These forests provide many benefits: They store large amounts of carbon, are home to numerous wild species, provide food and fuel for local people, purify water supplies and improve air quality. Replenishing them is an urgent global imperative. A newly published study in the journal Science by European authors finds that there is room for an extra 3.4 million square miles (0.9 billion hectares) of canopy cover around the world, and that replenishing tree cover at this full potential would contribute significantly to reducing the risk of harmful climate change
But there aren’t enough resources to restore all tropical forests that have been lost or damaged. And restoration can conflict with other activities, such as farming and forestry. As a tropical forest ecologist, I am interested in developing better tools for assessing where these efforts will be most cost-effective and beneficial.
Over the past four years, tropical forestry professor Pedro Brancalionand I have led a team of researchers from an international network in evaluating the benefits and feasibility of restoration across tropical rainforests around the world. Our newly published findings identify restoration hotspots – areas where restoring tropical forests would be most beneficial and least costly and risky. They cover over 385,000 square miles (100 million hectares), an area as large as Spain and Sweden combined.
The five countries with the largest areas of restoration hotpots are Brazil, Indonesia, India, Madagascar and Colombia. Six countries in Africa – Rwanda, Uganda, Burundi, Togo, South Sudan and Madagascar – hold rainforest areas where restoration is expected to yield the highest benefits with the highest feasibility. We hope our results can help governments, conservation groups and international funders target areas where there is high potential for success.
Earth’s cornucopia of life has evolved over 550 million years. Along the way, five mass extinction events have caused serious setbacks to life on our planet. The fifth, which was caused by a gargantuan meteorite impact along Mexico’s Yucatan coast, changed Earth’s climate, took out the dinosaurs and altered the course of biological evolution.
Today nature is suffering accelerating losses so great that many scientists say a sixth mass extinction is underway. Unlike past mass extinctions, this event is driven by human actions that are dismantling and disrupting natural ecosystems and changing Earth’s climate.
My research focuses on ecosystems and climate change from regional to global scales. In a new study titled “A Global Deal for Nature,” led by conservation biologist and strategist Eric Dinerstein, 17 colleagues and I lay out a road map for simultaneously averting a sixth mass extinction and reducing climate change.
We chart a course for immediately protecting at least 30% of Earth’s surface to put the brakes on rapid biodiversity loss, and then add another 20% comprising ecosystems that can suck disproportionately large amounts of carbon out of the atmosphere. In our view, biodiversity loss and climate change must be addressed as one interconnected problem with linked solutions.
The whale shark is the largest fish in the world, but much of its lifecycle remains shrouded in mystery. These gentle giants gather in just a handful of places around the globe – something which has long baffled scientists – but our new research has started to explain why. Better understanding of whale shark movements could help prevent further population loss in a species that has already experienced a 63% population decline over the past 75 years.
When swimming solo, the whale shark, which can grow up to 18.8 metres in length and 34 tons in weight, travels all over the world. Recently, a group of scientists tracked the remarkable journey of one whale shark across the Pacific from Panama to the Philippines. At more than 12,000 miles it proved to be one of the longest migrations ever recorded.
Yet whale sharks are known to come together at just a few specific locations around the world. Anything from ten to 500 whale sharks may gather at any one time in areas off the coasts of Australia, Belize, the Maldives, Mexico and more.
Researchers warn of a serious threat to fish, mussels and other marine species as carbon dioxide acidifies the world’s waters and increases temperatures.
LONDON, 7 July, 2015 – Pink salmon – the smallest and most abundant of the Pacific salmon species, and a supper table mainstay in many parts of the world – may be swimming towards trouble.
And they are not the only dish likely to disappear from the menu. Mussels, oysters, clam and scallop could all become scarcer and more expensive as the seas become more acid. And as the world’s waters warm, fish will start to migrate away from their normal grounds at an ever-increasing rate.
Previous studies have repeatedly and consistently explored potentially problematic consequences of change in the pH value of the world’s oceans. The higher the carbon dioxide concentrations in the air as a consequence of the burning of fossil fuels, the greater the change in oceanic acidity levels.
But researchers at the University of British Columbia, Vancouver, and colleagues looked at the special problems of freshwater fish.
Only about 0.8% of the world’s water is fresh – that is, found in lakes and rivers – but freshwater species represent 40% of all fishes. Salmon spawn and the young are reared in fresh water, before taking to the seas to mature, then returning to repeat the cycle.
