Forests make heatwaves ‘initially warmer’


During heatwaves forests reduce their evaporation, causing the atmosphere to warm up even more, say researchers.

During extremely long periods of heat, however, this reduction enables the forests to continue their evaporation for longer, so the net effect is ultimately one of cooling in relation to the surroundings, explained a team of scientists led by Ryan Teuling from Wageningen University in the Netherlands.

Writing in the journal Nature Geoscience, Dr Teuling worked on the investigation in collaboration with climate researchers from a number of European countries.

The study was prompted by recent heatwaves in Europe, which had raised interest in questions about the influence of land use on temperatures and climate.

Up to now, scientists had assumed that a lack of precipitation during heatwaves automatically led to a reduction in evaporation.

That reduction was thought to be less for forests, because trees, with their deeper root systems, have more water available to them. Examination of the precise role of land use, however, has been largely neglected up to now.

The study found large differences in evaporation strategies during heat waves. Grasslands evaporate more at higher temperatures and stop only when no more water is available.

Forests, in contrast, respond to higher temperatures by evaporating less, which leaves more water at their disposal.

During brief heatwaves, therefore, the greatest warming is found above forests, but during prolonged heat waves the increased evaporation of grasslands ends up causing a shortage of water.

This can lead to exceptionally high temperatures, such as those measured in France in the summer of 2003.

This mechanism might also offer an explanation for the unusually high temperatures near Moscow this summer, the researchers suggest.

In these types of extreme situations, forests in fact have a cooling effect on the climate.

The research was done on the basis of observations made above forests and grasslands in Europe by an extensive network of flux towers. For areas without towers, satellite data were used.

Source: Wageningen University press release

Date: 06/09/2010

Illegal logging continues to plague Madagascar’s rainforest parks


Despite government assurances that it would crack down on the rosewood trade, illegal logging continues in Madagascar’s rainforest parks, according to new information provided by sources on the ground and reported in Wildmadagascar.com.

The sources report logging in three parks: Mananara, Makira, and Masoala. All three are known for their high levels of biodiversity, including endangered lemurs.

Rosewood logs are being transported to Tamatave (Toamasina), Madagascar’s main port, despite a national moratorium on logging and export of precious hardwoods. Most rosewood ends up going to China, where it is in high demand for furniture.

The Malagasy sources report that local law enforcement—the new Brigade Mixte Forestière established to reduce logging—is impeded the Forest Ministry, which has failed to grant them the right to use search warrants on private property.

The sources also claim that rosewood confiscated by authorities is being stolen from official stockpiles.

Illegal logging exploded last year in the aftermath of a military coup that displaced the democratically-elected, but increasingly autocratic president, Marc Ravalomanana.

National parks, especially in the North-East of the country, were ransacked by loggers employed by timber barons who traditionally capitalize on political instability or natural disasters to replenish timber stocks and traffic ill-gotten wood.

Madagascar is now ruled by a “transition authority” that has so far shown little inclination to hold free and fair elections and has been be slow to address the logging crisis despite pressure from the international community.

Source: Wildmadagascar.com

Date:06/09/2010

Twiglet: Abscission; abscisic acid


Topical for this time of year (in the northern hemisphere at least), abscission referes to the rejection of plant organs, such as leaves in the autumn.

This occurs at an abscission zone, where hydrolytic enzymes reduce cell adhension. The process can be promoted by abscisic acid and inhibited by respiratory poisons, and is controlled in nature by the proportions and gradients of auxin and ethylene. Other hormones may be involved.

Abscisic acid is a terpenoid compound that is one of the five major plant horones. Althought it is synthesised in the chloroplasts, it occurs throughout the plant body and is particularly concentrated in the leaves, fruits and seeds.

It has a powerful grown inhibiting properties generally and also promotes leaf abscission and the senescence of plants and/or their organs, and induces the closing of the stomata and dormancy in seeds and buds.

Its effect is antagonistic to the plant growth hormones, and it is thought to act by inhibiting the synthesis of protein and nucleic acids.

Source: Oxford Dictionary of Plant Sciences

China timber sector looks at tougher EU/US import rules


The China Timber and Wood Products Circulation Association (CTWPCA) is seeking to establish a body to help importers navigate new environmental regulations in the US and EU that restrict trade in illegally logged timber, reports the International Tropical Timber Organization (ITTO).

In a recent market report, ITTO said that Chinese importers fear failing to meet the new regulations that govern the sourcing of timber products.

The US’s Lacey Act and the EU’s FLEGT ruling put the burden of responsibility on importing companies, holding them to the environmental laws of producing countries.

Companies found to be sourcing illegally logged timber could be subject to fines or worse.

A company accused of using illicit rosewood from Madagascar, was the first company to be charged and investigated under the Lacey Act.

The legislation was amended in 2008 to include “anyone who imported, exported, transported, sold, received, acquired or purchased the wood products made from that illegal timber, who knew or should have known that the wood was illegal.” The firm’s case is pending.

According to ITTO, CTWPCA believes traders need “guidance and support” on the new international requirements.

The body would also set up a “responsible procurement system” for timber imports, seek to address corruption in the timber import and trade sector, and aim to help Chinese timber traders meet international standards.

China already has guidelines governing Chinese companies operating forest concessions overseas.

These compel companies to abide by local environmental laws and take measures to reduce pollution. However, some observers suggest that there is no indication that these mandatory rules are being enforced.

