Each day, our cities are exposed to pollution from cars, power stations, industry etc. All of these release particulate matter (aka particulates) and various gases - such as carbon dioxide, carbon monoxide, sulphur dioxide, and nitrogen oxides. The pollutants in many of our city streets frequently exceed the World Health Organisation (WHO) guidelines.
Particulate matter is the sum of all solid and liquid particles suspended in air - it may include dust, pollen, soot, smoke and various liquid droplets. These particulates are often divided into
- PM10 particles - that have a diameter of 10 micrometers or less, are inhalable and may pass into the lungs and then the bloodstream. And,
- PM2.5 particles have a diameter of less than 2.5 micrometers - these are very fine and often contribute to the haze in the air.
Many particles form as a result of complex reactions between sulphur dioxide and nitrogen oxides.
Woodlands and forests provide us with a number of ecosystem services - things that contribute directly or indirectly to our well being. Perhaps most obviously, woodlands and forests can provide us with sustainable sources of wood and timber; other products include fruits (e.g. acai) and nuts (brazils, walnuts), honey and medicines.
Sadly, often our management of these resources does not make for happy reading. Over-exploitation of natural resources is not, however, a new phenomenon. History furnishes us with many examples of deforestation / clearance of woodlands - from China, Japan, the Indus valley, etc. long before various European / colonial influences came to bear. Read more...
Forestry is a surprisingly important part of the Swiss economy and the sector employs 90,000 people, with 1.3 million hectares of Switzerland being given over to forestry. To put this in a UK perspective, it is about the same amount of forestry land as Scotland and is a little more than England (which has 1.1 million hectares of forest). The reason why Switzerland, smaller in size than England, has as much forestry land is that a much higher percentage of the countryside is given over to trees - Switzerland has 31% tree cover which is much more than England's 9% and is high even compared to Scotland which only has 17%. In fact European countries are generally more forested than the UK - with Finland at a whopping 76% tree cover and even France is 27%, so Switzerland stands at just above the european average. Read more...
We are all dependent on ecosystem services even if we are not quite sure what they are. At the most basic of levels, early humans benefitted from the products of nature (fruits and seeds to eat, animals to hunt) - that is, food or provisioning . Shelter from the harsher aspects of climate and weather was also needed and provided; be it by the canopy of woodlands and forests, or the branches and other materials in woodlands used to make a simple shelter.
Ecosystem services permeate every aspect of our lives. Take soil, for example ‘Where would we be without fertile soil ?’ Obviously fertile soils provide us with the best conditions for our agricultural crops and for maximising growth in our greenhouses and orchards, but beyond that soil has many important functions. The organic material of the soil, humus, can absorb and retain water. It plays a vital role is the regulation of water run-off. Read more...
Nitrogen pollution, in the form of nitrates, ammonia and various oxides of nitrogen, is a threat to ecosystems, ecosystem services and biodiversity. Monitoring and measuring such pollutants in rain and air borne particles is expensive and, ideally, needs frequent samples.
It has been estimated that some 400,000 tonnes of airborne pollution are deposited over Britain each year. Research by Dr H Harmens et al at the Centre for Ecology and Hydrology (Bangor) has indicated that there may be a simpler and cheaper way of gauging nitrogen pollution - through the assessment of the state of local moss populations. Read more...
One of the gold medal winners at this year’s Chelsea Flower show was the garden entitled “Gardening for Champions”. This garden shows how simple changes to urban gardens can help the environment through
- Encouraging pollinating insects
- Saving water
- Cutting carbon dioxide emissions
The garden, which was designed by Martin Walker, is based on research carried out by academics ** from the University of Leeds; it shows how simple changes to urban gardens can make a positive contribution to ecosystem services. The garden offers a number of practical suggestions, Read more...