What are Interspecific interactions?

Interspecific interactions are the relationships and interactions between different species living together in a shared habitat

Broadly, in what three different categories do interspecific interactions fall into?

Competition, predation (and herbivory), and symbioses (mutualism, commensalism, and parasitism).

When does competition occur?

Competition -\- occurs when individuals (from the same or different species) compete directly or indirectly for the same limited resources. Competition negatively affects all individuals involved and may harm their survival and/or reproduction.

What does Predation involve?

Predation +\- involves one organism (the predator) that kills and eats another organism (the prey).

What is the predator-prey population cycle?

Predator and prey populations often cycle through time in relation to changes in climate and resource abundance. This is called the predator-prey population cycle.

Describe the predator-prey population cycle.

As the prey population increases, the predator population often increases as well. However, as the prey population grows, predation pressure and increased competition for resources may cause the prey population to decline. In turn, the predator population may decline as well.

What are scavengers?

Predators that consume the remains of dead organisms.

When does herbivory occur?

Herbivory occurs when a non-plant species feeds on a plant species. Herbivory can involve the consumption of all or part of a plant. So, unlike predation, herbivory does not always result in the death of an individual. (form of predation)

What are symbioses?

Symbioses are close, long-term associations between two or more species.

What kind of symbiotic relationships are there?

Mutualism, Commensalism and Parasitism.

What kind of mutualistic relationships are there?

Facultative and obligate mutualism.

What is Facultative mutualism?

When species participate in facultative mutualism, they benefit from a symbiotic association with another species but are not dependent on it.

What is Obligate Mutualism?

When species are involved in obligate mutualism, their survival is dependent on their symbiotic association with another species.

When does Commensalism +\0 occur?

Commensalism occurs when one species benefits from a symbiotic association while the other is neither harmed nor helped.

When does Parasitism occur?

Parasitism occurs when a species (the parasite) lives in or on another species (the host). The parasite obtains its nutrition by feeding on the host’s tissues or fluids, and the host is harmed in the process.

Parasitism can be divided into what types?

- Endoparasites found within a host - ectoparasites occurring on the host’s body.

What are the two categories of interactions between individuals?

- When interactions occur between individuals of the same species, they are called intraspecific interactions. - When interactions occur between individuals of different species, they are called interspecific interactions.

What do interactions in general affect?

They affect community structure.

When does competition occur?

Competition occurs when individuals compete directly or indirectly for the same limited resources, such as food, space, or mates.

What does competition affect?

Competition is one of the most important interactions that regulates (or controls) populations in a community.

Competition can be defined as what two types?

Competition can be intraspecific or interspecific.

What is intraspecific competition?

Individuals of the same species share the same niche. In turn, they compete for the same resources. This is known as intraspecific competition.

When does intraspecific competition tend to increase?

Intraspecific competition tends to increase with population density. This is because at high population densities there are more individuals competing for the same number of limited resources. So, an increase in intraspecific competition can slow population growth.

What is Interspecific competition?

Individuals of different species do not share the exact same niche—but they may compete for some of the same resources. This is known as interspecific competition.

What can interspecific competition influence?

Interspecific competition can influence the geographic distribution and range of species. One species can exclude another species from an area by successfully competing for similar resources, such as prey or nesting sites.

Why is the outcome of competition among species dynamic?

A species may compress or shift its niche when interspecific competition restricts its use of resources. In contrast, if there is little or no competition, a species may expand its niche. Environmental variation can allow competing species to coexist. In some cases, one species will have a temporary advantage over another. However, once environmental conditions change, the advantage may shift to another species.

What is resource partitioning?

Different species have different niches, which allows them to share resources in a community and avoid competition. This is called resource partitioning (also called niche partitioning). Resource partitioning involves species using different resources, occupying different areas of a habitat, or feeding during different times of the day.

What is the competitive exclusion principle?

The competitive exclusion principle states that different species cannot coexist in a community if they compete for all of the same resources. According to this principle, if two species use the same resources but one has an advantage over the other, the species with the advantage will outcompete and dominate the other. Over time, this can lead to the decline or extinction of the disadvantaged species.