Source: Mongabay.com

Date: 02/09/2010

REDD+ could do more harm than good, forestry experts warn


As governments across Latin America prepare to implement a new financial mechanism aimed at mitigating climate change by curbing carbon emissions from the destruction of tropical forests, experts have warned against a “one-size-fits-all” approach.

Instead, they are calling for flexible, balanced solutions to the surrounding this new mechanism.

Among the experts’ main concerns are that the wealthy and powerful could capture many of the benefits, largely at the expense of rural communities, including indigenous groups.

Organised by Mexico’s National Forestry Commission and the Swiss government, with scientific support from the Center for International Forestry Research (CIFOR), a recent conference’s findings and recommendations will be feed into a UN Forum on Forests (UNFF) meeting scheduled to take place in early 2011, marking the launch of the International Year of Forests.

The Mexico gathering brought together scientists, as well as representatives of governments and non-government organisations, for discussions on governance, decentralisation and REDD+ in Latin America.

Under REDD+ (for reducing deforestation and forest degradation), industrialised countries will provide developing nations with sizeable sums of money in exchange for verifiable storage of carbon in forests, in addition to the conservation and sustainable management of forests.

Forest destruction currently accounts for up to 18% of annual global carbon emissions. Several Latin American countries, including Mexico, have taken the lead in designing REDD+ schemes and stand to benefit significantly.

“Good forest governance – involving transparent and inclusive relationships between governments, forests and the people who depend on them – is fundamental for ensuring that REDD+ helps forest-dependent communities move out of poverty, instead of fueling corruption and funding entrenched bureaucracies,” said Elena Petkova, a CIFOR scientist.

“REDD+ schemes could either flounder on governance failures or flourish under successful governance.”

The central aim of the conference in Oaxaca was to provide science-based advice on the design and implementation of REDD+ schemes, so these schemes can capture carbon and reduce emissions effectively, while at the same time generate significant benefits from sustainable forest management that are equitably shared.

“About 40 years of public sector investment in curbing deforestation, while producing many local successes, has fallen far short of its goal,” said another CIFOR scientist, Andrew Wardell, who was also attending the conference.

“REDD+ might be our last chance to save the world’s tropical forests. So, it’s extremely important to get it right in Latin America and elsewhere.

“This region holds nearly a quarter of the world’s forests, upon which millions of people depend, and over the last five years, it has accounted for 65% percent of global net forest loss.”

Source: CIFOR press release

Date: 03/09/2010

US wolf re-introduction still leaves aspens quaking


The re-introduction of wolves in a US National Park in the mid-1990s is not helping quaking aspens (Populus tremuloides) to become re-established, as many researchers hoped.

In a study published in the journal Ecology showed that the population of wolves in Yellowstone Park was not deterring elks from eating young trees and saplings.

It was assumed that the presence of wolves would create a “landscape of fear”, resulting in no-go areas for elks.

Researchers writing in the Ecological Society of America’s (ESA) journal said that the aspens were not regenerating well in the park as a result of the elk eating the young trees.

However, they added that the conventional wisdom suggested that as the wolves were predators of the elk, it was thought that the elk would eventually learn to avoid high-risk areas in which the wolves were found.

This would then allow plants in those areas – such as aspen – to grow big enough without being eaten and killed by the elk. And in the long-term, the thinking went, the habitat would be restored.

In this latest study, lead author Matthew Kauffman – a US Geological Survey scientist – suggested the findings showed that claims of an ecosystem-wide recovery of aspen were premature.

“This study not only confirms that elk are responsible for the decline of aspen in Yellowstone beginning in the 1890s, but also that none of the aspen groves studied after wolf restoration appear to be regenerating, even in areas risky to elk,” Dr Kauffman explained.

Because the “landscape of fear” idea did not appear to be benefiting aspen, the team concluded that if the Northern Range elk population did not continue to decline (their numbers are 40% of what they were before wolves), many of Yellowstone’s aspen stands were unlikely to recover.

“A landscape-level aspen recovery is likely only to occur if wolves, in combination with other predators and climate factors, further reduce the elk population,” observed Dr Kauffman.

The paper, Are wolves saving Yellowstone’s aspen? A landscape-level test of a behaviorally mediated trophic cascade, has been published online in Ecology. The authors of the paper are: Matthew Kauffman (USGS), Jedediah Brodie (University of Montana) and Erik Jules (Humboldt State University).

Source: ESA press release

Date: 01/09/2010

North Korea begins agroforestry scheme to halt degradation


A “pioneering agroforestry project” in North Korea is restoring heavily degraded landscapes and providing much-needed food for communities, says the World Agroforestry Centre.

Jianchu Xu, the Centre’s East-Asia co-ordinator,  said agroforestry – in this case the growing of trees on sloping land – was uniquely suited to DPR Korea for addressing food security and protecting the environment.

“What we have managed to achieve so far has had a dramatic impact on people’s lives and the local environment,” he explained.

“Previously malnourished communities are now producing their own trees and growing chestnut, walnut, peaches, pears and other fruits and berries as well as medicinal bushes.”

Following the collapse of the socialist bloc in 1989 and a lack of subsidies for agriculture in DPR Korea, famine and malnutrition became widespread in rural areas.

DPR Korea is a harsh mountainous country where only 16% of the land area is suitable for cultivation, data from the Centre suggests.

It addded that out of  desperation in the 1990s, people turned to the marginal sloping lands but this had a price: deforestation for cropping land and fuelwood left entire landscapes denuded and depleted of nutrients.

