Sweden and involves five countries — Angola, Botswana, Namibia, Zambia, and Zimbabwe — boasting the biggest population of elephants on earth, a quarter of a million.
During Angola’s prolonged civil war, an estimated 100,000 elephants were slaughtered, their ivory sold to buy arms. In 2001, a year before the war ended, fewer than 40 were left in the country’s Luiana reserve. Six years later, after Namibia and Botswana agreed to open a strategic 22-mile gap in a maze of border and veterinary fencing (keeping wild buffalo or infected cattle from contaminating Botswana’s herds), Chase counted 8,000. Bull elephants had scouted Angola’s thinly-populated southern reserves, found conditions to their liking, and returned to northern Botswana to lead herds home to Angola. Once there, they skirted landmines, having perhaps learned through bitter experience how to sniff them out. Their message was clear: Give us a way back, and we will come.
Launched in March after a treaty signing last August, with $26 million pledged by Germany’s development bank, KAZA requires five sovereign nations to tiptoe through similarly explosive territory, setting aside old grievances and compelling national interests. If they succeed, KAZA may help lift people out of poverty and protect one of the last functional large-scale ecosystems left on the continent: the Okavango Delta, a massive wetland that waxes and wanes annually as rivers pour off the Angolan highlands, fanning out into the baking Kalahari and drawing some of the region’s most threatened wildlife — black rhino, African wild dog, and hundreds of species of birds.
In just one of KAZA’s parks, Zambia’s Kafue, tourism could grow from less than $5 million annually to almost $50 million in little more than a decade, according to a consultant’s report. That could be multiplied across the conservation area, which contains more than 40 protected areas: national parks, forest and game reserves, and community conservancies.
But the project faces daunting obstacles: insufficient funding, conflict between people and wildlife, fear of disease outbreaks among cattle, and a recently reported steep decline in wildlife numbers. Critics are also concerned that the project may end up enriching foreign tourism companies rather than local communities.
Westerners think of parks as pristine, but as one expert puts it, “Wilderness areas with no human impacts do not exist in Africa.” Only well-established national parks, such as Bostwana’s Chobe, have no human inhabitants; fewer still thrive on the traditional model of armed guards and fences. KAZA — not a park but a “transfrontier conservation area”— has a human population perhaps as high as 2.5 million. Over half its land is communally managed, used for subsistence farming or grazing. While the idea of linking parks across borders has been around since 1932, recent developments in southern Africa have created urgency around transfrontier plans, particularly bottlenecks wrought by fencing (required by the EU’s subsidized beef export market), which effectively trapped tens of thousands of elephants in northern Botswana.
“An Africa without fences” is the vision of the Peace Parks Foundation. Founded in 1997, it has enrolled every country in southern Africa in the effort, raising millions from donor countries, encouraging private investment, and supporting colleges to train wildlife rangers and tourism staff. Progress has not been without pitfalls: The group was vilified for its high-handed, top-down approach as it expanded South Africa’s Kruger National Park into Mozambique. While peace parks are dismissed by one Cape Town academic as another “grandiose scheme... foisted upon Africa,” there are now 10 in the region, with four more in the planning stage, ranging north to Tanzania.
An idea kicking around international circles since the early 1990s, KAZA was self-consciously designed to be a grassroots affair. Early supporters — including Conservation International, the WWF, and the Wildlife Conservation Society — looked to Namibia’s home-grown and highly successful conservancy movement, which had presided over a resurgence in the country’s wildlife, decimated during the long struggle against occupation. At independence, in 1990, Namibians wrote conservation into their constitution, and the fledgling republic soon backed community-based conservation groups — called conservancies — to create jobs.
At the news that a single elephant hunt might be worth $10,000, “word went through communities almost overnight,” says Chris Weaver, director of WWF in Namibia. “Poaching stopped very, very quickly.” Communities eagerly registered to guard, monitor, and manage their wildlife and have reaped benefits from ecotourism, controlled hunting, and sustainable harvesting of wild plants. Popular and effective, 71 conservancies have been registered so far, creating 1,700 full time and 8,000 seasonal jobs and earning roughly $6 million in 2010, with communities investing the money in health clinics and schools. As conservancies build corridors across the country, Namibia has protected almost 40 percent of its land and earned a reputation as a spectacular place to see rhino, cheetah, desert lions, and other wildlife.
