project on loss of biodiversity threatened endangered and extinct species pdf

Project On Loss Of Biodiversity Threatened Endangered And Extinct Species Pdf

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Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Trans-Amazon Highway being cut through the rain forest near Altamaria, Brazil—one example of the detorestation that takes place along with traditional frontier expansion.

Biodiversity & Species Conservation

Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Trans-Amazon Highway being cut through the rain forest near Altamaria, Brazil—one example of the detorestation that takes place along with traditional frontier expansion. Photo courtesy of Nigel J. D iscussions of the current extinction crisis all too often focus on the fates of prominent endangered species, and in many cases on deliberate overexploitation by human beings as the cause of the endangerment.

Thus black rhinos are disappearing from Africa, because their horns are in demand for the manufacture of ceremonial daggers for Middle Eastern puberty rites; elephants are threatened by the great economic value of ivory; spotted cats are at risk because their hides are in demand by furriers; and whales are rare because, among other things, they can be converted into pet food.

Concern about such direct endangerment is valid and has been politically important, because public sympathy seems more easily aroused over the plight of furry, cuddly, or spectacular animals. The time has come, however, to focus public attention on a number of more obscure and to most people unpleasant truths, such as the following:.

The primary cause of the decay of organic diversity is not direct human exploitation or malevolence, but the habitat destruction that inevitably results from the expansion of human populations and human activities. Many of the less cuddly, less spectacular organisms that Homo sapiens is wiping out are more important to the human future than are most of the publicized endangered species. People need plants and insects more than they need leopards and whales which is not to denigrate the value of the latter two.

Other organisms have provided humanity with the very basis of civilization in the form of crops, domestic animals, a wide variety of industrial products, and many important medicines.

Nonetheless, the most important anthropocentric reason for preserving diversity is the role that microorganisms, plants, and animals. The loss of genetically distinct populations within species is, at the moment, at least as important a problem as the loss of entire species. Once a species is reduced to a remnant, its ability to benefit humanity ordinarily declines greatly, and its total extinction in the relatively near future becomes much more likely.

By the time an organism is recognized as endangered, it is often too late to save it. Extrapolation of current trends in the reduction of diversity implies a denouement for civilization within the next years comparable to a nuclear winter. Arresting the loss of diversity will be extremely difficult. A quasi-religious transformation leading to the appreciation of diversity for its own sake, apart from the obvious direct benefits to humanity, may be required to save other organisms and ourselves.

Let us examine some of these propositions more closely. While a mere handful of species is now being subjected to purposeful overexploitation, thousands are formally recognized in one way or another as threatened or endangered.

The vast majority of these are on the road to extinction, because humanity is destroying habitats: paving them over, plowing them under, logging, overgrazing, flooding, draining, or transporting exotic organisms into them while subjecting them to an assault by a great variety of toxins and changing their climate.

As anyone who has raised tropical fishes knows, all organisms require appropriate habitats if they are to survive. Just as people cannot exist in an atmosphere with too little oxygen, so neon tetras Paracheirodon innesi cannot survive in water that is 40F 4. Trout, on the other hand, cannot breed in water that is too warm or too acid. And the bacteria that produce the tetanus toxin cannot reproduce in the presence of oxygen.

In order to persist, Bay checkerspot butterflies Euphydryas editha bayensis must have areas of serpentine grassland to support the growth of plants that serve as food for their caterpillars and supply nectar to the adults. Whip-poor-wills, red-eyed vireos, Blackburnian warblers, scarlet tanagers, and dozens of other North American birds must have mature tropical forest in which to overwinter see Terborgh, , for example.

Black-footed ferrets Mustela nigripes require prairie that still supports the prairie dogs on which the ferrets dine. Those politicians and social scientists who have questioned the extent of current extinctions are simply displaying their deep ignorance of ecology;. The food resource of the animals in all major ecosystems is the energy that green plants bind into organic molecules in the process of photosynthesis, minus the energy those plants use for their own life processes—growth, maintenance, and reproduction.

In the jargon of ecologists, that quantity is known as the net primary production NPP. Humanity is now using directly e. This is a minimum estimate of human impact on terrestrial systems. Since Homo sapiens is one of conservatively 5 million species, this may seem an excessive share of the food resource.

But considering that human beings are perhaps a million times the weight of the average animal since the overwhelming majority of animals are small insects and mites and need on the order of a million times the energy per individual, this share might not be too unreasonable.