In an attempt to reverse the situation, an innovative project began in 2002 involving the Swiss Agency for Development and Cooperation (SDC) and Korea’s Ministry of Land and Environmental Protection. The World Agroforestry Centre was later brought in to provide technical advice.

A system of establishing user groups with one representative from each family enabled demonstration plots to be set up and a large number of households have benefited from knowledge about growing multi-purpose trees.

Using these types of trees have helped  improve and stabilise soils, as well as provide fertilizer, fodder or fruits.

To further support the development of appopriate skills in North Korea, the World Agroforestry Centre has announced plans to publish an agroforestry manual.

The Centre added that work was also underway to develop an agroforestry policy for sloping lands management, as well as establishing an agroforestry inventory.

Source: World Agroforestry Centre press release

Date: 27/08/2010

Trying to curb the appetite of tree-hungry chopsticks


For the humble chopstick, life is predictable, reports Alice-Azania Jarvis in the Independent newspaper.

Start off as a tree, one of the 25 million felled each year for the purpose. Spend a brief few weeks, newly-whittled, encased in paper. Then wind up on someone’s plate, where you are expertly used to shovel noodles, or rice, or meat into a mouth.

Then that’s it. It’s time to face the great landfill in the sky. Millions of chopsticks meet their end like this. In fact, billions – 45 billion a year in China alone, taking with them some 100 acres of birch, poplar and bamboo forest a day.

It is one reason why attempts are under way to turn the Chinese off their disposable cutlery and on to the longer-lasting kind.

In 2006, the Government introduced a 5% tax on all disposable wooden chopsticks following petitions from schoolchildren and citizens’ group.

Since then, efforts to curb the wooden sticks’ use have increased. A BYOC (Bring Your Own Chopsticks) movement has been actively petitioning for sustainable options for some time.

Described by the China Post as a collection of “young yuppies”, they carry around their own implements when dining out. Occasionally, claims the Post, restaurant owners take it upon themselves to reward the yuppies’ efforts with a complimentary bowl of soup.

Greenpeace launched a campaign with the slogan “say no to disposable chopsticks.” In 2008, activists dressed as orang-utans invaded corporate cafeterias – Microsoft, Intel and IBM among them – to discourage diners from going disposable.

Then, earlier this year, the Chinese Ministry of Commerce joined with five other government departments to warn that companies using disposables could soon face legal restrictions. They claimed to “aim at decreasing the use of the throwaway utensil”.

“Production, circulation and recycling of disposable chopsticks should be more strictly supervised,” they explained.

It’s a stark about-face for the Chinese government. Prior to the measure, they had actively encouraged disposables’ use. They were, reasoned authorities, more hygienic that their reusable cousins.

The debate over throwaway instruments, while raging in China, is by no means limited to chopsticks.

In the UK, disposable cutlery is thought to be used for an average of three minutes before being discarded.

Plastics – including convenience cutlery, crockery and cups – account for 7% of office waste. That’s before the countless millions of knives, forks and spoons churned out by fast food restaurants, cafes and supermarkets are taken into account.

Recent years have seen the rise of the Carry Your Own Cutlery (CYOC) movement, while websites such as recyclethis.co.uk offer readers advice on how to reuse their plastic implements.

Increasingly, retailers are under pressure to offer – if not reusable – then at least recyclable options.

Starbucks recently pledged to introduce renewable materials during its next round of store upgrades and has committed to using entirely recyclable cups by 2015. Pret-a-Manger, meanwhile, has pledged to go “landfill-free” by 2012.

Not everyone has been so quick to change. McDonald’s, while using recycled paper in much of its packaging, defends its choice of plastic cutlery on the grounds that washing up would waste energy.

How effective China’s measures will be remains to be seen. The BYOC has been slow in picking up active support, and the government’s waste warning, while a step in an environmentally-friendly direction, is more bark than bite.

Legislation is looming, though as yet there are few concrete incentives for diners to trade in their disposables. Wooden chopsticks cost restaurant owners a fraction of what the more durable alternatives do, since the cost of sterilisation is high.

What’s more, the alternative melamine-resin chopsticks have a notoriously high formaldehyde content, which is neither great news for the environment nor diners’ health.

Polls by news outlets have found broad support for reusable items. Some 84.2% of participants told a recent Sina.com poll that they would swap for more durable options.

Still, analysts point out that the authorities’ interest is divided: environmentally, cutting down on chopsticks makes sense; economically – in the short term at least – it doesn’t.

More than 300,000 people are employed by the wooden chopstick industry, across 300 factories. Exports of their wares bring in $200m a year.

In 2009, it was claimed that 300 restaurants in Beijing had ceased to provide disposable chopsticks. In a country of some 1.3 billion diners, there’s a long way left to go.

Source: Independent

Date: 31/08/2010

Deadly oak disease hits Welsh private woodland


An outbreak of the pathogen Phytophthora ramorum, otherwise known as sudden oak death, has been discovered for the first time in Wales on trees in a privately-owned woodland, reports the Forestry Commission Wales.

Staff from Forestry Commission Wales and the Food & Environment Research Agency (Fera) have visited the owner of the woodland in Denbighshire and a notice has been served to fell the infected Japanese larch trees. Only a small number of trees are infected, and the owner will use the timber on site.

Sudden oak death is a fungus pathogen that kills many of the trees that it infects. It was first found on Japanese larch trees in Wales in June this year in public woodlands  near Port Talbot, near Bridgend.

