What is air pollution?

Air pollution is often associated with the deposit of black particles seen on windows, leaves and buildings in urban areas. However, much of the air pollution in Britain today is largely invisible and so more difficult to detect, although you may be able to smell the pollutents from car exhausts, farmyards and heavy industry.  Some pollutents contain ammonia and oxides of nitrogen (nitric oxide and nitrogen dioxide). Although nitrogen is essential for the growth of all living organisms, too much nitrogen can cause problems. Ammonia and oxides of nitrogen can stimulate the growth of some plants and fungi but stop others from developing, thereby changing the natural around us. Lichens do not like excessive nitrogen in any form, but may grow particularly well when they are growing close to sources of ammonia. There is also a fungus, commonly known as tar spot that is found on sycamore trees, that we believe is sensitive to air pollution including nitrogen dioxide.

Habitats.

Part fourteen mammals of the mountain sides.

Britain`s mountains are not very high-only one, Ben Nevis is, above 4,000 ft (1,200m)- but they are bleak places for warm blooded creatures to live, especially in winter. For roughly every 500ft (150m) of height above sea level, it gets almost two degrees colder. Rain and mist as well as stronger winds also add to the chill. Trees rarely grow on high, windswept uplands, so there is little shelter. Consequently, few mammals live on the exposed high ground. Although they forage on the heights in summer, red deer and, to a lesser degree, mountain hares move to lower ground for the winter. Small mammals, such as field voles that live amid the upland grass, do not make long migrations. Although they lose a lot of body heat because they have a large surface area of skin in relation to their bulk, they can find shelter in burrows or among thickets of heather or bilberry. Despite the cold, small spiders and insects are surprisingly numerous amid upland vegetation, and provide food for pygmy shrews. Stoats thrive on field voles but will also take meadow pipits and other upland birds. Crows and foxes search the mountain- sides for carrion such as dead hares and sheep. Small herds of feral goats may be seen in a few mountainous areas. They vary widely in colour, ranging from white to piebald, skewbald, dark brown or black. Young goats are not likely to be seen before April. In their winter pelage, mountain hares look like snow against the dark heather. They show up only when they move. On upland slopes they take the place of rabbits and brown hares. Many upland areas now have commercial plantations of dense conifers(some wildlife trusts are now taking some of these out). They rob mountain hares of their living space, but may provide homes for pine martins. Red deer move down the valley during winter, returning in spring. Stoats have great camouflage in winter because of their winter pelage. It also helps to preserve body heat, because white fur radiates less than dark fur. Where there are meadow pipits there may also be pygmy shrews. Both feed on tiny insects among the stones and heather. Pygmy shrews remain well hidden but nay be heard squeaking.

Where to find lichens?

Lichens will grow on almost any surface including trees, rocks, earth and artificial surfaces such as concrete and tarmac. Lichens grow best in light  where they are not competing directly with tall grass, shrubs and climbing plants. Lichens that are highly sensitive to air quality and have been used to detect sources of pollution. In the past, when the air in many places was highly polluted by sulphur dioxide, few lichens could survive, creating lichen deserts around many industrial and urban areas. Lichens are now returning to British towns and cities, and they can still provide a great deal of information about our air quality.

What do lichens look like?

Unlike mosses and flowering plants, lichens do not have green leaves or a stem. They may be pale or bright coloured and commonly occur in three forms.

1, Leafy lichens have leaf-like lobes closely or loosely attached to the bark from the lower surface.

2, Bushy lichens are branched and shrub-like, attached to the bark at the base.

3, Crusty lichens are closely attached as if painted on the bark.

What are lichens?

In my next set of blogs i am going to be talking about lichens and the air quality that surrounds them.

Lichens are made up of two or more different organisms living together, a fungus and an alga. The fungus provides the body (thallus) in which the algal partner can live, protected from damaging conditions such as high levels of light (ultraviolet radiation) and lack of water (drought). The algal partner provides the essential carbohydrates (food for the fungus) from carbon dioxide and water, with the aid of sunlight. This close, interdependent relationship is referred to as a symbiosis.

The cervidae family.

Part six the reindeer.

Around two hundred thousand years ago reindeer were numerous in Britain, the icy landscape must have resounded to the noise of thousands of clicking hooves as herds migrated between summer and winter feeding grounds. But the herds started to dwindle, maybe it was of the climate change as the climate got warmer after the ice age. The remaining reindeer lived in Scotland. Knowbody knows when the last reindeer`s died out, but their was a small colony reintroduced to the caingorms in 1952 which is believed to total around one hundred and fifty today. They were a domesticated herd from Sweden that were released by Aviemore. The reindeer`s long, sweeping antlers and large hooves are distinctive. Their coat colour varies widely, but many of the animals are greyish or brownish. Their thick winter coat is paler. In late Summer bulls grow a prominent mane of white hair that persists through the winter. Bulls are about forty eight inches (1.2 meters) at the shoulder with the cows being smaller.During the summer months the male reindeer`s (bulls) are usually solitary, they join up with the female (cows ) herds and the young animals for the September-October mating season. This is called a rut when a male reindeer will challenge rival bulls for the right to mate with as many cows as possible. The bulls will roar and scrape their hooves in the mud and thrash around in any vegetation. They will also urinate so that they can leave their scent, they will hold the cows in a harem. After the rut, the bulls separate from the herd but follow it. Cows grow antlers, the only female deer to do so. The antlers have flattened main branches and points with forward pointing branches with secondary branches. The bulls antlers are bigger than the cows. The bulls shed their antlers in Autumn or in early Winter, the cows carry theirs until Spring. In winter, therefore, the cows can use their antlers to defend feeding patches cleared for themselves and their calves. Short grasses, sedges and lichens are the reindeer's main food. In winter they use their hooves to scrape the snow away to expose the lichens, perhaps they find them by smell. In the Spring they enjoy eating willow and birch shoots.  In North America they are known as caribou, this derives from a Red Indian word meaning shoveller. Calves are born in May or June, unlike most other deer, have no spots and can walk within an hour. The calves begin to develop antler pedicles (stalks) when they are about two months old. Their antlers are fully grown after their first winter ends. Old bulls cast their antlers soon after the rut in September or October, they then grow new ones during winter. A reindeer's broad, cloven hooves are splayed to spread its weight and prevent it from sinking to deep into the snow. The hooves make a clicking sound when they walk.

Habitats.

Part thirteen the beauty of limes.

As far back as the roman times, the tall, stately lime tree was planted for its shade and sweet scent diffused by its flowers. Avenues of lime graced the formal gardens of Louis XIV in France and Charles II in England. Afterwards, lime avenues took their place in landscaped gardens of the great landowners. Many of these trees are now reaching the end of their lives, and need to be replaced by young trees. One lime, the silver lime, is particularly resident to heat, drought and pollution, so does well as a street tree where there is space for it to grow. Various species of lime flower at different times, giving bees a continuous supply of nectar for much of the summer. The flowers of large-leaved lime open in June and July, hanging from long, pale green, leaf like bracts.