Yet human beings can be thought of as co-opting NPP not only by direct use but also by indirect use. These estimates alone both explain the basic causes and consequences of habitat destruction and alteration, and give reason for great concern about future trends. Most demographers project that Homo sapiens will double its population within the next century or so. Optimists who suppose that the human population can double its size again need to contemplate where the basic food resource will be obtained.

Unhappily for that notion, the riches of the sea have been quite carefully measured. The basic reason is that efficient harvesting of the sea requires the exploitation of concentrated pools of resources—schools of fishes and larger invertebrates.

People cannot efficiently harvest much of the NPP that resides in tiny phytoplankton the green plants of the sea or in the zooplankton animals too small to swim against the currents. Humanity appears to be already utilizing about as much of oceanic NPP as it can on a sustainable basis.

This discrepancy in the ability of Homo sapiens to exploit terrestrial and oceanic NPP is reflected in the general lack of an extinction crisis in the seas. Except for such organisms as some whales and fishes that are threatened by direct exploitation, animals that spend their entire lives in the open sea are relatively secure.

Aside from some limited environments, such as certain coral reefs, the effects of habitat destruction are relatively small away from shorelines and estuaries. This situation could, of course, change rapidly if marine pollution increases—a distinct possibility. The extirpation of populations and species of organisms exerts its primary impact on society through the impairment of ecosystem services.

All plants, animals, and microorganisms exchange gases with their environments and are thus directly or indirectly involved in maintaining the mix of gases in the atmosphere.

Changes in that mix such as increases in carbon dioxide, nitrogen oxides, and methane can lead to rapid climate change and, in turn, agricultural disaster. As physicist John Holdren put it, a carbon dioxide-induced climatic change could lead to the deaths by famine of as many as a billion people before Destroying forests deprives humanity not only of timber but also of dependable freshwater supplies and furthermore increases the danger of floods.

Destruction of insects can lead to the failure of crops that depend upon insect pollination. Extermination of the enemies of insect pests a usual result of ad lib pesticide spraying can terminate the pest control services of an ecosystem and often leads to severe pest outbreaks.

The extinction of subterranean organisms can destroy the fertility of the soil. Natural ecosystems maintain a vast genetic library that has already provided people with countless benefits and has the potential for providing many, many more. These examples can be multiplied manyfold—the basic point is that organisms, most of which are obscure to nonbiologists, play roles in ecological systems that are essential to civilization.

When a population playing a certain role is wiped out, ecosystem services suffer, even if many other populations of the same organism are still extant. If the population of Engelmann spruce trees Picea engelmanni in the watershed above your Colorado home is chopped down, you could be killed in a resulting flood, even though the species of spruce is not endangered.

Equally, if that were the last population and it were reduced to just a dozen trees so that, technically, the species still existed , you would not be spared the flood, and chance events would likely finish off the Engelmann spruce eventually anyway. In most cases, numerous genetically diverse populations are necessary to ensure the persistence of a species in the face of inevitable environmental changes that occur naturally.

The existence of many populations spreads the risk so that unfavorable conditions in one or a few habitats do not threaten the entire species. And the presence of abundant genetic variation within a species virtually assured. That resource is largely irreplaceable.

Along with fossil fuels, rich soils, ancient groundwater, and mineral deposits, genetic diversity is part of the inheritance of capital that Homo sapiens is rapidly squandering. What then will happen if the current decimation of organic diversity continues? Crop yields will be more difficult to maintain in the face of climatic change, soil erosion, loss of dependable water supplies, decline of pollinators, and ever more serious assaults by pests. Conversion of productive land to wasteland will accelerate; deserts will continue their seemingly inexorable expansion.

Air pollution will increase, and local climates will become harsher. It might, for example, miss out on a cure for cancer; but that will make little difference. As ecosystem services falter, mortality from respiratory and epidemic disease, natural disasters, and especially famine will lower life expectancies to the point where cancer largely a disease of the elderly will be unimportant.

Humanity will bring upon itself consequences depressingly similar to those expected from a nuclear winter Ehrlich, Barring a nuclear conflict, it appears that civilization will disappear some time before the end of the next century—not with a bang but a whimper. Preventing such a denouement will prove extremely difficult at the very least; it may well prove to be impossible.