KAZA hopes to capitalize on that model, using conservancies to reestablish wildlife corridors between existing parks and reserves. Of the five KAZA partners, only Angola, one of the poorest countries in the world, has no community-based program. Zimbabwe, grandfather of such management schemes in the 1980s, is also lagging in the final years of Robert Mugabe’s rule, blocked from receiving foreign funding. Botswana presents a mixed picture. Known for high-end ecotourism in the Okavango, it launched a network of trusts in 1993, eventually involving some 10 percent of the population, but its heavily-bureaucratized system has been less successful than Namibia’s.
More densely populated Zambia (with 14 million people, compared to Botswana and Namibia, with two million each) last year launched its first community conservancy, Simalaha, on its southern border with Namibia, right in the heart of KAZA. Funded by $2.8 million from the Swedish Postcode Lottery, Simalaha is designed to link Botswana’s Chobe and Zambia’s Kafue across a critical floodplain, providing safe passage for elephants between the two parks. Namibia and Zambia are already running joint anti-poaching patrols in the area.
Announcing plans to initiate a temporary sanctuary for wildlife, senior chief Inyambo Yeta, a traditional leader who sits on the board of the Peace Parks Foundation, spoke wistfully of the lost richness of local forests. “We want Simalaha to teem with wildlife once again,” he said.
KAZA program manager Victor Siamudaala has praised the “overwhelming” support from communities and governments. But, as Weaver emphasized, future success may be KAZA’s worst enemy, judging by the experiences of the conservancies. Escalating human-elephant conflict has become so prevalent it has acquired its own acronym: “HEC.” In 2010, wild elephants rampaged through a southern Angolan settlement, trampling houses and farms and sending some 4,000 people over the border into Namibia, which had 11 people killed by elephants that same year. Throughout KAZA, farmers are learning to exploit every imaginable elephant deterrent, from vuvuzelas (plastic horns) to chile bombs, a mixture of dried elephant dung and peppers that is burned to create a stinging, smoke haze. Namibia has initiated payments for crop damage and funeral costs, while emphasizing that conflict cannot always be avoided.
Serious questions about KAZA’s viability remain. Mike Chase, an elephant ecologist who founded Elephants Without Borders in 2004, has documented the species’ return to Angola and radio-collared a number of pachyderms, mapping elephant corridors throughout the region, as well as barriers — fences, roads, crops, settlements — that block them. His recent aerial survey showing that elephants have stabilized at around 128,000 in northern Botswana is considered the most accurate to date.
Chase was recently employed by the Botswana government to fly additional surveys over the country’s vast northern stretches, once a wildlife stronghold, to census other large mammals. “We were completely blown out of the water,” he says of tallying steep declines in wildlife outside of Chobe National Park. Results showed a 90-percent reduction in wildebeest — from more than 23,000 in 1999 to fewer than 2,000 in 2010 — and similar declines in warthog, zebra, kudu, lechwe, tsessebe, sable, and roan. Chase attributes the losses not only to a 20-year drought but also to increased human use, fencing, and grazing of cattle, used in Botswana to calculate “lobola,” or bride price. In Chobe itself, however, many species are increasing.
Chase is still optimistic about KAZA, pointing out that “ten years ago, you couldn’t get the governments to sit around a table together.” David Cumming, a transfrontier expert in Harare, Zimbabwe, is less sure. His 2011 review of “constraints” faced by peace parks is sobering, noting that KAZA’s planning documents focus heavily on development and fail to set clear objectives regarding conservation. Financing is inadequate, with even established national parks “grossly underfunded.”
He asks a critical question: Can the creation of larger landscapes devoted simultaneously to development and conservation — not strictly protected as parks — reverse wildlife declines while benefiting communities? Unless people get “real benefits,” Cumming told me, “connectivity is probably not going to be maintained.”
It remains to be seen whether conservation corridors roughed out on maps will materialize. Elephants cannot wait forever, fenced in by wire, crops, and settlements. Nor can local people, who are, as Cumming dryly calls them, “the de facto resource managers.”
Correction. May 16, 2012: The original version of this story incorrectly stated that Namibia’s 71 conservancies earned $700,000 last year. The article should have stated that Namibian conservancies earned roughly $6 million in 2010.
