The Discipline of Biogeography - Essay Example

? Geography The discipline of biogeography has enabled researchers to develop a comprehensive understanding of the planet byproviding a deep insight regarding a range of concepts. This essay focuses on expounding upon the selected ideologies and theories of the subject to promote the integration of contemporary and traditional perspectives. In order to achieve this aim, the scope of this paper encompasses an analysis of the hydrological cycle, an assessment of the food chain, biomes and zoogeographic regions, examinations of soil development and its formation, the theory of continental drift and the modern development of plate tectonics and an evaluation of the conflict regarding Pleistocene and the interglacial stage that is currently facing the scientific community to assist the improvement of current public policies. 1. Describe the paths of water through the hydrologic cycle. Explain the processes and the energy gains and losses involved in the changes of water between its 3 states. Operationally, we often most concerned with water does when it reaches the solid earth, both on the surface and in the sub-surface. Explain the relationship between the saturated zone, the water table, a ground water well and the cone of depression, all within the sub-surface. The paths of water in the hydrologic cycle can be categorized and examined to assist the comprehension of the key processes in hydrology. According to Waite (2010) the determination of the quantity of water that makes way through these identified paths is dependent upon the conditions of the area under assessment and the seasonal variations. O’Callaghan (1996) defines the phenomenon in a series of stages and states that the initial path of water that is associated with the hydrologic cycle occurs upon the entrance of water into a river basin as a consequence of precipitation which could take the form of rain, hail or snow (1) once, the water transitions from this path the point of interception is determined through the surface of land which could be vegetation or the soil surface (2) this phase of the hydrological cycle is followed by the movement of the water towards the plants or within the soil in addition to the possibility of evaporation which is succeeded by recondensation and precipitation (3). O’Callaghan (2006) comments that in a scenario where the movement of the water is directed towards the soil surface, the water essentially penetrates through the pores of the soil and once the infiltration capacity reaches its maximum, the remaining water covers its path by taking the form of small channels, accordingly, another scenario reflects the possibility of water amassing within the soil system (4) additionally, in case of the saturation of soil horizons water movement occurs as interflow and ultimately goes into rivers and streams. The aforementioned analysis primarily highlights the inflow of water through the hydrologic cycle however, it is important to understand the significance of key pathways which allow water outflow. These pathways include; the process of evaporation, the river network and the groundwater pathways (O’Callaghan, 1996). Any change in the 3 states of water is marked by distinct processes during which energy is either lost or gained. When ice acquires sufficient heat, the solid matter transforms into liquid through the release of heat energy. During this process, the bonds of heated atoms and molecules are broken. The phase change which transforms solid matter into liquid is called melting in which thermal energy is gained. Consequentially, the phase change of freezing is characterized by a loss of energy while, the process of vaporization is marked by the absorption of heat or gain in energy from the surrounding to allow the bonds between molecules and atoms to break. The water zones within the subsurface in humid regions are categorized on the basis of their depth and contents of water and the lowest constituent of these three stratums is known as the zone of saturation (Petersen, Sack and Gabler, 2010). According to Owen, Pirie and Draper (2010) the water table exists at the top of a saturated zone and the point at which it meets with a depression is the location where a lake emerges. Furthermore, the hole for a well is drilled from the ground into the saturated zone, the relationship between the water table and a ground water well is that the former dictates the quantity of water in the latter (Owen, Pirie and Draper, 2010). Consequently, if the water from a well is drained out the water table surrounding the well also declines, this results in the creation of a cone of depression (Owen, Pirie and Draper, 2010). 