B4.2.1 Ecological niche as the role of a species in an ecosystem Notes

The Ecological Niche Plays A Unique Role in an Ecosystem

1. In every ecosystem, each species occupies a unique role, referred to as its ecological niche.
2. This niche integrates both biotic (living) and abiotic (non-living) factors, defining how a species survives, grows, and reproduces in its environment.

Key Components of an Ecological Niche

1. Zones of Tolerance for Abiotic Variables

1. A species’ habitat is determined by its zones of tolerancefor factors like temperature, light, and moisture.
2. These abiotic conditions define where a species can live and thrive.

2. Food Source and Nutrition Specialization

1. Species obtain energy through photosynthesis (e.g., plants) or by consuming other organisms (e.g., animals, fungi).
2. To reduce competition, species often specialize in a specific mode of nutrition or adapt to unique food sources.

3. Interactions with Other Species:

1. Many species rely on others for critical ecosystem services, including:
   1. Pollination of flowers.
   2. Seed dispersal by animals.
   3. Recycling of nutrients, like decomposers breaking down organic material.
2. These interactions help maintain balance within ecosystems.

Multidimensional Nature of the Ecological Niche

1. A Complex Role: A species’ ecological niche is multidimensional, encompassing all factors necessary for survival:
   1. Abiotic factors (e.g., light, temperature, pH).
   2. Biotic interactions (e.g., competition, predation, symbiosis).
2. The Consequences of Overlap: When two species share overlapping niches, competition intensifies, potentially leading to the exclusion of one species or forced adaptation.