Key Concepts in Ecology and Biological Interactions
Key Concepts in Ecology
- Ecological Factor: The characteristics of the environment that affect living organisms. They can be abiotic and biotic.
- Adaptation: The evolution of organisms so that they are able to survive in a specific environment. They can be morphological, physiological, and behavioral.
- Population: A group of organisms of the same species that inhabit the same territory and that can reproduce together.
- Biotic Potential: The maximum reproductive potential of a population, which is the difference between the birth rate and the death rate.
- Community: A set of populations of different organisms that live together in the same geographical area within a particular habitat.
- Biodiversity: The biological variability among and between species in a community, as well as the diversity between communities and ecosystems themselves.
- Ecological Succession: The sequential order in which plant communities, and the animal species associated with them, change over time.
Examples of Biological Interactions
| Interaction | Species 1 | Species 2 |
|---|---|---|
| Commensalism | Vulture | Dead deer |
| Inquilinism | Owl | Tree |
| Parasitism | Tapeworm | Human |
| Predation | Snake | Mice |
| Competition | Tree | Shrub |
| Competition | Lion | Leopard |
| Symbiosis | Fungi-Algae | None |
Primary and Secondary Succession
Primary Succession
An uninhabited zone is colonized by pioneer organisms with few nutritional requirements. The soil is progressively enriched and biodiversity increases. The progressive evolution leads to a community that is very stable (climax).
Secondary Succession
This occurs when a community loses an important part of its population. This can be caused by events such as climate change, natural disasters, or erosion. After this, secondary succession occurs: a new evolutionary process which results in a new community.
Types of Populations
- Invertebrate Colonies: The individuals that make up a colony are connected and related to each other. They are produced by asexual reproduction from the same parent.
- Family Groups: The individuals that make up a family come from a pair of animals whose offspring stay together with the family unit.
- Caste System of Social Insects: These individuals come from one mother. They have anatomical and physiological differences which dictate their role in the community.
- Social Groups: These individuals tend to live together and support each other mutually. Sometimes these groups are transitory, such as during migrations.
Adaptation to Water Scarcity
- Water storage in special tissues.
- Drought-resistant seeds.
- Leaves with a small number of stomata that open at night to reduce water loss.
- Deep and extensive root systems.
- Hard, leathery, small leaves to reduce water loss.
- Annual plants complete their life cycle in the season that favors their development.