Climate Change Hastens Population Extinctions - Essay Example

Topic: Climate change hastens population extinctions The purpose of the study was to evaluate the impact of climate change on the population extinction of two species of checker spot butterflies. Precipitation data available was evaluated against the population simulations. The results indicated that the precipitation variability accelerated butterfly extinction by affecting the habitat and host plant growth cycle Literature Review The effect of climate change in the extinction process of the checker spot butterflies is the topic of review in the study. There are a number of literatures available with relevance to this topic. Geologic, fossil and ecological records have provided the evidence for the variable nature of the climate whose occurrence in the past has caused the evolution of various eco systems of the earth (Emmanuel, W.R, Stughart, H.H, Stevenson, M, 1985, p.29-43). The change caused in the precipitation rate which is one of the resultant effects of the climate change is expected to affect the interaction between the checker spot butterfly larvae and its host plant. This reason when coupled with the disturbance of the habitat of the butterfly would aggregate the problem when it is observed in relation with the dispersal ability of the species. The study was taken with the hypothesis that extinctions of two populations of the checkerspot butterfly, Euphydryas editha bayensis, were caused by a combination of habitat loss and regional climate change in the form of increasing variability in precipitation (McLaughlin et.al, 2002). Euphydryas editha bayensis is a beautiful and charismatic butterfly species which is a resident species of Western North America. (Dyke, F.V, 2008,p.128). Taylor, K. E. and Penner, J. E. (1994, pp. 734 – 737) has described the major cause of climate change as man made carbon and other Green House Gas emissions in addition to the natural changes in climate. Several detrimental effects like Sea-level rise, Hurricanes, Diseases, Famines, Desertification and Species loss has been pointed out as the impacts of climate change.(Morris, Julian 1997,p.5-17). Though this study had only general indications towards the impact of climate change on species loss, this indication has been reiterated by a number of literatures which state that climate change would affect the population of animal and plant species. Christina Figueres & Maria Ivanova (2002,p.205) has argued that climate change would affect the major components of our biosphere including air, the ocean, the range of animal and plant species and the climate system itself. A study by J. B. Hughes, Daily, G. C. & Ehrlich, P. R. (1997) further confirmed that population loss occurs due to climate change and the same affects species diversity and the delivery of critical ecosystem services. Graham, R. W. & Grimm, E. C. (1990,p.289–292) predicted that the differing extremes of climate change would alter species distributions, life histories, community composition and ecosystem function. These literatures correlate with the assumption of the current study that climate change can hasten the population extinction process. While considering the reduction in the population of a particular species in a specified area, the possibilities of the migration of the discussed population to other desirable climatic zones also must be considered. Julian Morris (1997,p.5-17) has suggested the possibility of the migration of the species which are adapted to cooler weather would be forced to move to more cooler habitats in the event of continuous rise in temperature. However in the case of the checker spot butterfly, Euphydryas editha bayensis, when its dispersal ability is considered, the hypothesis put forward by the study becomes meaningful. The role of precipitation in affecting the population has been emphasized in a number of studies. The study by Julian Morris (1997,p.5-17) has stated that species continuously evolve in relation to the environmental changes and it seemed quite justified to him that the number of species could actually increase in response to global warming. The same study had found that this possibility was more observed with an increase in the amount of rainfall. Though the work of Julian Morris does not directly suggest that with decrease or variability in precipitation, the population may be negatively affected, it supports the view that precipitation is an integral factor in the survival and development of species. The current study further relates the survival of the species with the temporal overlap of the larvae of the butterfly and the particular growth stage of the host plant. This relation of the larvae and its host plants which are Plantago erecta, Castilleja densiflora, and Castilleja exserta are asserted by the work of Cushman, J. H., Boggs, C. L., Weiss, S. B., Murphy, D. D., Harvey, A. W. & Ehrlich, P. R. (1994,p.194-200). There are a number of studies done on the effect of climate change on the plants and their growth cycle. Jon Bates, Tony Svejcar, Richard Miller, Ray Angell, and Roxane Bailey (1998,p. 220-239) has confirmed that the precipitation timing and the variation in the rate of the downpour would affect the growth cycle and the vegetation of Sagebrush or Bunch grass. Shannon Cathleen Morsello (2007) has stated that the senescence of chickpea was affected by the variation in precipitation. In a study on the temporal association of the thrips population and the growth cycle of host plants, it has been reported that rainfall may also positively influence thrips population growth by delaying senescence of winter host plants during late spring allowing more time for thrips to proliferate (Kirk, W. D. J. 1997). These literatures reiterate the role of precipitation on the host plant growth cycle and thus its effect of precipitation on the species population. Responses of various species to climate change across the Northern Hemisphere are well demonstrated by changes in the timing of growth stages especially the earlier onset of spring events, migration, and lengthening of the growing season (IPCC, 2007). The loss of habitat due to the interference of climate change would further hasten population extinction. Numerous studies have been conducted on the correlation of regional climate effects on terrestrial species and they reveal consistent responses