Reprinted with permission from Yale Environment 360
Model Shows Debris Field In Pacific From Japanese Tsunami
A new animation developed by researchers at the University of Hawaii’s International Pacific Research Center (IPRC) illustrates the likely path of the spreading field of debris caused by retreating waves from last year’s gigantic tsunami in Japan. The model — based on satellite data and a network of scientific buoys showing sea surface height, ocean surface winds, and ocean currents — shows that debris swept into the Pacific by the event now likely stretches across an area covering 5,000 kilometers by 2,000 kilometers. Much of the debris was initially pulled by the strong Kuroshio Current, which travels in a northeasterly direction past eastern Japan before shifting east in the Kuroshio Extension and then into the North Pacific Current. The Japanese government has estimated that about 5 million tons of debris was pulled into the ocean; about 70 percent sank to the seafloor, with about 1.5 million tons still floating. Some of that debris is expected to reach North America within the next two years. A separate computer animation depicting the Earth’s ocean patterns over a two-year period has been unveiled by NASA.
Watch the video
Photo by Official U.S. Navy Imagery/flickr/Creative Commons
Reprinted with permission from Yale Environment 360
In Fight to Save Coral Reefs, Finding Strategies that Work
In four decades as a marine biologist, Nancy Knowlton has played a key role in documenting the biodiversity of coral reefs and the threats they increasingly face. In an interview with Yale Environment 360, she assesses the state of the world’s corals and highlights conservation projects that offer hope of saving these irreplaceable ecosystems.
When marine biologist Nancy Knowlton began studying coral reefs in the early 1970s, the world’s scientists had little understanding of just how diverse and complex these ecosystems were — and the key role they played in the health of the planet’s oceans. Nor did they fully grasp the scale of the threats that would bear down on coral reefs in the coming decades.
Today, however, thanks to the work of Knowlton and other marine biologists, science understands not only how varied and numerous coral species are, but also how extraordinarily diverse life is in the world’s oceans: At least 2 million species are estimated to exist in the marine world, and the figure could be far higher. Knowlton, a scientist at the Smithsonian Institution, has simultaneously been elated by the rapid pace of discoveries, while also growing increasingly alarmed by the perils facing coral reefs, including overfishing, disease, and climate change.
These days, Knowlton is focusing on solutions and has launched a series of events called “Beyond the Obituaries: Success Stories in Ocean Conservation,” inspired, in part, by the desire to reassure young scientists that there is still time to save the world’s corals and to safeguard marine biodiversity. In an interview with Yale Environment 360 Web editor Kevin Dennehy, Knowlton highlights projects that are stemming coral losses, including a comprehensive conservation program on the Great Barrier Reef and smaller-scale efforts in places like Mexico. “I felt it was really important to give people a reason to think that there is something you can do,” says Knowlton. “We all need more than doom and gloom.”
Yale Environment 360: An important element of your research has been determining just how biodiverse the world’s coral systems are. How much more do we know today about this biodiversity than we knew when you began your career?
Nancy Knowlton: We know a lot more, but there are still a lot of unknowns out there. When I started my career people assumed that even if marine organisms came from very different places but looked reasonably similar, they were all one species. And that’s a problem I worked on for a long time when I first started, just trying to figure out how many of these so-called cryptic species there were. And we know a lot more about that now… It’s not that we have discovered all the cryptic species on the planet, but I think at least people are prepared to recognize that there’s a lot more biodiversity than we ever thought.
e360: Just how important have new technologies, including genetic testing, been in getting to this better understanding?
Knowlton: Well, with DNA barcoding there are some groups where it doesn’t work very well, just because it turns out they don’t have that much variation in the genes that are typically used for barcoding. But in general genetics are really helpful. In some groups it confirms what you already knew, but in other groups — things where the species are really similar — it gives you a clear indication whether they are the same species or not.
But on the other hand there are still huge numbers of species and places that have never been studied... We don’t really know how many species live in the ocean. The most recent estimate was about 2 million species, 95 percent of which have never been described. But even that could be too small.
e360: Beyond determining just how many different species there are, much of your research has involved the relationship between corals and the countless other organisms they support.
