Sie sind hier


tree destruction

forest fire. @ Peter J/
July 2012

Forest fires and their causes

The summer of 2010 became a 'once a century' disaster for Russia: the country had to fight over 600 severe forest fires, more than 50 people died. At the height of the incineration almost 200,000 hectares (494,000 acres) were aflame. In the following year, too, disastrous fires swept over vast areas [1]. And in summer 2012 again: in the Amur area alone more than two million hectares (five million acres) of forest were destroyed [2].

This has, of course, something to do with a global trend for higher temperatures that also wipes out eucalyptus forests in Australia, causes a prolonged drought in the southwest of the US, killing over five million urban shade trees in 2011 in Texas alone [3], and has caused even two 'once a century' droughts in the Amazon Basin. But insiders know that the heavy forest fires in Russia are no surprise but rather the quittance for a neglected national forest management: a few years ago, the new national forest law abolished the majority of local forestry offices. How the risk of forest fires is enhanced by forest mismanagement has been shown by recent studies in the USA.


Weltkarte mit Waldbränden

composition of satellite images with overlaid graph of forest fire frequency (2010)
red: very often, yellow: most often

© DPA / NASA / GSFC / MODIS Rapid Response


The USA too are struggling with ever more severe and bigger fires, mainly in the Southwest. Arizona, New Mexico and Texas have become so dry that huge, explosive fires consumed millions of acres of vegetation in the summer of 2011. The role of 'climate change' in this is still unclear, the more immediate cause seems to be the intermittent weather pattern called La Niña. What experts do see is that some areas that are burning this year may never return as forest — they are more likely to grow back as heat-tolerant grass or shrub lands. It is also becoming clear that the wide-spread method of clear-felling contributes to wildfires because the resulting landscape of brushwood and young trees is more susceptible to drought and catching a spark than the old trees with their developed roots and fire-proof bark.

There is also an emerging scientific consensus about another form of forest mismanagement: by suppressing the (natural) mild ground fires that used to clear out underbrush and limit tree density, many US forests are now hopelessly overgrown with brushwood. During droughts, such areas become tinderboxes. In some areas the dense brushwood has become so high that fires also damage the crowns of the old trees – which had been safe from most fires when the forests had been managed by nature.

The government agrees that many forests throughout the West need to be thinned, and some environmental groups have come to agree too. But the small trees and brush have little commercial value, especially in a weak economy, and funding for the thinning is thinning itself. For the time being, the Forest Service can treat only small sections of forest that pose the biggest threats. [4]

[1] Spiegel Online, Juli 2011 and topic overview (both German)
[2] Spiegel Online, Juli 2012 (German)
[3] Jim Robbins, Why Trees Matter, NY Times, April 11, 2012
[4] Justin Gillis, With Deaths of Forests, a Loss of Key Climate Protectors, NY Times, Oct 1, 2011

large buttressed tree in primary rainforest in Ecuador. © Dr. Morley Read/
Jan 2012

World's biggest trees disappear

Long-term studies in Amazonia, Africa and Central America show that proportionally, the biggest and oldest trees of the world vanish more rapidly than the younger tree populations.

Big trees may comprise less than 2% of the trees in a forest but they can contain 25% of the total biomass! They are vital for the health of whole forests because they produce large amounts of seeds. 'With their tall canopies basking in the sun, big trees capture vast amounts of energy. This allows them to produce massive crops of fruits, flowers and foliage that sustain much of animal life in the forests. Their canopies help moderate the local forest environment while their understory creates a unique habitat for other plants and animals,' says William Laurance, a research professor at James Cook University in Cairns, Australia.

But after clearfelling around them, 'their tall stature and relatively thick, inflexible trunks, may make them especially prone to uprooting and breakage near forest edges where wind turbulence is increased.'

Another cause for the disappearance of the ancients is fragmentation of forests, caused by roads, farms and settlements. 'Fragmentation of the forests is now disproportionately affecting the big trees,' says Laurance. 'Not only do many more trees die near forest edges, but a higher proportion of the trees dying were the big trees.'

Droughts and global warming are another problem: 'In cloud forests, big trees use their branches and crowns to rake the mist and capture water droplets. Recurring warmer weather,' however, seems to 'push clouds up to higher elevations depriving them of sources of moisture'.

Big tree species also disappear because their seedlings don't find favourable growing conditions anymore. After human intervention, aggressive shrubs may invade the forest floor or benevolent fungi may be driven out by pathogenic species. And seedling and young tree mortality rates rise due to warm winters which fail to kill pests.

New pests and diseases also spread due to human trade in plants and timber products. In the 1960s and 70s, the peak of the Dutch elm disease which had spread globally via infected timber, killed the majority of the old elm trees of the world. And now, new and often non-native organisms and bacterial infections are threatening oak, ash and other species, while North America's ancient alpine bristlecone pines (Pinus longeava; the oldest trees in the world) are falling victim to a voracious beetle and an Asian fungus (see Jim Robbins, Old Trees May Soon Meet Their Match, NY Times).

source: John Vidal, World's giant trees are dying off rapidly, studies show, The Guardian, 26 Jan 2012

the old oak at Crewkerne. © Ben Hartshorn
July 2009

People power saves oak tree

The venerable old Lucombe oak (Quercus x hispanica, a cross between the Cork Oak, Q. suber, and the Turkey Oak, Q. cerris; cultivated in 1762 by William Lucombe) in Henhayes Crewkerne, Somerset, was found to have a fungus infection (or perhaps just be in the way of a new sports center development?), deemed a hazard and due to be felled by the local council. The council's insurers appeared to be bullying the councilors into taking drastic action and threatening to sue any individual who stood in the way.

