ES MODULE 2 chapter 15 BIODIVERSITY

Mass extinctions

Period in time when large numbers of both land and marine species became extinct (when dinosaurs were wiped out). Causes of mass extinction are debated. Some say major changes in climate and increased volcanic activity are responsible. Other scientists hypothesize that events such as meteorite strikes could have triggered mass extinctions.

Initially hunting was allowed under the endangered species act, but what did researchers realize?

but researchers realized that even when habitats are protected, individual species sometimes need protection.

Relationship between biodiversity and ecosystem function

-Biodiversity has a positive effect on many aspects of ecosystem function. There is a positive relationship between the richness of tree species and primary production in most of the world's forest.

Biodiversity hotspot Endemic species

-Biodiversity hotspot: an area with an especially large number of species -Endemic species: A species that is restricted to a certain geographic region and is thought to have originated there. -Lots of times species are only found in a specific hotspot.

How does climate change affect biodiversity?

-Climate change is a threat because species have evolved to live within certain temperature ranges, and when these ranges are exceeded and a species cannot adapt to the new temperatures, or when the other species it depends on (for food) cannot adapt, its survival is threatened

What is predator control? Is it effective?

-Efforts to reduce the populations of species that compete with humans for crops or game. -In an attempt to help ranchers, who argued that wolves, mountain lions, and eagles killed their livestock, U.S. federal and state governments used to pay hunters to kill top-level predators -its effectiveness is questionable

How can we use the IPAT equation to measured the reduction in biodiversity

-Higher levels of affluence and population generally reduce biodiversity. An analysis of fifty nations finds that economic growth rates speed the loss of biodiversity, and the effect is most important in affluent nations. In poor nations, economic growth has little effect on biodiversity. Conversely, the effect of economic growth is exacerbated by population growth -Institutions and technology can slow the loss of biodiversity. Agricultural expansion reduces biodiversity. Spending on conservation technology slows the loss of biodiversity

biodiversity is a valuable source of genetic information, but uncertainty about who owns that information has caused the market to undervalue the information. Explain this.

-If a pharmaceutical company that finds a drug owns its genetic information, then governments have no incentive to preserve natural ecosystems. But if local governments own the genetic information and charge a high price for its use, pharmaceutical companies have less incentive to analyze species for medicinal compounds. As a compromise, the value of genetic diversity has been brought into the market through a series of agreements between pharmaceutical companies and nations with high biodiversity

As international trade has increased, plants and animals are carried around the world. In some cases these plants and animals establish population in their new environments. What are these called. What effect can they have?

-Introduced species -In most cases, introduced species have little impact. In other cases, introduced species enhance their new environment by restoring functional biodiversity -about 64 percent of introduced species are similar to species that went extinct over the previous 130 thousand years -But in some cases alien species become invasive which is defined as an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.The impacts of alien species are even more disruptive when they affect keystone species.

Relationship between species number, extinction rate, and island size

-Large islands have more species because extinction rates generally decline as the size of an island increases. -Big islands generally have more diverse habitats than smaller islands and this variety creates more niches -On the other hand extinction increases with the number of species present. Having more species increases the number of species that can go extinct. -The presence of more species usually implies a small population size for each species, which increases the likelihood of species going extinct. -Increasing species richness increases the potential for competition

What factors contribute to species richness include the definition of dispersal.

-Larger islands have more species than smaller islands. -The arrival of new species, immigration. Islands that are super isolate and therefore do not experience a lot of immigration tend to have fewer species. - dispersal is the ability of organisms to reach new environments and the distance a species can travel to find new environments. Organisms that have a high dispersal ability can contribute to species richness in many ecosystems.

How does land diversity compare to ocean diversity

-Life originated in the sea therefore plant and animal diversity in oceans is greater than on land. -The most diversity in the ocean is found in coral reefs. The most diversity on land is found in tropical forests -Species richness is greatest near the equator and declines toward the poles

How is investing in biodiversity in a sense 'food insurance'? Why is biodiversity insurance valuable?

