Earth is an awesome place to live, as far as we know, its the only one of its kind. With all of the vast amount of precious resources, its no wonder so many movies have been made about other civilization from distant worlds that have wanted to conquer us. The verse “from sea to shinning sea” has a definite true meaning too the beauty it describes.With all of this beauty at our finger tips, why would anyone want to cause harm to it, for the sake of expansion, profit, or industrialization? The choices we make in our free society about resource use can have grave consequences if we don’t use them wisely and responsibly. These choices can negatively influence the biodiversity in an area.The text Environment: The Science Behind the Stories, defines biodiversity as the sum of all organisms in an area (Withgott & Brennan, 2006, p 115) Biological diversity or biodiversity is the diversity of plant and animal life in a particular habitat.The negative impact of population growth and over consumption can lead to the decline of many organisms or extinction. (Withgott & Brennan, 2006, p 295) According to our text there is a connection to biodiversity loss and extinction, Extinction is only part of the effects of biodiversity loss. Some of the major threats to biodiversity are the loss of species and ecosystems caused by a growing human population. As the human population passes the six billion mark, we have used roughly half of the world’s forests. We use roughly half of the world's net primary productivity for human use. We use most available fresh water, and we harvest virtually all of the available productivity of the oceans. It may be a coincidence, but it seems to me that the relationship between human usage and species disappearing and ecosystems being destroyed are related to each other. (Withgott & Brennan, 2006, p 295)Many species today have been either diminished or eradicated.” (Withgott & Brennan, 2006, p 304) It’s as if the “circle of life “is on fire going. This may not have too much of impact on you or me, we can run down to the nearest Subway and grab a bite, but for developing nations it can be drastic. I spent 18 months chasing down Taliban in Afghanistan, and clean water was hard to come by. You would be surprised at the value of bottled water. Young children were not interested in chocolate, they wanted my water.The negative impact on biodiversity also has a trickle down effect on our planets ecosystem. A perfect example of this is when, a larger number of plant species means a greater variety of crops; greater species diversity ensures natural sustainability for all life forms; and healthy ecosystems can better withstand and recover from a variety of disasters.Ecosystems are defined by the text “a collection of living things and the environment in which they live” (Withgott & Brennan, 2006, p 180). Biodiversity helps ecosystem maintain its productivity. The text states that high level of biodiversity helps increase the stability of organism communities. It acts as a natural shield from disturbances. It could be looked at as nature’s tolerance to change. Just as we have developed immunity to certain types of disease. Everything is linked together and if one thing fails the whole house can come crashing down. (Withgott & Brennan, 2006, p 311)There are many other actions that also contribute to population depletion of certain species. Over hunting , poaching and over harvesting can cause, habitat alteration. Some causes such as climate change are still being debated. There always seems to be politics in the middle of science when it comes to environmental protection. Extinction can also be Mother Nature’s way of cleansing the planet. I am not to sure how the dinosaurs and us would have co- existed. Our text states, “If organisms did not naturally go extinct, we would be over run by dinosaurs, trilobites, ammonites, and the millions of other types of creatures that vanished from Earth long before humans appeared”.(Withgott & Brennan, 2006, p 301) Science has proven there have been five mass extinctions during the past half- billion years of Earth history. “At the end of the Ordovician, Devonian, Permian, Triassic, and Cretaceous periods, 50-95% of the world’s species appear to have gone extinct. This can compared with forest fires today. It seems as if the opinion of such fires is changing. I am not too sure if Smokey would agree. The cleansing process allows our ecosystem and biodiversity to rebound to equal or higher levels, but it takes millions of years”. (Withgott & Brennan, 2006, p 302) I don’t want my generation to be responsible for the next “mass extinction”. There is documentation of hundreds of cases of “human induced species extinction over the past few years such as the “Gray Wolf”, Do Do , and almost the Blue Whale. Our own national icon the “Bald Eagle” has had to fight for its survival as well. Have you seen the claws on that thing, I would not want to fight one. (Withgott & Brennan, 2006, p 302) Today, extinction rates are higher than normal due to our accelerated population growth. Making room for modern society by development of land reduces natural habitat which in turn declines the population of our endangered species, which may lead to starvation and extinction. “The worst thing that can happen during the 1980s is not energy depletion, economic collapse, limited nuclear war, or conquest by a totalitarian government. As terrible as these catastrophes would be for us, they can be repaired within a few generations. The one process ongoing in the 1980s that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats. This is the folly that our descendents are least likely to forgive us.”- E.O. Wilson, 1985In conclusion, Biodiversity refers to the number and variety of species, of ecosystems, and of the genetic variation contained within species. Roughly 1.4 million species are known to science, but because many species are recorded, an estimated 10-30 million species likely exists at present. Biodiversity is threatened by the sum of all human activities. It is useful to group threats into the categories of over-hunting, habitat destruction, and invasion of non-native species, domino effects, pollution, and climate change. Habitat loss presents the single greatest threat to world biodiversity, and the extent of this threat can be approximated from species-area curves and rates of habitat loss. The spread of non-native species threatens many local species with extinction, and pushes the world's biota toward a more uniform and widely distributed sub-set of survivors. Climate change threatens to force species and ecosystems to migrate toward higher latitudes, with no guarantee of suitable habitat or access routes. These three factors thus are of special concern.
PHS 100 Environmental Studies. Professor: David Terrell
Warner Pacific College September 21, 2009,
References:Wilson, E. O. 1971. The Insect Societies. Belknap Press of Harvard Univ. Press, Cambridge, MA.
Withgott, J. , & Brennan, S. (2008). Environment: The Science Behind the Stories (3rded.). New York. Pearson Benjamin Cummings. ISBN: 13: 978-0-8053-9573-
No comments:
Post a Comment