Biological Diversity, Animal Behavior & Endangered Species



Unit 2 Biological Diversity Study Guide

1. What is biodiversity? What is the underlying cause of biodiversity?

❖ Biodiversity is the variability among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems.

❖ Biodiversity forms the foundation of the vast array of ecosystem services that critically contribute to human well-being.

❖ Biodiversity is important in human-managed as well as natural ecosystems.

❖ Decisions humans make that influence biodiversity affect the well-being of themselves and others.

2. What is the underlying cause of biodiversity?



❖ Habitat loss and destruction

❖ Alterations in ecosystem composition

❖ Over Exploitation

❖ Invasive species

❖ Pollution and contamination

❖ Global climate change

3. Biological diversity involves the following concepts. Explain each:

❖ Genetic diversity – variety of genes in a species to allow for it to have an reproductive advantage

❖ Habitat/ecosystem diversity- large area with different biomes for organisms to thrive

❖ Species diversity- number of different species and their abundance.

4. Why is biodiversity high in some places but low in others?

❖ Unique Climates and Conditions

One of the most significant and naturally occurring causes of differences in biodiversity across the world is differences in climate. Mountain tops and deserts are naturally low in biodiversity, for the simple reason that their unique climates are not suitable to many types of life. Plants and animals have as much difficulty surviving in the thin atmosphere on freezing mountain tops as they do living in hot, waterless deserts. As such, these climates support very low biodiversity. On the other extreme, moist, tropical zones like the Amazon rainforest support some of the highest levels of biodiversity in the world. Numerous varieties of plants and animals can thrive in these environments.

❖ Pollution and Environmental Destruction

Even in the most biodiverse regions of the world, like rainforests, human pollution can reduce biodiversity. This is because pollution does not uniformly affect all species. Some species, for example, might be more resistant to the impact of a toxic oil in a water supply, while another species might be killed almost to extinction because of the pollutant. The loss of a single species can throw off a food web, and lead organisms that relied heavily on that species as a source of food to also die. In the process, numerous species may die or even go extinct, which reduces biodiversity considerably.

❖ Invasive Species

Invasive species are another type of environmental factor that can vastly reduce biodiversity. While invasive species are frequently introduced by humans, they sometimes occur naturally. Introducing a new species to an new environment can often lead to a disruptive change in food webs, which can reverberate throughout a region and cause numerous other species to go extinct. In the 1950's, for example, British colonists introduce a species of perch into Africa's Lake Victoria, and the perch killed off numerous other species in the lake. The fish that the perch killed, in turn, no longer ate the algae that grew in the lake, so the algae population bloomed and then decayed, resulting in decreasing oxygen levels in the lake, which then became inhospitable to many forms of life. This is an example of how one small invasive species can turn a high biodiversity region into a low one. (A local example would be the zebra muscles that are invaiding local lakes.)

❖ Overhunting or Overuse

Overhunting or overuse of a species can have the same adverse impact on biodiversity as an invasive species or pollution. Overusing or overhunting just one species in an ecosystem can disrupt food chains and impact the ability of numerous other species to survive. But sometimes the threat is not due to food web disruption. In the Amazon rainforest, for example, the spider monkey plays an important role in helping the the tree species Inga ingoides survive by distributing its seeds manually and through feces. As the spider monkey has been hunted almost to extinction, the Inga ingoides have largely failed to reproduce, and thus have also declined in population. The overhunting of just one species can thus rapidly reduce the entire biodiversity of a region.

5. Why is biodiversity important in an ecosystem?

❖ Biodiversity and food: 80% of human food supply comes from 20 kinds of plants. But humans use 40,000 species for food, clothing and shelter. Biodiversity provides for variety of foods for the planet.

❖ Biodiversity and human health: The shortage of drinking water is expected to create a major global crisis. Biodiversity also plays an important role in drug discovery and medicinal resources. Medicines from nature account for  usage by  80% of the world’s population.

❖ Biodiversity and industry: Biological sources provide many industrial materials. These include fiber, oil, dyes, rubber, water, timber, paper and food.

❖ Biodiversity and culture: Biodiversity enhances recreational activities like bird watching, fishing, trekking etc. It inspires musicians and artists.

