Dominant species

Definition

Dominant species are those that have a significant influence on the structure and function of a community due to their abundance or biomass. They play crucial roles in shaping the ecosystem, affecting the types of organisms that can thrive in their environment, and influencing nutrient cycling and energy flow. Their presence can determine the composition of other species and often establishes the habitat for various organisms.

5 Must Know Facts For Your Next Test

1. Dominant species can be plants, animals, or even microorganisms, but they are typically those that occupy a large biomass or abundance within an ecosystem.
2. In many terrestrial ecosystems, dominant plant species play a key role in determining the types of animal species that can inhabit the area.
3. The removal or decline of a dominant species can lead to significant changes in community structure and potentially result in the collapse of the ecosystem.
4. Different ecosystems have different dominant species based on factors such as climate, soil type, and available resources.
5. Understanding dominant species is crucial for conservation efforts as they often indicate the health and stability of an ecosystem.

Review Questions

• How do dominant species influence the composition and structure of their communities?
  • Dominant species influence their communities primarily through their abundance and biomass, which can dictate the available resources for other organisms. For example, in a forest, dominant tree species may provide shelter and food for various animal species while competing for sunlight and nutrients. Their presence also helps shape the microhabitats, determining what other plants and animals can thrive in that ecosystem. By establishing these conditions, dominant species play a vital role in maintaining ecological balance.
• Discuss the potential impacts on an ecosystem if a dominant species were to be removed.
  • Removing a dominant species can lead to significant ecological disruption. For instance, if a dominant tree species is cut down, it may lead to increased sunlight penetration that favors fast-growing weeds and underbrush. This change can alter the habitat for many animal species that relied on the original tree for food or shelter. Additionally, such removals can trigger cascading effects throughout the food web, potentially leading to declines in populations of other dependent species and overall biodiversity loss.
• Evaluate the role of dominant species within the framework of ecological succession and its implications for biodiversity.
  • Dominant species play a crucial role during ecological succession by dictating which organisms can thrive at different stages. Early successional dominant species may improve soil quality or provide shade, which sets the stage for later successional communities. As these ecosystems mature, shifts in dominance can either promote or hinder biodiversity. If a single dominant species monopolizes resources, it might limit other species' abilities to establish themselves, reducing overall biodiversity. Conversely, a diverse array of dominant species can support a richer community structure, enhancing resilience against environmental changes.

Related terms

Keystone species: A species that has a disproportionately large impact on its environment relative to its abundance, often maintaining the structure of the ecosystem.

Biodiversity:

The variety of life in a particular habitat or ecosystem, including the number of different species and their relative abundance.

Ecological succession: The process by which ecosystems change and develop over time, leading to more complex and stable communities.