3.2: Community Ecology
- Page ID
- 175758
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Keystone Species
Until the late 1800s, Bison (Bison bison) numbered tens of millions in the Great Plains of the United States. By 1890, roughly 1000 Bison were left because the United States government campaign to eradicate the native people, their culture, and habitats they relied on. Slowly, a movement started to try and save Bison from extinction. It took until the early 2000’s for Bison numbers to reach a half a million. During this time, scientists were able to observe the Bison reintroduction back into the Great Plains. Bison were found to be the most critical species to restoring and maintaining the function and diversity in the Great Plains community. Both plants and animal populations in the community were strengthened from the return of the Bison. Understanding community dynamics is essential to conserving and restoring these systems and the species that define them. This is particularly critical for communities with one particular species that acts as a keystone to the health of the system.
Figure \(\PageIndex{a}\): American bison with starlings on its back. Image by NPS Photo(opens in new window) [NPS Photo] [NPS photos] (Public Domain)
Populations typically do not live in isolation from other species. Populations that interact within a given area form a community. The organisms that form a community are found in habitats, physical environments where organisms live; however, biotic (living) components are considered part of a community. Scientists study ecology at the community level to understand how species interact with each other and compete for the same resources.
- 3.2.1: Biotic Interactions
- This page explains biotic interactions between organisms, including intraspecific and interspecific relationships. It differentiates between antagonistic interactions, where one species is harmed (e.g., competition and trophic interactions), and facilitation, involving beneficial relationships like commensalism and mutualism.
- 3.2.2: Trophic Interactions
- This page discusses trophic interactions, where one organism feeds on another, including predation, herbivory, and parasitism. These relationships benefit one species while negatively impacting the other, often leading to nutrient loss or death. The energy flow through these interactions is essential and can be represented through food chains and food webs, with an example of a hawk preying on a vole illustrating the concept.
- 3.2.3: Community Structure and Dynamics
- This page explains the complexity of communities as ecosystems shaped by structure and dynamics. It highlights the role of keystone species in influencing biodiversity. The page details community dynamics and how they evolve through primary succession on bare rock and secondary succession after disturbances, emphasizing the role of pioneer species and existing soil in recolonization.
- 3.2.4: Data Dive- Bison Impacts In Prairies
- This page examines a 2017 study on the role of bison in tall-grass prairies, revealing their positive impact on plant competition. It highlights that bison contribute to richer grassland habitats by reducing bare ground and increasing the diversity of herbaceous forbs. The findings suggest that bison are beneficial for plant species diversity, offering valuable insights for future conservation initiatives in these ecosystems.
- 3.2.1: Biotic Interactions
- This page explains biotic interactions between organisms, including intraspecific and interspecific relationships. It differentiates between antagonistic interactions, where one species is harmed (e.g., competition and trophic interactions), and facilitation, involving beneficial relationships like commensalism and mutualism.
- 3.2.2: Trophic Interactions
- This page discusses trophic interactions, where one organism feeds on another, including predation, herbivory, and parasitism. These relationships benefit one species while negatively impacting the other, often leading to nutrient loss or death. The energy flow through these interactions is essential and can be represented through food chains and food webs, with an example of a hawk preying on a vole illustrating the concept.
- 3.2.3: Community Structure and Dynamics
- This page explains the complexity of communities as ecosystems shaped by structure and dynamics. It highlights the role of keystone species in influencing biodiversity. The page details community dynamics and how they evolve through primary succession on bare rock and secondary succession after disturbances, emphasizing the role of pioneer species and existing soil in recolonization.
- 3.2.4: Data Dive- Bison Impacts In Prairies
- This page examines a 2017 study on the role of bison in tall-grass prairies, revealing their positive impact on plant competition. It highlights that bison contribute to richer grassland habitats by reducing bare ground and increasing the diversity of herbaceous forbs. The findings suggest that bison are beneficial for plant species diversity, offering valuable insights for future conservation initiatives in these ecosystems.
Attribution
Modified by Rachel Schleiger and Melissa Ha from Community Ecology from Environmental Biology by Matthew R. Fisher (licensed under CC-BY(opens in new window))
Modified by Erin Rempala.