The Vancouver scientists report in Nature Climate Change that they tested very young embryos in water at acidity levels expected at the end of this century, and observed them for 10 weeks.
They found that these laboratory-reared salmon were smaller, and their ability to smell was reduced, which could mean problems in returning to their spawning grounds or for scenting danger and responding to it.
“It is not too late for society to benefit greatly from immediate reductions in CO2 emissions”
At the age of seaward migration, they were less able to use oxygen in their muscles, which promised problems finding food, evading predators or making long journeys.
“The increase in carbon dioxide in water is actually quite small from a chemistry perspective, so we didn’t expect to see so many effects,” said Michelle Ou, lead author of the study. “The growth, physiology and behaviour of these developing pink salmon are very much influenced by these small changes.”
Salmon aren’t the only freshwater fish at risk from climate change. Research published in the journal Environmental Toxicology and Chemistry reveals that a rise in water temperatures of 5°C could make common pesticides and industrial contaminants ever more toxic.
Ronald Patra, an environmental scientist at the Department of Planning and Environment in New South Wales, Australia, and colleagues tested rainbow trout, silver perch, rainbowfish and western carp gudgeon at temperatures higher than optimum for the species and in the presence of endosulfan, chlorpyrifos and phenol − all of which wash into waterways from the land.
Results varied according to pollutant, species and temperature, but, overall, all three chemicals became increasingly toxic as water temperatures rose.
On the coast of Mangalore in southwest India, where mussel farming has become a growing industry, researchers decided to test future toxicity conditions for the green mussel.
The Society of Experimental Biology meeting in Prague learned that the bivalves were raised in high temperature and low salt conditions and exposed to toxic algae and bacteria of the kind that might be expected in a changing climate, which in turn affected the timing of the monsoon in ways that could lower seawater salinity.
“This is likely to increase the chance of outbreaks of toxic plankton blooms and make farming bivalves such as mussels increasingly challenging,” the meeting was told.
But changes to water chemistry – once again, the shift in pH values as yet more carbonic acid builds up in the seas – create problems enough for the commercial shellfisheries.
Wiley Evans, research associate at the Ocean Acidification Research Centre of the University of Alaska Fairbanks, and colleagues report in the Public Library of Science journal PLOS Onethat shellfish farmers off the Alaska coast might, at extra expense, have to start modifying the sea water in their hatcheries because, the researchers reported, they expect “significant effects” from acidification by 2040.
The scientists monitored for 10 months the effects of water chemistry changes on oyster, clam, scallop and other shellfish larvae.
Alaska – with a limited growing season, melting glaciers that affect salinity, and with colder waters that more readily dissolve carbon dioxide – is a special case.
But in general, as researchers have repeatedly found, increasingly corrosive waters would make it more difficult for shellfish to exploit the calcium carbonate minerals needed to make shells.
But a 5°C average warming in global atmospheric temperatures – and climate scientists have repeatedly warned that this is possible before 2100 – means that fish are likely to migrate away from their existing habitats considerably faster than they are doing now.
Jean-Pierre Gattuso, of the Oceanological Observatory in Villefranche, France, and colleagues looked at the evidence on a global scale and report in Science journal that, without attempts to mitigate global warming, the oceans and the creatures in them will be seriously affected by temperature changes and acidification.
This is very bad news for the millions of people in the communities that depend on the seas for a living.
“On a positive note, we still have options to substantially reduce these impacts now, but the longer we wait the fewer and fewer options we have,” warns co-author William Cheung, of the fisheries centre at Canada’s University of British Columbia.
Commenting on the research, Jason Hall-Spencer, a professor of marine biology at Plymouth University in the UK, said: “This review screams at me that the evidence is in, and it is not too late for society to benefit greatly from immediate reductions in CO2 emissions.” – Climate News Network ……………’
Diving in the clear blue waters of the Caribbean in March, I saw why the obituary for the Caribbean’s ocean health has been written multiple times.
Invasive lionfish are overpopulating and preying upon native fishes. Overfishing and pollution have enabled algae to devastate coral reefs. Those corals lucky enough to escape the algae are being bleached by rising ocean temperatures due to the continuing advance of climate change.
The Caribbean isn’t alone — all of our oceans are under assault from human activities, threatening the benefits we receive from them.