6. What are the characteristics of an endangered species?

Endangered species are animals or plants that are so few in number that it is possible they may become extinct in the near future. A species can become endangered due to changes in the environment, predators, disease, or from the impact of humans. While a wide variety of species have become extinct -- from the Tasmanian tiger to the Dodo bird -- they do share some common characteristics.

Habitat: Animals or plants that live in a small area, such as an island or cave, are vulnerable to extinction. They may be unable to relocate or adapt to changes in their environment. Species that have a specialized habitat, such as marshes, are also at risk. For example, the Ivory-billed Woodpecker needs old-growth forests, which when cut for lumber cannot quickly be replaced. Many bat species dwell in caves and cannot easily find new homes.

Diet: The more limited the diet of a species, the more likely it is to become extinct. General herbivores, which eat a wide variety of plants, are better able to find food when their environment changes than a species such as the Giant Panda, which eats mainly the slow-growing bamboo plant. The black-footed ferret survives almost entirely on prairie dogs, which are viewed by farmers and ranchers as a pest that threatens their livestock.

Reproduction: Species that live a long time and have few young are vulnerable to extinction. They are not as resilient to population losses as fast-reproducing species. For example, small rodents have a high mortality rate and have large litters, sometimes multiple times a year. Larger animals that face fewer predators tend to produce fewer offspring. Some produce just one offspring at a time and do not reproduce every year.

Size: Larger animals are more vulnerable to extinction. They require larger habitats in which to find food and mates. Mountain lions have territories of up to 116 square miles (300 square km).

Commercial Value: Animals or plants that are sought after as pets or for their commercial value have often faced extinction. Rhinoceros are often hunted for their horns, which are considered an aphrodisiac in some cultures. The Sturgeon fish, a source of caviar, is now endangered due to overfishing. Many species of tiger have become extinct or are endangered because of demand for their fur.

7. What is the current reasoning as to why things are becoming extinct at such a fast rate?

Human interactions and population growth – Conservationists say rate of new species slower than diversity loss caused by the destruction of habitats and climate change

8. What is the main reason for the sixth mass extinction?

❖ The Earth's sixth mass extinction is already underway — and humans are the driving force behind it, according to a new study. The researchers say “human activities are driving the latest mass extinction event. A ballooning human population, habitat destruction to make way for new settlements or agricultural production, climate, ocean acidification, and soil, water, and air pollution are all wiping species off the face of the Earth.”

❖ "Recent extinction rates are unprecedented in human history and highly unusual in Earth's history," according to a study in the journal Science Advances. "Our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years."

❖ Researchers used "extremely conservative assumptions" to determine extinction rates that prevailed in the past five annihilation events. Still, they found the average rate of vertebrate species lost over the past century was up to 114 times higher than normal.

9. List 3 endangered species.

Asian Elephant, Black rhino, Indian Tiger

10. Summarize the Endangered Species Act.

The Endangered Species Act of 1973 (ESA) was signed on December 28, 1973, and provides for the conservation of species that are endangered or threatened throughout all or a significant portion of their range, and the conservation of the ecosystems on which they depend. The ESA replaced the Endangered Species Conservation Act of 1969. Congress has amended the ESA several times.

❖ It is illegal for Americans to import or trade in any product made from an endangered or threatened species unless it is used for an approved scientific purpose or to enhance the survival of the species.

❖ Authorizes the Marine Fishery Service and the U.S. Fish and Wildlife Service to identify and list all other endangered & threatened species.

❖ These species cannot be hunted, killed, collected or injured in the U.S.

11. Explain in situ vs ex situ.

In Situ would be trying to help a threatened species recover in their natural habitat leaving it there and protecting it with laws. Ex situ would be to bring them out of their habitat to a zoo or animal preserve to be cared for.

12. How do scientists account for the development of life on earth?

Using the fossil record, DNA & chemical analysis and ice cores.

13. What is biological evolution by natural selection, and how can it account for the current diversity of organisms on the earth?