-Society may be willing to buy insurance against the ongoing loss of biodiversity by paying now to preserve biodiversity that may be of use in the future. -It allows farmers to practice agricultural techniques that are highly productive but would be too risky without insurance. -Modern farmers plant a few highly productive varieties of corn, wheat, or rice over large areas. Although this generates large amounts of money for farmers and food for people in most years, it is also risky. -By creating one huge, genetically identical food source, farmers speed the evolution of new pests and diseases. -These new pests or diseases could cause major crop failures—a risk that is mitigated by preserving the genetic diversity of crops

The number of species on the earth is determined by the balance between Speciation and extinction. Describe there two terms. Currently which do we have more of.

-Species numbers increase via speciation, which is the process by which evolution generates new species -species numbers shrink via extinction, which occurs when a species fails to reproduce and no individuals remain -The rate of extinction is greater than the rate of speciation therefore, the number of species is shrinking due to human activity

Passenger or redundant species

-Species whose loss would have little effect on ecosystem function. -Although no two species occupy the same niche, sometimes the degree of overlap is sufficient to minimize the effect of their loss

Protected categories fall into six categories, which allow different levels of human participation. What are the extremes of these?

-Strict nature reserves severely control and limit human visitation, use, and impacts -At the other extreme, protected area with sustainable use of natural resources conserve ecosystems, habitats, cultural values, and traditional natural resource management systems

What effect can alien species have on a ecosystem?

-The introduction of alien species increases rapidly with the booming international trade and travel. They can become invasive then they displace indigenous species or spread into habitats where they were not previously common.

What is ethnobotany? How is it used

-The study of how different groups of people, including indigenous cultures, use plants and animals. -This knowledge has been passed from one generation to the next and is very valuable for drug companies.

Humans are the most effective predators on the planet. Our ability to hunt and harvest shrink the populations of species and can reduce biodiversity. How?

-These high rates of hunting or harvesting often exceed the maximum sustainable yield and cause populations to decline -hunting may create so-called "empty ecosystems," which are ecosystems where animal populations are greatly reduced even though there are no obvious sign of disturbance, such as deforestation. Because of these effects, hunting and harvesting of wildlife is the second largest cause for the global decline in biodiversity and local extinctions

When looking for organisms with these chemical compounds that are good for drugs, where do researchers look?

-They might look at organism that are genetically related to species that already provide commercially important drugs. -Or, they might look that species that live in ecosystems where chemical defenses could be useful. Like the tropical rain forest where high levels of biodiversity imply a large number of potential predators, or extreme environments. Organism that live in these environments are extremophiles and they require special adaptions.

scientists have developed four criteria to choose among efforts to preserve biodiversity. What are they?

-Uniqueness. Higher priority is given to unique species. This ranking is based on their potential contribution to the growing collection of genetic knowledge: genetically unique species may contain information that is not available in other species. -Usefulness. This usefulness can be either commercial value (such as that offered by wild salmon), or the degree to which humans like the species (consider the bald eagle or the giant panda). -Probability of extinction. What are the odds that a species will go extinct if society does nothing? Or if some effort is expended, will that effort lower the probability that the species will go extinct? Clearly it does not make sense to try to preserve a species that is unlikely to become extinct, or a species that will become extinct even if society tries to save it. -Cost. Conservation efforts for some species may be small compared with the effort required to save others. Based

What are keystone species?

-a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically

In locations where the economic value of the land conversion is greater than the value of biodiversity, market based mechanisms seek to preserve biodiversity via biodiversity offsets. What are biodiversity offsets?

-are conservation activities designed to give biodiversity benefits to compensate for losses - ensuring that when a development reduces biodiversity new, bigger or better nature sites will be created. -Biodiversity offsets are considered a market-based mechanism because developers need to consider the cost of the offset when they contemplate a project that would reduce biodiversity

How does biodiversity decline as humans add nutrients?

