Affect of Density on Intraspecific Competition in Marigolds Eric Flatt Undergraduate Student (Marine Biology Concentration) Department of Biology Tennessee Tech University Cookeville, TN 38505

Project Summary All plants live in environments with different numbers/densities of each in which they have to compete. My objective with this experiment is to prove that these different densities affect intraspecific competition in marigolds.

Project Summary Continued I plan to accomplish this by planting marigolds in different densities of 2, 4, 8, 16, 32, and 64 in six different flower pots. After five weeks I will measure the plant density, survivorship, total weight, mean weight, mean stem weight, mean leaf weight, mean stem length, and mean growth rate for the plants of each pot. I expect the results from this data to show that density does affect intraspecific competition in marigolds and possibly other plants as well.

Introduction Plant competition has been the object of ecologists’ studies for several years. Most experimental studies in plant competition over the past several years have involved manipulating the densities of one or more plant species and quantifying the response of other plants (Miller 1990). The ability of a plant to endure the suppression of its neighbors often varies among species (Peltzer and Wilson 2001).

Introduction Continued For many species, a density increase results in total weight, height, reproduction and/or survival decrease (Lentz 1999). A great deal of research has been devoted to understanding how plant species affect and respond to each other and how the interactions affect the dynamics, structure, and evolution of the plants in the vicinity (Connolly, Wayne, and Bazzazz 2001).

Objective/Hypothesis Statement Objective: The objective of this experiment is to find out whether or not density affects intraspecific competition in marigolds. Hypothesis: Density will have an affect on intraspecific competition in marigolds. Null Hypothesis: Density will not have any affect on intraspecific competition in marigolds.

Methods and Materials As I said earlier, I will measure the plant density, survivorship, total weight, mean weight, mean stem weight, mean leaf weight, mean stem length, and mean growth rate for the plants of each pot. Then I will construct graphs showing plant density versus mean plant weight, total plant weight, stem length, mean stem weight, mean leaf weight, mean growth rate per plant, and survivorship.

Methods and Materials Continued Data Form for Research Experiment

Expected Results and Benefits The expected results for this experiment are that the density will affect the measurements for the intraspecific competition data. The benefits that could come for this experiment are that ecologists would have a better understanding of how density can affect competition amongst plants such as marigolds and why some plants may be driven to extinction because the greater densities of them there are then the more likely they will negatively affect each other, thus killing each other off.

Project Timeline February- research of literature and get supplies for experiment March- conduct experiment throughout this month April- finish experiment and calculate data/results

Budget Six flower pots- $ 7.00 Balance Scale- $38.50 Ruler- $0.75 Marigold seeds- $3.25 Total= $ 49.50