Biological evolution, refers to the change of living things over time. Charles Darwin concluded that biological evolution occurs as a result of natural selection, which is the theory that in any given generation, some individuals are more likely to survive and reproduce than others. In order for natural selection to occur in a population, several conditions must be met:

❖ Individuals in the population must produce more offspring than can survive. Human beings are somewhat unique among living things in that we can make conscious choices about how many offspring we have. Most other organisms, however, produce as many offspring as they can.

❖ Those individuals must have different characteristics. During Darwin’s time, no one knew where these differences came from. Now scientists know that differences in organisms arise due to mutations in DNA combined with the mixing of genetic information during sexual reproduction.

❖ Offspring must inherit some characteristics from their parents.During Darwin’s time, the laws of inheritance were just beginning to be figured out, so Darwin didn’t know exactly how parents passed on their traits. Modern scientists know that traits are inherited when parents pass genes on to their offspring.

❖ Organisms with the best-suited characteristics for their environment are more likely to survive and reproduce. This is the heart of natural selection. If there’s competition for survival and not all the organisms are the same, then the ones with the advantageous traits are more likely to survive. If these traits can be inherited, then the next generation will show more of these advantageous traits.

If these four conditions are met, then the new generation of individuals will be different from the original generation in the frequency and distribution of traits. This is the theory we use to account for all biodiversity on Earth.

14. How do extinction of species and the formation of new species affect biodiversity?

As environmental conditions change, the balance between formation of new species and extinction of existing species determines the earth's biodiversity.

15. How did we become such a powerful species in a short time?

Humans have survived and thrived because we have certain traits that allow us to adapt and modify parts of the environment to increase our survival chances. Evolutionary biologist attribute our success to three adaptations:

❖ Strong oppossiable thumbs that allow us to use tools

❖ Ability to walk upright which frees up our hands and give us great agility

❖ Complex brains which allows us to develop many skills, including the ability to use speech to transmit complex ideas

16. How have human activities affected the Earth’s biodiversity?

There is no doubt that human civilization has had a negative impact on biodiversity, particularly since the industrial revolution. Overfishing and hunting, the destruction of habitats through agriculture and urban sprawl, the use of pesticides and herbicides, and the release of other toxic compounds into the environment have all taken their toll, particularly on vertebrates. 

17. How serious is tropical deforestation?

Deforestation may meets some human needs, it has profound, sometimes devastating, consequences, including

❖ social conflict

❖ extinction of plants and animals

❖ climate change

❖ Reasons for tropical deforestation:

o The poor become subsistence farmers to feed their families

o Government subsidies make the wood cheaper

o Governments give title to the land where the poor clear and colonize the land

o Easy financing of large scale projects in rainforest areas for developing countries

o Failure to value ecological services of forests

18. How can we sustain tropical forest?

Strategies for preserving tropical forests can operate on local to international scales.

❖ On a local scale, governments and non-governmental organizations are working with forest communities to encourage low-impact agricultural activities, such as shade farming, as well as the sustainable harvesting of non-wood forest products such as rubber, cork, produce, or medicinal plants. Parks and protected areas that draw tourists—ecotourism—can provide employment and educational opportunities for local people as well as creating or stimulating related service-sector economies.

❖ On the national scale, tropical countries must integrate existing research on human impacts on tropical ecosystems into national land use and economic development plans. For tropical forests to survive, governments must develop realistic scenarios for future deforestation that take into account what scientists already know about the causes and consequences of deforestation, including the unintended deforestation that results from road-building, accidental fire, selective logging, and economic development incentives such as timber concessions and agricultural subsidies.

❖ Finally, on the national and international scale, an increasing value in the global marketplace for products that are certified as sustainably produced or harvested—timber, beef, coffee, soy—may provide incentives for landowners to adopt more forest-friendly practices, and for regional and national governments to create and enforce forest-preservation policies. Direct payments to tropical countries for the ecosystem services that intact tropical forest provide, particularly for carbon storage to offset greenhouse gas emissions, are likely to become an important international mechanism for sustaining tropical forests as more countries begin to seriously tackle the problem of global warming.