-by reducing the number of niches: No two species can share the same niche. Human actions that add nutrients reduce niche dimensionality and ultimately biodiversity, by reducing the number of limiting nutrients -by shifting the site of competition from below ground to above ground: Below ground competition for nutrients can support many species because there are many ways to create separate niches. But above ground, light is the limiting factor, and there is generally one strategy for capturing light; grow taller than your neighbor. As a result, there are fewer niches for capturing light, which reduces niche dimensionality, and ultimately, reduces biodiversity

What are the big ways have humans altered the way land is used? What effect does habitat conversion have on biodiversity?

-conversion of forest to cropland and pasture -converting natural systems to urban areas -Both of these are fueled by population growth -reduced biodiversity by eliminating habitats in a given biome. -As the area covered by a particular type of biome is reduced, so too is the number of species that can be supported in that smaller area

Command and control mechanisms preserve biodiversity by protecting individual species and entire habitats. What is an example of this?

-in-situ conservation: the conservation of species in their natural habitats. -Sometimes these efforts need to be supplemented by ex-situ conservation which is the process of protecting an endangered species of plant or animal outside its natural habitat; for example, by removing part of the population from a threatened habitat and placing it in a new location, which may be a wild area or within the care of humans.

Lots of species supply food products! Even species that don't directly supply food are essential in the production of food. Explain agrobiodiversity.

-refers to biodiversity among agricultural crops of livestock, such as the genetic diversity of wheat varieties or cattle breeds. -Agrobiodiversity is important for food security because in the event that a particular crop variety fails due to drought, flooding, or a disease, another variety might survive to avoid food shortages.

What are some of the environmental services that biodiversity provide? If the asset is managed properly what can happen?

-stabilize climate (decreasing the atmospheric concentration of CO2 offsets some of the warming effect of increased solar radiation), pollinate flowers, control pest, soil formation. -it can provide a sustainable steam of economically important services.

Even though the law states that biological criteria alone b used to assess the threat to a species, what is the other way species are listed?

-the cost/benefit of preserving that species. -there is little evidence that policy makers use any of the four criteria to allocate funds among species. Instead research indicates that funds are allocated idiosyncratically (choosing to preserve the bald eagle and salmon)

What is the single greatest threat to biodiversity?

-the large-scale alteration of natural ecosystems by humans; such conversions are known as changes in land use or land cover. -Changes in land use or land cover are known as habitat conversion, which is the change of land quality, for example, through land transformation or intensification of land use (deforestation and reforestation; urbanization; desertification and conversion to agriculture, such as wetland drainage; irrigation; and degradation due to overgrazing)

Besides being edible why are some plants and animals valued? These plants and animals are being traded. What are the consequences of that?

-their fur, skins, teeth, horns, shells, beauty, or rarity and are used for food, clothing, decorative items, pets, and traditional medicine -Beyond the threat to the populations being collected or harvested, the wildlife trade spreads diseases

Why are biodiversity offsets imperfect?

-there is no single measure by which the loss of biodiversity at one site can be directly compared to the biodiversity preserved at another site. -there can be time lags between the loss of biodiversity at the development site and the preservation at the offset -Finally, the biodiversity outcome at the offset sites is uncertain and so the compensation at the offset site is often many time the loss at the development site.

In an ideal world policy makers would examine their options for preserving biodiversity. Each option would have a cost, and each would preserve a certain amount of biodiversity. Policy makers would be able to choose among options in a way that saved the greatest amount of biodiversity. How come this is not feasible?