Our nervous systems evolved to respond to short-term crises—the potential loss of a mate to a rival, the sudden appearance of a bear in the mouth of the cave. For most of human evolutionary history there was no reason for natural selection to tune us to recognize easily more gradual trends, since there was little or nothing one could do about them.

The human lineage evolved in response to changes in the ecosystems in which our ancestors lived, but individuals could not react adaptively to those changes, which usually took place slowly. The depletion of organic diversity and the potential destruction of civilization may, ironically, be an inevitable result of our evolutionary heritage. If humanity is to avoid becoming once again a species consisting of scattered groups practicing subsistence agriculture, dramatic steps will be necessary.

They can only be briefly outlined here. Simply setting aside preserves in the remaining relatively undisturbed ecosystems will no longer suffice. In most parts of the planet such areas are too scarce, and rapid climatic changes may make those preserves impossible to maintain Peters and Darling, Areas already greatly modified by human activities must be made more hospitable for other organisms; for example, the spewing of toxins into the environment leading to intractable problems like acid deposition must be abated.

Reducing that scale will be an especially difficult task, since it means that the environmental impacts of the rich must be enormously curtailed to permit the poor a chance for reasonable development. Although improvements in the technologies used to support human life and affluence can of course help to ameliorate the extinction crisis, and to a limited extent technologies can substitute for lost ecosystem services, it would be a dangerous miscalculation to look to technology for the answer see, for example, Ehrlich and Mooney, In my opinion, only an intensive effort to make those improvements and substitutions, combined with a revolution in attitudes toward other people, population growth, the purpose of human life, and the intrinsic values of organic diversity, is likely to prevent the worst catastrophe ever to befall the human lineage.

Curiously, scientific analysis points toward the need for a quasi-religious transformation of contemporary cultures. Whether such a transformation can be achieved in time is problematic, to say the least. We must begin this formidable effort by increasing public awareness of the urgent need for action. People everywhere should understand the importance of the loss of diversity not only in tropical forests, coastal zones, and other climatically defined regions of the world but also in demographically delineated regions such as areas of urbanization.

The geological record can tell us much about catastrophic mass extinctions of the past. That, and more intensive studies of the living biota, can provide hints about what we might expect in the future. At the present time, data on the rates and direction of biodiversity loss remain sparse and often uncertain. As a result, estimates of the rate of loss, including the number and variety of species that are disappearing, vary greatly—in some cases, as pointed out by E. Wilson in Chapter 1 , by as much as an order of magnitude.

Moreover, scientists have also differed in their predictions of the eventual impact that will result from the diminishing biodiversity.

Some aspects of these challenges are explored in the following five chapters comprising this section and are reflected throughout this volume. Ehrlich, A.

Biodiversity loss

This lists the logos of programs or partners of NG Education which have provided or contributed the content on this page. In collaboration with. The Sixth Mass Extinction? Lesson Driving Question : How have humans impacted the Earth for better and for worse? Guide students in debriefing the activity by adding to their Know and Need to Know chart based on their research. Investigating an Endangered Species and its Biome: Students will complete the environmental and human influences portion of their handout in this activity.

The core threat to biodiversity on the planet, and therefore a threat to human welfare, is the combination of human population growth and resource exploitation. The human population requires resources to survive and grow, and those resources are being removed unsustainably from the environment. The three greatest proximate threats to biodiversity are habitat loss, overharvesting, and introduction of exotic species. The first two of these are a direct result of human population growth and resource use. The third results from increased mobility and trade.

Earlier, we defined biodiversity as the total richness of biological variation and examined reasons why it is important see Chapter 7. In this chapter, we examine the many threats to biodiversity that are associated with the human economy. The emphasis is on severe damage that is being caused, especially that associated with losses of species and of natural ecosystems. Extinction refers to the loss of a species or another named biological entity referred to as a taxon over all of its range on Earth. Extirpation is a more local disappearance, with the taxon surviving elsewhere. Extinction represents an irretrievable loss of a unique portion of the biological richness of Earth, whereas it may be possible to re-establish an extirpated taxon from a surviving population. Extinctions have always occurred as a result of natural influences.