There is no doubt: We need significant action to secure ocean health and prosperity for the people that depend on it. Several recent developments make me confident that we can put oceans on a path to recovery:
1. The number and size ofmarine protected areas are increasing.
Protected areas are not new: Since the creation of Yellowstone National Park in 1872, hundreds of thousands have been established around the world. It took longer for the concept to be applied to the ocean, in the form of marine protected areas (MPAs), and only 3% of the ocean — an area larger than the United States — is covered by MPAs. This kind of marine management is catching on, though.
More marine protected area coverage will keep ecosystems intact, shelter biodiversity (including important commercial species) and boost coastal economies through tourism.
2. Signs offisheries recovery are growing.
It has been a while since we have had any objectively good news about fisheries. In 1974, 10% of global fish stocks were overexploited. By 2011, that percentage rose to 29%. This is alarming because fisheries are a source of essential nutrition for people — worldwide more than 3 billion people get much of their protein from fish. For years, warnings about overfishing were ignored due to short-term economic and political interests, but in some parts of the world that trend has shifted.
The number of overfished stocks in the U.S. declined from 31% of known fish stocks in 1997 down to 16% in 2014. Nations such as Iceland and New Zealand, which have enforced catch limits and created incentives for fisheries recovery, also report that overfishing has stopped and that some stocks are recovering.
Chronic overfishing remains a problem, especially in countries with weak governance and large populations of small-scale fishers with few economic alternatives. Showing that properly managed fish stocks can recover, though, is a great sign.
3. New technologyincreases monitoring and enforcement.
Technology has helped accelerate ocean exploitation: Better boats, fish-finding technology and fishing gear enable fishers to go farther and deeper, and on the high seas, it’s easier to pursue destructive activities without concerns about environmental impacts.
Technology, however, can also keep an eye on distant waters. Several systems now use GPS information from vessel transmitters to track a boat’s actions at sea. By applying algorithms to vessel movement patterns, it is possible to identify vessels fishing illegally.
Ocean conservation — viewed as a luxury few countries could afford when busily pursuing economic development and poverty alleviation — is changing as more countries realize their people depend on healthy oceans for nutrition, livelihoods, protection from storms and other benefits.
Increased awareness and desire for action is manifesting itself through adoption of the Ocean Health Index, which defines ocean health in terms of its ability to provide a range of benefits to people. Since its launch in 2012, 15 countries are using the Index to set priorities and to take action for ocean health.
5. There is a growing appetite for global action on oceans.
I have spent the last quarter-century working on marine conservation and have seen support for global action to conserve our oceans grow substantially in recent years. Heads of state, ministers, CEOs and development organizations have realized their constituents and businesses depend on oceans, and that our impacts need to be brought under control.
The draft set of Sustainable Development Goals, to be finalized this September, includes one dedicated to oceans, which is receiving outspoken support from country delegations and CEOs. Earlier this year, countries agreed to begin discussions on how to better manage areas beyond national jurisdiction, where weak governance currently threatens sustainability. The reason for my visit to the Caribbean in March was to attend a meeting of the Global Blue Growth Network, a group of countries and organizations working to build capacity and guidelines for sustainable blue growth.
6. Conservation actions are recovering endangered species.
On my eye-opening Caribbean dive, I saw a ray of hope: the shadow of a green sea turtle in the distance.
Green and hawksbill turtles were once a much-valued source of tortoiseshell and of meat for turtle soup. So many turtles were taken, however, that numbers plummeted and the species became endangered.
Their numbers have been rising since the 1970s, thanks to improved legislation and trade regulation; awareness campaigns by environmental groups; and alternative livelihood options for coastal inhabitants — they can make more money from taking tourists to see live turtles than they ever could have made from killing them.
In Barbados, thousands of hawksbill nests are now laid each year; in Costa Rica, nesting numbers of green turtles have increased exponentially in a few decades. The revival of these turtles shows that through concerted actions, we can recover the health of our oceans.
What are your reasons for hope for the oceans? Feel free to share them in the comments on this blog.
Sebastian Troëng is the senior vice president and managing director of CI’s Betty and Gordon Moore Center for Science and Oceans. …….’
In my last post, I noted how the water supply on Atauro is rarely more than a trickle. Late last week our freshwater team turned up something very surprising: a flowing stream that even some of the island’s residents didn’t know about.
