ENV100Y5 Lecture Notes - Lecture 30: Flightless Bird, Lake Baikal, Passenger Pigeon

35 views3 pages

whitehornet945

28 Jun 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Module 3: June 4-June 15

Date: Tuesday, June 12

SESSION 32: CONSERVATION OF SPECIES AND HABITATS (II)

Readings: Chapter 9

Equilibria

● Being able to predict equilibrium number for island (a habitat surrounded by something

that is not a habitat)

● Make predictions based on how close that area is to a source of species that can arrive

there and how large the area is (size and distance have an effect on immigration rate

and the extinction rate)

○ Things close to a source of immigrants will have a higher rate of immigration

○ Goes down as niche spaces get filled and will eventually go down to zero

○ With extinction when there is a huge number of species the extinction rate will go

up, but it will be faster on a small area patch

● These null models allow us to predict what should be going on if nothing is happening -

how many species should be in an area, and if the observation deviates from that it tells

us something is going wrong

● It allows us to predict for a given size and proximity to a source of immigrants; how

biodiversity we expect species to be - least: small area, far from a source of immigrants

“Islands” don’t have to be in the ocean

● Very much created by humans

Spatial Factors that Drive Species Richness:

● Fragmentation and Isolation (how big and far away from immigrants)

○Fragmentation usually means habitat degradation

■ Natural: heterogeneous landscape

■ Human-driven: degrading habitat

■ Try to exploit an area without damaging it - gaps are created within

natural habitats; as development proceeds, these gaps expand, join

together, and eventually dominate the landscape, stranding islands of

habitat in their midst

○Isolation limits recovery from local extinction

Habitat Fragments are “islands”

● E.g. forests fragmented by roads and logging can trigger an extinction or extirpation

● Small, isolated fragments lose diversity fastest

● “Core” vs. “edge” habitat

● Fragmentation is an important driver of biodiversity loss

○ It was thought that if you save 10% of habitat, you could recover species

● Importance of corridors

find more resources at oneclass.com

Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in

yifanyang and 39662 others unlocked

ENV100Y5 Full Course Notes

Verified Note

69 documents

Document Summary

Session 32: conservation of species and habitats (ii) Being able to predict equilibrium number for island (a habitat surrounded by something that is not a habitat) Make predictions based on how close that area is to a source of species that can arrive there and how large the area is (size and distance have an effect on immigration rate and the extinction rate) Things close to a source of immigrants will have a higher rate of immigration. Goes down as niche spaces get filled and will eventually go down to zero. With extinction when there is a huge number of species the extinction rate will go up, but it will be faster on a small area patch. It allows us to predict for a given size and proximity to a source of immigrants; how biodiversity we expect species to be - least: small area, far from a source of immigrants. Islands don"t have to be in the ocean.

Related Questions

Question 402 pts

You go on an expedition to the mountain forests of the remote island of Halmahera, Indonesia. You discover a new species of arboreal primate that is only found deep in the forest. It is endemic to a single mountain range and is found nowhere else. Logging companies are beginning to explore the area and may start building roads soon in order to provide access to the remote forest for logging.

What effects could road building have on the primate population within the next 10 years?

SELECT ALL THAT APPLY (You may need to select more than one answer)

Higher light penetration and lower relative humidity could make areas alongside the roads less suitable for the primates

The likelihood of contracting a new disease would increase in the primate population

Speciation could occur so that populations in isolated forest fragments could split into different species

Its population could increase because of the greater availability of forest edges for foraging

Flag this Question

Question 412 pts

Which of the below is NOT an example of an ecosystem service?

Pollination of crops by native bees

Revenue generated by clear-cutting of tropical dry forest

The presence of an intact forest maintaining constant water flow in streams throughout the dry season in a tropical region

Rainforest trees removing carbon from the atmosphere

Flag this Question

Question 422 pts

Climate change must be factored into the design of new conservation areas and in new land acquisitions made by current reserves. Which of the below types of habitat would be given highest priority for conservation in light of climate change?