Knowlton: Yes. I started working on just how many species are out there. No one had actually ever even done a complete count of everything in one place. And since many of these species were likely to not be described, we thought we’d just go straight to the genetics and say, ‘How many genetically distinct things are out there?’ And so we started doing things like collecting small bits of dead reef or putting out little apartment-like houses for organisms to settle into and then bringing them back at the end of the year and see how many things we could find. And we didn’t even try to put a name on anything. We just used barcoding. Because in this case we were working with crabs and shrimps, and for those barcoding actually works really well. And we found, for example, using samples from around the world, there are almost as many crab species in six square meters of coral reef as in all of Europe.
e360: Why is the biodiversity and complexity of these reef ecosystems so important?
Knowlton: Part of it is just that we care a lot about all the different stars in the universe and these are the creatures that we share our planet with. So just understanding the diversity in terms of knowing who we share the planet with I think is important and interesting. Are there two million species? Are there 10 million species? It’s a basic question of what life is like.
In addition, this kind of diversity on reefs supports big tourism industries. And some of that diversity turns out to be important for medicine. The classic example for that are cone snails. There are hundreds of species of cone snails, and each species has quite a complex cocktail of toxins. Some of these have already been commercialized for use as pain relievers, and people have really just begun to explore how many possible medicines might be derived just from that single group of snails.
e360: Among other things that scientists have learned is that the health and abundance of coral species haven’t always been consistent through the planet’s history. Could you describe some of the ups and downs for coral throughout the history of the planet and some of the factors that have influenced these changes?
Knowlton: Well, corals depend on certain kinds of conditions. In fact, the earliest reefs weren’t built by corals at all. They were built by bacteria. And then there have been times in Earth’s history when most of the reefs were built by large clams. Corals themselves probably date back at least to the time of the dinosaurs... And there have been places where at times there have been lots of coral reefs, and times when there haven’t been that many. Right now we happen to be in a time when there are quite a few. Or at least there used to be quite a few. We’ve lost a lot of living coral actually in the last couple of decades.
e360: We seem to be living in a time when their very existence seems to be at risk. Could you talk about some of these threats?
Knowlton: Traditionally, the biggest threats to corals were considered to be overfishing and poor water quality. And in both cases what happens is that corals are in a kind of a never-ending struggle with seaweed. Seaweeds grow a lot faster. And in order for you to have corals around rather than just a lot of seaweeds, you need fish that eat seaweeds. And also if there’s too many nutrients in the water seaweeds go crazy. And corals do better in sort of nutrient-poor water. So those two things have until relatively recently been the biggest threats to corals.
Increasingly climate change is a serious problem. Because what happens is that the corals have in their tissues little single-celled algae that they depend on for food. It’s a really wonderful example of a mutualism where the coral provides shelter and nutrients to the algae and the algae through photosynthesis provide food for the coral. And the corals die if they lose their algae. The problem is that these algae are very sensitive to even small increases in temperature above the normal maximum. You only need about one or two degrees centigrade above the normal seasonal maximum before you start having these algae being unable to photosynthesize properly. And then they wind up being kicked out of the coral, and the coral turns kind of ghostly white because it loses all these algae that were in their tissues. It’s called coral bleaching, and if you look at a bleached coral you can see right through the tissue, which becomes almost transparent to the skeleton, which is stony white.
e360: And, as you say, it doesn’t take much warming to trigger these changes.
Knowlton: It doesn’t take much, which is why coral reef biologists are so worried about global warming, because the trajectory for the future is just more and more of the same. And we’re already at the edge for some corals. For example in 1998, about 80 percent of the corals in the Indian Ocean bleached and about 20 percent of them died. And that would be like if in New England you had a really hot summer, and 80 percent of the trees lost their leaves and 20 percent of them never got them back again. They [corals] grow really slowly. They are the trees of the marine environment in the tropics.
So when you look at climate change models that suggest these hot temperatures [could] become even an annual event by 2020... I mean, it’s hard to know how many things will go extinct, but reefs as complex three-dimensional ecosystems can only tolerate so much before they really are going to start vanishing everywhere on the planet. In addition, you’ve got the side problem of having too much carbon dioxide in the atmosphere, and it dissolves in the ocean, making the ocean more acidic. And that’s also really bad for corals because it makes it much harder for them to build their skeletons. In the past the stressors have been mostly local, and now they are increasingly becoming global.
e360: It seems that some of these stressors might be making the coral more vulnerable to disease. It’s draining all their energy.
