1. Explain how human activities can cause an imbalance in biogeochemical cycling and lead to problems such as cultural eutrophication and fish kills.
Eutrophication is a naturally occurring, slow, and inevitable process. However, when it is accelerated by human activity and water pollution called cultural eutrophication, it can lead to the premature aging and death of a body of water. Cultural eutrophication occurs when humans speed up the aging process by allowing excessive amounts of nutrients in such forms as sewage, detergents, and fertilizers to enter the ecosystem.
2. Compare and contrast the traits and growth patterns of opportunistic versus equilibrium populations.
Opportunistic species use the r-strategy. They produce millions of eggs and sperm since only a small percent will actually meet, join, and become offspring. Opportunistic species are often the first to colonize a new environment with a “boom and burst” growth pattern, with a short life cycle. They tend to “crash” when they run out of food, space, oxygen, sunlight, or whatever the limiting factor is in that environment. Examples are most insects, and corals, barnacles, clams, scallops and oysters, who spawn and fertilize their eggs in the water.
Equilibrium species use the K-strategy. The carrying capacity of the environment. These species produce much fewer offspring and usually brood them and/or take care of them in other ways. The populations of these species may first grow exponentially, but the growth levels off when they reach the carrying capacity of the environment. They prefer a stable predictable environment and have a long life cycle. Most birds and mammals use this strategy, as well as some live-bearing fish like dogfish sharks.
3. Compare and contrast indirect versus direct values of biodiversity, and provide examples.
Biodiversity is the degree of variation of life. This can refer to genetic variation, species variation, or ecosystem variation within an area, biome, or planet.Maintaining biodiversity has a direct economic value to humans, as well as indirect economic value because our ecosystem is affected by any imbalances in the environment. For example, a lack of trees will mean we don’t have enough oxygen to breath. A lack of fish will mean many animals that feed of sea creatures will die.
4. Describe two traits that represent a sustainable society and two traits of a non-sustainable society.
A few traits of a sustainable society is to use only renewable energy sources. Having a stable population, we would need to keep the population at about the same level. No more exponential growth, meaning that we would not have an economic system that needs growth to maintain itself. Another trait is recycling and reusing as much as possible. If we take what we have and use it again or use it for another purpose we save the need of having to produce another item. In doing so we can help cut back on our production and pollution. It takes a bit more energy to recycle, but if we put items people no longer use back into the system we save the need of having to extract the resource from the Earth thus helping to reduce what we produce and the associated pollution.
Some traits of a non-sustainable society would be primary use of non-renewable fossil fuel energy, which leads to creating smog, acid precipitation, and other pollutants entering our ecosystem. Over use of minerals and environmental resources such as water and land is another way societies become unstable. People overexploit environmental resources because they initially seem inexhaustibly abundant.