Exam 1: Ecology and How to Do It

A manipulative field experiment was conducted to test the hypothesis that nitrogen pollution affects biodiversity.In this study,a field was treated for 4 years by adding nitrogen to it regularly.A potential limitation to this study is:

Variation in your data affects the standard error.Your standard error will be smaller if:

You conduct an experiment to test if water temperature affects developmental time of dragonfly nymphs.You only had time to set up three replicates for each of three temperature treatments: 10,13,and 15 degrees Celsius.Each replicate is one individual nymph.Therefore,you have data on the developmental rate of three nymphs at each temperature treatment.The data show some variation within each treatment.You conduct your statistical test and your resulting p-value is 0.85.These results indicate the result was not significant.However,you can interpret this result another way,which is:

Which field of ecology studies trends and fluctuations in the number of individuals of a particular species at a particular time and place as a result of birth and death rates and interactions between predators and prey?

If an ecologist studies interbreeding between populations and how that affects which organisms live in a community,they would be working on scales that include:

In your experiment,you manipulate temperature to test if it has an effect on the abundance of an insect species.If your null hypothesis stated that temperature has no effect on insect abundance,and your p-value was equal to 0.80,then you would conclude what?

In the case of the Hubbard Brook Experimental Forest,hydrogen ion concentration in precipitation was measured over a period of more than 40 years.Why was it important to track the concentration of hydrogen ions in precipitation over such a period of time? Why not use just a few years?

Say you go and measure the diameter of trees in old growth forests throughout 30 plots of land in Argentina.You want to know if tree size differs between sites.This is an example of what type of study?

An ecologist wants to study what plants colonize a site after a volcano has erupted.She plans to compare what plant species were once there with what plant species begin to grow in a matter of a few months.What term best describes the process she is interested in studying?

The principal sources and approaches used to gather ecological evidence include ______.