Keystone Species Essay Example | Topics and Well Written Essays - 1750 words

Keystone Species - Essay Example The populations of big-cat prey including the red coati (Nasua nasua), the agouti (Dasyprocta variegata), and the paca (Agouti paca) are about ten times higher than on Cocha Cashu, Peru, where big cats still live. However, this increase may result from natural population variability rather than the lack of jaguars and pumas. The extreme removal of herbivores and frugivorous mammals would drastically affect forest regeneration, altering tree species composition, but the effects of modest changes in densities are less clear. The sea otter (Enhydra lutris) is a keystone predator par excellence (Duggins 1980). A population of around 200,000 once thrived on the kelp beds lying close to shore from northern Japan, through Alaska, to southern California and Mexico. In 1741, Vitus Bering, the Danish explorer, reported seeing great numbers of sea otters on his voyage among the islands of the Bering Sea and the North Pacific Ocean. Some furs were taken back to Russia and soon this new commodity was highly prized for coats. Hunting began. In 1857, Russia sold Alaska to the United States for $7,200,000. This cost was recouped in forty years by selling sea otter pelts. In 1885 alone, 118,000 sea otter pelts were sold. By 1910, the sea otter was close to extinction, with a world-wide population of fewer than 2,000. It was hardly ever seen along the Californian coast from 1911 until 1938. The inshore marine ecosystem changed where the sea otter disappeared. Sea urchins, which were eaten by the otters, underwent a population explosion. They consumed large portions of the kelp and other seaweeds. While the otters were present, the kelp formed a luxuriant underwater forest, reaching from the sea bed, where it was anchored, to the sea surface. With no otters to keep sea-urchins in check, the kelp vanished. Stretches of the shallow ocean floor were turned into sea-urchin barrens, which were a sort of submarine desert. Happily, a few pairs of sea otters had managed to survive in the outer Aleutian Islands and at a few localities along the southern Californian coast. Some of these were taken to intermediate sites in the United States and Canada where they were protected by strict measures. With a little help, the sea otters staged a comeback and the sea urchins declined. The lush kelp forest grew back and many lesser algae moved in, along with crustaceans, squids, fishes, and other organisms. Grey whales migrated closer to shore to park their young in breaks along the kelp edge while feeding on the dense concentrations of animal plankton. Keystone predators sometimes are more effective within certain parts of their range. The sea star (Pisaster ochraceus) is a keystone predator of rocky intertidal communities in western North America (Paine 1995). This starfish preys primarily on two mussels Mytilus californianus and Mytilus trossulus. A study along the central Oregon coast showed that three distinct predation regimes exist (Menge, B. A., and T. L. Freidenburg. 2001). Strong keystone predation occurs along wave-exposed headlands. Less strong predation by sea stars, whelks, and possibly other predators occurs in a wave-protected cove. Weak predation occurs at a wave-protected site regularly buried by sand. If keystone species do exist, how do the links within a system dominated by such a

Research Paper -- essays research papers

Wireless Fidelity In the last few years the world has undergone a tremendous and unprecedented technological change with the attack of the Information Technology revolution. Earlier it was e-mail that changed the way people communicate, and then online shopping became the order of the day, gradually online banking caught up and the list goes on and on. The new trend, Wi-Fi, or Wireless Fidelity, allows you to connect to the Internet from your couch at home, a bed in a hotel room or at school, all without wires. As author Harold Davis nicely puts, â€Å"Wi-Fi is a wireless technology just like a mobile phone and Wi-Fi enabled computers send and receive data indoors and out; anywhere within the range of a base station. Wi-Fi certification means that you will be able to connect anywhere there are other Wi-Fi CERTIFIED products — whether you are at home, the office, school and other public areas equipped with a Wi-Fi Access Point device† (35). Customers with the capability to tap into w ireless Internet networks at certain universities and Starbucks coffee shops in US will soon be able to browse the Web in a very inexpensive way using the wireless internet technology Wi-Fi WLAN use radio technologies called IEEE 802.11b or 802.11a to provide secure, reliable, fast wireless connectivity. Michael Galagher notes that, â€Å"A Wi-Fi WLAN can be used to connect computers to each other, to the Internet, and to wired networks (which use IEEE 802.3 or Ethernet)† (120). Wi-Fi WLANs operate in the unlicensed 2.4 and 5 GHz radio bands, with an 11 Mbps (802.11b) or 54 Mbps (802.11a) data rate or with products that contain both bands (dual band), so they can provide real-world performance similar to the basic 10BaseT wired Ethernet networks used in many networked environments. Competition has already driven down the costs of deploying 802.11b networks which can now be deployed by businesses to give their employees mobility within the business. Home users can buy 802.11b kit to extend their DSL or cable broadband Internet access wirelessly to the entire house. James LaRocca points out that, â€Å"In universities and schools a wireless network can allow computers to be integrated more effectively into teaching as classes no longer need to be held in computer lab† (48). In ... ...The master key also serves as a password by which users can be authenticated and granted network access. WPA was designed to be a software upgrade to WEP, so most existing wireless devices should be upgradeable to WPA via a firmware (define) update. In order to take advantage of WPA, all network devices like access points and clients must be upgraded. The first WPA-enabled products are expected in the early Spring of 2003, and upgrades for existing products should be available at around the same time or shortly thereafter. For Wi-Fi to really take off in homes, its needs to capture the public imagination and make the initial equipment costs seem even more trivial – similar to when TV sets were drastically reduced in price . "Wi-Fi is a key step for home networking, but it still doesn't solve issues of developing home entertainment," agrees Roland Berger's Kintz. That's probably true. But coming up with an attention grabber doesn't seem so impossible with Intel and Microsoft already pouring millions of dollars into Wi-Fi technologies and major carriers such as VoiceStream and AT&T figuring out how to make the technology work for them.