The outbreak in South Wales was the first time P. ramorum has been encountered on larch elsewhere in Great Britain since it was first discovered on larch in South-West England in 2009.

The woodland owner, Wendy Charles-Warner, contacted Take Cover, to say: “We feel rather aggrieved at the tone of the [Forestry Commission] press releases stating that we have been served with enforcement notices as if we were responsible for this outbreak and somehow in the wrong.

“We could take no steps to prevent this disease which is mainly airborne, have done nothing wrong and have at every point done everything we can to assist the forestry commission.”

A motor rally set to attract thousands of spectators to South Wales in July was postponed as a result of an ou6tbreak of the tree disease.

The route of the Swansea Bay Rally ran through forests that had been hit by the infection.

Richard Siddons from the Forestry Commission Wales said the organisation was “determined to minimise the impacts of this serious tree disease on woodlands, and the support of woodland owners in looking out for early signs of P. ramorum infection will play a key part in achieving that”.

It seems as if the warm but wet summer has been a key driver in the development of tree pathogens, with a number of cases making the headlines.

In April, a group of woodland experts expressed their fears for the future of British native oaks in light of the emergence of a disease called Acute Oak Decline, a bacterial infection that, they warned, could be as devastating for the English Landscape as Dutch elm disease in the 1970s.

They called for much more financial support from the UK government to help tackle the problem through research and land management measures.

In July, the Forestry Commission announced a £600,000 support package for woodland owners in South-West England and Wales to help tackle the outbreak of P. ramorum infection on larch trees. The package is part of Defra’s £25 million, five-year Phytophthora management programme.

Forestry Commission Wales is developing a complementary programme of support for private woodland owners who have P. ramorum confirmed on their land. Details of this support will be announced in September.

Ms Charles-Warner, in her comment to the story on this blog (see below for her full response), added: “

The ‘package of assistance’ that the Commission have announced is £300 per hectare, which we are not receiving or going to receive.

“If you have knowledge of tree felling you will appreciate that in a situation where stringent biosecurity measures have to be used and the trees have to be felled and brashed by hand that is a paltry sum, even in the highly unlikely event that you receive it.

She went on to say that she was “deeply concerned” about the situation: “If the Commission wishes landowners to report Phytopthora Ramorum and control it, in order to protect commercial forestry, then realistic support needs to be in place.

“Many landowners faced with a the prospect of funding felling and site clearance work themselves with the attendant stress and unpleasantness, are likely to ignore the disease and not report it.”

More information about sudden oak death can be found on the Forestry Commission’s website at www.forestry.gov.uk/pramorum.

To find out more about the support fund or to report suspected P. ramorum infection in their trees, woodland owners should contact Forestry Commission Wales’s Grants & Regulations Office on tel: 0300 068 0300 or email: bww.ts@forestry.gsi.gov.uk.

Source: Forestry Commission Wales press release

Date: 25/08/2010

British public ‘ignorant about trees’


According to a survey reported in Horticulture Week, a trade magazine, more than three-quarters of the people questioned believed that the main role of trees was to provide shade.

The questions, posed on behalf of Velvet Tissues – a UK-based toilet paper firm – also had a few more positive messages when it came to people’s attitudes towards trees, such as 75% agreed that trees featured in a favourite memory and 9% remember kissing a childhood sweetheart under a tree.

More than two-thirds of the people questioned considered the oak to be the UK’s most iconic tree, yet – depressingly – a third were not able to identify it.

The survey is hardly scientific,  and it is surely closely tied to a PR campaign in which the company describes itself as a tree lover (its website says it plants three trees for every one it cuts down to make its products), we felt it was worth featuring on this blog.

Sadly, it was not possible to get more details on the survey’s background because there is nothing on the company’s website and Horticulture Week only ran a very short story on the findings.

Source: Horticulture Week

Date: 25/08/2010

Africa push for ‘great tree wall’


African leaders are meeting in Chad to push the idea of planting a tree belt across Africa from Senegal in the west to Djibouti in the east, reports the BBC News website.

The Great Green Wall project is backed by the African Union and is aimed at halting the advancing Sahara Desert.

The belt would be 15km (nine miles) wide and 7,775km (4,831 miles) long.

The initiative, conceived five years ago, has not started because of a lack of funding and some experts worry it would not be maintained properly.

The BBC’s Tidiane Sy in Senegal says the initiative has the full backing of Senegalese President Abdoulaye Wade, who is in Chad with 10 other heads of state to discuss desertification.

His government has created the website dedicated to the Great Green Wall. But our reporter says many other leaders seem ready to forget the project.

At the Copenhagen Climate Change summit last year, for instance, the Senegalese delegation made a presentation on the project.

It is envisaged that the belt would go through 11 countries from east to west.

The trees should be “drought-adapted species”, preferably native to the areas planted, the Great Green Wall website says, listing 37 suitable species.

The initiative says it hopes the trees will slow soil erosion; slow wind speeds and help rain water filter into the ground, to stop the desert from growing.

It also says a richer soil content will help communities across the Sahel who depend on land for grazing and agriculture.

Senegal says it has spent about $2m (£1.35m) on it and communities are being encouraged to plant trees.

The BBC’s former Chad correspondent Celeste Hicks says older people in N’Djamena – where the conference is being held – talk anecdotally about how the capital city has become a dustbowl over the last 20 years as the Sahara Desert has encroached southwards.

