Ecological niche

Dr. K. Rama Rao
Govt. Degree College
TEKKALI; Srikakulam Dt. A. P
Phone: [phone]

1. An ecological niche is the role and position a species has in its environment; how it meets its needs for food and shelter, how it survives, and how it reproduces. A species' niche includes all of its interactions with the biotic and abiotic factors of its environment.

2. Fig 1: and abiotic factor at ecological niche

3. Concept of Ecological Niche: For a species to maintain its population, its individuals must survive and reproduce. The fundamental niche of a species includes the total range of environmental conditions that are suitable for existence without the influence of interspecific competition or predation from other species.

4. The ecological niche describes how a species interacts within an ecosystem. The niche of a species depends on both biotic and abiotic factors, which affect the ability of a species to survive and endure

5. Fig 2: Species interaction ecological niche

6. Biotic factors affecting a species' niche include food availability and predators. Abiotic factors affecting ecological niche include temperature, landscape characteristics, soil nutrients, light and other non-living factors.

7. An example of an ecological niche is that of the dung beetle. The dung beetle, as its name suggests, consumes dung both in larval and adult form. Dung beetles store dung balls in burrows, and females lay eggs within them

8. Fig 3: Ecological niche of the dung beetle

9. The dung beetle in turn influences the surrounding environment by aerating soil and rereleasing beneficial nutrients. Therefore , the dung beetle performs a unique role in its environment.

10. Importance of Ecological Niches Ecologists use the concept of the ecological niche to help understand how communities relate to environmental conditions, fitness, trait evolution and predator-prey interactions in communities. This becomes ever more important as climate change affects community ecology.

11. Interspecies competition: Ecologists refer to   coexistence  when describing ecological niches. Two competing species cannot exist in one ecological niche. This is due to limited resources. Some species of ants, the insects will compete for nests and prey as well as water and food.

12. Fig 4: Interspecies competition ecological niche

13. Competitive exclusion principle:  Ecologists use the competitive exclusion principle to help understand how species coexist. The competitive exclusion principle dictates that two species cannot exist in the same ecological niche. This is due to competition for resources in a habitat.

14. Fig 5: Species coexist ecological niche

15. In  R*  Theory, multiple species cannot exist with the same resources unless they differentiate their niches. When resource density is at its lowest, those species populations most limited by the resource will be competitively excluded.

16. In  P*  Theory, consumers can exist at high density due to having shared enemies. Competition plays out even at the microbial level. For example, if  Paramecium aurelia  and  Paramecium caudatum  are grown together, they will compete for resources.  P. aurelia  will eventually overtake  P. caudatum  and cause it to go extinct.

17. Fig 6: Competational growth at ecological niche

18. Overlapping Niches Given the fact that organisms cannot exist in a bubble and must therefore naturally interact with other species, occasionally niches can overlap. To avoid competitive exclusion, similar species can change over time to use different resources.

19. Fig 7: Overlapping Niches

20. Resource partitioning:  Partitioning means separating. Simply put, species can use their resources in ways that reduce depletion. This allows the species to coexist and even evolve. Ex: Dolphins and Seals, which eat similar species of fish. However, their home ranges differ, allowing for a partitioning of resources.

21. Fig 8: Resource partitioning niches

22. in the jack pine forest of Michigan, the Kirtland’s warbler occupies an area ideally suited for the bird. The birds prefer nesting on the ground between the trees, not in them, among small undergrowth.

23. Fig 9: Warbler nesting niches