By 2020 the world’s population could well have doubled to around 12 billion people

By 2020 the world's population could well have doubled to around 12 billion people. Are there just too many people in the world, or is it a question of a better and fairer distribution of the world's resources?† The question is asking if there are too few resources available for the increasing population, or if there are just too many people in the world. The keywords in the question are population and resources. By population, the question is referring to the number of people in the world and by resources; it is asking if there are enough natural assets, such as water, food, oxygen and space. The problems caused by an increasing population include the depletion of natural resources, such as non-renewable energy supplies, and food supplies. Currently resources, and population are very unevenly spread and most supplies occur in areas where they are not needed. Mankind has reached the point of the exponential curve. Earths population doubled in the 40-year period from 1960 to 2000, from 3 billion to 6 billion. In the last two years, the population has grown another third of a billion people. That offers the possibility of a doubling time of only 27 years to reach 12 billion. Partly as a result of this, it is reported that 420 million people live in countries that no longer have enough cropland to grow their own food. They have to rely on imports. The reduction of cropland could be caused by an increase in pollution, creating negative effects on the environment, or it could be due to the expansion of urban areas due to an increasing population. A quarter of the developing world's cropland is being degraded, and the rate is increasing. The greatest threat may not be shortage of land, but a shortage of water. More than half a billion people live in areas prone to droughts. In the next twenty years, that number will increase five times, to between 2.4 billion and 3.4 billion people. Currently, that means half of Earth's population will run out of water within 20 years. It is impossible to farm animals and grow crops without water, which will therefore lead to a decrease in food availability, especially in areas already suffering from famines. A recent report, released by the World Watch Institute, declares that, â€Å"Mining consumes 10% of the world's energy, spews out toxic emissions, and threatens 40% of the world's undeveloped forests.† These effects could be drastically reduced but, unfortunately, governments are not moving quick enough to stem the tide. This indicates that it is suspected that a major contributing factor to the problem is the attitudes of people. Very few governments are taking radical measures in an attempt to prevent the foreseen problems of the future. The reason for this is that because the problems are not yet taking a huge effect, by the time the effect becomes apparent it will be too late, and any attempts at solving the problem will be useless. One of the great challenges for governments is to help their poorest citizens feel secure in their own homes, make a living and improve their environment. Around 1.2 billion people live in absolute poverty – surviving on less than a dollar a day. As populations spiral upward, the underground water tables are dropping. Many regions face severe drought. Deserts are growing. Forests are being cut down and the land they leave behind is wasting away. Since forty percent of all vegetable and grain food supplies come from irrigated land, a failing water supply creates sever food shortages. Many countries are facing water shortages in the twenty-first century, especially India, whose population passed one billion in May 2002. They are currently expanding by 18 million per year. Water withdrawals now double the environments ability to re-supply. Half of India's grain harvest comes from irrigated land. World Watch reports, â€Å"In a country where 53 percent of all children are already malnourished and underweight, a shrinking harvest could increase hunger-related deaths.† Another threat is shrinking croplands. Some nations already depend almost entirely upon imported food. Eventually, the food will simply not be available to those nations. First, increased costs will drain those nations of their economic cash flows, and one day, the exporting nations will not be able to supply food at any price. Among the countries where shrinking croplands threaten food supplies are Nigeria, Ethiopia, and Pakistan. Nigerias population will increase from its present 111 million to a estimated 244 million by 2050, while its grain-land per person will stay the same. That means each person will have less than half the current supply. Pakistan is expected to grow from its current 146 million to 345 million by 2050. By that time, each person will be dependent upon a piece of grain-land the size of a tennis court. Japan, South Korea and Taiwan already import 70 percent of their grain. Water supplies are fixed by nature. They cannot be increased. On the other hand, an ever-increasing population can deplete them. This is also true of croplands. I feel that although an increasing population is having a drastically negative effect upon the depletion of the world's resources, and that resources are clearly unfairly distributed. It is the richest and relatively most sparsely populated countries, particularly Western Europe and America that receive the highest share of the world's natural resources. This is because they are the richest countries and can therefore afford to grow their own resources as well as import others, yet offer very little money for them. The effect this has is that the worlds resources are being unfairly relocated into the richest countries where it could be claimed that they are being wasted. It is clear that the richest countries currently have an excess of resources that they could share across the world to help combat the problem stated by the question. The problem with this is that it is non-profitable and the countries would lose a lot of money, which in a materialistic world is more important than tackling issues of poverty and malnutrition.