of the habitats of the fauna species and of the fauna species itself to climate changes. These responses include poleward and elevational range shifts of flora and fauna. The ecosystems and the habitats all across the world has been affected by the changes in climate. A review of the relevant published data on such occurrences on biological systems, done by Intergovernmental Panel on Climate Change (IPCC, 2007) concluded that 20 percent to 30 percent of species assessed were at risk of extinction from climate change impacts within this century if global mean temperatures would exceed 2-3 °C (3.6-5.4 °F) relative to pre-industrial levels. The effect of temperature on population of the species also has been studied by a number of researches. However the effect of temperature is one of the unanswered parts in the current study. Various researches have had differential views on how an increase in temperature would affect populations. Kerr (1997) had stated with accordance to the most reliable evidence that based on the analysis of 80 million years old fossil records it could be noted that mammals were peculiarly resistant to temperature change and that warming tends to increase biodiversity, not reduce it. Dealing with the population of all fauna and flora in general, Moore, T.G (1997,p.50-64) had argued that studies of climate history revealed the occurrence of sharp changes in temperatures over brief periods of time in repeated frequency, but these had never set into motion any disastrous feedback systems that led either to a runaway heating that caused the cooking the earth or a freezing that eliminated all life. These studies nullify the possibility of major contribution of temperature rise towards population extinction. Studies on birds have also proved that climate change hastens population extinction. Using associations between climate variables and birds, Price and Glick (2002,p.31) and Price and Root (2001,p. 371-379) assessed the potential for large shifts in range of numerous bird species in United States. The association of bird species population on the surrounding climate and also on the availability of suitable climate, which in turn in turn is affected by climate change, is also confirmed by these literatures. However the role of climate change as a possible cause of extinction of the checker spot butterfly, Euphydryas editha bayensis, has been reiterated by other researches as well. Dyke, F.V (2008,p.128) in his study on the extinction pattern of the checker spot butterfly, Euphydryas editha bayensis, has analysed that in relation with the climate change predictions, the extinction process of the butterflies had shifted their range both upward and northward in geographical elevations. Thus the relation of the extinction of the discussed species with climate change and habit loss as assumed by the current study has been confirmed by the literatures available. Conclusion The literatures which were referred had however indicated the relevance of the hypothesis made by the study. Literatures available on indications of climate change in the historic records confirmed the conceptual and theoretic aspects of climate change in relation to the study on the effect of climate change in hastening population extinctions. The incidents of extinction of checkerspot butterfly were also found in a number of studies. Literatures pertaining to the unanswered part of the subject were also refereed to. Similar studies on different species including birds further serve as a background to the study. Effects of climate change on altering the growth cycles of plants were confirmed with reference to related literature. Further research on the extinction of the species and its relation with climate change would help to have a better understanding on the role of climate change in hastening population extinction. REFRENCES Cushman, J. H., Boggs, C. L., Weiss, S. B., Murphy, D. D., Harvey, A. W. & Ehrlich, P. R. 1994. Oecologia 99, 194–200. Dyke ,F.V. 2008. Conservation Biology: Foundation & Applications, New York: Springer.128 Emmanuel, W.R, Stughart, H.H, Stevenson, M, 1985,Climate Change & the Broad Scale Distribution of terrestrial eco system complexes. Climate Change: 7: 29-43 Figueres, C& Ivanova, M .2002. Climate Change: National Interest Or A Global Regime. Global Environmental Governance: Options & opportunities Ed. Daniel C Esthy & Maria H Innovana, US: Yale School of Forestry & Environmental studies,.205-221. Graham, R. W. & Grimm, E. C. (1990) Trends in Ecology. Evoution. 5, 289–292. IPCC, 2007: Climate Change 2007: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Third Assessment Report of the Intergovernmental Panel on Climate Change Eds. Parry, Martin L., Canziani, Osvaldo F., Palutikof, Jean P., van der Linden, Paul J., and Hanson, Clair E. Cambridge: Cambridge University Press J. B. Hughes, Daily, G. C. & Ehrlich, P. R. 1997 Science 278, 689–692. Jon, B. Tony , C. Richard,M. Ray A, & Roxane, B. 1998. Influence Of Precipitation Timing On Sagebrush/Bunchgrass Vegetation. Late Quaternary vegetation and climate in the Great Basin.. 220-239 Kirk, W. D. J. 1997. Distribution, abundance and population dynamics. In: Thrips as crop pests. Ed.T. Lewis , Oxon, UK: CAB Kerr, R.A. 1996. ‘Millenial Climate Oscillation Spied, Science, 271:146. Moore, T.G. “Warmer is Better - Ed. Morris Julian, Westminster: IEA Environment Unit, 1997.50-64 Morsello,S.C.2007. The Role of Temperature and Precipitation on Thrips Populations in Relation to the Epidemiology of Tomato Spotted Wilt Virus Raleigh: North Carolina State University Morris, J. 1997. Climate Change – Prevention or Adaptation” Climate Change - Challenging the Conventional Wisdom. Ed. Morris Julian. Westminster: IEA Environment Unit, 5-17 Price, J. Glick, P. 2002. The birdwatchers guide to global warming, National Wildlife Federation; The Plains, VA: American Bird Conservancy. 31 Price, J. T. Root, T. L. 2001. Climate change and neotropical migrants. In: Rahm, J.; McCabe, R, eds. Changing climates of North America: political, social, and ecological: transactions of the sixty-sixth North American Wildlife and natural resources conference; 2001 March 16-20; Washington DC. Washington DC: Wildlife Management Institute. 371-379. Taylor, K. E. and Penner, J. E. 1994 ‘Response of the Climate System to Atmospheric Aerosols and Greenhouse Gases’, Nature, 369, 734 – 737. Read More