Biotic Interactions in Plant Communities - Speech or Presentation Example

Download file to see previous pages EXTINCTION ESTIMATES MADE IN THE 1990s Due to Deforestation (Karkee, 2004). Estimate and Method of estimation % Global Loss per decade 10 million sp. Annual Loss 30 million sp. Annual Loss Source 0.2-0.3% annually based on tropical deforestation rate of 1% annually 2-3% 20,000-30,000 60,000-90,000 Wilson (1989, 1993) 2-13% loss between 1990 and 2015 using species area curve and increasing deforestation rates 0.8-5.2% 8,000-52,000 24,000-156,000 Reid (1992) Loss of half the species in the area likely to be deforested by 2015 8.3% 83,000 250,000 Raven (1988) Fitting exponential extinction functions based on IUCN red data books 0.6-5% 6,000-50,000 18,000-150,000 Mace (1994) Colombia and the Amazon Basin is a good example of deforestation and the impacts are evident as per the effects described below. One of the regions that have been greatly influenced by deforestation is the Amazon Basin. Tree felling in the Amazon is much greater compared to any other region of the world. The Amazon tropical forest, which approximately account for 2,488,642 square miles, lost fifteen percent of its forest cover in1970 alone (Naik, 2010). For example, Brazil, which is a residence to about one-thirds of the tropical forests of the world, has been incurring an average loss of 21,536 square miles of forest cover yearly, over the last few years (Olsen, 2009). Deforestation and the consequences on biodiversity interactions In areas of intense deforestation, there exists alterations in microclimate and change in plant reproduction, biological structure and animal distribution, among many other aspects of the forest. Climate change due to overexploitation of forests and plant communities results into loss of biodiversity both the flora and fauna. Climate change causes rise in temperature and low moisture availability in the affected regions and even spreads out (Eade, 2011). Due to the change in climate, there emerges simultaneous increase in the occurrence of fires which actively destroy the plant communities. Forests assist to uphold the temperature at a low level and avert it from rising. In the deficiency of forest, the earth surface radiates all the heat that the atmosphere does not absorb but instead hit the earth’s surface. Such heat combined with an increase in the concentration of carbon dioxide leads to an increase in the atmospheric temperature (Haldar, 2011). Average species lost compared to deforestation rates (Eade, 2011). Climate change emanates into harsh conditions that can easily results into extinction of some animal and epiphytes community. A good example is the scenario whereby, Mycchorizal fungal interactions between plants and the fungi are affected. These two have a symbiotic relationship. In sustaining base level of supply of food, rain forests depend on the microbe’s action of decaying and rotting. In the event that forest cover is reduced, the fungi have less survival rates since they depend on trees for both habitat and food (Haldar, 2011). The impact of deforestation leads to changes in aquatic systems through excessive evaporations. The salinity level increases and the temperature becomes unbearable hence, habitat of the aquatic flora and fauna compromised. Excessive carbon IV oxide due to deforestation also chokes the flora and fauna that are found in the aquatic ecosystem hence reduction of the species that are not best suited for this environment for example, algae ...Download file to see next pagesRead More