A Critical Analysis of Oscar Wildes Importance of Being...

Running Head: CRITIQUING PLAY 1 Critiquing Play [Name of the Writer] [Name of the Institution] [Date of Submission] Table of Contents Introduction 3 Discussion 3 The Critical Summary 3 The Act One Part I 3 The Act One Part II 4 The Act Two Part I 4 The Act Two Part II 5 The Act Three Part I 6 The Act Three Part II 6 The Themes / Message of the Play 7 Sincerity and Manners 7 The Dual Identity 8 The Critique of Marriage 8 Idleness of the Aesthete and the Leisure Class 9 The Plot vs. Characterization 9 The Analysis of Character 9 The Structure Analysis of Plot 10 The Title of the play 11 Conclusion 12 Critiquing Play Introduction The play, The Importance of Being Earnest, is written by Oscar Wilde and was first performed in London at St. Jamess Theatre on fourteen February of the year of 1895. In order to escape burdensome social obligations, fictitious personal was maintained by the protagonists in this farcical comedy. The resulting satire of Victorian ways and the triviality through which the institutions were treated are the significant themes of the play that worked within the social conventions of late Victorian London (Brophy, 1947). The humor of the play was praised by all the contemporary reviews; whereas, its explicit lack of social messages were a significant concern for some people. Discussion The Critical Summary The Act One Part I An unrealistic and a highly stylized world in which truly little seems toShow MoreRelatedThe Importance Of Being Earnest By Oscar Wilde1243 Words   |  5 PagesBiography An exuberant nonconformist and controversial playwright, eminent author Oscar Wilde produced critically acclaimed literary works that defined the essence of late Victorian England. Posthumously recognized for his only novel The Picture of Dorian Gray and satiric comedy The Importance of Being Earnest, Wilde initially acquired criticism for his immoral and unconventional style of writing. Additionally, to his dismay, strife followed Wilde in his personal life as he was notoriously triedRead MoreEssay on Oscar Wilde and His Fairy Tales5131 Words   |  21 PagesOscar Wilde and His Fairy Tales I. Introduction Wilde, Oscar (Fingal O’Flahertie Wills) (b. Oct. 16, 1854, Dublin, Ire ?d. Nov. 30, 1900, Paris, Fr.) Irish wit, poet and dramatist whose reputation rests on his comic masterpieces Lady Windermere’s Fan (1893) and The Importance of Being Earnest (1899). He was a spokesman for Aestheticism, the late19th-century movement in England that advocated art for art’s sake. However, Oscar Wilde’s takeoff of his enterprise and, his shaping of his characteristicRead MoreOscar Wilde and His Fairy Tales5266 Words   |  22 PagesOscar Wilde And His Fairy Tales I. Introduction Wilde, Oscar (Fingal OFlahertie Wills) (b. Oct. 16, 1854, Dublin, Ire ?d. Nov. 30, 1900, Paris, Fr.) Irish wit, poet and dramatist whose reputation rests on his comic masterpieces Lady Windermeres Fan (1893) and The Importance of Being Earnest (1899). He was a spokesman for Aestheticism, the late19th-century movement in England that advocated art for arts sake. However, Oscar Wildes takeoff of his enterprise and, his shaping of his characteristic