Define "Intraspecific Competition" and explain this competitionwhithin plants, and provide an example with a specific plantspecies.
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Worksheet 5 â Competition
This worksheet is designed to help you:
Understand the differences between intraspecific and interspecific competition.
Determine factors that may drive competition in nature.
Answer/address all of the following questions. In all cases, we require that your work be typed and that you make computer printouts of spreadsheets, graphics, or statistical output.
Provide 2 examples of intraspecific competition and 2 examples of interspecific competition. Cite your sources (16pts). Explain which scenario has more intense competition.
2. Produce a table showing the average number of beans collected by each individual during each foraging experiment (20pts).
An example raw data table is provided below â you are required to make a summary table from this information (hint: do not include raw data, only summary values, in a summary table).
3. Produce a bar graph (or bar graphs) reporting the experiment averages with appropriate error bars for each foraging experiment (16pts).
4. Provide null and alternative hypotheses for each foraging experimentâa total of 5 sets of hypothesis. (6 pts)
(hint: the 5 hypotheses will be (1) intraspecific competition between small beaked birds (experiment A), 2) Intraspecific Competition between large beaked birds (experiment B), (3) interspecific competition for small beans (experiment C), (4) Interspecific competition for large beans (Experiment D), 5) high vs. low density intraspecific competition (average A vs. average E).
5. Perform appropriate statistical tests for each hypothesis (12pts).
(hint: you are attempting to find out if there is a significant differences between two populations â for (i) and (ii) the statistical test will be paired and for (iii) the statistical test will be unpaired)
6. Discuss the results of each statistical test, and explain why you observed these patterns (15pts).
7. Explain how competitionâboth intraspecific and interspecificâdrove the evolution of Darwinâs finches (below) to develop specialized beak shapes? What do the different species compete for, and why are differences in morphology (e.g. bill shape and size) important? (15 pts)
Fish represent a _________ life history type, whereas most organisms die very quickly and produced quickly in large quantities.
Select one:
a. Equilibrial
b. Opportunistic
c. Benificial
d. Aytpical
Question text
What type of survivorship curve is typically represented by humans?
a. Type III
b. Type II
c. Type I
d. Type 0
If 2 members of one species are competing directly for nutrients, mates, etc, this is labeled as:
a. Intraspecific competition
b. Interspecific competition
c. Specific competition
Which of the following is NOT a common density-dependant factor of population ecology?
a. Waste buildup
b. habitat destruction
c. limited food
d. limited territory
A species in danger of extinction throughout all or most of itâs home range is called:
a. Endangered
b. Threatened
c. Repressed
d. Depressed
Plant competition lab:
Objectives
In this lab, we will conduct an experiment to test both interspecific competition (between radish and collards plants) and intraspecific competition (radishes competing with radishes, or collards competing with collards). To determine if competition is occurring, we will measure survival, plant height, and aboveground biomass. Once the lab is completed and the data are collated from the entire class, you will then need to make graphs and answer the questions at the end of the lab.
Procedure:
Take 9 pots. Use only pots of the same shape (square or round); do not mix types.
Fill the pots with soil to within ½ inch of the top.
Thoroughly water the soil (until it runs out the bottom).
Add more soil if necessary to bring up the level to within ½ inch of the top.
Place the appropriate number of seeds on the soil surface. Be sure the seeds are evenly spaced. In the mixed species pots, intersperse the two species. See the table below for the nine different treatments.
Cover the seeds with a thin layer of soil. DO NOT water the soil again.
Label the pot with your name and the treatment on a piece of tape.
Before harvesting any plants in a pot, collect the following data:
Number of surviving radishes
Number of surviving collards
Average height of surviving radishes (cm)
Average height of surviving collards (cm)
2. After counting and measuring surviving plants, clip each plant where the stem meets the soil. If your pot is a mixed-species treatment, separate radishes from collards.
3a. For single-species treatments:
Weigh all plants within a pot for the total aboveground biomass (g)
Divide the total aboveground biomass by the number of plants that were alive in the pot, to calculate the mean aboveground biomass (g per plant)
3b. For mixed-species treatments:
Weigh all the plants of each species separately, for total aboveground biomass (g) for each species
For each species separately, divide the total aboveground biomass by the number of plants of that species that were alive in the pot, to calculate the mean aboveground biomass (g per plant, within a species)
Experimental Design
Single-species treatments (intraspecific competition tests)
4 collard seeds
16 collard seeds
36 collard seeds
4 radish seeds
16 radish seeds
36 radish seeds
Mixed-species treatments (interspecific competition tests)
2 collard + 2 radish seeds (4 total seeds)
8 collard + 8 radish seeds (16 total seeds)
18 collard + 18 radish seeds (36 total seeds)
Your mixed-species seeds should be arranged in a Latin square design, as shown below (the immediate neighbors of each seed are the other species).
--> Questions to consider about this lab
A. Hypotheses:
B. Which treatments are the controls and which are the experimental treatments?
C. What are the replicates in this experiment? How many are there for each treatment?
D. Do you see any inherent sources of bias in this experimental design?
E. Are there any problems with the experimental design that you can identify which might make interpretation of the data difficult or impossible?