The country has made efforts to plant a green belt of trees around the capital, and tens of thousands of young trees are being grown in nurseries on the outskirts of the city, she says.

But so far little has been done to transplant these trees to the northern desert areas to become part of the Great Green Wall.

Source: BBC News website

Date: 17/06/2010

Boost for Indonesian ‘ecosystem restoration’ forest


Indonesia’s forests  received a boost when the nation’s government announced plans to double the size of the country’s first forest for “ecosystem restoration”, according to a joint press release issued by the RSPB.

It says that Indonesian Forest Minister Zulkifli Hasan has announced that he will expand the 52,000 hectare concession held by Burung Indonesia, the RSPB (UK) and BirdLife International in central Sumatra to a total area of 98,000 hectares.

According to the RSPB, the restoration area now equals two-thirds the size of greater London and is greater than the size of Singapore.

The bird conservation group welcomed the news, adding that other applications for ‘forest restoration’ licences are being submitted to the nation’s forestry ministry.

In 2009, the ministry is reported to have received as many applications for forest restoration licences as it did for logging concessions.

Applications for forest restoration totalled a further two million hectares, and are now being assessed.

The 98,000 hectares where the minister announced he would grant “ecosystem restoration” is within Harapan Rainforest, one of the last remaining areas of dry lowland Sumatran forest and is one of the most threatened rainforests in the world.

It is home to a host of rare animal and plant species, including the critically endangered Sumatran tiger (Panthera tigris sumatrae), of which fewer than 300 remain in the wild.

It supports an amazing 55 mammal species, including the globally-threatened Asian elephant (Elephas maximus sumatranus) and Malayan tapir (Tapirus indicus), as well as the world’s rarest stork – the Storm’s stork (Ciconia stormi) – and a rich diversity of other wildlife.

An initial licence of 52,000 hectares was granted to the environmental consortium in 2008, allowing them to protect, nurture and restore the forest in a former logging concession.

Illegal logging has been significantly decreased and forest fires, which once released significant carbon dioxide emissions, have been all but stamped out. Not only is the forest an important carbon store, but the tree planting programme in Harapan Rainforest is capturing more carbon from the atmosphere.

Botanic experts from the Royal Botanic Gardens, Kew in the UK have identified a plant growing in the forest, Emblemantha urnulata B. C. Stone, that is unique to the area and had only been recorded twice before.

Agus B. Utomo, the Executive Director of Burung Indonesia, said: “The Ministry of Forestry had the foresight to create a new form of forest management in 2004 with the ‘ecosystem restoration’ licence.

“We’re delighted that ecosystem restoration is now an integral part of forest management strategies in Indonesia. As a result, Burung Indonesia is already planning to expand our portfolio of ecosystem restoration concessions.”

Source : RSPB press release

Date: 18/06/2010

Cancer drug derived from rainforest shrub set for human trials


A potential cancer drug developed from an Australian rainforest plant is set to progress to human trials, reports the Strait Times.

Quoting the AFP wires, the newspaper explains that the drug is being put forward to the next stage after fighting off inoperable tumours in pets.

Queensland firm QBiotics Limited said its EBC-46, derived from the seeds of a tropical rainforest shrub, was ready to be tested on humans after successfully treating solid tumours in more than 100 dogs, cats and horses.

“We’ve treated over 150 animals… with a variety of tumours, and we’re prepared to move into human studies,” explained chief executive Victoria Gordon.

Dr Gordon said the results so far indicated the drug could work to counter a range of malignant growths, such as skin cancers, head and neck cancer, breast cancer and prostate cancer.

She said the drug works like a detonator inside tumours, prompting inactive beneficial white cells to begin to fight and destroy the cancer.

The company is reported as spending six years developing the drug since the previously unknown molecule in the native Australian plant blushwood was discovered.

It hopes to raise enough funds to begin human trials in 2011.

Dr Gordon said the compound proves the value of retaining Australia’s unique tropical rainforests.

Source: The Strait Times (Singapore)/AFP

Date: 14/06/2010

UK elms – ‘not out of the woods yet’


Colin Tudge, the author of The Secret Life of Trees, is invited by the UK’s Telegraph newspaper to give his reaction to efforts to breed a Dutch elm disease-resistant species.

Library image from Take CoverIt’s an interesting read as he gives his reaction to this battle with nature, so here it is:

Could the English elm, so sadly laid low by Dutch elm disease, make a comeback? Paul King, who breeds trees at Raine in Essex, is on the case. Nearly 25 years ago he acquired cuttings from a few mature trees. He has now multiplied the tissues to produce a whole new generation of young elms that seem to be resistant (and are on sale for £120 apiece). Scientists at the Forestry Commission’s research centre in Surrey welcome his initiative – they are on the case, too – but are cautious. Resistance, they point out, is a tricky business.

The English elm, Ulmus procera, is probably not a “true” native – Britain has only 39 “truly” native trees – and was most likely introduced by Neolithic farmers from south-east Europe, via Spain. But it is an honorary citizen, treasured for its usefulness and its looks, favourite of landscape painters, notably of Constable; a tree of open woodland but just as happy in hedgerows where, if it was left alone, it flourished by the tens of millions. In the West Country it was known as “the Wiltshire weed”.

