Discuss the ways in which distinctive ecologies can develop along routeways (10 marks)
Routeways such as roads, railways and canals can provide habitats for many species of plant and insect life because they often act as protected areas in which ecological succession can occur. There are several ways in which this can happen.
One way in which ecologies can develop along routeways is that plant seeds, e.g. Oxford ragwort or buddleia, that have become windborne can be transported along by cars or trains and are often planted in railway sidings or along grass verges next to main roads. In the case of roads, nitrogen in exhaust fumes can be beneficial to the growth of some species of wildflower, which encourages them to spread further along the protective area of the grass verge, which is an area almost untouched by human interference due to its proximity to heavy traffic, therefore meaning that plant species have a lot of freedom to grow and spread. This in turn then encourages an increase in plant, bird and animal life along the routeway, creating a diverse ecosystem - such as along the M4 corridor, which has become a home to kestrels and other birds of prey due to the increase in the number of insects and small mammals who inhabit the area.
In addition, some human activities along routeways can affect the types of plant species that can be found there. For example, the spreading of salt/grit on roads in icy conditions can lead to halophiles (salt-loving plants) inhabiting the area, and as many grass verges are regularly maintained by weeding/mowing, natural succession can sometimes be restricted due to the fact that plant species are not allowed to grow naturally and can sometimes be managed by the use of chemical pesticides, possibly resulting in a plagioclimax. Furthermore, afforestation by groups such as the highways agency (who have planted over 1.8 billion trees in order to soften noise and make routeways aesthetically pleasing) can introduce new species of...