19. What is ecological restoration?

Ecological restoration aims to recreate, initiate, or accelerate the recovery of an ecosystem that has been disturbed. Disturbances are environmental changes that alter ecosystem structure and function. Common disturbances include logging, damming rivers, intense grazing, hurricanes, floods, and fires. Restoration activities may be designed to replicate a pre-disturbance ecosystem or to create a new ecosystem where it had not previously occurred. Restoration ecology is the scientific study of repairing disturbed ecosystems through human intervention.  Virtually all the worlds' ecosystem types have been the subject of restoration efforts, but particular attention has been paid to ecosystems most impacted by human activities, such as wetlands, grasslands/rangelands, riparian areas, and tropical forests. 

20. What are some Ecological Restoration Methods used for sustaining an ecosystem?

❖ Restoration to former natural state

❖ Rehabilitation into a functional/useful ecosystem (mining sites, landfills, clear-cut forests)

❖ Remediation after extraction methods, industrial exploitation so there contains no chemical contaminants (mining, brownfields)

❖ Replacement with another ecosystem (tree farm for forest)

21. Why should we care about protecting wild species?

It is essential to take actions to protect wildlife from extinction. By doing so, we do not only ensure their survival, but also the diversity of the ecosystem. As a result, it will help improve the ecological health of the earth. Listed below are some of the reasons why wildlife protection is essential.

❖ Promote Biodiversity; Biodiversity is essential for a healthy and functional ecosystem. If wildlife is extracted from its natural habitat, the delicate balance of the ecosystem will be disturbed which will then lead to disastrous results. For instance, there is a wide diversity of species living in a tropical rain forest. If any species should become extinct, the food chain will be disrupted affecting all the species. For this reason, promoting biodiversity is one of the main reasons why we should protect wildlife.

❖ Beneficial For Humans: One can learn a lot from animals which can benefit the human race. For instance, a lot of medicines have been derived from the chemicals produced by animals. These medicines are then used to help cure various health conditions, such as heart diseases, disorders, and other illnesses. In fact, based on the statistics provided by the U.S Fish and Wildlife Service, more than 25% of the medicinal prescriptions given every year contain chemicals from animals. For instance, there are scientists who are studying venom from the pit viper to cure the symptoms of Melanoma, and the venom from a tarantula can help fight neurological disorders.

Wildlife protection is essential because if the animal is gone, it will be impossible to study and learn from them. Unfortunately, a lot of wildlife has disappeared from earth due to human activities, such as the Bali tiger, Mexican grizzly bear, and the Japanese wolf.

❖ Conservation Of Natural Habitat: When we conserve and protect the natural habitat of wildlife species, we enrich our planet. To do so, we must keep the animals in their natural place. Conservation of natural habitats will also be beneficial for humans since it helps keep the essential watersheds intact and ensuring clean, fresh water.Today, there are now wildlife preservation programs wherein they allow the animals to roam freely in their natural habitat. Some of these programs also allow the animals to interact with humans. This is beneficial since it educates the people and raises awareness regarding the importance of protecting these wildlife species.

22. Which human activities endanger wildlife?

❖ Species endangered by unsustainable hunting: Overhunting and overfishing have threatened animal species since aboriginal Europeans, Australians, and Americans developed effective hunting technology thousands of years ago. The dodo, passenger pigeon, great auk, and Steller's sea cow were hunted to extinction. Unstainable hunting and fishing continue to endanger numerous animals worldwide.

❖ Introduced or invasive species entering the ecosystem: In many places, vulnerable native species have been decimated by non-native species imported by humans. Predators like domestic cats and dogs, herbivores like cattle and sheep, diseases, and broadly-feeding omnivores like pigs have killed, starved, and generally outcompeted native species after introduction. Some destructive species introductions, like the importation of mongooses to the Pacific islands to control snakes, are intentional, but most of the damage caused by exotic species and diseases is unintended. Species living on islands are especially vulnerable to introduced predators. In one case, the accidental introduction of the predatory brown tree snake to the Pacific island of Guam in the late 1940s caused a severe decline of native birds. Prior to the introduction of the snake there were 11 native species of birds on Guam, most of which were abundant. By the mid-1980s seven of the native species were extinct or extirpated on Guam, and four more were critically endangered. The Guam rail, a flightless bird, is now extinct in the wild, although it survives in captivity and will hopefully be captive-bred and released to a nearby, snake-free island.