Knowlton: Yes. And we actually know, for example, that if you have a big coral-bleaching event, corals don’t always die. But what sometimes happens is after a big bleaching event even the corals that recover subsequently succumb to disease and die from disease. And we’ve seen that in a number of places. So disease is actually a huge problem on coral reefs.
In the Caribbean, in particular, another coral that used to be really common on the reef were the branching corals — the staghorn corals and elkhorn corals — and they’re now listed under the Endangered Species Act because disease has essentially decimated their numbers throughout their entire range. Sort of like Dutch Elm disease underwater.
e360: Much of your earlier research was done in the Caribbean, in Jamaica. What was the state of the coral reefs in that part of the world at the time? And what kind of changes physically have you seen in recent decades?
Knowlton: You know, I always start my talks by showing a picture that I took as a grad student in 1975. And at that time there was living coral everywhere. The bottom was about 70 percent living coral. And we knew the reefs weren’t in pristine condition because there were essentially no big fish. In fact there weren’t that many fish at all because Jamaica is a really poor country and subsistence fishing had basically stripped the reef of most of the fishes because people were desperate to just feed their families... It’s very hard to say, ‘Don’t fish for five years and then they’ll come back.’ So we knew the fish communities weren’t in great shape, but the corals were spectacular. And I have to say there were a lot of distinguished coral reef biologists working in Jamaica at the time... None of us really predicted what would happen.
First in Jamaica we had this huge hurricane [Hurricane Allen in 1980], which broke corals up into little bits and killed a lot of them. And then there was this big disease — not of corals, but of the black spine sea urchin. Because there were no fish around it was the most important seaweed-eater on the reef. And this disease wiped out almost all of the sea urchins throughout its range and, as a result, the seaweeds went absolutely crazy. And throughout the Caribbean most of the reefs flipped from coral-dominated state to a seaweed-dominated state. So within about ten years of my starting to work in Jamaica the reefs effectively vanished.
e360: What are some of the other more vulnerable regions in the world as far as the state of reefs?
Knowlton: Well, anywhere near people is potentially vulnerable, unless people really get together and figure out what they’re going do to make sure they don’t lose their reefs. The Australians are the gold standard for reef protection, the Great Barrier Reef Marine Park Authority. A third of it is off limits to fishing and that is incredibly important in terms of giving reefs resilience, which is the ability to bounce back if something bad happens.
e360: What part can and should marine protected areas play?
Knowlton: Well, in the developed countries, marine protected areas — in the tradition of take a part of the habitat and put it off limits to fishing — is a critical component of reef management. Because fishing pressure can be so intense elsewhere that you need those pockets of protection where big fish are allowed to grow up and make lots of babies. And those big protected areas — or big networks of areas — can also work in some of the remote places where there aren’t many people.
But a lot of reefs are in places in the coral triangle in New Guinea, Indonesia, the Philippines, where it’s very difficult, for socioeconomic reasons, to just put reefs off limits. But there you can take advantage of more traditional management schemes that people have used for decades or centuries. It’s more about managing fishing than putting fishing off limits.
e360: Does it make sense to target certain areas where the stressors are less and the coral systems are still relatively biodiverse?
Knowlton: Well, I think that’s in fact what people have done. For example the big marine protected areas that were set aside in the Pacific under the Bush Administration, those were very important because so many of them are so remote they are in pretty good shape. They still have pretty intact fish communities and very healthy coral communities. That is an important part of the approach that you need to take. Now, those areas are not protected from warming waters or ocean acidification. But what you see when you look at those places is that they do have a lot of resiliency. They have bleaching, but they are able to bounce back. So that kind of protection does play an important role.
Ultimately, if we don’t do something about carbon dioxide concentrations in the atmosphere, local management will not succeed. But effective local management actually buys incredibly important time while we figure out how we’re going to deal with the carbon dioxide problem.
e360: In the face of some of the grim projections you started this ‘Beyond the Obituaries’ series of events. What was your thinking in setting this up?
Knowlton: When I was at Scripps [Institution of Oceanography], I created something called the Center for Marine Biodiversity and Conservation, and a big part of what that center did was graduate education. And I used to stand up in front of fundraisers and talk about what the center did and why it was important. I’d talk about the students, and I started thinking ‘Why did they come to the center to get a graduate degree?’ And I started realizing that they thought of themselves as medical students, except their patient was the planet instead of a person. And I started thinking, in medical school we don’t train everyone to write obituaries. We train them to solve medical problems, not just record the demise of people. So I started thinking about how what a disservice we are doing to these students. They really needed more than doom and gloom. We all need more than doom and gloom.
