Ecology Test Answers

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Ecology Take Home Test

1)In the given info, there were two groups, an experimental and control group of flowers and sagebrush in a desert landscape that were identical except that the experimental group had a fence enclosed around it. Also, there was a predation relationship between the wildflowers and the kangaroo rats because the kangaroo rats eat wildflowers. Assuming that the fence was limiting the space of the experimental plot, competitive exclusion caused the extinction of the 4 other wild flowers. To begin, there was some interspecific competition, which happens when individuals of different species compete for a resource that limits their survival, between the 5 flower species in the experimental plot because they had their space limited to the fence that they were enclosed in. this competition was a density dependent factor in that the death rate rose when population density in the plot rose. Also, some of the specie’s ecological niches (like what nutrients they needed and how many branches would form) would have had to been the same or else they could coexist together. Then, one of the species of wildflower might have had a reproductive advantage like thorns to repel the kangaroo rats which would have allowed them to prosper and the other species to die out. This is the principle of competitive exclusion. On a tangent, the kangaroo rats would have learned to stay away from the wildflower with thorns by classical conditioning because they paired the idea of getting stung with eating that particular wildflower species and eventually stopped.

The control plot, on the other hand, did not have a fence, so they had all the room to grow and didn’t not have to compete for the resources. The reason they didn’t grow even more from this is because they have reached their climax community. The population in the control plot was stable and had reached their max ecological growth.

2)In a terrestrial biomes, there are two main factors that determine the distribution of biomes. One factor is a disturbance, which is an event such as a storm, fire, or human activity that changes a community by removing organisms from it and/or altering the resources available. For example, fires kill woody plants and keep a savanna from becoming the woodland that climate alone would otherwise support. Another factor in terrestrial biomes is the climate. For example, where the temperature is really high and humidity is low may be a desert, but where temperature is high and humidity is also high might be a rainforest.

In aquatic biomes, however, the factors above might play a role but there are other, more important factors that are also involved. These factors are, but not limited to water depth to see how far the light can travel for photosynthesis, degree of light penetration, distance from shore, and if the biome is found in open water or near the bottom.

All biomes, however share Abiotic or nonliving chemical and physical factors, such as temperature, water, salinity, sunlight, rocks and soil, and climate. Climate is an especially important determinant of biome location. Because climate patterns are latitudinal over the Earth’s surface, the patterns of biome distribution are also latitudinal.

In a comparison of the two biomes, tropical forest and desert, it is clear that there are vast differences and similarities between the two when it comes to vegetation. First of all, a similarity is that both biomes rely on photosynthesis to make food, but the vegetation in the desert will most likely undergo C4 or crassulacean acid metabolism where stomata open during the night and close during the day in order to conserve water and CO2. Another difference is that desert plants are normally low and scattered, while tropical forest plants are tall, layered, and condensed. Tropical forests usually contain a bounty of epiphytes like bromeliads and orchids, as opposed to deserts which usually contain cacti, deep rooted and thorny shrubs,...
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