The first sign of trouble came in 1910 when the fungus Ophiostoma ulmi, a distant and degenerate cousin of the truffle, started killing trees in mainland Europe. It acquired its name, Dutch elm disease, in 1921 because it was first properly researched in Holland. It arrived in Britain by 1927 and looked very nasty. Happily, the disease died down by the Forties, after killing 10 to 40 per cent of our elms. Dr Tom Pearce of the Forestry Commission predicted, in 1960, that such a thing should not happen again – unless, he added, “the fungus completely changes its present trend of behaviour”.

Which it duly did. A new, closely related species of Ophiostoma appeared in North America – Ophiostoma novo-ulmi. It arrived in Britain in 1967 on imported logs, and throughout the Seventies and into the Eighties it killed about 25 million out of about 30 million elms, including most of the particular English species, Ulmus procera.

Dutch elm disease has all the biological attributes needed to be thoroughly nasty. It is one of the many “wilt diseases” of trees, which spread through the vessels of the xylem and block them. The spores are carried passively with wonderful efficiency in the sap, through the whole tree, and spread via the roots of separate trees that are often joined underground. The spores don’t live long once the tree has died and so should die out as their host succumbs – but they have a trump card: they are carried from tree to tree and from forest to forest by flying bark beetles of the genus Scolytus.

There is some innate resistance among the world’s many species of elm. The Ophiostoma fungus probably arose in Asia, so the Asian elms have evolved in its presence – and have developed considerable resistance. Breeding programmes are afoot in Europe to introduce genes from Asian species into European types by various means – and may yet succeed. Meanwhile, as Paul King has found, even within susceptible species, such as Ulmus procera, there will usually be some resistant strains. If they can be bred, perhaps we will have a new resistant strain.

So why the caution? Well, for one thing, it depends what the tree is really resistant to: the fungus or its insect vector? Paul King’s new trees are probably not resistant to the fungus itself, but are simply less palatable to the beetle. Of course, the fungus can’t usually infest the tree without the beetles – but it surely would be better to be specifically equipped with genes that would protect it even if beetles did get in.

The sad tale of Britain’s elms parallels that of the American chestnut, Castanea dentata – with some intriguing contrasts. For the American Indians and for the first immigrant Europeans, the American chestnut was a wonder tree. Its nuts were a food staple – and supported 40 million wild turkeys for good measure – and its trunks provided timber. There were so many that a squirrel could travel from chestnut to chestnut from Maine to Georgia without setting foot on the ground, or so the story went.

But the overconfident forestry “improvers” of the 19th century were still not content. They began to import Asian species with bigger nuts, to crossbreed. Inevitably, the newcomers came with their own diseases. And the American chestnuts, beset by novel pathogens, succumbed. By the end of the Twenties, the American chestnut, once perhaps the commonest North American broadleaf, was all but gone.

Again, through too much zeal, the Americans felled great swathes of chestnuts to create a firewall against the spread of infection. This failed to contain the disease – but it did, so some biologists suggest, remove the myriad genetic variations from among the wild trees, which might have included some that would have conferred resistance.

By leaving our own beleaguered elms to live on in the hedges, and nurturing the few survivors, as Paul King and others have been doing, we may avoid that final fate. (In truth, the American chestnut might not quite be dead. At least, George W Bush planted one outside the White House on Arbor Day in 2005 – but it is a hybrid: 15 per cent of its genes are from resistant Asian species. It is a sad relic, like an exhumed dodo).

Overall, the message is mixed. We could see the heroic efforts of a few growers and scientists as a triumph of human ingenuity over natural adversity – the continuing tale of “man’s conquest of nature”. Or we could see this endeavour as a desperate, last-ditch attempt to ward off the consequences of our own folly. For these are tales of hubris. We thought we could do what we liked in the name of commerce. But actually, life is more complicated than we ever supposed – and in the end, it is beyond our ken. Cause and effect relationships in nature are non-linear, which means it is intrinsically impossible to predict the outcome, beyond saying it won’t be good.

Source: Telegraph newspaper

Date: 09/06/2010

Wales to update its ancient woodlands map


Forestry Commission Wales has announced plans to update the nation’s Ancient Woodland Inventory.

Take Cover library image In a press release, the commission said that these habitats, which date back to at least the 17th Century, “support many species of plants and wildlife that depend on the evolving but continuous environments created by dead and dying wood and broken sunlight”.

It added that the inventory was first produced about 30 years ago, and since then, technology for gathering data had improved dramatically and better sources of information had come to light.

The update, which will be carried out over the next 12 months, will identify former ancient woodlands that have subsequently been planted with conifer trees to satisfy the demand for timber over many decades.

These woodlands are known as Plantations on Ancient Woodland Sites (PAWS).

This information will guide decisions on restoring some of the PAWS to their natural state by removing non-native trees and planting native broadleaf species such as oak, birch, rowan and ash.

“Such work helps to increase the variety of different plant and wildlife species in the woodland by improving habitats and providing food and shelter,” the commission explained.

Wood pastures – ancient and veteran trees found on grazed sites – will also be systematically recorded as part of the update to the inventory.

Despite the ecological value of wood pasture, it has no legal protection, so identification on the inventory may help protect these sites from damage or destruction.

The concept of  “ancient woodland” was developed in the 1970s and 1980s, when studies showed that woodlands that have had a continuous woodland cover for centuries were typically of higher nature conservation value than those that had developed recently.

The baseline date of 1600 AD was adopted because reasonable maps were available from this time (in England, at least).

But the commission admitted that it was an arbitrary date, and there was no clear ecological cut-off.