-there is no single measure of biodiversity. -Should policy makers seek to maximize species richness, species evenness, or some combination of the two? -Furthermore, economists cannot measure the economic benefits generated by plants and animals that are not traded in markets. As a result, the problem of preserving biodiversity cannot be solved using a simple cost-benefit approach

Describe the market-based mechanism called Ecotourism

-which the United Nations describes as tourism contributing to the conservation of natural environments that is planned, developed, and operated with local communities in a way that contributes to the well-being of local communities. Much ecotourism consists of nature preserves in developing nations that are visited by tourists from developed nations. Such visits have generated hundreds of millions of dollars for host nations.

What are the two mechanisms that evolution creates new species via?

Allopatric speciation: occurs when a population becomes geographically isolated from its parent population and then accumulates genetic or behavioral changes that differentiate it from the original population. These changes would be driven by random changer in the gene pool, which are known as random drift. Or, by natural selection which may favor traits different from those favored in the original location. Sympatric speciation: the process through which new species evolve from a single ancestral species while inhabiting the same geographic region. individual traits isolate a subpopulation from the parent population, which allows the populations to evolve separately

Society has sought to preserve biodiversity through a series of national and international laws. In the United States the most visible of these laws is the Endangered Species Act of 1973. To identify species that need protection, species are designated as either endangered or threatened. What is the difference?

An endangered species is any species that is in danger of extinction throughout all or a significant portion of its range. A threatened species is any species that is likely to become an endangered species in the foreseeable future throughout all or a significant portion of its range

What is the reason market-based mechanisms can be super effective

Because command and control strategies do eliminate the economic incentives that cause the loss of biodiversity

Captive breeding of animals and artificial propagation of plants

Captive breeding refers to the breeding of animals in human controlled environments such as wildlife reserves, zoos and other conservation facilities. Artificial propagation is the process of making new plants from different parts of plants via cuttings, layering, division, and grafting. In the case of both plants and animals, the intent frequently is to reintroduce organisms to the wild

In the United States, protected areas and their habitat is a key component of the Endangered Species Act. The Act requires the USFWS to designate critical habitat for listed species. What is a critical habitat?

Critical habitat is a specific geographic area(s) that contains features essential for the conservation of a threatened or endangered species. To determine critical habitat, the USFWS considers the species' needs for space, food, water, light or other nutritional requirements, breeding sites, seed germination and dispersal needs, and lack of disturbances. Protection of critical habitat may include blocking public or private construction that would damage habitat

What is habitat fragmentation? How does it affect biodiversity

Habitat fragmentation is the breakup of a continuous habitat, ecosystem, or land use type into smaller areas. Fragmentation's effect on biodiversity is determined in part by the size of the remaining habitat. Generally, breaking habitat into many smaller pieces has a greater effect on biodiversity than retaining one large area

Breaking the forest into smaller fragments generates longer edges, which create transition zones between different land covers. What effect does this have on biodiversity

In some cases these edges can improve species diversity by creating areas that support species that cannot exist in either of the adjacent land covers. In many cases fragmentation can disrupt ecosystem processes such as nutrient cycling and predator-prey relationships. These disruptions often are caused by edge effects, which expose forest species to unfavorable conditions such as stronger winds, temperature changes, increased incidence of fire, increased predation, and competition from exotic and pest species. Edge effects often have a strong positive effect on invasive species. In total, edge effects may be as important as the outright loss of habitat.

Are large or small animals more likely to go extinct?

Large

How can the disruptive effect of alien species can be explained using evolutionary theory?

Most species evolve with other species. In their original habitat, which is known as their native range, a variety of predatory, parasitic, and disease organisms often keep the populations in check. But many of these limiting factors are left behind when species are introduced to a new environment, which is known as their naturalized range. In the naturalized range, the lack of predators, parasites, or disease allows the population of alien species to grow and increase its use of energy and nutrients, which leaves less for native species, causing native populations to decline

Background extinction

Slow ongoing rates of extinction. Caused by a variety of mechanism, such as disease and competition. Background extinction rates imply that species have an average lifespan.

