Ecosystems and Biology - AP Environmental Science

Heavy decomposition of plant and animal matter contribute to highly acidic soil in tropical rainforests. Additionally, abundance of plant life in tropical rainforests results in "soil leaching," which means that the nutrients in the soil are drained and taken up by the plants themselves.

Boreal forests have extremely low temperatures and are characterized by pines and other evergreens. "Temperate forests" are characterized by moderate and more fluctuating temperatures, whereas the taiga stays cold year round. Taiga is found in parts of the world such as Northern Alaska, Canada, and Siberia.

Top predators will generally never "grow unchecked". By the very nature of their diet (dependent on other populations), predator population growth is limited by the availability of their food. The famous study of lynx-hare population fluctuations demonstrates how a predator population will adjust to lower prey populations.

Latitude is not considered in climate evaluations; for instance, the poles are considered deserts based on their precipitation levels per year, meaning deserts can occur along the equator or the poles. Temperate and tropical forests also exhibit similar precipitation levels, but due to their temperature differences, they are considered separate biomes.

Though grasslands and deserts share some of these characteristics, the tundra is the only biome listed that is characterized by a short growing season, harsh winters, no trees, mostly migratory animal species, and less than 10in of rain per year.

Don't be fooled into associating moisture retention with rainforests: Those plants don't require such an adaptation since rainfall is plentiful. A subtropical desert, however, is characterized by high temperatures, very low precipitation and warm soils, and thus plants must adapt to prevent water loss.

The correct response is deciduous forest **.**The unique characteristic of the deciduous forest is that the trees shed their leaves each year. Maple and Oak trees are common in this biome. Prairie grasslands do not contain trees, rather they contain fields of grasses. The desert biome does not receive as much rainfall as the deciduous forest, nor does it contain many hardwood trees that shed their leaves. While the coniferous forest contains lots of hardwood trees, they very rarely shed their leaves. The coastal chaparral biome does not receive as much rainfall, and is dominated by small trees and shrubbery.

Humidity, atmospheric pressure, and wind are all aspects of climate but not the determining factors. In the higher latitudes, temperature is the more important factor. In the lower latitudes, precipitation is the more important factor.

The correct response is desert. The desert environment is characterized by low rainfalls (less than 25 cm per year). They are one of the most dry biomes on the planet. The desert biome also has highly variable temperature swings, with high temperatures during the day and low temperatures at night.

Polar forests are also known as "taiga"

There is no arid forest, as most arid regions are home to mostly shrub and brush-like plants. Arid areas with trees are not dense like true forests.

Brazil, Indonesia, Peru, and Zaire contain over half of the world's tropical rainforest biome. Mexico does contain some rainforest that extends into Guatemala, but not as large an area as the other countries listed.

Boreal forest, also known as "taiga," is a biome spread across the northernmost latitudes, including Canada, Alaska, Russia, and parts of northern Europe. It is characterized by coniferous forests and generally low temperatures.

Transpiration concerns the process through which water is carried through plants from roots to small pores in leaves, where it evaporates into the atmosphere. Thus transpiration is not a part of the carbon cycle, which concerns the biochemical exchange of carbon.

All of these are biogeochemical cycles:

Carbon cycle - plants and animals consume carbon dioxide and release carbon dioxide during decomposition or respiration, then the carbon dioxide returns to the atmosphere.

Phosphorus cycle - similar to the carbon cycle, plants and animals consume phosphorous and release it during decomposition. Then the phosphorous returns to the ground and waterways by way of bacteria and processes such as mineralization.

Nitrogen cycle - this is the most complicated biogeochemical cycles. This is because it takes place in multiple situations, including: nitrogen fixation, nitrification, denitrification, and ammonification.

Hydraulic cycle - the water cycle. Water evaporates, wind moves air (and water), precipitation occurs.

The Atmosphere is largely the source of Carbon in the Carbon cycle. Plants utilize photosynthesis to convert atmospheric Carbon Dioxide into Glucose. Animals consume this Glucose and store it in their bodies until they die. the Ocean hosts a large amount of dissolved Carbon Dioxide gas and has Calcium Carbonate as a storage place in oceanic organisms like coral.

K-strategist populations are more commonly regulated by density-dependent limiting factors. Their population sizes hover around a carrying capacity that is dependent on factors that increase in severity with the density of the population. On the other hand, r-strategist populations are regulated by density-independent limiting factors. They reproduce rapidly until a density-independent factor causes many of them to die.

Cultural carrying capacity suggests that humans have secondary needs, such as entertainment, palatable food, and mental/spiritual development. These non-vital resources can only be spread equally among a population of a limited size. Cultural carrying capacity describes the limitation on population size after taking into account these factors.

A frequent questions asked by sustainability scientists is: Should the optimum sustainable population be based on cultural carrying capacity? Many would agree yes, for the reason that when cultural capacity is transgressed, living conditions spiral downwards and life is reduced to the struggle for mere survival. In such conditions, human inventiveness and creativity become obsolete.

Population growth can follow either a J curve trend or an S curve trend. A J curve represents exponential, or unrestricted growth. An S curve represents logistic, or restricted, growth and accounts for the carrying capacity of an environment.

In a J curve model, the population will continue to grow even when it has reached capacity. In an S curve model, the population will stagnate and stabilize at a maximum value when capacity is reached.

Clumped distribution patterns localize individuals around scarce resources in environments where they are not equally distributed throughout. The clumping of organisms around these resources attracts predators and makes for easy predation. Because of the scarcity of water in desert, plain and tundra biomes, it is seen in large quantities in nature.