3 Ecological Interactions Free Online FlashCards

What do +, −, and 0 mean in ecological interaction shorthand?

The shorthand records each species’ effect: + means benefit, − means cost, and 0 means no substantial effect.

What causes competition between organisms?

Competition occurs when organisms use the same limited resource, such as food, water, light, or space.

How do intraspecific and interspecific competition differ?

Intraspecific competition occurs among members of the same species; interspecific competition occurs between different species.

What can strong interspecific competition do to populations or species distributions?

Strong competition between species can cause one population to decline or restrict where each species occurs.

How can resource partitioning help competing species coexist?

Resource partitioning is the use of different foods, locations, or times by competing species, reducing direct competition and helping them coexist.

What defines predation, and how are its effects represented?

In predation, a predator captures and consumes prey, usually killing it. The predator benefits and the prey is harmed: + / −.

How can prey abundance affect predator and prey numbers in turn?

When prey become abundant, predators may increase; increased predation can then reduce prey numbers.

What is herbivory, and how does it often differ from predation?

Herbivory is the consumption of plants or algae by animals. Herbivores often eat only part of an organism rather than killing it.

How can plants and herbivores adapt in response to one another?

Plants may limit damage with thorns or distasteful chemicals, while herbivores may have adaptations that help them overcome these defenses.

What is mutualism? Give an example involving pollination.

In mutualism, both species benefit (+ / +); for example, a pollinator gains food while transferring pollen that can help a flower reproduce.

What characterizes commensalism, and why can it be difficult to confirm?

In commensalism, one species benefits while the other is not noticeably helped or harmed (+ / 0). A truly neutral effect can be difficult to demonstrate.

What happens to parasite and host in parasitism?

In parasitism, a parasite gains resources from a host and harms it, usually without killing it immediately (+ / −).