In history we have seen periods of mass extinctions. The current rates of extinction are similar to those that prevailed during these mass extinction events. What is different now though?

The current loss of species is caused by a variety of human activities

More than half the time human medicines contain one of more compounds derived from or pattered after a living organism. How come plants and other organism make chemical compounds that are food for what ails humans?

These benefits are a consequence of diffuse chemical coevolution, in which natural selection favors individuals that accumulate compounds effective against a wide variety of enemies.

Lots of species act as pollinators. What services does this provide.

They place pollen from one plant on the stigma of a flower from another plant. They are critical to sexual reproduction by flowering plants. Pollination services are crucial to the majority of primary food crops. Farmers loveee pollinators. As biodiversity decreases the population of wild pollinators decrease. Farmers turn to managed pollinators (honeybees), but we are losing those as well.

How do scientists forecast the rate of extinction associated with habitat destruction?

Theyuse forecasts for the rate and spatial pattern of habitat conversion and the species-area relationship.

Zoos, aquaria, and botanic gardens

This approach entails the collection of living organisms for research and public awareness

Plant tissue collections

This method includes of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture

Non-human predators usually hunt the easiest prey to catch, such as the youngest, sickest, and oldest members of a population. Conversely, humans target the largest, healthiest individuals. What affect does this have on these species?

With human hunting, more individuals are left that are small or have some sort of 'defect'. Now these reproduce and continue to make small offsprings.

Gene banks

are a type of biorepository that preserve genetic material. A common example of this form of conservation are seed banks that store seeds for crops or endangered plants

Biocentric versus Anthropocentric

biocentric: The ethical position that nonhuman species have value in and of themselves and have the right to exist independent of their usefulness to humans. Anthropocentric: The ethical position that the value of nonhuman species is determined by their value to people.

Ecosystem diversity

describes the variety of biomes such as coral reefs, forests, and wetlands. Also involves variation within ecosystems regarding the number and types of organism, habitats, and ecological processes such as nutrient cycling. (undisturbed praise versus cornfield)

To protect and reestablish wild populations, command and control strategies preserve entire habitats. What is a protected area?

is a clearly defined geographical space, recognized, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of a natural habitat. These areas conserve biodiversity by maintaining key habitats, providing refugia, allowing species to migrate and maintaining natural processes.

Where on the globe does biodiversity peak?

mid-latitudes (30-50degrees) in deeper water. Productivity is high and significant amounts of this productivity falls to the bottom as particulate organic carbon int he form of fecal matter and dead organisms. -This carbon forms the base of the food chain in deep-water environments, where there is not enough solar energy to support photosynthesis.

How does warfare affect biodiversity?

positive effect: People avoid warzones, which tends to reduce economic activities that diminish biodiversity, such as extracting natural resources negative effect: warfare can hasten the loss of biodiversity if soldiers use local animals as a source of food or use natural resources, such as ivory or diamonds, to pay for military efforts

Has the modern industrial food system increased or reduced agrobiodiversity?

reduced. The widespread use of genetically uniform modern crop varieties has caused agricultural crop to lose about 75% of their genetic diversity in the last century. This phenomenon is known as genetic erosion​, and it makes our food supply more vulnerable to pests and disease

Genetic diversity

refers to the genetic information in the DNA of plants, animals, and microorganisms.

Biodiversity. List the three levels at which biodiversity is measured.

refers to the number and variety of species. -Genetic diversity -ecosystem diversity species diversity

Species richness versus species evenness

species richness: the number of species present in an area species evenness: the distribution of individuals among species and measures whether individuals are distributed evenly among species or represent a few of the many species present.

enemy release hypothesis

states that the population of an alien species can grow rapidly (escape) if the number of pathogens it leaves behind in its native range exceeds the new pathogens it accumulates in its naturalized rage

What are the negative effects of banning Rhino horns?

the underground market made rhino horns even more valuable so illegal poaching increased because they could get so much money for hunting the.