2. The food chain is a valuable concept in biogeography. Give an example of a specific food chain, labeling the various levels of the food chain. After looking at characteristics of food chains, explain how a geographer’s approach to the study of organisms might be different than biologist’s study of organisms; what would each try to emphasize more than the other? What exactly is a biome? Compare/contrast the concept of the biome with that of the zoogeographic region. Compare/contrast the floral characteristics of 2 of the following biomes: Desert, Tundra, Midlatitude Grassland and Boreal Forest. A food chain may contain multiple levels which is a characteristic that depends upon the ecosystem being examined. An example of a food chain which exists in the water ecosystem is that of the algae, protozoa, small carnivorous fish and large carnivorous fish (Bharatdwaj 2006). Algae (Producer) ? Protozoa (Herbivore) ? Small Fish (Small Carnivore) ? Big Fish (Large Carnivore) (Adapted from Bharatdwaj, 2006) Observing the techniques of examining food chains in biogeography, it can be stated that the methodologies of evaluation that are utilized in the discipline are distinct. As suggested by Bharatdwaj (2006) the subject of biogeography has evolved from the notions that are discussed in earth sciences and natural history which has essentially equipped the discipline with the expertise of exploration by drawing from wider conclusions, perspectives and principles which transcends the limited scope of a biologist’s study on organisms. The concept of biome in biogeography is vast such that it encompasses the characteristics, aspects and features of a community with regards to a particular bioclimatic region (Taylor 1984). On the contrary, the notion of a zoogeographic region focuses on a much narrower concept as it revolves around fauna that are characteristic of a particular region thereby ignoring the factor of their ability to adapt to the wider environment. The Tundra biome is characterized by features such as barren land, minimal presence of vegetation and a climate that is either polar or arctic (Bharatdwaj 2006). Similarly, the desert biome shares certain features with the Tundra as both biomes are marked by the presence of extreme conditions that are not the most ideal for sustaining life. Accordingly, the floras and faunas that do exist in these biomes display a tremendous ability to adapt to the cold climatic condition of the Tundra and the extremely hot temperatures of the desert. 3. Theorize the difference in soil development in adjoining. What are the soil-forming factors? Explain the importance of the nature of the parent material to soil formation and type. Then, cite at least 2 examples in which the influence of parent materials might be outweighed by other soil-forming factors. Explain the “struggle” between the internal and external processes in shaping the Earth’s surface. What are the different ways that the surface of the Earth is changed over time? According to Waring and Running (2010), the soil development on forested areas is marked by the presence of three layers which are known as L, F and H and these horizons play a critical role throughout the progress of the forested area’s soil profile. On the contrary the soil development of sloped areas is highly dependent upon the topography of the area, for example, the pace of soil development in north-facing slopes is slower in comparison with surfaces which face the south. Accordingly, grassed flat areas allow for the accumulation of soil by firmly holding it on the surface, however, the process of soil development in such areas is also influenced by soil-forming factors that include; climate, parent material, biota, topography and time. The parent material is the foundation that dictates the principles which inherently guide soil formation. Thus, the texture and composition of the soil is dictated by the elements, chemicals and mineral compositions of the parent material. In the case of zonal soils, the soil formation factor of climate singlehandedly acts as the most dominant feature which has the ability to undermine the influence of parent material due to its prolonged presence. Another example of that can be related to this discussion is associated with the factor of time. This observation implies that immature soils that are in their early stages of development are more likely to be influenced by the parent material; however, this impact gradually diminishes with the passage of time. The underlying driver in soil formation is the ecosystem and its ability to impact the procedure is categorized under internal and external processes of soil formation. The distribution of internal processes postulates that additions, losses, transfers and transformations of the soil are essentially driven by external soil forming factors because the latter is a part of the wider environment which governs the progress of soil formation (Holliday 2004). 