Wednesday, October 17, 2007

Some More on Ecology

Hey guys, today we learned more about ecology. We learned that organisms interact with the enviornment, and face both biotic and abiotic factors. Biotic environment would be food, competitors and the predators.
Abiotic environment would include sunlight temperature water and soil. (Don't forget nutrients cycle while sunlight is always being input into the environment.) Populations are groups of individuals that are the same species at the same location.
Populations have all different ranges (how much area they live across), pattern spacing (how in the ecosystem the population is spread out), and sizes. When it come to the range they have geographical limitations.
Prey, predators, temperature, and water all act as boundaries for the range of populations. The boundaries sometimes allow for change, so the range can expand or contract. Endangered species are endangered due to limitations on range and their habitats.

There are three types of population spacing for populations. There's clumped ex: schools of fish or packs of wolves. Clumped spacing is the most commom and is an evolutionary advantage because it provides protection. There is uniform ex: birds. Uniform spacing can occur due to direct interaction with other individuals within a species, and it can involve an individual being territorial.
Also there is random spaccing ex: plants in a forest. For population size there are two factors that increase size and two that decrease the size. Birth and Immigration both increase population size, and to balance it out death and emigration decrease the size. Growth rate is looked at with three factors in mind. One is the ratio of male to female. The second is at what age females are able to reproduce. Also lastly, age structure. Factors that can control the growth and decline of populations are involved in demography. Scientists gather information on the populations and create statistics based upon their information. They can also use the information to create survivorship curves. Also scientists keep track of the number of individuals of each age group.

Tomorrow's sherpa will be Kelly S.

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