❖ Habitat destruction: Many species have become extinct or endangered as their natural habitat has been converted for human land-use purposes. The American ivory-billed woodpecker, for example, once lived in mature, bottomland hardwood forests and cypress swamps throughout the southeastern United States. These habitats were heavily logged and/or converted to agricultural land by the early 1900s. There have been no reliable sightings of the American ivory-billed woodpecker since the early 1960s, and it is probably extinct in North America. A related subspecies, the Cuban ivory-billed woodpecker, is also critically endangered because of habitat loss, as is the closely related imperial woodpecker of Mexico. Tropical deforestation presents represents the single greatest threat to endangered species today, though destruction of coastal and shallow marine habitats associated with anthropogenic global warming may present an even larger challenges in the future. While there was little net change (-2%) in the total forest cover of North America between the 1960s and the 1980s, the global area of forested land decreased by 17% during that period. Conversion of species-rich tropical forests in Central America, South America, Africa, and the Pacific islands to unforested agricultural land accounts for most of the decline. (Ironically, tropical soils have such poor structure and nutrient content that they generally cannot support profitable agriculture once the forest biomass has been removed.)

23. What is reconciliation ecology and what are its goals?

Reconciliation ecology is the branch of ecology which studies ways to encourage biodiversity in human-dominated ecosystems. Michael Rosenzweig first articulated the concept in his book Win-Win Ecology, based on the theory that there is not enough area for all of earth’s biodiversity to be saved within designated natural preserves. Therefore, humans should increase biodiversity in human-dominated landscapes. By managing for biodiversity in ways that do not decrease human utility of the system, it is a "win-win" situation for both human use and native biodiversity. The science is based in the ecological foundation of human land-use trends and species-area relationships. It has many benefits beyond protection of biodiversity, and there are numerous examples of it around the globe. Aspects of reconciliation ecology can already be found in management legislation, but there are challenges in both public acceptance and ecological success of reconciliation attempts.Reconciliation ecologists believe increasing biodiversity within human dominated landscapes will help to save global biodiversity. This is sometimes preferable to traditional conservation because it does not impair human use of the landscape and therefore may be more acceptable to stakeholders. However, not only will it encourage biodiversity in the areas where it takes place, but many scholars cite other benefits of including biodiversity in human landscapes on both global conservation activities and human well-being.

❖ Habitat connectivity benefit: Increasing wildlife habitat in human-dominated systems not only increases in situ biodiversity, it also aids in conservation of surrounding protected areas by increasing connectivity between habitat patches. This may be especially important in agricultural systems where buffers, live fences, and other small habitat areas can serve as stops between major preserves.

Educational benefits: Placing importance on native ecosystems and biodiversity within human landscapes increases human exposure to natural areas,[which has been shown to increase appreciation of nature. Studies have shown that students who participate in outdoor education programs show a greater understanding of their environment, greater willingness to act in order to save the environment, and even a greater enthusiasm for school and learning. Green spaces have also been shown connect urban dwellers of all ages with nature, even when dominated by invasive species. Reconnecting people with nature is especially important for conservation because there is a tendency for people to use the biodiversity present in the landscape they grew up in as a point of comparison for future trends.

Psychological benefits: The results of reconciliation ecology can also improve human well-being. E. O. Wilson has hypothesized that humans have an innate desire to be close to nature and numerous studies have linked natural settings to decreased stress and faster recovery during hospital stays. Many examples of native plants and animals taking advantage of human dominated landscapes have been unintentional, but may be enhanced as part of reconciliation ecology. Others are intentional redesigns of human landscapes to better accommodate native biodiversity. These have been going on for many hundreds of years including examples within agricultural systems, urban and suburban systems, marine systems, and even industrial areas.

24. How serious is tropical deforestation, and how can we help sustain tropical forests?

At least half of the world’s terrestrial plant and animal species live

in tropical rain forests. Large areas of tropical forest are burned to make way for cattle

ranches and crops up to 7000 fires a day. They are shrinking at alarming rates.

❖ How should rangeland resources be used, managed, and sustained? Suppress growth of invasive species, rotational grazing, reduce soil erosion, replant barren areas, use less fertilizer and herbicides.

