What are the three human affected sources of greenhouse gases in the atmosphere. 75words 704-705

Krogh (2011), states that the three human affected sources of greenhouse gases in the atmosphere are from the burning of fossil fuels, deforestation, and the amount of cattle we raise. These three affects either put in too much carbon dioxide into the atmosphere or doesn’t produce enough. The burning of fossil fuels, such as coal, gives off a great deal of carbon dioxide gases into our atmosphere. Deforestation is the cutting sown of trees, which eliminates the carbon dioxide needed for photosynthesis among other plant life. It also has the effect of putting too much CO2 into the atmosphere because trees are known to take up CO2 and make oxygen for the atmosphere instead. Another greenhouse effect produced by humans is in the amount of cattle and rice we need to grow. Since we have to mass produce crops and cattle for the alarming number of human growth, this ultimately allows high amounts of gases into our atmosphere.

You are hiking with a friend and reach the peak of a mountain after a long climb. On your climb upward, you had a clear trail with a little grass and small shrubs along the way. But looking down the other side, you see lush vegetation and many broadleaf trees farther down the slope. Your friend wonders why there is such a big difference. What explanation can you offer your friend? 75 words

I would let my friend know that he/she is seeing the effects of the rain shadow. Krogh (2011), says that mountain ranges force air to rise, and drops its moisture on the windward side (pg.711). As a result, when the air travels over to the other side of the mountain it no longer as any moisture to drop. This obviously leaves no more rain to fall to nourish plant life and animal life, leaving it dry and inhabitable to much animal life.

Compare and contrast ecological dominants with keystone species and give examples. 200 words 671-672,G5,G8

Krogh (2011), defines ecological dominants as a species that is abundant and obvious in a given community (pg.G5). He goes on to define keystone species as a species whose absence of a community would bring significant change in that community (Krogh, pg.G8). In an ecological dominant community it is usually always seen as a community of plants and shrubs. In the keystone species, its community is usually always seen in animal life such as the sea star. Although they are known to be of small numbers they produce a huge impact on our ecosystem when disturbed. For example, in the keystone species once a predatory animal is removed from its habitat the others in the “community” face the dangers of other predators. This can result in the elimination of a species. While in the ecological dominants community, they are always so largely populated that they take over others for survival. Krogh (2011), gives an example of the Kansas prairie fields that are dominated by tallgrass for the ecological dominants, and the predatory sea star Pisaster ochraceus for the keystone species (pg.672). As stated above, they are different in the way they affect the ecosystem, but they are similar in the way that they are both a type of species.

Give an example of why keystone species play a large role in community despite the fact that they may be present in relatively small numbers. 200 words 671-673

Keystone species are relatively smaller in numbers but have a huge impact on the ecosystem when disturbed. Keystone species are known as predators that can control a single community and without them the other species within the community may not be able to survive. This can be seen through the example that Krogh (2011) gives with the predatory sea star Pisaster ochraceus (pg.672). This is a good example because even though they live in moderately small quantities, once you remove it from its community the results can be catastrophic for the rest of the community. Removing the predatory sea star would leave the rest of them vulnerable to other predators, and may end in the extinction of them if the predatory sea star does not return. In other words, once the sea star has been removed it starts a trickling down effect on other sea animals among its biomass. More and more species that live in or near the sea star ecosystem will start to disappear due to lack of food or the overpowering of other predators in the sea. Another result of the of removal of a keystone species is now newer species are able to come in and take over the habitat they once lived in so they can flourish and live in that ecosystem.

Explain the four types of biological community interaction and give examples. 500 words

The four types of biological community interactions are: competition, predation and parasitism, mutualism, and commensalism. The competition interaction is a competition between two or more species (Krogh, pg. 674). This is a competition among species for resources in order to survive. These species do not compete by fighting, but rather by gathering enough resources to outlive the next species. This competition can be between species of the same or a different community. This competition can result in the extinction of a species because of lack of resources to survive. Krogh (2011), give the example of competition between the P. aurelia and the P. caudatum (Krogh, pg.674). In this experiment, both organisms were grown in the same test tube. It was documented that instead of either one trying to attack the other, the P. aurelia just outgrew the P. caudatum. This ultimately resulted in the P. caudatum to die out due to lack of room and resources (Krogh, pg.674). This type of biological interaction can be seen in many different types of species. It can also be seen in resource partitioning. This is where two species don’t attack one another for resources, but they take up two different sides of the resource in order to survive, thus leaving one another alone for the time being. The second biological community interaction can be viewed between predation and parasitism. This is where one species benefits while a different species is affected. Predators will obtain their resources through eating their prey, while parasites will live on other species and obtain its food through them. A big difference between the two is that they predator doesn’t live on its prey like the parasite. Also, the predator kills for its food, and the parasite won’t always kill its host for resources. Krogh (2011), give an example of the predator interaction with the common house cat and the rat (Krogh, pg.676-677). The cat preys on the rat as a vital food resource. He also gives the example of the strangler fig tree for the parasitism interaction. This tree will wrap its roots around a host tree to obtain nutrients and eventually killing it (pg.676). The third biological interaction is mutualism. Mutualism is an interaction between different species that does not end up in the harming of either one of them. Instead is a helpful interaction among the two different species. Krogh (2011), shows the interactions between the rhinoceros and the oxpecker birds as a good example of this mutualism interaction (pg.680). In this example, the oxpecker bird will sit on the back of the rhino eating any foreign objects off of it, and the rhino in return will provide a safe place for the bird to reside. The fourth type of interaction within communities can be seen through commensalism. This interaction is also among different species, but it results in one of the species flourishing while the other is left unaffected. An example of this type of interaction is explained with a bird and a tree (Krogh, 2011). Birds tend to make nest within the branches of a tree to have a place to live and flourish while leaving the tree unaffected of its existence.