With reference to one plagioclimax that you have studied, assess the impact of human activity on plant succession. (10 marks)
Plant succession is the process by which one plant community replaces another over time. Human activity can have an impact on the succession of plants in a number of ways these are known as arresting factors. A plagioclimax community is a habitat in which the impact of humans has subsequently meant that the ecosystem has been prevented from developing further. The plagioclimax with which I will give reference in this essay is heather moorland. It must be noted that much of the present vegetation in the UK is a plagioclimax as a result of clearance.
Heather moorland provides a choice example of a plagioclimax in the UK. The areas where heather moorland is most prominent are the North York Moors, the Pennines and Eastern Scotland. Much of the land where Heather ...view middle of the document...
Heather and other hardier plants such as Bracken, Grasses and Scrub Woodland began to dominate upland areas which had been impacted by humans felling the deciduous woodland in the area. With these upland areas being used for sheep grazing and other forms of farming, young Oak and Ash trees were unable to establish themselves in the poor soil and were otherwise eaten by farm animals, therefore preventing the regeneration of the climax deciduous woodland. Therefore it is fair to conclude that in this sense human beings have had an enormous impact on the plant succession in a number of upland areas across the UK.
In addition humans have further stopped the restart of succession in areas dominated by heather moorland as the heather is maintained and managed by burning. The main reason for why humans maintain heather in the UK, is because it provides the choice environment for the infamous Grouse. Grouse shooting is a particularly popular practise and is incredibly lucrative for those who own land on which Grouse can be reared and shot and therefore as a result many landowners want to keep the heather moorland rather than allowing it to regenerate as deciduous woodland. The burning of heather every three to four years encourages new heather shoots and eliminates less fire-resistant species and this means that the Grouse can continue to live in these areas. So one could further argue that humans have also had an impact on plant succession because of another of their needs, money.
After careful thought it is undeniable that human beings have had an overwhelming effect on the plant succession in areas which are of the plagioclimax community of heather moorland, as if they hadn’t felled trees in these areas, the climax woodland would still be there as a result of succession. It must further be noted that if humans did not burn or graze animals on the Heather moorland then deciduous woodland would be regenerated. Therefore to conclude I believe that human beings have a profound effect on plant succession and that the impact which humans have had on heather moorland justifies my conclusion.