Michelle van Velzen, forestry and environment policy and programme manager at Forestry Commission Wales, said: “Ancient woodlands are a precious and finite resource that cannot be recreated.

“This update to the Ancient Woodland Inventory will ensure we have the most comprehensive and accurate information on the extent and nature of ancient woodlands in Wales.”

The update to the inventory will be completed in March 2011 and the new information will be supplied to local authorities for their use when developing planning policy that affects woodland.

Source: Forestry Commission Wales press release

Date: 11/06/2010

Dutch elm disease ‘resistant’ trees go on sale


More than 2,000 healthy English elms have been produced from a single tree which survived the devastating disease in the 1970s, the UK’s Telegraph newspaper reports.

Take Cover library imagePaul King, who runs a tree nursery, stumbled upon the mysteriously unharmed specimen while he worked to clear hundreds of diseased elms and took cuttings from it.

Over the next 23 years, the paper says, he used the samples to nurture hundreds of saplings which have the same resistant traits as the 200-year-old parent tree.

Mr King sent the sample plant tissue off to a laboratory for micropropagation.

Now, nearly 25 years later, the cuttings have produced 2,000 healthy trees which are set to replace the dwindling English elm population.

The trees (Ulmus procera) are believed to repel the beetle which carries the Dutch Elm disease.

The 10ft tall trees are available to buy from Mr King’s business, The Tree Nursery in Rayne, Essex, and cost £120 each.

Mr King said: “We have been working hard on the project for 23 years.

“I was working dismantling and clearing diseased elms when Dutch Elm disease hit, and saw how many were destroyed.

“But as we worked in this particular area, we noticed that there were a few trees which seemed to be resistant to the disease.

“While other trees around them died, these were totally unharmed by the Dutch Elm disease.

“After about 10 years, they were still surviving while every other tree in the area had died and we knew they must be resistant.

“So an expert from the local council took cuttings from one of the mature trees for me, which survived – and then kept surviving.

“We realised we had something on our hands here and I sent them off for micropropagation, and before I knew it I had a production.

“The original trees, which are around 150 to 200 years old, are still surviving less than five miles from the nursery and the first cuttings are still 100% in leaf.

“The trees we have propagated are all still in full leaf, even though there is Dutch Elm disease in the hedges just two or three metres from them.

“We can say they are extremely resistant to Dutch Elm disease.”

Dutch Elm Disease is native to Asia but was accidentally introduced in Europe in 1910, although it only killed a small proportion of trees.

It gets it name after it was isolated in Holland in 1921.

It had largely died out by 1940 but in 1967 a new and deadlier strain of the disease arrived in Britain on a shipment of elm tree logs from North America.

The disease killed an estimated 25 million elm trees throughout the UK.

Source: Telegraph newspaper

Date: 07/06/2010

Oak disease ‘threatens British landscape’


The continuing spread of a deadly disease that affects the UK’s native oak trees is causing concern among tree professionals and conservation groups.

Take Cover library photoThe BBC’s environment reporter Mark Kinver writes that Acute Oak Decline (AOD), caused by a bacterial infection, can kill an infected tree in just a few years.

Some tree experts are comparing AOD to Dutch elm disease, which killed millions of trees throughout the UK during the 1970-80s.

They said extra funds for more research into the disease were urgently needed.

Although AOD has been confirmed in 55 cases, the number of trees displaying symptoms was steadily increasing, delegates at the Royal Forestry Society’s (RFS) annual conference were told.

The disease affects the UK’s two native species of oak – sessile and pedunculate. To date, there have been no confirmed cases in other species of oaks found in Britain, such as Turkey and red oaks.

‘Extensive bleeding’

Information from Forest Research, the scientific department of the UK Forestry Commission, says the new disease affects oaks more than 50 years old.

Symptoms are “extensive stem bleeding” in which dark fluid seeps from small cracks in the bark and runs down the tree trunk.

In early stages of the disease, the health of a tree’s canopy does not appear to be affected, but it may become thinner as the tree succumbs to AOD.

On its website, Forest Research says: “The incidence of AOD in Britain is unquantified at this stage, but estimates put the figure at a few thousand affected trees.

“The condition appears to be most prevalent in the Midlands and investigations to determine the extent of the disorder are under way.”

A spokesman told BBC News: “Forest Research pathologists have isolated a previously unidentified bacterium they believe is highly likely to be playing a key role in the Acute Oak Decline observed in Leicestershire and elsewhere.

“However, the full cause of the condition is thought likely to be complex, involving a number of factors besides the bacterium. A research report is currently awaiting peer review.”

‘Major threat’

Tree organisations are calling for more funding to be made available to allow researchers to better understand the full impact of the disease.

John Jackson, the organiser of the RFS’s conference, said: “Urgent action is not an option – it’s a necessity.”

Hilary Allison, policy director for the Woodland Trust, added: “The impact of the loss of an iconic tree both from our countryside and towns would be catastrophic, and therefore has the capacity to be a major threat to the UK’s oak woods.”

“I have never seen anything like it,” said Peter Goodwin, co-founder of Woodland Heritage.

“Its spread over the last two years has been quite alarming.”

Mr Goodwin told BBC News that very little was known about the virulent bacteria responsible for the disease.

“We’ve never had a bacterium that is capable of doing what this one is doing.”

He suggested that people were possibly the main way in which the disease was spread from tree to tree, but added that “natural vectors” – such as squirrels, birds and insects – could also play a role.

“I think this is the worrying thing, we all want to know what are the vectors that is spreading it. Is it airborne? We just don’t know.”