The freshwater team, led by CI Timor-Leste Country Director Trudiann Dale, hiked for hours over rough terrain until they discovered the water flowing out of a limestone cave system. Within the crystal-clear water, the team found a range of freshwater insect species.
Creatures of the Night
Later, we took a night hike in the rainforest, which proved to be extremely challenging. Guided by a barefoot Timorese man who was as agile as a mountain goat, we spent several hours scrambling down valleys and over fallen trees.Fortunately, our efforts were rewarded.
First, we saw a civet — a small mammal with a raccoon-like face — high in the trees. Then we caught three geckos of an undescribed species! Only one individual of this kind of reptile had ever been found before. Our records will help to ensure the species is properly named and that a proposed protected area includes the locations where it lives.
We set a few live traps to see if we could capture a civet, a task we knew would be extremely difficult. If we caught one, we’d be able to find out if the island’s civet population was different from the mainland civet.
The next morning we returned to the traps. Most were empty … but one contained a civet! We couldn’t believe our luck.
The animal looked like a dark-colored palm civet. By comparing its DNA to that of other civets, we’ll learn whether it’s a new species. We took photos and videos of the civet, fed it fruit to keep it nourished and collected several hairs for the DNA sample. We then set the civet free and watched it scamper up a tree, none the worse for wear.
To the Bat Caves
Another group of mammals that has been poorly surveyed in Timor-Leste is bats. We have therefore begun a preliminary study to map bat caves and ensure that their most important habitats are included within our proposed protected area.
Our initial survey has so far turned up three bat species:
A small fruit bat, with a face like a tiny dog and tough, thin wings.
A large insectivorous bat, with an odd-shaped nose and large ears that allow it to use vibrations to detect insects.
A tiny insectivorous bat no more than 3 centimeters in length!
It’s incredible to see these marvels of nature up close — bats are truly amazing beasts. After measuring and collecting DNA samples from the bats, we released them, hoping to catch more in the coming days.
A Future Tourist Destination?
While conducting our survey, we’ve also been assessing the ecotourism potential of the area. If Timor-Leste can benefit financially from protecting nature on this small island, then there is a greater likelihood that it will be well-managed and kept intact. Our initial assessment is that if the area is managed carefully, it has huge tourism potential. We have found some fabulous walks, breathtaking viewpoints and pristine snorkeling sites.
Yesterday we visited a particularly spectacular site: a long, narrow valley that runs down to a small village by the sea. Lined by high limestone cliffs, the valley was full of caves and festooned with massive fig trees. The valley’s rainforest is kept damp by the lack of full sunlight and the clouds and sea mist that cover the hills each night. The trees were draped in orchids and ferns, and noisy birds flew through the canopy.
As we walked down the path, I saw a large tokay gecko in a hollow tree. Upon closer inspection, we saw that it was a huge female covered in bright orange spots — guarding eight eggs that were in the middle of hatching! We watched three eggs hatch as the mother looked on guardedly, displaying a maternal instinct unusual to see in a lizard.
An Unexpected Discovery
As I was about to walk farther down the path, I heard a distinctive squeak. Much higher-pitched than a bird or mouse, the sound meant only one thing: a shrew. These small insectivorous mammals are widespread around much of the world, but only one had ever been found in Timor, and none on Atauro!
I stood absolutely still and waited. The tiny shrew came out from under a rock and began rummaging in the leaves. I leapt over and grabbed a handful of leaves where it had been and quickly stuffed them in a bag. I peered in to see if I’d caught it — success! The first record for the island, and almost definitely an undescribed new species of mammal.
That night, we were full of excitement discussing our list of species likely new to science: a rodent, a shrew, at least two lizards and probably a wide range of plants and freshwater insects. It’s amazing that such a small island can hold so much rare and unstudied life.
Again, I was struck by the fact that when people respect nature and truly value the gifts it provides, everyone benefits: the people who rely on the forests for fresh water, the visiting tourists who come for stunning views of forest and pristine coral reefs, the sharks offshore that swim in protected waters — and of course, the tiny shrews that call the forest home.
Much of the Earth was once cloaked in vast forests, from the subarctic snowforests to the Amazon and Congo basins. As humankind colonised the far corners of our planet, we cleared large areas to harvest wood, make way for farmland, and build towns and cities.
