What Are The Three Environmental Factors That Affect Grasshopper Population Size

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Pre-Lab Questions
1. A population is a group of the same species that live in the same area and sometimes compete or can mutually benefit one another. A group of organisms will only be considered a population if they live in the same area in space and time. N is the true population size for a given group of organisms. This number is unlikely to be completely known. Whereas N hat is an estimate of population size.
2. There are two methods of sampling, direct and indirect. Direct sampling is an actual count of a population in a given area and is generally not easily feasible. Whereas indirect sampling is an estimate with subsamples of a population in a given area. This requires some extrapolation in order to estimate the total population, generally
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A warm extended fall will allow for a larger number of eggs to be laid, whereas dry conditions in the fall will limit embryo development within the eggs and lower the population number. Most importantly a warm humid summer has the increased potential of disease in grasshopper populations which will help reduce densities the following year. Moisture also has an effect on population sizes. Heavy downpours will only have an effect if it occurs after an extensive hatch. In most cases moisture through snow cover in the winter will determine mortality rate, wherein winters with little snow cover will result in higher mortality rate because many grasshopper eggs will freeze. Forage availability will also act as a control for a grasshopper population. Grasshoppers are voracious feeders eating approximately one-half of their body weight in green forage per day. At densities of 30 per square yard grasshoppers have been known to consume all green forage available. When food becomes unavailable the population will crash, whereas when food is plentiful the population will rise. Eventually these three factors will interact and cause for the stabilization of grasshopper populations for a given …show more content…
A). The grasshopper population at the Wednesday site location decreased over a timeframe of 3 years. It is possible that the environmental factors that affected that area caused the grasshopper population to decline. The influences of temperature, moisture and forage availability could have long lasting impacts on the grasshoppers ability to survive and reproduce. It is possible that a combination of harsh weather and low foliage growth limited the grasshopper population at the grassland/tall forb meadow with shrub encroachment site to carrying capacity until conditions change. It is possible that the large population size in 2012 was due to extraordinary conditions suitable for grasshopper populations to expand and the only possible option was for the grasshopper population to fall over the course of 3

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