Explain the human and biophysical factors which place at least two ecosystems at risk
Ecosystems are often depicted as the interactions between flora and fauna through physical processes and chemical means. All ecosystems are somewhat vulnerable however they all differ based on their level of vulnerability and adaptation to change which is typically caused by biophysical factors and human impacts. Cronulla sand dunes and the Amazon rainforest are two varying ecosystems which are affected by the wind, temperature, precipitation, global warming and erosion as well as human impacts such as trampling, seawall management, deforestation and mining.
The atmosphere plays a pivotal role in the changing climates and weathers in ecosystems putting them at risk of change and vulnerability. Cronulla sand dunes (CSD) is one prominent Australian ecosystem which is at risk of change due to its eastern coast location and exposure to easterly winds. The Wanda sand dunes in Cronulla are 8m above sea level, 34, 03’ south and extend 5km inland. Due to its location, CSD is susceptible to significant impact and risk of its development as it is subject to Easterly winds which typically accompany intense low pressure systems. The sand source area at the Wanda sand dunes is medium to coarse grained rock naturally allowing an easier process of Aeolian transportation as the sand is light weighted and easier to carry. The volume of transportation of sand is determined by velocity and vegetation cover; the less the vegetation cover the easier it is for the wind to carry away exposed sand particles. This process eventually leads to the decreasing sand dune height and eventually may eradicate allowing ease of access for waves to reach inland. The wind and process of Aeolian transport therefore put CSD at great risk of change and vulnerability. In contrary, the well renowned Amazon rainforest receives high rates of rainfall and temperature due its location which runs through the equator at 10, 25’ and the Andes mountain range nearby. Furthermore, its large size of 8,235,430 km offers a large array of flora species which are in need of a nutrient cycle through precipitation and hot climates. The nutrient cycle is dependent on the decomposers’ efficiency of quickly breaking down a mass of dead waste material which supply the plants’ thirst for nutrients. Decomposers work efficiently when the rates of temperature and rainfall are high and therefore feed the needed nutrients for the plants providing them with further growth. Due to this, the rainforest will be impacted favourably as it causes the increase of large biomass and high rates of primary productivity. Precipitation and climate are an important factor in the nutrient cycle and more importantly allow a great change in the Amazon rainforest. In whole, the elements of the atmosphere, specifically weather and climate, have significant impacts on CSD and the Amazon rainforest.
Natural stress is the leading contributor in the change and levels of vulnerability within an ecosystem. Along with natural stress comes, erosion; a major factor in the change of the Cronulla sand dunes. Dune erosion occurs when storm surge elevates waves higher on the beach, allowing them to attack and erode the coastal dune. As sand is removed from the dune, the front face becomes very steep, or scarped. The overall volume and elevation of the dune is reduced due to the erosion process. Dune erosion makes properties behind the dune more vulnerable to future storms and the potential for backwash. In 1974 a huge storm surge coinciding with a high tide resulted in a massive erosion event on the Cronulla beaches. Wanda beach dunes have accreted, see figure 1.1. This area does not undergo consistent maintenance and exhibit's a number of erosion issues. Erosion has contributed in the change of the CSD and has increased CSD’s level of vulnerability. Global warming also impacts various ecosystems around the globe due to it being spread