UN Report: Nature’s Dangerous Decline ‘Unprecedented’; Species Extinction Rates ‘Accelerating’

Biodiversity loss , also called loss of biodiversity , a decrease in biodiversity within a species , an ecosystem , a given geographic area, or Earth as a whole. Biodiversity , or biological diversity , is a term that refers to the number of genes , species, individual organisms within a given species, and biological communities within a defined geographic area, ranging from the smallest ecosystem to the global biosphere. A biological community is an interacting group of various species in a common location. Likewise, biodiversity loss describes the decline in the number, genetic variability, and variety of species, and the biological communities in a given area.

We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide. By transformative change, we mean a fundamental, system-wide reorganization across technological, economic and social factors, including paradigms, goals and values. It is the first intergovernmental Report of its kind and builds on the landmark Millennium Ecosystem Assessment of , introducing innovative ways of evaluating evidence.

Saving Endangered Species: A Case Study Using Global Amphibian Declines

Biodiversity refers to the total variety of life on Earth, or the total variety of life in a given area.

Chapter 27 ~ The Biodiversity Crisis

This page has been archived and is no longer updated. These categories range from 'Extinct' to 'Least Concern' Figure 1. At the highest levels of threat, taxa are listed as 'Critically Endangered,' 'Endangered,' or 'Vulnerable,' all of which are given 'Threatened' status. A series of quantitative criteria is measured for inclusion in these categories, including: reduction in population size, geographic range size and occupancy of area, total population size, and probability of extinction. The evaluation of these criteria includes analyses regarding the number of mature individuals, generation time, and population fragmentation.

Угадать ключи к ним невозможно. Если вы думаете, что можно ввести шестьсот миллионов ключей за сорок пять минут, то пожалуйста. - Ключ находится в Испании, - еле слышно произнесла Сьюзан, и все повернулись к. Это были ее первые слова за очень долгое время. Сьюзан подняла голову. Глаза ее были затуманены. - Танкадо успел отдать его за мгновение до смерти.

 - Я уверен, у него все под контролем. Давай не… - Перестань, Чед, не будь ребенком. Мы выполняем свою работу. Мы обнаружили статистический сбой и хотим выяснить, в чем. Кроме того, - добавила она, - я хотела бы напомнить Стратмору, что Большой Брат не спускает с него глаз.

Он вообще не в курсе дела. Сьюзан смотрела на Стратмора, не веря своим ушам. У нее возникло ощущение, что она разговаривает с абсолютно незнакомым человеком.

Там тоже были группы из четырех знаков. - Потрясающе, - страдальчески сказал директор.  - У вас, часом, нет такой же под рукой. - Не в этом дело! - воскликнула Сьюзан, внезапно оживившись. Это как раз было ее специальностью.

Бринкерхофф покраснел до корней волос и повернулся к мониторам. Ему хотелось чем-то прикрыть эти картинки под потолком, но. Он был повсюду, постанывающий от удовольствия и жадно слизывающий мед с маленьких грудей Кармен Хуэрты. ГЛАВА 66 Беккер пересек зал аэропорта и подошел к туалету, с грустью обнаружив, что дверь с надписью CABALLEROS перегорожена оранжевым мусорным баком и тележкой уборщицы, уставленной моющими средствами и щетками.

Habitat Loss

 Стратмор только сделал вид, что звонил по телефону. Глаза Хейла расширились. Слова Сьюзан словно парализовали его, но через минуту он возобновил попытки высвободиться. - Он убьет .

 Меган, - сказал он печально. - Я полагаю, что у вашей подруги есть и фамилия. Беккер шумно вздохнул. Разумеется. Но мне она неизвестна.

Офицер покачал головой, словно не веря своим глазам. - Я должен был вам рассказать… но думал, что тот тип просто псих. - Какой тип? - Беккер хмуро взглянул на полицейского.

Я читала об .

guide pdf and pdf


  1. MaritГ© B.

    A constant RLI value over time indicates that the overall extinction risk for the group is constant. If the rate of biodiversity loss were reducing, the RLI would show an.

    12.04.2021 at 09:45 Reply
  2. Edipo O.

    Biodiversity loss includes the extinction of species plant or animal worldwide, as well as the local reduction or loss of species in a certain habitat , resulting in a loss of biological diversity.

    13.04.2021 at 04:12 Reply
  3. Ahmedbogy

    (A) The numbers of threatened mammal species and (B) those with ranges 19+ million members; + million publications; k+ research projects endangered (13). biodiversity loss, employing the species-area rela-.

    13.04.2021 at 23:05 Reply

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