❖ What problems do parks face, and how should we manage them? Too many visitors, private owners in parks, money needed to fix, loss of species, pollution – need to buy up private owners, charge more, and make parking lost off the site.

❖ How should we establish, design, protect, and manage terrestrial nature reserves?By passing laws world wide for protection of biodiversity, including ecosystems, species and populations, promote the long-term survival of the species and other elements of biodiversity they contain by maintaining natural processes and viable populations and by excluding threats. To meet these objectives, conservation planning must deal not only with the location of reserves in relation to natural physical and biological patterns but also with reserve design, for example the watershed that they will rely on.

25. How do biologists estimate extinction rates, and how do human activities affect these rates?

It is difficult to measure we have to use the biodiversity methods of sampling and counting species and the Shannon Weaver method. All species become extinct. Since humans arrived, rate of extinction has gone up 100 to 1,000 times and by some estimates 10,000 times Conservative extinction rates 0.01% - 1.0%

Other information to review:

Explain HIPPO or HIPPCO

What is the difference between intrinsic and extrinsic?

How do scientist measure biodiversity?

What do the vales R, H and E mean in regards to biodiversity?

Sample Questions:

Endemic species are

|a. |usually the dominant species within an ecosystem |

|b. |on the brink of extinction |

|c. |widely distributed, found especially on large continents |

|d. |limited to just one location, such as an island |

|e. |well established and show the least risk of extinction |

Wildlife in the Serengeti is currently threatened by

|a. |plans to build a highway that passes through the park |

|b. |pollution from a nearby coal power plant |

|c. |an invasive fish that has been introduced into the major river that flows through the park |

|d. |plans to legalize hunting of most of the large animal species in the park |

|e. |an overabundance of elephants |

Many of the hot spots for biodiversity are located in areas that are considered to be

|a. |developing |

|b. |transitional |

|c. |industrialized |

|d. |post-industrial |

|e. |developed |

Which of the following statements concerning biodiversity hot spots is correct?

|a. |they are only found in developed countries |

|b. |there are more hot spots in developed countries than developing countries |

|c. |they tend to be in countries with the highest densities and growth rates |

|d. |they are found in countries with the lowest population density |

|e. |they are found in equal numbers in both temperate and tropical regions |

Fragmenting one large park or preserve into many small parks with human habitation in between them is most likely to lead to which of the following?

|a. |Increase in gene flow within species |

|b. |increase in the population of top carnivores |

|c. |Decrease in the proportion of edge habitats |

|d. |Stabilization of microclimates |

|e. |Reduction in species diversity |

Which of the following statements about exotic species is true?

|a. |Exotic species are only introduced accidentally, never intentionally. |

|b. |Exotic species are always a threat to biodiversity. |

|c. |Plant species are never exotic species, since plants are not mobile. |

|d. |Overharvesting is a direct cause of the introduction of exotic species. |

|e. |Exotic species are also called alien species. |

Which of the following characteristics is most likely to lead to an inbreeding depression?

|a. |gene flow |

|b. |sexual reproduction |

|c. |ecosystem variability |

|d. |low genetic diversity |

|e. |large population |

As the number of Flying Foxes decrease in the Pacific Islands, the trees that grow from the seeds dispersed by the Flying Fox decreases as well. This is an example

|a. |k-strategist |

|b. |fragmentation |

|c. |conversion |

|d. |a threatenend species |

|e. |ecological extinction |

Which of the following statements about exotic species is true?

|a. |Exotic species are only introduced accidentally, never intentionally. |

|b. |Exotic species are always a threat to biodiversity. |

|c. |Plant species are never exotic species, since plants are not mobile. |

|d. |Overharvesting is a direct cause of the introduction of exotic species. |

|e. |Exotic species are also called alien species. |

Fishing regulations on the size and type of nets used when fishing for tuna help protect endangered turtle species in the open ocean is an example of ______________________.

What is most significant when determining the diversity of an ecosystem?

What are the causes of the current (sixth) mass extinction?

A species of plant that provides nutritional and/or medicinal benefits for humanity would be referred to as having ________________ value.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download