The key difference between competitive exclusion and resource partitioning is that competitive exclusion is a principle that says two species competing for identical resources can’t coexist, while resource partitioning is the division of limited resources by species to avoid interspecies competition in an ecological niche.
There are different types of organisms living in one niche. They will have to find a way to coexist with each other in their ecological niche. Sometime resources may be limited in their niches. At that time, resource partitioning is an important thing in order to prevent intra-specific and inter-specific competition between them. In contrast, competitive exclusion principle says that two species can’t coexist in an ecological niche if they compete for identical resources.
CONTENTS
1. Overview and Key Difference
2. What is Competitive Exclusion
3. What is Resource Partitioning
4. Similarities Between Competitive Exclusion and Resource Partitioning
5. Side by Side Comparison – Competitive Exclusion vs Resource Partitioning in Tabular Form
6. Summary
What is Competitive Exclusion?
Competitive exclusion is a principle in ecology that says two species competing for the same limited resource (identical resources) cannot coexist. In other words, it says that two species can’t coexist if they occupy exactly the same niche. If two species compete for the same limited resource, it will affect both species negatively since species with identical niches also have identical needs. Resources are often limited in habitats. Therefore, the dominant species will take advantage and dominate in the long term. Eventually, the weak species may face extinction or behavioural shift toward a different ecological niche.
Figure 01: Competitive Exclusion
A good example that can be used to explain competitive exclusion is the two types of single-celled microorganisms, Paramecium aurelia and Paramecium caudatum. When these two species culture in same test tube which has fixed amount of nutrients, P. aurelia eventually outcompetes P. caudatum for nutrients, leading to the extinction of P. caudatum.
What is Resource Partitioning?
Resource partitioning refers to the division of limited resources by species to avoid competition between them in an ecological niche. In resource partitioning, the species divide a niche to avoid competition for resources. In order to avoid interspecies competition or competitive exclusion, two species which were competing for the same resources may evolve over a long time to use different resources or occupy a different area of the habitat (e.g. use a different part of a forest or different depths of a lake), or feed during a different time of day. As a result, they may use largely non-overlapping resources and thus have different niches too.
A good example that explains the resource partitioning is the two species of Anolis lizards (Anolis evermanni and Anolis gundlachi) compete for food or insects. One species hangs out within a couple of meters of the ground while the other species feeds in the branches above two meters. It describes the resource partitioning between two species, especially the use of different areas of the habitat.
What are the Similarities Between Competitive Exclusion and Resource Partitioning?
- Competitive exclusion and resource partitioning are two concepts in ecology.
- Competitive exclusion can be avoided by resource partitioning.
What is the Difference Between Competitive Exclusion and Resource Partitioning?
Competitive exclusion principle tells us that two species can’t have exactly the same niche in a habitat and stably coexist. But, in contrast, resource portioning is the division of the niche by species to avoid competition for resources. So, this is the key difference between competitive exclusion and resource partitioning. Furthermore, competitive exclusion does not support the co-existence of two species competing for identical resources, while resource partitioning helps the species to coexist since it creates less direct competition between them. Thus, this is another difference between competitive exclusion and resource partitioning.
Summary – Competitive Exclusion vs Resource Partitioning
Competitive exclusion tells that two species can’t coexist together indefinitely if they have identical niches or if they compete for an identical resource. Eventually, the dominant species out-competes the weaker species for the resources, and the weaker species may face extinction or use of different niches over a long time. Moreover, over a long time, these species can evolve and divide the resources to avoid interspecies competition. They tend to use different resources or occupy a different area of the habitat or feed during a different time of day. So, this is called resource partitioning. So, in summary, this is the difference between competitive exclusion and resource partitioning.
Reference:
1.“Niches & Competition (Article) | Ecology.” Khan Academy, Available here.
2. “Resource Partitioning: Definition, Theory & Examples.” Study.com, Available here.
Image Courtesy:
1. “Competitive-20Exclusion-20Principle” By Dhanscom17 – Own work (CC BY-SA 4.0) via Commons Wikimedia