r selection, K selection

In class, we discussed two types of reproduction strategy, r selection and k selection. R selection is when a population is far below the carrying capacity of an unstable environment. R-strategists are identified by short life expectancy, early maturity, small size, strong sex drive, and low intelligence. They often produce many cheap offspring and give them little care. R-strategists aim to make use of ephemeral resources and ensure that at least some offspring survive in unstable environment. Examples for r-strategists are bacteria and frogs. K selection is when a population is at or near the carrying capacity of the environment. K-strategists are identified by long life expectancy, late maturity, strength, weak sex drive, and high intelligence. They often produce few expensive offspring and give them much care. K-strategists tend to favor individual that slowly developing in order to successfully compete for resources. Examples for k-strategists are human, cat, and dog.

The survivorship curve has three different types: Type I, Type II and Type III. Type I represents k-strategist. It shows that k-strategists lost most of the individuals quickly but a few survived individual live much longer than the rest. Type III represents r-strategist. It shows that the r-strategist lost the individuals eventually as age increases. Type II shows the curve between Type I and Type II.

After the “Household pets and pests” activity, we concluded that pets tend to be k-strategist and pests are r-strategists. However this is not universally true as some people have pets that are r-strategists. For example, my friend has fish ,which is r-strategist, as pets. Species with k selection strategy tends to have more intimate relationship with human as they live longer and has higher intelligence than species with r selection strategy. 

http://www.bio.miami.edu/tom/courses/bil160/bil160goods/16_rKselection.html

http://dictionary.reference.com/browse/k-selection

http://dictionary.reference.com/browse/r-selection

Ecosystem Diversity

1. Why do tropical rainforests have such immense diversity? How do they maintain their diversity?
As questions said, tropical rainforests have immense diversity. They are home of over 5 million species such as insects, plants, and animals. The reason why rainforests have immense diversity is trees. As its name, they get a lot of rainfalls, which provide animals and plants water. Also, temperature of rainforest region is warm, which makes condition of rainforest better to live.
2. What role do tropical forests play in stabilizing climate and atmosphere? Can we take advantage of and enhance their ability to store carbon? Why is this important? Tropical forests plays pretty significant role in stabilizing climate and atmosphere. From the activity about the carbon level that we did before, I was able to know that carbon level affect to temperature, which have close connection with climate and atmosphere. Of course there are a lot of trees in tropical forests. Those trees absorb carbon dioxide and emit oxygen, which lowers carbon levels. By lowering carbon level, they stabilize climate and atmosphere.

3. How can the data from a tropical rainforest that explains species diversity and abundance be helpful in managing and protecting temperate forests such as those in Yellowstone National Park or any other ecosystem on planet Earth? We can know that every single species have their own important role in food chain. For example, when the wolves in Yellowstone National Park were gone, the balance of ecosystem diversity was broken. As a result, species that were consumed by wolves and below them increases and decreases severely, which means it is unstable.