SELECT ALL THAT APPLY (You may need to select more than one answer)

Small isolated patches of habitat

Long and narrow areas of habitat that are oriented parallel to latitude

Patches of habitat that join existing conservation areas

Elevational gradients

Flag this Question

Question 432 pts

The Ngorongoro Crater lion population in Tanzania is isolated from nearby Serengeti lion populations. In 1962, the population crashed due to disease, dropping from 90 individuals to less than 20. The population of lions today is currently exhibiting a high rate of sperm abnormalities, which are rare outside the crater population. What is the likely cause of this?

SELECT ALL THAT APPLY (You may need to select more than one answer)

Matings between closely related individuals

Natural selection for fitter sperm phenotypes

Radiation from the crater that is causing new mutations

Lower genetic diversity than normal populations of lions due to a population bottleneck in 1962

Flag this Question

Question 442 pts

What is considered to be the most likely hypothesis for the cause of the extinction of the Pleistocene megafauna?

Hunting by early humans

An asteroid collision that changed the climate

Massive volcanic eruptions that strengthened the greenhouse effect and led to global warming

The global radiation of marsupial mammals that outcompeted the megafauna and made them go extinct

Will rate when all are answered.

As temperatures in an African savanna increase and rainfall decreases, it would most likely change into

tiaga

desert

tropical rainforest

temperate forest

What is imprinting? Give an example.

fixed assocation, such as hatching ducks recognizing the first animal they see as their mother

a learned behavior, such as a wasp circling during a search for food, so that it can return to its nest

alteration of instinct, such as a spider changing the type of web it weaves depending upon the environment

Opportunistic species

provide extensive care for their offspring

produce many offspring

reproduce later in life

What are the five agents of microevolution?

gamete production; mating; fertilization; caring for offspring; formation of herds

photosynthesis; respiration; mitosis; meiosis; fertilization

mutation; gene flow; nonrandom mating; genetic drift; natural selection

Microevolution is

new species

minor extinction of species

changes in allele frequency in a population

Which of the following is does not help defend against predators?

Toxins made by plants that injure caterpillars feeding on the plant

The large eyespots on a moth's wing that can startle a hungry bird

Thorns on a plant

Many plants have brightly colored fruit and flowers

Humans have a favored birth weight, neither too small nor too large. This is

stabilizing selection

disruptive selection

artificial selection

directional selection

What is a keystone species?

the first organism that populates an area

an organism upon which the entire ecosystem depends

the first fossils found in the earliest rock strata

As temperatures in the Arctic warm, which of the following changes may occur?

Tundra will be replaced by taiga

Taiga will be replaced by tundra

Temperate forest will be replaced by taiga

Tundra will be replaced by desert

Taiga will be replaced by temperate rain forest

What is desertification?

restoration of vegetation and water to deserts

areas adjacent to deserts also become deserts

abandonment of a habitat by animals

Evolution occurs at the level of

individuals

populations

communities

The maximum population that the environment can support is called the

biotic potential

environmental resistance

carrying capacity

replacement reproduction

demographic transition

A population with relatively more pre-reproductive individuals is common in _____-developed countries

less

Endangered species sometimes breed in captivity. Why are such species endangered in the wild?

Their population density is too high

Loss of habitat

Their environment is polluted

Abiotic components of an ecosystem include

only animal life

only plant life

living components only

nonliving components only

both living and nonliving components

Carbon returns to the atmosphere

as carbon dioxide

from respiration of plants

by the burning of fossil fuels

from respiration of animals

All of the answer choices are correct

Why does the Tropical Rain Forest contain an abundance of antibiotic compounds?

