Biology

Lab Report: Intraspecific Competition in Sunflower Seedlings

Introduction

Competition occurs when organisms use a shared resource that is in short supply, such as food, water, sunlight, or living space. There may not be enough of the resource for any given individual to survive or to reproduce. Competition does not necessarily involve competitors ever meeting (mobile organisms such as animals), or being adjacent to each other (non-motile, such as plants or fungi). As a result of competition, birth rates are lower, death rates are higher, or both. Population growth rates decline and population size is lower at equilibrium. Competition is a density dependent effect. The more densely populated an area is the more competition will occur.

Competition occurs among individuals within a population ( Intraspecific Competition), or between different species (Interspecific Competition). In Intraspecific Competition, individuals compete with their own species when populations grow, and therefore individuals are more closely packed and/or resources are scarcer. The faster the resources are being used up, the higher the level of competition.

In this experiment, we studied the effects of population number on the amount of competition that occurred in sunflower seedlings. In other words, we were able to determine the effects of the population density of the sunflower seedlings on the competition for various resources, such as light, water, nutrients and growing space. Our hypothesis was that growth of the sunflower plants with a higher population would be inhibited due to competition. The higher the population, the higher the inhibition rate. Therefore, The pot with the least amount of seedlings in it will contain plants that grow larger than that of the pots with a high number of seedlings.

Materials and Methods

In this experiment, three pots were set up and filled with moistened potting soil. The area of the potting soil was measured and...