4. Describe the general sequence of events in continental drift since the time of 5 separate continents 450 million years ago. What is the difference between the older continental drift theory by Wegener and the more recent plate tectonic theory? Plate tectonics theory explains many seemingly unrelated phenomena. Explain how the patterns of volcanoes and earthquakes related to plate tectonics. Explain several pieces of evidence that combine to make the theory of plate tectonics the one that is generally accepted. Since its publication in 1915, the theory of continental drift which was presented by Alfred Wegener revolutionized the development of biogeography. The evaluations of the theory have aimed to describe a general sequence of events to present the phenomenon in a systematic and comprehensive manner. This general sequence essentially commences by the division of Pangea into Laurasia and Gondwanaland approximately 180 million years ago till the creation of various continents as they are known presently (Shaw and Goffinet, 2000). Furthermore, contemporary postulations that define the chronology of events refer to the continental shifts of the Atlantic and the extensive glaciations of regions such as India, Australia and Antarctica which took place 380 to 250 million years ago. Despite of its contributions to biogeography the theory of continental drift is identified as a rather simplistic version of the modern ideology of plate tectonics. While, Wegener believed that the continents of the world emerged as a consequence of the breakup of Pangea, plate tectonics postulates that the breakup of land masses occurred much earlier than when Wegener suggested it did. As noted by Rafferty (2010) the general acceptance of plate tectonics as a theory has occurred because the principle describes the movement of the planet’s interior plates which in turn explains the incidence of phenomenon such as earthquakes. Not only is this theory capable of explaining this notion but it also sheds light on the presence of volcanoes and the evolution of the Earth’s surface since the beginning of time. 5. Provide a reason why some scientists believe the Pleistocene is over and a reason why other scientists believe we are now in an interglacial stage. Some believe, for example, that since areas of pack ice and glacial ice still exist we are still in an ice age. Others, on the other hand, seeing the rapid retreat of ice and snow pack in many areas, believes that this period of glaciations have ended. So, using some other justifications, why do we see some differences in interpretation? Is there some scientific data available that can support both sides view? If so, provide it. Why hasn’t this controversy been solved? What impact does this division of views have on the public policies that are enacted by state, national and international bodies? The conflict of interpretation regarding the end of the Pleistocene age and the advent of the interglacial stage is widely debated amongst members of the scientific community and rightly so. Even though, the present geologic time period which is known as the Holocene has existed for the past 11,000 years it is still uncertain whether the human race has been able to transition to a new epoch or whether this phase is not yet the actual transition. For Hieb and Hieb (2007), this argument is merely a matter of opinion rather than a definite realization of scientific facts. For example, the researchers argue that the development of the idea of Holocene Maximum occurred 7500 to 4000 years before the present date when industrial pollution and other contaminants had not been developed yet. This observation implies that the current epoch is a part of an interglacial cycle which was witnessed 120,000-140,000 years ago (M. Hieb and H. Hieb, 2007). The researchers also comment that this period was referred to as Eemian Interglacial Period which was similar to the climatic situation of today; however, upon the departure of the epoch the period of ice age was restored (M. Hieb and H. Hieb, 2007). The uncertainties surrounding the climatic change across the globe can be attributed as the core reason why this controversy is yet to be resolved. As suggested by the research of Parker (2010), the region of Arabia is experiencing a Pleistocene climate change which is one of the several global observations that has sparked the ongoing debate thereby, raising concerns regarding the implementation of international and national policies concerning biogeography. Conclusion The principles of biogeography are based on the foundations that have been provided by the disciplines of earth sciences, natural history and geography to establish a comprehensive perspective regarding the development of the planet since the beginning of time. This notion implies that the theories of the subject allow researchers to establish concrete observations regarding the formation of volcanoes, the occurrence of earthquakes, comprehension of the hydrological cycle and an understanding of biomes and ecosystems to promote the wider objectives of the discipline. The preceding discussion has provided an insight into the discipline by assessing the contemporary theories of the subject in association with its foundations. References Bharatdwaj, K. (2006). Physical geography: Biogeography. Discovery Publishing House. Hieb, M., & Hieb, H. (2007). Global Warming: A Chilling Perspective. Holliday, V. T. (2004). Soils in archaeological research. Oxford University Press. 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(2010). Forest ecosystems: Analysis at multiple scales. Elsevier. Read More