The area is crowded, leading to random production of useful compounds

The area is wet. plants had to develop resistance to fungi and bacterial infections

There is a great diversity of plants, leading to random production of useful compounds

The carrying capacity of the environment for a species is determined by

the reproductive rate of the organism

the number of organisms of that species

the state and national wildlife laws pertaining to that species

a complex

the limited productivity of the environment and the environmental resistance to the biotic potential of the organism

An introduced species that breeds and spreads is

resourceful

harmful

native

dominant

invasive

What is disruptive selection?

environmental influences that select against change

environmental influences that promote one phenotype versus all others

environmental influences that promote two or more phenotypes versus all others

Natural selection acts on

individuals

populations

communities

Two populations of birds live in the same area but have different sleep/wake cycles. This is

behavorial isolation

mechanical isolation

geographical isolation

temporal isolation

An insect that resembles the face of a snake avoids predation by

camouflage

warning coloration

mimicry

chemical defense

mutualism

Unselfish acts that help others in a group so that they increase their chances of surviving and reproducing is called

imprinting

mimicry

altruism

learning

instinct

If an environment changes rapidly, organisms with ____ will be more likely to survive and reproduce.

the correct allele frequency

existing neutral mutations

existing beneficial mutations

How did geology influence Darwinâs thoughts?

It demonstrated that the earth was very old, therefore there was enough time for species to evolve

it demonstrated that all continents were similar

it demonstrated the presence of many fossils

The founder effect occurs when

large groups of individuals leave their home population and establish new settlements, mating only among themselves

many members of a population die, resulting in a great loss of genetic diversity

many members of a population reproduce causing too much genetic diversity within the population

small groups of individuals leave their home population and establish new settlements, mating only among themselves.

The greenhouse effect is due to high atmospheric

Nitrogen

Ammonia

Carbon monoxide

Carbon dioxide

Oxygen

What are the Reproductive Barriers that keep species separate?

lack of food; lack of habitat; lack of potential mates; lack of nesting sites; lack of genetic variation

mountains; canyons; glaciers; bodies of water (for terrestrial animals); areas of land (for aquatic animals)

habitat isolation; temporal isolation; behavioral isolation; mechanical isolation; gamete isolation

What is directional selection?

environmental influences that select against change

environmental influences that promote one phenotype versus all others

environmental influences that promote two or more phenotypes versus all others

Which of the following is correct when describing a predator-prey cycle?

A decline in the numbers of predators causes a decline in the number of prey

A decline in the numbers of prey causes a decline in the number of predators

An increase in the number of predators triggers an increase in the number of prey

An up-and-down cycle will be seen for the prey animal

A seasonal die-off that will occur without the other species present

Why are top-level predators (lions, eagles, humans) so rare in a community?

Only a small amount of the energy is passed from one trophic level to the next

They do not breed as fast as other animals

Because of predation by higher predators

It is difficult for them to learn how to capture prey

Their job is to keep the population size of other animals in check

Alleles conferring bright color to male guppies are common because

they make males less visible to predators

they help males identify each other

they are preferred by females

Organisms that obtain their energy from producers or other consumers are

autotroph

heterotroph

producer

autotroph and producer

heterotroph and producer

What is the environmental impact of strip mining?

lack of trees exposes the surface of the earth, promoting runoff and loss of adjacent trees

removal of minerals from the soil hampers growth of vegetation

it causes a potential increase in volcanic activity

Two populations of squirrels are separated by a mountain range and would not be capable of interbreeding. This is an example of:

behavorial isolation

mechanical isolation

geographical isolation

temporal isolation

What is a danger of overfishing?

humans will become dependent upon fish

selection for smarter fish that can avoid being caught

driving the population back into the lag phase

What is meant by prezygotic versus postzygotic speciation mechanisms?

before versus after formation of a zygote

before versus after meiosis

before versus after gamete formation

The relatively short term changes in allele frequencies within a species or population is

artificial selection

microevolution.

speciation

macroevolution

Avoidance of a location with predators is the result of

imprinting

mimicry

altruism

learning

instinct

What is the difference between Density-Dependent and Density-Independent Factors on populations?

density-dependent factors exert a greater influence when there are more individuals; density-independent exerts the same influence on all individuals regardless of their number

density-dependent factors exert a greater influence on larger, more dense individuals; density-independent factors exert the same impact on individuals of all size

density-dependent factors exert the same influence on all individuals regardless of their number; density-independent factors exert a greater influence when there are more individuals regardless of their number

