Discuss the relative importance of physical and human factors in accounting for changes to vegetation over time within ecosystems in the British Isles Essay

There be many factors that account for the flip-flops to the botany everywhere time within ecosystems in the British islets, such(prenominal)(prenominal)(prenominal) as human race race military action, climate, dent, elucidation availability and intensity and natural disasters. The characteristics of the vegetation that are influenced by these factors are height, statistical distribution, variety of species, adaptations and density of the vegetation. Some of these factors hasten relatively little influence on the episode victimization, whereas differents have a outstanding influence over a long period of time, such as human activity. These factors, over time, run in the get onion of a episode until the climatic flood vegetation is reached. However, sometimes these factors freighter mean that a plagio coming is reached, as they prevent the time from progressing any further and the climatic climax vegetation is never achieved, which in the UK are Oak, Hawthorne and Birch trees.This succession results in the development of an ecosystem. An ecosystem is a dynamic, st competent milieu which is be of interacting and functioning biotic and abiotic components and can be of any size. There can be composed of variety of successions, such as litho sears in grass domain and timberland areas for example the Isle of Aaron, psamoseres along the coastline or small scale urban successions in change areas. In an ecosystem, all the component are characterised as biotic, for example animals and plants, or abiotic for example climate, pH, soil characteristics or d rainwaterage. These biotic and abiotic factors determine the changes to the vegetation in the ecosystem overtime as they have a great effect on it, such as flooding and animal grazing. Within the ecosystem, there are inputs, outputs, stores and flows which transfer minerals, nutrients, water and light energy. The most all important(p) input is light energy from the sun, which is the source of any forage chain.Producers start a food chain, but they would non be able to do so without the 2% of energy provided by the sun to allow photosynthesis to go by. 10% of this energy is wherefore transferred through the trophic levels in the food chain, from the autotrophs, through the consumers to the detritivores. Energy is wooly at each stage as a result of movement, excrement and heat loss. As long as there is sufficient sunshine, consumers get out continue to be able to economic consumption the vegetation in an ecosystem is a food source, which will have a dramatic affect on the characteristics of the vegetation. In this case, both human and carnal characteristics are equally important for accounting to changes in the vegetation. Nutrients in an ecosystem are transferred through the nutrient cycle, a balanced cycle which ensures that there are enough nutrients for the ecosystem to brave out.This cycle is represent in a Gersmehl Diagram. An example of an ecosystem is a temperate broad-leaved woodland. The principal(prenominal) human factor that affects the development of a temperate deciduous woodland is deforestation. Deforestation occurs for a number of reasons to use the timber for commercial use, to use the land for agriculture or to use the land to build on. one time the land has been deforested, it will never be able to be apply for the same environment again as the soil washes away in the rain. Therefore, human activity has an extremely king-size impact on the development of vegetation as it can result in the environment decent inhospitable. One of the strong-arm factors that affects the distribution of vegetation is the height and density of the exsisting vegetation.This is because the to a greater extent dense the canopy layer, te less light will riddle through the leaf mosaic to the shrub layer. This means that only plants that contain little sunlight will be able to survive, unless they have adaptations that change them to ab sorb as much sunlight as possible such as having bread flat leaves so that they have a large surface area, or flowering earlier or later than other plants, such as Dogs Mercury and Bluebells. Another strong-arm factor that affects the distribution of vegetation is the climate. If an area receives too little or too much rainfall, the plants will not be able to survive. On average, the temperate deciduous woodland should receive around 750-1500mm of rain per year. If this number is greatly exceeded, consequently the soil will become saturated and the area will flood, smother the plants as they do not have accession to sufficient type O and carbon dioxide.On the contrary, if there is not enough rainfall wherefore the plants will also die because they do not have access to a plentiful supply of minerals that the water contains such as atomic number 7 and magnesium. One type of succession that can form an ecosystem is a lithosere. A lithosere is a plant succession that begins life o n a saucily exposed leaning surface, such as one left evident as a result of glacial retreat, tectonic uplift as in the formation of a raised beach, or volcanic eruption. The lithosere succession is initiated by pioneer plants, such as blue and green alga with colonise the sock as there are into a roofy of nutrients available and they have no ancestry systems, so they can survive in the hostile conditions.The succession then progresses due to the pioneer plants breakup the rock, resulting in a release of nutrients. This then means that mosses, lichens and liverworts are able to thrive on that ground as the moss can absorb nutrients from rain water and they provide their own energy from photosynthesis. These plants chemically decay the rock by releasing acids, and carnally decay the rock as a result of their root systems, leading to an amelioration of the plants so that the lithosere can progress to the next seral stage.Herbs grasses and small flowering plants can promptly col onise in these conditions, which are followed by ferns, brackens and small shrubs as the soil is now mysterious enough to support their roots and their seeds become lodged in the cracks made by the moss, so colonisation continues. Once these plants die and decay, they leave humus which adds to the cornucopia of the soil and enables much developed plants to grow in their place. At this stage, the soil is developed enough and contains enough nutrients that it can host small tress, such as Alder and Rowan. Once these trees die, the lithosere is able to reach its climatic climax vegetation of Oak, Birch and Pine.There are many physical and human characteristics that affect the development of a lithosere. In the Isle of Aaron, there is no vegetation in areas of high relief. This is because the seeds for the plants slide down the slope, and do not colonise the steepest areas but colonise the top and bottom of the slope. Another physical factor which causes a lack of colonisation is the saltiness spray from the sea. The salt dehydrates the rocks that it lands on, so the area becomes inhospitable to the hardiest of plants. The prevailing winds from the south west result in a higher wind chill factor, therefore temperatures are lower, resulting in receding conditions. The winds also deliver seeds which can colonise the area, if the niche conditions that have been created are an appropriate for their survival.The southerly facing beaches receive more light and heat energy, therefore decreasing the time in which it takes for the succession to reach its climatic climax vegetation. This is because the increased heat energy results in more photosynthesis taking place, as photosynthesis needs carbon dioxide, water and sunlight to occur. As a result, the plant has more energy and so the root systems develop at a fast rate, weathering the rock. In this particular example, the physical factors have a great effect on the development of the lithosere as its development is reg ulated by factors such as climate, relief of land and pH of the environment.A plagioclimax is when human activity interferes with the succession of a sere and prevents it from reaching its climatic climax vegetation. Human activity which causes a plagioclimax to occur could be deforestation, animal grazing or recruit clearance. Conversely, it is not exactly human activity that can result in a plagioclimax. infixed disasters such as floods and volcanic eruptions can also result in a plagioclimax being reached. However, if the plagioclimax is reached as a result of physical activity then it is generally not maintained and secondary succession can occur, which is when plants develop on land that has previously been vegetated. An example of a plagioclimax is the broom moorland in the North York Moors.The North York Moors were once covered in woodland, and heather would have featured in very small quantities. However, as a result of sheep grazing and deforestation, the regrowth of th e climatic climax vegetation has been prevented and now heather is the dominant species. To control the uplands and encourage new heather shoots, managed intense is employed every 15 years, a technique that eliminates the less fire resistant species, allowing heather to dominate and conserves as many nutrients as possible.To conclude, I think that both physical and human factors play a probative role in accounting for changes in vegetation over time in the British Isles. However, I regain that physical factors have a greater impact in the long term that human factors, as physical factors are such that they generally change the environment or habitat on a permanent basis, such as climate change. Nevertheless, I believe that human factors play a significant role in changes to vegetation over time, but I feel that human intervention is not as long term as a change made as a result of physical factors because humans generally have the control and power to continuously change the envi ronment and possibly restore it back to the way in which it was originally, whereas physical factors are not controlled.