Friday, February 29, 2008

Old growth forest

source : From Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Old_growth_forest


Old growth forest, also called primary forest, ancient forest, virgin forest, primeval forest, frontier forest or (in the UK) Ancient Woodland, is an area of forest that has attained great age and so exhibits unique biological features. Old growth forests typically contain large live trees, large dead trees (sometimes called "snags"), and large logs. Old growth forests usually have multiple vertical layers of vegetation representing a variety of tree species and age classes.

Forest regenerated after severe disruptions, such as clear-cut or fire is often called second-growth or regeneration until a long enough time passes that the effects of the disturbance are no longer evident. Depending on the forest, this may take anywhere from a century to several millennia. Hardwood forests of the eastern United States can develop old-growth characteristics in one or two generations of trees, or 150-500 years.

Old growth forests may be home to rare species which depend on this now-rare habitat, making them ecologically significant. Biodiversity may be higher or lower in old growth forests than in second-growth forests depending on specific circumstances. Logging in old growth forests is a contentious issue in many parts of the world.

Thursday, February 28, 2008

Tree management

Introduction
The Tree Section is responsible for the care, maintenance and management of all trees on Waltham Forest Council land. We provide expert advice, inspections and surveys, planting programmes, and issue any maintenance works to external contractors. This specialist service is provided for the Highways, Asham Homes, Education, Green Spaces and Social Services departments and Planning issues.

The Tree Section also provides advice to the public concerning privately owned trees, however we do not carry out maintenance works on private land.

At present there are approximately 20,000 Highways owned trees in the borough which are generally pruned every three years, however, financial restrictions have recently altered this pruning regime and the Tree Section is currently reviewing its maintenance programme. Although full surveys are yet to be completed it is estimated that there are another 35,000 trees owned by the other departments combined.

The Tree Section is also responsible for Larkswood and Ainslie wood in which there are numerous trees that are yet to be surveyed.As can be seen there is a large tree resource in the borough of which the community can be proud. The benefits of trees are well documented and for the tree resource to improve and continue to thrive within the borough it is imperative that they are managed correctly and responsibly.
Benefits of trees
The trees in the borough are for the benefit of the whole community and provide many advantages to the environment in which we live. Trees reduce energy use, clean the air, enhance wildlife habitats and offer psychological benefits for humans that research is just beginning to define. Older and larger trees often maximise these benefits - one large tree can provide oxygen requirements for approximately four people. Urban trees and forests come in many forms, varying from street trees to park groves and garden thickets. Regardless of what collective or solitary forms they appear in, all trees are capable of providing multiple benefits. Trees absorb pollution, prevent soil erosion, reduce glare, enhance recreation areas, protect against cancer-causing ultraviolet rays, turn vacant areas into playgrounds, serve as teachers, identify communities, provide employment and even catalyse spiritual and creative inspirations.
Ecological benefits
Planting trees combined with reducing impervious surfaces - such as car parks and pavements - buffers bodies of water from runoff and associated pollution. Trees provide shade and help reduce radiated temperatures from buildings and roads thereby reducing energy use in heating buildings. They provide habitats and food for wildlife and provide "green corridors" for wildlife to travel from one habitat to another. Trees also help to reduce noise pollution either by providing a dense barrier of sound deadening vegetation or by producing opposing sound waves - when leaves, twigs and branches rustle - to the obtrusive noise thereby helping to cancel the noise out.

Social benefits
Social benefits are well documented in a number of studies. Urban trees can have a positive impact on the financial success of commercial areas, a recent study indicates that shoppers are willing to pay as much as 10% more for goods and services if businesses are located in tree-lined streets. Studies have also shown that property values can be up to 15% higher in "green and leafy" areas. Perhaps more unexpectedly research has revealed that residential buildings with greener surroundings had fewer crimes committed in the area; this reduction included both property crimes and violent crimes. This study also linked green environments with reduction in mental fatigue, a condition that often accompanies violent behaviour.

Trees improve health
If an urban forest had no other benefits, this factor alone should establish trees as an extremely important resource within the borough: trees actually improve the physical and mental health of human beings. It is a fact that trees trap airborne particulates and reduce carbon dioxide. The result: pollution is reduced and the air becomes much healthier to breathe.

Believe it or not, research studies show that an environment with trees can reduce human stress and recovery time for hospital patients. Surgical recovery patients - looking out of windows at trees versus a barren landscape or concrete jungle - had shorter hospital stays. Also, these patients having access to natural views required fewer medications for pain and received two-thirds fewer negative evaluations by nurses.