All of the organisms in a given location or area is termed a

peer group

flock

community

population

herd

The concentration of the pesticide DDT would be highest in

a minnow

a mosquito larva

a seagull

plankton

algae

Our biosphere is

the Earth

the atmosphere

the ocean

land on Earth

fresh and salt water

What is meant by âcarrying capacityâ?

the amount of food produced in an ecosystem

the extent of energy required to maintain an ecosystem

the number of individuals that can be supported by an ecosystem

Species living on another is

resource partitioning

coevolution

symbiosis

predation

niche sharing

One species feeding on another is

competition

a community

an ecosystem

predation

symbiosis

Populations of different species interacting with one another in a natural environment is called

competition

a community

a biome

predation

symbiosis

Which of the following is not a biogeochemical cycle?

ATP cycle

water cycle

carbon cycle

phosphorus cycle

nitrogen cycle

Horses became larger and faster to escape predators. This is

stabilizing selection

disruptive selection

artificial selection

directional selection

Check the Course Announcements at the beginning of the week following the deadline for Part 1 to discover exactly what happened to the deer population on the Kaibab plateau. This information is essential for completion of Part 2.

The second part of your project is to take what you've learned about the Kaibab forest ecosystem and write an accurate description of the boom and bust of this deer population, using correct ecological language. Consider as many of the aspects of these events as you can. Be sure to consider the effects on the other species in the ecosystem as well.

Refer to your on-line materials and the appropriate sections of your textbook. Your discussion should include (but not be confined to) consideration of all of the following concepts: carrying capacity, predator/prey relationships, population cycling, resource partitioning, competitive exclusion, fundamental and realized niches, food chains, food webs and trophic pyramids.

Note that the purpose of this exercise is for you to demonstrate to me that you understand these important concepts of ecology by utilizing them accurately and appropriately in the description of the disaster in the Kaibab forest. Your essay must include both clear indications that you understand the meanings of these principles and clear indication that you understand how these principles can be used to describe what happened to the ecosystem on the Kaibab plateau.

information given of part one: On the north rim of the Grand Canyon, an area called the Kaibab plateau, there is a conifer forest called the Kaibab forest. The forest's trees include pine, fir and spruce. Shrubbery includes a variety of willows, raspberries, etc. A hundred years ago, this forest was a stable ecosystem, housing, among other species, a population of about four thousand mule deer.

These deer were hunted by local Native Americans, who used them for food and other materials. They were also hunted by predators like pumas, wolves and coyotes.

In 1906, the US made this region into a National Game Preserve. With the intent of protecting the deer, hunting was forbidden. Bounties were paid for killing the pumas, wolves and other large animals that preyed on the deer. By 1925, more than 6000 predators had been killed, virtually wiping out the ecosystem's large predators.