But the citizens of Crewkerne did not obey and began the Save the Oak! Save Henhayes! campaign and flew in arboreal experts from Germany with more precise scientific equipment – which proved that the tree had a future! The campaigners collected over 2,000 names supporting a petition and the council agreed to preservation rather than destruction, at least for the following three years.

The campaign showed, so their spokesman, Green politician B. Hartshorn, said, that 'we need to value and protect our green spaces and the species that inhabit them. … We have a magnificent oak tree to enjoy.'

Update Feb 2013: The tree still stands.

sources: BBC News
This is Dorset

tropical deforestation and landscape fragmentation in Colombia, mostly due to coca crops. ©
March 2009

Drug production kills trees and people

Since the United States and the UN 'took over' Afghanistan from the Taliban, the annual opium production has increased over 5400 per cent – 150 tonnes in 2001, 8200 tonnes in 2007. The 2007 harvest produced about 820 tonnes of heroin and at the Uzbekistan border, UN troops found themselves in the strange position of having to wave through the convoys of black jeeps. All this land growing poppies cannot be used for food production or reforestation! The chemical waste products of the heroin labs pollute additional land.

Worse for the trees is the situation in Latin American countries ruled by cocaine. Here, unlike in Afghanistan, US involvement has actually helped to destroy 1.15 million hectares of coca, but in Colombia for one, production has not actually fallen. In March 2009, 'Latin America declares war on drugs a failure' (The Guardian Weekly, 13 March 09, pp1-2).

In Latin America, armed groups seeking new land for coca are clearing rainforests killing and evicting the inhabitants. 'Some 270,000 Colombians were forced to flee their homes in the first half of 2008' (The Guardian Weekly), the situation in Venezuela is equally bad.

The Colombian government has created a website for 'Awareness about cocaine's ecocide in Colombia'. Note: This website disappeared in late 2012 – now that's worrying!

veils of rain over forest landscape. © Dudarev Mikhail/
Oct 2008

Tree vapours cool planet

Forests store carbon and help in this way to prevent global warming. But they do more: scientists in the UK and Germany have now discovered that trees release a chemical that thickens clouds above them, which then reflect more sunlight and cool the Earth more sufficiently.

The scientists looked at chemicals called terpenes that are released from boreal forests across northern regions such as Canada, Scandinavia, Russia and Siberia. But other trees also produce terpenes so the cooling effect should be found in other regions too, including the tropical rainforests.

The terpenes react in the air to form tiny particles called aerosols. The particles help turn water vapour in the atmosphere into clouds. The particles released by pine forests, for example, double the thickness of clouds some 1,000m above the forests, which causes them to reflect an extra 5% sunlight back into space. 'It might not sound a lot, but that is quite a strong cooling effect. … It gives us another reason to preserve forests,' says Dominick Spracklen of the Institute for Climate and Atmospheric Science at Leeds University.

The research suggests that the destruction of old-growth forests could accelerate global warming more than was thought, and that protecting existing trees could be one of the best ways to tackle the problem.

source: David Adam, Chemical released by trees can help cool planet, scientists find, The Guardian, 31 October 2008

World Tree on the backside of the French 1-Euro coin
Oct 2008

Global deforestation costs more than the 'financial crisis'

The world's shrinking forests cost us up to US$5 trillion a year – far more than the current banking crisis. Environmentalists hope the sobering calculation, made by a European Union commissioned team, will focus political will on funding conservation.

Read more

the yew tree that stood in the garden of the Richard Jefferies Museum. © Tom Saunders
Sept 2008

Swindon Borough Council destroys old yew tree

An old yew tree (in the media described as '800 years old' but really about 250 years of age), major literary and spiritual importance, was axed by Swindon Borough Council on 25 September 2008 when no-one was around to stop the destruction.

The tree had been much appreciated by the poet Richard Jefferies (1848-1887) who had lived there in his time. The Council said the tree's roots were threatening the building.

Comment: It is a wide-spread paradigm that a building is seen more important than a tree by default and without question. And sadly, cutting down the entire living being is always cheaper than a closer investigation and careful partial surgery.

Compare Telegraph article

the word Classified in front of rough blackened background
Feb 2004

US army destroys ancient trees in Iraq

Iraq used to have the largest concentration of Date Palms on the planet. In the 1960s and '70s, about 30 million trees produced at least 578,000 tons of high-quality dates annually, the countries second largest export after oil.

But the Iran-Iraq war in the 1980s (one incident alone destroyed the five million trees of the southern Ras al-Bisha grove), and the destructive agricultural policies of Saddam Hussein's regime reduced the Date population of Iraq to about 13 million (43% of the original number).

The US authorities claim to be working on the problem. A February-2004 agreement states that the USAID's Agricultural Development Program aims to buy 40,000 Palms (0.0013%) for orchards and nurseries, while the Iraq Agricultural Ministry will provide land, personnel, logistics and maintenance for the orchards.

However, the US and British series of air strikes in March 2003 coincided with the pollination period of Date palms and brought all hopes of an abundant harvest that year to an end. As for 2004, as journalist Patrick Cockburn reported in the Independent:

"US soldiers driving bulldozers, with jazz blaring from loudspeakers, have uprooted ancient groves of Date Palms as well as Orange and Lemon trees in central Iraq as part of a new policy of collective punishment of farmers who do not give information about guerillas attacking US troops."

What if someone really doesn't know anything?

source: TreeNews Autumn/Winter 2004