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

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

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

Report: Trees in the urban realm


Although the findings from the UK’s Tree and Design Action Group were published in 2008, it is worth reprising here.

The group, comprising of professionals and organisations, looked at the threat facing urban trees, while highlighting the benefits they bring to local communities.

It says that trees enrich the urban landscape by “improving health and well-being for people and the environment”.

It goes on to say that the report also highlights that urban trees mitigate temperature extremes, reduce pollution and increase real estate values.

“In terms of climate change,” the group suggests, “trees have been identified as being a key element of any urban climate change adaptation strategy.

“Trees are uniquely placed to be widely integrated into the urban fabric, providing a shading and cooling mechanism.

“Without this cooling mechanism, cities of the future – London in particular – are likely to be very inhospitable places.”

However, the group says that while there is awareness about the role trees can play in making cities habitable in the future, current design and planning systems make it very difficult to plan for the future.

“The services and infrastructure needed in cities to achieve high densities living generally militates against the presence of trees.

“Climate change will add to these pressures and create a landscape devoid of large trees unless practical steps are taken by a range of professional bodies working in partnership.”

It builds on the London Assembly Environment Committee’s 2007 report “Chainsaw Massacre“, which highlighted the loss of street trees in London. It found that more large tree species were being cut down rather than being replaced.

The Trees in Towns II report, commissioned by the Department for Communities and Local Government, echoed this findings for the rest of England.

Source: Trees and Design Action Group (TDAG)

Date: December 2008

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