Forest Research advises people working in affected areas to take appropriate measures to limit the chances of AOD being carried to new sites.

“The most important thing we can do in this and other cases is to research and understand the causes so that we can provide appropriate management advice for tree owners and woodland managers,” the spokesman added.

“It is also important that we remain vigilant against accidentally importing new and damaging pests and diseases from outside Great Britain.”

Source: BBC News website

Date: 28/04/10

US Forest Services announces plan to save at risk forests


US Forest Service chief Gail Kimbell announced $50 million in grants to permanently protect 24 working forests across 21 States, as part of the  Forest Legacy Program, a USDA press release said.

The programme is designed to permanently protects important private forestland threatened by conversion.

“The Forest Legacy Program conserves open space, which allows us to respond to climate change, improves water quality and flows and connects children to nature,” said Agriculture Secretary Tom Vilsack.

“The strength of the Forest Legacy Program is the co-operation between States, partners and private landowners, all working together to protect environmentally and economically important forests that are threatened by conversion.”

Examples of 2009 projects include: forest essential for wildlife and recreation in Maine; pine ecosystem critical for threatened and endangered species in Arkansas and working forests that support rural jobs in Oregon.

The Forest Legacy Program promotes voluntary land conservation by operating on the principle of “willing buyer, willing seller”.

Private forest landowners are facing increasing real estate prices, property taxes and development pressure, which result in conversion of forests to other land uses.

The Forest Legacy Program focuses on conserving working forests – those that provide clean water, forest products, fish and wildlife habitat and recreational opportunities.

Most Forest Legacy Program projects are conserved through conservation easements, allowing landowners to keep their forestlands while protecting them from future development.

Source: USDA press release

Date: 18/05/2009

Tree-killing hurricanes ‘could contribute to global warming’


A first-of-its kind, long-term study of hurricane impact on US trees shows that hurricane damage can diminish a forest’s ability to absorb carbon dioxide from the atmosphere, Science Daily reports.

Tulane University researchers examined the impact of tropical cyclones on US forests between 1851 to 2000 and found that changes in hurricane frequency might contribute to global warming.

The results are published in the Proceedings of the National Academy of Sciences.

Trees absorb carbon dioxide as they grow, and release it when they die – either from old age or from trauma, such as hurricanes.

The annual amount of carbon dioxide a forest removes from the atmosphere is determined by the ratio of tree growth to tree mortality each year.

When trees are destroyed en masse by hurricanes, not only will there be fewer trees in the forest to absorb greenhouse gases, but forests could eventually become emitters of carbon dioxide, warming the climate.

Other studies, notes Tulane ecologist Jeff Chambers, indicate that hurricanes could intensify with a warming climate.

“If landfalling hurricanes become more intense or more frequent in the future, tree mortality and damage exceeding 50 million tonnes of tree biomass per year would result in a net carbon loss from US forest ecosystems,” says Dr Chambers.

The study, which was led by Tulane postdoctoral research associate Hongcheng Zeng, establishes an important baseline to evaluate changes in the frequency and intensity of future landfalling hurricanes.

Using field measurements, satellite image analyses, and empirical models to evaluate forest and carbon cycle impacts, the researchers established that an average of 97 million trees have been affected each year for the past 150 years over the entire United States, resulting in a 53-million ton annual biomass loss and an average carbon release of 25 million tons.

Forest impacts were primarily located in Gulf Coast areas, particularly southern Texas and Louisiana and south Florida, while significant impacts also occurred in eastern North Carolina.

Chambers compares the data from this study to a 2007 study that showed that a single storm – Hurricane Katrina – destroyed nearly 320 million trees with a total biomass loss equivalent to 50–140% of the net annual US carbon sink in forest trees.

“The bottom line,” observes Dr Chambers, “is that any sustained increase in hurricane tree biomass loss above 50 million tons would potentially undermine our efforts to reduce human fossil fuel carbon emissions.”

Study contributors include Tulane lab researchers Robinson Negrón-Juárez and David Baker; George Hurtt of the Institute for the Study of Earth, Oceans, and Space at the University of New Hampshire; and Mark Powell at the Hurricane Research Division, National Oceanic and Atmospheric Administration.

Source: Science Daily

Date: 10/05/2009

Ancient trees ‘need public funded protection’


One of Britain’s leading experts on trees has expressed astonishment over the lack of public funding to protect ancient trees, reports Horticulture Week.

Ted Green, an adviser to the Queen who was awarded an OBE recently for services to ancient trees, said state cash was needed because of trees’ landscape and cultural importance.

“These trees are old archives of gene banks,” said Green. “They are reservoirs of resistance — that is why they are still standing.”

He told a conference for Wealden District Council recently: “It is important to allow them to go through the natural ageing process and not tidy them away.”

Chris Hannington, Wealden District Council’s landscape and biodiversity officer, said: “There are many threats to the survival of ancient trees.

“Poor management, inappropriate tree surgery and global warming are all important issues affecting them.”

Wealden’s ancient trees are among the largest concentrations in northern Europe and were surveyed recently by Wealden ancient tree survey officer Ali Wright.

Of the 24,000 recorded ancient trees in the UK nearly 1,000 of them — 4% — were in Wealden. These included yew trees that could be 1,000 years old.

Wealden District Council is currently consulting on a set of guidelines to encourage developers to preserve veteran trees.

Source: Horticulture Week

Date: 06/05/2009

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