AP Environmental Science Chapter 5 week questions

Human understanding of the way biological communities work is still very limited. Trying to reintroduce a species to solve a problem we created by taking the species away can create new problems that we were unaware of before. For example, hunters didn't want wolves because they competed with game. Shepherds didn't want wolves because they ate sheep. But getting rid of wolves had the unintended consequence of the elks eating up all the grass.

2. Sea Ranch, north of San Francisco found that when they brought in sheep to keep the grass down, the gopher population dropped-why?

Gophers are exposed where there is limited grass cover. The eagles were eating them.

3. Explain how altitude and latitude impact biomes, and why they differ.

Altitude negatively correlates with temperature. Latitude also negatively correlates with temperature. Higher altitudes and higher latitudes are lower in temperature.

4. Pick a climate diagram and explain how it describes the plants and animals that live there.

The climate diagram for San Diego indicates that there are two distinct seasons in year; a wet season from November until March, and a dry season for March until November. This is consistent with the climate suitable for the chaparral and shrubs that grow in the area, due to the occasional periods of drought that happen in the area.

5. Biomes evolve depending on what is constant, along with what is never present-explain with an example.

Biomes evolve in places where environmental factors are constant and predictable. For example, in a tropical biome, there is a constant amount of rain, such as in the Amazon. Therefore plants there have adapted to the amount of rain expected in the Amazon.

6. Most biomes are based on temperature, except for one-explain.

Deserts are biomes formed based not on temperature but rather humidity. Deserts can be hot as well as cold; in fact, the driest place on Earth is Antarctica (not the usual place we imagine when we think desert).

7. Why is photosynthesis greatest near the shore? Compare with Hadal zones.

Near the shore the water is warm and there is lots of sun. Hadal zones are dark and cold and so there is no photosynthesis.

8. What three factors impact life in a lake?

Light, temperature, and oxygenation.

9. Dams are ecologically damaging for two reasons, both involving temperature-explain.

Dams only last for about 50 years before they become mud basins from silt being carried downstream. Then they have cold water where the water used to be warm. The cold water pulls minerals out and fish now have mineral poisoning. Those damn dams!

10. Streams and rivers demonstrate "continuity". Explain, and why this is critical to the study of pollution, species and biodiversity.

What goes into a stream or river will come out the other side. A polluting source upstream will release pollutants that travel downstream, getting into anything that it encounters along the way. This is useful to know for identifying sources of pollution in bodies of water. Since streams and rivers are also long and linear ecosystems, they can be easily disrupted by dams and other manmade constructions, emphasizing the importance of preserving river systems to protect the species and biodiversity that depend on it.

11. Compare genetic, species, and ecological diversity.

Genetic diversity is the total number of genetic characteristics in the gene pool of a given species. Species diversity is the number of different species in a given area. Ecological diversity is the total number of diverse ecosystems that exist in the world. Each higher category of diversity encompasses the preceeding level of diversity.

12. What connection do you see between biodiversity hot-spots in Figure 5.22?

They are mostly in tropical or Mediterranean climates and are on islands, coastlines, or mountains, places where there are physical barriers between habitats that encourage speciation.

13. Why would biodiversity increase stability of an ecosystem?

High diversity help biological communities better resist environmental stress and recover more quickly from disasters such as wildires or diseases. This is because there are more redundant stabilizing species that can act as a buffer in the case that some species do get wiped out. An example of how this works can be seen in comparisons between monoculture and polyculture; monoculture is vulnerable to disease that can wipe out the entire species, whereas polyculture will still have other species to fall back onto.

14. Explain how HIPPO might be different in Hawaii, Africa, Indonesia, Madagascar and North America.

HIPPO stands for habitat destruction, invasive species, pollution, population (human), and overharvesting. Each region suffers from these factors differently; for example, Hawaii has to deal with habitat destruction and invasive species but not other factors. Africa, with most countries still in poverty and lacking strong governments to enforce laws, suffer from all of these factors. Indonesia and Madagascar are island nations; both suffer from habitat destruction, invasive species from earlier periods of colonization, and more recently pollution. North America is relatively developed in most places; it suffers from habitat destruction, pollution, and overharvesting as a result of industrialization. Invasive species are also common. Population growth has been decreasing however; whether or not this is too late to reverse the loss of biodiversity though remains to be seen.