A Green Environment for Now and the Future

In the past, the major need of people in this world was arable land. Man did not have to think about animate things. However, now the adverse effects on forests through over-population and the development of various chemical elements in the atmosphere have led to irregular rainfall and global warming. This global warming has brought changes in climate, including making perennial snow mountains melt, thereby adversely affecting not only human beings but also other living species.

This dangerous situation is being taken very seriously by the world. In the past the perennial snow mountains of Tibet had very thick snow. Older people say that these mountains were covered with thick snow when they were young and that the snows are getting sparser which may be an indication of the end of the world. It is a fact that climate change is a slow process taking thousands of years to realize its effect. Living beings and plant life on this planet also undergo change accordingly. Man's physical structure too changes from generation to generation along with the change in climatic conditions.

Because of the growth in the population, a large number of trees are cur for fuel, and to reclaim land for agricultural cultivation. In the case of Tibet, too, the Chinese have now destroyed its ancient trees in a similar way to shaving a man's off. This is not simply the destruction of trees but it also means harming what belongs to the Tibetans. Similarly, the continuing decline in forests in many parts of the world, including America, is adversely affecting the already changing global climate, thus upsetting the lives, not only of mankind, but also of all living beings.

Tuesday, February 26, 2008

Monday, February 25, 2008

Wildlife worries over lack of rain

-By Mark Kinver
BBC News science and nature reporter

The RSPB says 2006 is one the worst breeding seasons on record for wetland birds.

Rainfall in England and Wales over the past 18 months has been the second lowest since 1976, but water levels in parts of central and southern England are at their lowest level since the 1930s.

"If you have a dry winter like the one we have had then you are not able to make the wetlands suitable for the birds you are trying to attract," says Phil Burston, the RSPB's senior water policy officer.

He said fewer birds such as lapwings, redshanks and snipes have arrived at the charity's wetlands reserves.

"Our reserve at Elmley Marshes in Kent would, in a normal year, have about 200 pairs of lapwings.

"Last year it had 80 pairs, and this year it looks as if we have just 60 pairs. So the trend is downwards."

Mr Burston says that a number of birds that did arrive have made no attempt to nest because conditions are too dry.

He says although the breeding season closes towards the end of June, a dry summer will make matters worse.

"The adults and the young have to find food, such as invertebrates in moist soils. So if these wetlands dry up then the waders will not be able to get access to their food. If that continues, they will eventually die."

To help alleviate the problem, the RSPB has been granted a 28-day licence by the Environment Agency to pump water from a nearby creek on to the marsh.

Fears for fish Elsewhere, the Environment Agency says it is already seeing the consequences
of the prolonged dry period. These include an algal bloom in a lake in Hampshire, and the deaths of
hundreds of fish that became trapped in a shallow stream in Berkshire.

"Because it has been relatively wet during April and May, the impacts have been isolated," says Environment Agency water resources manager Glenn Watts.







Reservoir in 1976 (Image: BBC)

A long, hot summer will hit aquatic wildlife, experts say



"However, as we head into the summer they will become more obvious. River levels will drop quite quickly this year unless there is relatively high rainfall."


Mr Watts warns that fish populations will be one of the main casualties of a hot summer: "We would see much lower river flows, oxygen levels dropping,
resulting in more fish being stressed, if not more deaths."


He says that low water levels would also mean that many species would not be able to reach their spawning grounds, remaining in the main rivers, leaving them within the easy reach of predators.


"We will also see more algal blooms, more weed growth, resulting in the
rivers looking quite different," Mr Watts adds.


'Ecological crisis'


This month has seen an increase in evaporation rates and soil losing its moisture, which the Centre for Ecology and Hydrology (CEH) believes marks the end of the "recharge season" for this year.

In its latest hydrological summary, the centre says groundwater levels and river flows are set to decline through the summer, with the prospect of exceptionally low flows by the autumn.

"Winter rainfall does control how much water is available in soils to tide plants over dry periods in the summer," says CEH spokesman Barnaby Smith. However, he says it is too early to be talking in terms of an "ecological crisis".

"If we have a wet summer we will probably not see too many adverse effects, but we will not need a particularly long dry period before some plants start to suffer," Dr Smith adds.