Not to undersell the enormous severity of the problem and the future prospects and future threats. But it is true that there are some things that are working out there. I just feel that it is very important to pay attention to what is working, to try to replicate successful models in other places.
What’s interesting about these success stories is that almost all of them were due to the actions of one or a small number of people initially. For example there’s this wonderful story about the success in Cabo Pulmo, where in this tiny very poor village in Baja California, this single family decided they could not continue to fish the way they were doing. They stopped fishing, and the fish rebounded incredibly. Tourism now provides much more income to the community than fishing ever did. And it was initially just a tiny number of people that were responsible for creating this really big change.
And so I felt it was really important in terms of the narrative of conservation to talk about the role of individuals, because so often when you talk to the general public they say, ‘Oh, it’s so sad. But there’s nothing we can do.’ And I felt it was really important to give people kind of a reason to think that in fact there is something you can do. Everybody can do something.
Reprinted with permission from Yale Environment 360
Young People Showing Less Interest in Green Issues, Study Says
A new study says that young people have become increasingly less interested in the environment and conservation issues over the last four decades. In an analysis of two longstanding surveys of U.S. high school seniors and college freshmen, researchers found that today’s generation of so-called Millennials are less likely to be concerned with the government or think about social problems, particularly related to environmental issues.
According to their findings, published in the Journal of Personality and Social Psychology, only 21 percent of young people today say they find it important to become personally involved in efforts to clean up the environment, compared with about 33 percent of younger Baby Boomers and about 25 percent of Generation Xers, the group of Americans born between the early 1960s and the early 1980s. About 15 percent of Millennials said they had made no effort to help the environment, compared with 5 percent of young Boomers and 8 percent of Gen Xers. “We have the perception that we’re getting through to people. But at least compared to previous eras, we’re not,” said Jean Twenge, a psychology professor at San Diego State University and one of the authors of the study.
Photo by JD Hancock/flickr/Creative Commons
Reprinted with permission from Yale Environment 360
Mysteries of Killer Whales Uncovered in the Antarctic
by Fen Montaigne
Two of the world’s leading experts on the world’s top marine predator are now in Antarctica, tagging and photographing a creature whose remarkably cooperative hunting behavior and transmission of knowledge across generations may be rivaled only by humans.
On the afternoon of January 10, at the tip of the Antarctic Peninsula, whale researchers Robert L. Pitman and John W. Durban stood on the bridge of a cruise ship, peering through binoculars for signs of killer whales. The Weddell Sea, where English explorer Ernest Shackleton and his men were locked in the sea ice nearly a century ago, was calm and studded with icebergs. It was raining, an increasingly common occurrence in summer in this rapidly warming part of Antarctica.
Around 3 p.m., Pitman spotted several of the distinctive triangular dorsal fins of killer whales two miles ahead. Soon, roughly 40 killer whales appeared on all sides of the cruise ship, the National Geographic Explorer, delighting the nearly 150 passengers on board.
Pitman and Durban stepped into a rubber Zodiac driven by a ship’s naturalist and cruised slowly toward the whales. Two large female killer whales approached, rolled on their sides, and “took a long look at us with wide open eyes as they passed a few feet under the Zodiac,” Pitman later recalled. One of the females surfaced next to the boat, and Durban, cradling a black crossbow, fired a satellite tag onto the middle of the whale’s dorsal fin. When the second female rolled on the surface, Durban fired a dart that would provide a tissue sample for scientific analysis. “Our skin donor,” Pitman said later.
Thus began more than a month of killer whale research in the Antarctic, conducted by two of the world’s leading experts on these top predators, whose killing power, Pitman says, “probably hasn’t been rivaled since dinosaurs quit the earth 65 million years ago.” I was a lecturer aboard the Explorer, and was able to watch the pair work for more than a week in the Antarctic.
As many as 50,000 killer whales roam the world’s oceans today, and roughly half of them are believed to live in Antarctic waters. Yet though killer whales may be the most recognizable creatures in the marine world, a great deal about them remains a mystery, especially in the Antarctic, and Pitman and Durban are now gathering basic information about their behavior and feeding habits . This baseline data is particularly important since climate change and other human impacts, such as overfishing and the accumulation of toxic chemicals, are rapidly altering the whales’ habitats and their prey.