15. Look up the mass extinction 65 MY ago, also known as the K-T extinction. Who discovered this, and where does he teach?

The Cretaceous–Tertiary extinction event occurred 65.5 million years ago and was first theorized by Luis and Walter Alvarez of theUniversity of California, Berkeley.

16. Why would deforestation (discontiguous forests) disrupt biodiversity? Look at this as a predator and a prey animal, as well as plant species.

Deforestation destroys habitat, which can lead to the extinction of the species living there. This can lead to the collapse of an entire ecosystem, as many species rely on each other for survival.

17. Compare the monoculture of modern farming (e.g. Nebraska) with what was there before human intervention. Make sure you include soil, animal and plant life.

Modern agriculture consists mainly of monoculture, where a single crop is grown over a large area. This contrasts with nature, where many species of plant life grow together in communities forming diverse ecosystems with native animal species as well. These ecosystems are more resilient and tolerant of stress and other environmental factors, better able to recover from a natural disaster. Monoculture on the other hand is extremely vulnerable to disease; a single pest or virus can destroy an entire field of crops, leaving nothing behind.

18. Using the concept of "Island Biogeography" explain and compare the Galapagos Islands vs. the Hawaiian Islands, and Molokai vs.Hawaii Island (where you live).

Two major factors that determine island biogeography are the size of the island and its distance from land. The Galápagos Islands are 7,880 km^2 in land area and about 1,000 km from the nearest land mass. The Hawaiian Islands are 16,636.5 km^2 in land area and about 3,000 km from the nearest land mass. Smaller islands and more remote islands are less likely to receive immigrants and vice versa. The relative age of the islands can also affect the degree of speciation that has happened. Molokai is smaller but older than Hawaii Island, which is larger and younger; the two places also differ in geography as Hawaii Island has been more active recently.

19. Why are invasive species such a threat to invasive species, and why would this be a greater threat here?

Invasive species are not a threat to invasive species, unless there is intraspecific competition between themselves...?

20. Why would pollution concentration impact an apex species more than another species lower on the food chain?

The concentration of pollution increases the further up the food chain you go. Apex predators are the highest and will receive the most concentrated dose. This has happened in real life in the case of DDT, when eagles started dying from the concentrated dosage accumulated from their prey.

21. Look up CITES and compare with ESA.

CITES is the Convention on International Trade in Endangered Species of Wild Fauna and Flora, and ESA is the Endangered Species Act. CITES is international while ESA is American. CITES mainly deals with international trade of species and its impact on the survival of the species in the wild. ESA protects species that are threatened as a result of economic growth and development.

22. Look at figure figure 5.35: where are we, where have you been, and what have you seen that matches/explains the map?

Uh... as a boarding student without means of transportation, I really have not gotten far. But I have been up to the summit of Mauna Kea, and did notice that the higher up you go, the less the biodiversity. To be honest, in my four years living here, I have not seen a single species of wildlife that qualifies as an endangered species.

23. What unique view or experience do you bring to a global discussion about biodiversity?

I'm not a big fan of animals, or plants for that matter, I will let the botanists work on biodiverstiy issues. On the other hand, I am very interested in bioengineering, although I think a lot of hardcore environmental people would not be super excited about that...

24. Given unlimited resources, what steps would you take to improve the global biodiversity situation?

If I had access to unlimited resources, the first step I would take is to use that resource to supply human populations instead of extracting it from nature and causing environmental destruction. Population growth should also be kept under control, as the boom of human population is what has been primarily responsible for the reduction of biodiversity in the world. Human intervention should not be used to reintroduce biodiversity, as biodiversity is a product of chance and years of evolution, something that we can not replicate under artificial conditions.