The loss of forest has wrought dramatic consequences for biodiversity and is the primary driver of the global extinction crisis. I work in Borneowhere huge expanses of tropical forest are cleared to make way for palm oil plantations. The biological cost is the replacement of some 150 forest bird species with a few tens of farmland species. But forest is also frequently retained inside or at the edges of oil palm plantations, and this is a pattern that is replicated globally.
The problem, according to new research published in Science Advances, is that the vast majority of remaining forests are fragmented. In other words, remaining forests are increasingly isolated from other forests by a sea of transformed lands, and they are found in ever-smaller sized patches. The shockwaves of loss thus extend far beyond the footprint of deforestation.
The great outdoors? Only the blue areas are more than 1km from the edge of the forest. (Joe Sexton/Danxia Song)
The team, led by Nick Haddad from North Carolina State University, used the world’s first high-resolution satellite map of tree cover to measure how isolated remaining forests are from a non-forest edge. Edges are created by a plethora of deforesting activities, from roads to cattle pastures and oil wells, as well as by rivers.
They found that more than 70% of remaining forest is within just 1km (about 0.6 miles) of an edge, while a 100 metre stroll from an edge would enable you to reach 20% of global forests.
Comparing across regions, the patterns they find are even starker. In Europe and the US, the vast majority of forest is within 1km of an edge – some of the most “remote” areas in these regions are a stones throw from human activity. “Getting away from it all” has never been more challenging.
If you want remote forests on a large scale you’ll have to head to the Amazon, the Congo, or to a lesser degree, central and far eastern Russia, central Borneo and Papua New Guinea.
These findings wouldn’t be cause for alarm if wildlife, forests, and the services that they provide humankind such as carbon storage and water, were unaffected by fragmentation. However, by drawing together scientific evidence from seven long-term fragmentation experiments, Haddad and colleagues show that fragmentation reduces biodiversity by up to 75%. This exacerbates the extinction risk of millions of forest species, many of which we still don’t know much about.
For undisturbed forest, head to Congo’s blue zone. (Joe Sexton/Danxia Song)
Forest species struggle to survive at edges because these places are brighter, windier, and hotter than forest interiors. Edges become choked by rampant vines and invaded by disturbance-tolerant, parasitic or invasive species that outcompete the denizens of dark forest interiors. In Borneo, for example, small forest patches house bird communities that are far more similar to those found in the surrounding oil palm than to those of larger forest tracts.
The survival of large, carbon-rich trees – the building blocks of any intact forest ecosystem – is reduced in smaller and more isolated forest fragments. These patches thus fail to maintain viable populations, which over time are doomed – an “extinction debt” yet to be paid.
Curassows hate deforestation. (fPat Murray, CC BY)
With so much global forest in close proximity to humans, larger forest animals such as chimpanzees, gorillas, tapirs or curassow birds are being hunted to extinction in individual areas. This shifts animal communities within the forest fragments to one dominated by small-bodied species. Further, hunters are willing to penetrate forests for several kilometres from edges in search of game, effectively making the truly wild global forest estate yet smaller.
Difficult Management Decisions
The insidious effects of fragmentation mean that the top conservation priority must be preventing further incursions into dwindling wildernesses. By preventing the first cut we can help to prevent global fragmentation and the further loss of biodiversity.
Of course, we should not ignore fragmented regions. Some of these, including the Brazilian Atlantic forest, Tropical Andes and Himalayas, share a toxic mix of hyperdiversity, endemic species with tiny ranges, and severe fragmentation. The critically-endangered Munchique wood-wren, for instance, exists only in a handful of peaks in the Colombian Andes, but these are now isolated from each other by cattle pastures and roads. Here we must seek to restore forest cover and improve connectivity between larger fragments if we are to prevent extinctions.
Large patches of the Amazon remain, but Brazil’s Atlantic forest is rarely more than 1km from an edge. (Clinton Jenkins)
However, the rapid expansion of human populations, greed, and meat consumption mean that more forest is likely to be lost, even if farm yield and efficiency can be improved to help bridge gaps between current and future demand. The difficult question is where should this expansion happen? Given the severe degradation of small and isolated fragments, perhaps conversion could target some of these patches, coupled with wilderness protection and expansion.
Next time I visit my local National Park – the highly fragmented Peak District – I will spare a thought for the species that are being harmed by their habitats being broken up into ever smaller chunks. There are no easy answers to the problems of fragmentation, but our forests urgently need a global management plan.