*Read the instructions* for Part 2, then consider this additional information about the Kaibab forest.
There are some hints in here to suggest the *minimum* range of the subjects you need to discuss to explain this; You will need to read the chapters and the course materials to understand the meanings of these concepts, and to be able to use them to explain the Kaibab disaster. There are other important concepts as well--so keep your eyes open as you read. It wouldn't hurt to go back and read the original description in Part 1, either. And you may find it necessary to do some quick browsing in areas of your book not directly related to ecology. (For instance, you might just want to do some looking into the nature and importance of the bark and twig ends on a tree.) Do not neglect the on-line essays which are provided for you in this Unit. What you should *not* do is Google the Kaibab, or look it up on a source like Wikipedia. This is not about what you can *discover* about the Kaibab forest.
Your grade will depend upon how completely you convince me you understand the concepts involved in this description. This is your test on ecology--your goal is to convince me that you understand the concepts and terminology of the subject, and can apply them to a real life situation.
Before we go on to the new information, there are a few things that came up as I was grading the Part 1 submissions which I think I should mention, just to keep you from straying in some incorrect directions.
First, remember that your concern is the fate of the Kaibab forest in the *immediate* sense--over tens of years, not thousands. There are no evolutionary issues here, at least in the short term (and that's your concern right now). So we won't be talking about adaptive radiation.
Also, keep your focus on the *Kaibab forest*, not on other ecosystems. Oh, and remember that the Kaibab is pretty isolated--emigration really isn't a reasonable alternative for the species living in this forest.
And finally, until we get to Part 3, the only human interaction we are considering is the initial decision to put bounties on those large predators, which led to their near-extinction in the area. You will be thinking a bit about human hunters trying to control the deer population toward the end, but the rest of the time you're just concerned with the natural processes going on in the ecosystem.
Okay, now on to the actual description of what happened in the Kaibab Forest as a result of killing almost all of the large predators. Remember, your task in Part 2 is going to be to describe and explain all of this using the concepts of ecology which you are learning in Unit 2 of the course.
*****
The primary, most immediate outcome of the removal of the predators from the ecosystem was that the deer population exploded, because the loss of the normal predator populations removed a primary source of population control. And the expanding deer population ate a *lot.* [Hint: explaining this requires discussion of population cycling, predator prey relationships and carrying capacities.]
As the deer population got larger and larger, their impact upon their favored food plants became extreme. They ate a much larger percentage of each year's plant populations, and they ate a larger portion of each individual plant. They also began to eat more from the plants which they didn't like so well--plants normally consumed by other herbivores in the ecosystem. In the winter, the starving deer ate about anything remotely resembling food, including twigs and bark from trees. As a result of the destruction of many of the twig ends of the trees, the spring tree growth was inhibited (why?). The stripping of the bark caused the death of some of the trees (why?). The extreme browsing on the herbaceous plants caused shifts in the plant population diversity, as the deer drove many of their favored plants into extinction within the ecosystem. [Hint: Explanation here will need to include discussion of resource partitioning, competitive exclusion, and realized vs. fundamental niches.]
All of this also impacted upon the rest of the animals in the ecosystem, since many of them depended upon the same kinds of food the deer ate, or depended upon the foods that the deer were eating because they could no longer get the food they favored. Then of course, the smaller predatory species (like foxes and owls) depended upon the health of those populations of small herbivores (like rabbits and mice). [Hint: sounds like food chains, food webs and trophic pyramids come into this part.]
After a couple of decades, the ecosystem was quite altered. The plant community was very different from what it had been before, and the deer herd, though not extinct, was composed of significantly smaller and weaker deer than the herd from the 1890s. (This was partially due to their straightened circumstances re. food, but also partially due to the absence of predators. Why would the removal of the natural predators cause this change in the general vigor of the deer in the herd (and why would the substitution of *human* hunting not exert the same positive influence)?)
Okay, the next phase of your assignment is to describe all the things going on in this ecosystem using the proper terminology that you should be learning from studying this unit of the course. Note that your use of terms like, for instance, "resource partitioning" needs to show that you understand not just what the concept means, but how it is reflected in this specific ecological disaster. Feel free to discuss this as much as you want to on your Discussion Board. Don't ignore the little questions tucked into the above description, and pay attention to those hints. Your response must demonstrate proper understanding of these concepts and how they are demonstrated by the disaster in the Kaibab forest.
This is the largest part of your exam project; your response should reflect the fact that this is a 50 point "essay" question. You are given a lot of organizational clues and hints about what issues you need to include in the information above. Make use of those things.

ENV100Y5 Lecture Notes - Lecture 30: Flightless Bird, Lake Baikal, Passenger Pigeon

ENV100Y5 Full Course Notes

Document Summary

Get access

Related Documents

ENV100Y5 Lecture Notes - Reconciliation Ecology, Gross National Income, Lake Baikal

ENV100Y5 Chapter Notes - Chapter 9: Gross National Income, Reconciliation Ecology, Invasive Species

ENV100Y5 Lecture Notes - Lecture 31: Cites, Reconciliation Ecology, Easter Island

Related Questions