Difference Between Allelopathy and Competition

The key difference between allelopathy and competition is that allelopathy is the phenomenon where organisms produce allelochemicals to either inhibit or enhance growth, germination, or survival of other organisms, while competition is the negative relationship between two organisms, which takes place due to the limited supply of resources.

Nutrition is an essential requirement for the survival of all organisms. Therefore, the method used by organisms to fulfil this requirement is vital for the sustainability of the organisms.  Allelopathy and competition are two types of relationships existing between two or more organisms. Organisms possess various adaptations towards these two phenomena.

CONTENTS

1. Overview and Key Difference
2. What is Allelopathy 
3. What is Competition
4. Similarities Between Allelopathy and Competition
5. Side by Side Comparison – Allelopathy vs Competition in Tabular Form
6. Summary

What is Allelopathy?

Allelopathy refers to a relationship shown by invasive plants. It is a type of relationship in which plants produce chemicals called allelochemicals either to inhibit or enhance growth, germination, or survival of other plants. In fact, these allelochemicals are secondary metabolites or by-products produced as a result of their metabolism. Several factors such as nutrient availability, temperature, pH and the availability of enzymes mediate the production of these allelochemicals.

Figure 01: Allelopathy

Allelopathic interactions are important for the determination of the species distribution in plants; hence, it plays an important role in the ecology of plants. In most instances, plants suppress the growth and germination of other plants via allelopathy. Thus, allelopathy is a type of chemical inhibition of one species by another.

Allelochemicals are present in almost all parts of the plant such as leaves, flowers, roots, fruits, or stems can have allelochemicals. Not only that, these chemicals can be present in the surrounding cells of the root system.

What is Competition?

Competition is a negative relationship between two organisms, which takes place due to the limited supply of resources for both organisms. These resources can be nutrition, water or shelter. Therefore, both biotic and abiotic factors are involved in this relationship. Further, this plays an important role in community ecology and ensures that the survival of the fittest takes place.

Competition between organisms can take place in two ways: intraspecific competition and interspecific competition. The interspecific competition takes place between two organisms of different species. They may compete for food, water and territory. Thus, there will be a negative impact on both organisms due to the lack of these requirements. However, the organism which is most resistant and adapted to the conditions may survive while the other will cease to exist.

Figure 02: Sea Anemones Competing for Territory

Meanwhile, intraspecies competition takes place between two organisms of the same species. Organisms of the same species compete for resources such as water, food and territory. Moreover, they compete for mating partners as well during their mating season. In plants, competition takes place for requirements such as sunlight. Therefore, they grow in different striations.

What are the Similarities Between Allelopathy and Competition?

• Both allelopathy and competition involve two organisms.
• Also, both ensure the survival of the fittest.

What is the Difference Between Allelopathy and Competition?

Allelopathy and competition are relationships that take place between two organisms. Allelopathy is the phenomenon where organisms produce allelochemicals to either inhibit or enhance growth, germination, or survival of other organisms, while competition is the negative relationship between two organisms, which takes place due to the limited supply of resources. While allelopathy brings about both positive and negative effects on both organisms, competition brings about a negative impact on both organisms. So, this is the key difference between allelopathy and competition. Besides, the types of allelopathy are positive and negative, while competition is divided as intraspecific and interspecific competition.

The below infographic summarizes the difference between allelopathy and competition.

Summary – Allelopathy vs Competition

Allelopathy and competition involve two organisms and ensure the survival of the fittest for a particular condition. Allelopathy refers to a relationship between two organisms where one organism secretes allelochemicals. Competition refers to a negative relationship in which two organisms compete for essential requirements such as nutrition, water and territory. So, this is the difference between allelopathy and competition.

Reference:

1. “Competition.” Biology Reference, Available here.

2. “Allelopathy In Plants: What Plants Suppress Other Plants.” Gardening Know How, Available here.

Image Courtesy:

1. “Clone war of sea anemones 2-17-08-2” By Eric Guinther at the English language Wikipedia (CC BY-SA 3.0) via Commons Wikimedia
2. “Casuarina litter” By Brocken Inaglory – Own work (CC BY-SA 4.0) via Commons Wikimedia

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