Scientists worldwide are still sorting out how many species and sub-species of killer whales — also known as orcas — exist in places like Alaska, the Pacific Northwest of the U.S. and Canada, and the North Atlantic. In Antarctica, Pitman and Durban — who work for the U.S. National Marine Fisheries Service in La Jolla, Calif. — have played a role in identifying three main types of killer whales in Antarctic waters and a fourth in the sub-Antarctic. The populations — likely separate species — differ in their distinctive black, white, and gray patterning; in the shapes of their dorsal fins and heads; in their geographic range; and in their food and foraging habits. Each individual has unique markings on the saddle behind the dorsal fin, and Pitman and Durban — who have amassed a collection of 40,000 photos of killer whales from Antarctic waters — have gotten to the point where they can recognize individuals and extended families.
But what has driven the men to pursue killer whale research is not the minutiae of markings or migration routes, but rather the extraordinary culture and habits of these cetaceans, whose cooperative hunting behavior and intergenerational transmission of knowledge is rivaled only by humans, Durban and Pitman contend.
Killer whales — Orcinus orca — are long-lived, with females surviving for up to 90 years or more. The whales travel in extended family groups, with offspring generally remaining with their mothers their entire lives. Stable groups of whales join together in pods composed of different matrilines (a dominant female and her offspring), and these related whales all communicate in a distinct dialect using an array of clicks, whistles, and pulsed calls. Killer whales — which gestate for 17 months — are believed to recognize their mother’s calls in utero and are born with the ability to immediately communicate.
As many as four generations of killer whales will travel together, passing on astonishingly sophisticated group hunting behavior from one generation to the next.
“You’ve got individuals that are spending 50, 60, 80 years together, and you can do a lot of things when you’re spending a lot of time with your family and related individuals,” Pitman told me in an interview. “You can hunt cooperatively. You can make sacrifices that other animals wouldn’t make. If you kill 50,000 seals in your lifetime, you get pretty good at it. And if you learn a few things you pass them on to your offspring. It makes them quite remarkable and very human-like in the things they do.”
“We have grandmothers, great-grandmothers, and great-great-grandmothers traveling in groups together with younger whales, imparting cultural knowledge,” added Durban.
Three years ago, farther south along the western Antarctic Peninsula, Pitman and Durban spent three weeks observing such behavior among a group of pack ice killer whales, also known as large type-B Antarctic killer whales. The men studied a hunting technique known as “wave-washing,” in which a pod of whales moves through ice floes, its members lifting their heads out of the water — a behavior known as “spy-hopping” — looking for their preferred meal: fat, fish-eating Weddell seals. Once they spotted a seal on an ice floe, the whales called in reinforcements and, two to seven abreast, swam toward the floe and washed the seal off the ice by creating a large wave with powerful strokes of their tails. Pitman and Durban then observed what they call the “butchering” of seals, with the whales first drowning the seals and then meticulously stripping off their skin to get at the choice flesh.
“It was shocking to see,” said Pitman. “You’re not used to animals doing things that are so canny.”
Pitman and Durban are now aboard the 331-foot Explorer, where they will remain until mid-February, as guests of Lindblad Expeditions and National Geographic Expeditions. As visiting scientists, they use the ship as a research platform, and even rely on passengers to help take close-up photos of the killer whales’ distinctive markings, an example of the “citizen science” that has helped identify hundreds of individual killer whales in hot spots such as Alaska and the Pacific Northwest. Pitman, 62, who has a sweeping mustache, has worked in the Antarctic for more than two decades and has studied killer whales for the past 15 years. Durban, 35, a burly Englishman with a black beard, first worked with killer whales as a 16-year-old assistant to a pioneering whale researcher in Washington state.
The 40 whales the men encountered in the Weddell Sea likely comprised three matrilines and belonged to an “ecotype” — or possibly new species — of Antarctic killer whale they refer to as a “small type-B”, related to the larger type-B “wave-wash” hunters. But little is known about the small type-B’s; Pitman and Durban have occasionally seen them feeding on gentoo and chinstrap penguins, but never on seals, and one of the goals of this year’s research is to get a better sense of what the small type-B’s are eating. The small type-B’s are roughly half the mass of a larger Antarctic killer whale, the type-A, which is found in more open water and hunts minke whales. Type-A males can grow to nearly 30 feet in length and weigh up to 10 tons.