Among the most vulnerable species of trees are birch and beech. The trees' shallow roots mean they are dependent on being able to access water near the surface.

One visible sign that trees were suffering from a lack of water would be the shedding of leaves much earlier than the autumnal norm.
In 1976, millions of trees were reported to have been killed by that year's prolonged summer drought.
"This is the sort of thing that we could see again happening this year, but it would depend upon a very long, hot, dry summer," says Glenn Watts.

Balancing act

Agriculture is one area that straddles both the demand for water abstraction and the environmental impact of water shortages. "It is too early to tell if the drought this year is going to be a problem for farmers because we have not got to the stage yet where crops are under stress," says National Farmers' Union (NFU) head of policy services, Andrew Clark.
"The concern for farmers comes in July or August when they want to know whether they will be able to use spray irrigation." Any water restrictions will particularly affect vegetable crops, such as potatoes and onions, which farmers need to continue watering over the summer months. "This is to make sure that we get the right size of potatoes, onions, parsnips, carrots etc that the retail market wants us to provide," Mr Clark
says.

He says farmers are offered guidance on irrigation. The NFU, Environment Agency, and the UK Irrigation Association have all issued advice on the wise use of water. "To be honest," says Mr Clark, "water is such a scarce resource that even in a relatively damp period all responsible irrigators would be looking at their
methods."

The Environment Agency's Glenn Watts says any savings that can be made now will prove invaluable if rainfall levels remain below average. "If we had average rainfall over the summer but another dry winter, similar to the previous two, then water companies will face similar difficulties to this year. "However, if we had a dry summer which was followed by a dry winter then we would face a very difficult situation."

Saturday, February 23, 2008

Learning from the Trees

What's a Druid without trees? For that matter, what's a world without trees? Yet most of us take trees for granted. When I was teaching honors and Advanced Placement English to gifted high school students, I gave the same assignment at the beginning of each school year. Go out tonight, I would instruct them, and hug a tree; then write about your experience.

My students were, of course, incredulous. This woman is nuts. Hug a tree? What's that have to do with learning English? But being the obedient little honors students that they were, everyone always completed her assignment.

The next day each student would read his journal entries aloud. Some were incredibly funny (usually written by self-conscious, he-man, athletic types who reported having crept about in the wee hours of the morning so as not to actually be SEEN doing this dirty deed). But ALWAYS, without exception, the students were amazed at what they felt. While they were aware that trees are alive, their awareness rested at some abstract intellectual level. Once they touched the living thing in its essence, they understood the meaning of the word "alive" in all its nuances.
For most of us, awareness is a touch (or a hug, if you will) away. I know of no other interaction that so immediately and intensely renders us aware of the life around us. So go hug a tree and write about your experience. Once you have completed the exercise, repeat it with another kind of tree. Was there a difference? In Charleston, we have a thousand-year old live oak which natives call "Angel Oak." The breadth and sheer power of this tree (protected in a city park) is incomparable. Each time I have visited and sat at its base, my back against its broad trunk, my feet on the humped stool of an exposed root, I am given what I call my "affirmations" (little signs that reaffirm for me the magic of the universe and my part in it). Sometimes it comes in the form of a visiting hawk; sometimes a horde of butterflies; sometimes I find unique feathers at its base. It provides acorns, moss, and ferns for my spellwork and, of course, a deep sense of peace.

I always leave three shiny copper pennies in its hollows in return. The crepe myrtles that adorn the city streets, on the other hand, are quieter trees. They stand like shy and beautiful women as I stroke their smooth, shiny, twisted trunks. Willows are sad trees whose song is a wistful whish-h-h in the breeze. Birches emote a sense of freshness and possibility. The tree has long been symbolic of life, but I also like to draw the analogy of the tree to the human brain.

Everything in the universe exists in macrocosmic and microcosmic forms. The solar system is mirrored by the atom, a factory by a colony of ants. So, too, are the branching dendrites of our brains which spread from each neuron like the branches of a tree. Dendrites pass information quickly from one neuron to the next, processing at an amazing rate. The better care one takes of a tree, the more branches it produces. The more one uses her brain, the more dendrites are produced. The more dendrites one possesses, the better one's potential for intellectual accomplishment. When Albert Einstein died and left his brain to be analyzed, the only real difference between it and the brains of other humans was in the amazing amount of dendrites Einstein possessed. Science has told us what the trees have always known, that proper use strengthens and enhances.