In the three weeks since the female killer whale was tagged, she and her pod have traveled many hundreds of miles in the Weddell Sea, sometimes skirting the pack ice. Durban and Pitman have tagged 15 Antarctic killer whales with the 1.4-ounce satellite transmitters over the last three years, and the results have greatly expanded knowledge of their habits, preferred habitats, and migrations. Six of the tagged type-B killer whales made rapid migrations, following a nearly identical northerly trajectory, past the Falkland Islands and beyond to the Atlantic Ocean off Brazil. One of the whales made a 6,000-mile round-trip journey from the Antarctic Peninsula to Brazilian waters and back again in just 42 days. Durban and Pitman believe the whales make these previously unknown migrations for one main purpose: shedding and renewing their skin, something they would be unable to do in frigid Antarctic waters because they would lose too much heat.
Four days after the scientists tagged the whale in the Weddell Sea, the Explorer was off the western Antarctic Peninsula, in the Gerlache Strait, a breathtaking passage flanked on both sides by glaciated mountains. There, the scientists encountered some old friends — an extended family group of roughly 70 small, type-B killer whales that spend much of their time in the strait.
Durban and Pitman photographed nearly all of the whales, and Durban — who possesses a photographic memory for killer whale markings — recognized many of the individuals from earlier encounters. Durban was unable to get positioned for a tagging shot with the crossbow, but 10 days later, on the following cruise, he managed to shoot a $2,500 satellite tag, as well as a $4,500 dive-depth tag, onto two killer whales in the Gerlache Strait. The depth tag would reveal some information on feeding habits they had long been looking for.
This is the kind of work that scientists worldwide are doing as they intensify research into a marine mammal long thought of as one species but that likely, in fact, comprises several distinct species. Genetic testing, for example, shows that so-called transient, mammal-eating killer whales in the Pacific Northwest diverged from the resident, fish-eating whales a half-million years ago and should perhaps be recognized as a distinct species, despite being found now in the same waters. This is not a purely academic matter, as distinct species, evolved to live in certain regions and eat certain prey, may be more vulnerable to environmental change.
That change is happening rapidly. Many groups of these apex predators have accumulated extremely high levels of PCBs and other toxic chemicals, with potentially harmful effects on development and reproduction. Global warming is also altering their world and that of their prey. As Arctic summer sea ice melts, for example, what will become of the predator-prey relationship between gray whales and killer whales as they gray whale migration extends deeper into the Arctic Ocean?
Meanwhile, in Antarctica, Pitman and Durban continue to unlock mysteries of killer whales. Last week, the depth tag they affixed to a killer whale in the Gerlache Strait showed that the whales were repeatedly making deep, nighttime dives of up to 1,900 feet off the western Antarctic Peninsula, an indication — for the first time — that these whales were most likely eating fish and squid on or near the sea floor.
Reprinted with permission from Yale Environment 360
Wide Variety of Threats Wiping Out World’s Big Trees, Expert Says
A litany of environmental threats, from forest fragmentation and logging to climate change and disease, are wiping out the world’s biggest trees, according to a published report. In forest ecosystems worldwide, research shows that giant trees have become particularly vulnerable to a changing environment, ecologist and tropical forest expert William Laurance writes in New Scientist magazine. Increased fragmentation has left big trees exposed to stronger winds, while dry conditions and warming temperatures have forced the giants of the forest to consume more energy simply to survive, allowing less energy for growth, Laurance writes. Climate change is also promoting the spread of exotic pathogens, such as Dutch Elm disease, which are devastating native forests. “The decline of big trees foretells a different world where ancient behemoths are replaced by short-lived pioneers and generalists that can grow anywhere, where forests store less carbon and sustain fewer dependent animals, where giant cathedral-like crowns become a thing of the past,” Laurance writes. In addition to providing a critical habitat for wildlife, big trees contribute to local rainfall by transpiring large of amounts of water through their leaves and store abundant amounts of carbon.
Photo by rickremington/flickr/Creative Commons
Reprinted with permission from Yale Environment 360

