Ecological Interactions, Food Webs, and Human Impacts in Biology

Biotic interaction

An interaction that involves living organisms.

Abiotic interaction

An interaction that involves non-living elements of the environment.

Organism

An individual living entity.

Population

Same species and live in same area and time.

Community

All of the populations/different species living together in one area.

Ecosystem

All of the biotic (organisms) and abiotic parts interacting in one area.

Trophic interaction

Interactions related to feeding, including predation and competition.

Predation

An interaction where one organism preys on another.

Competition

An interaction where two species use the same resources and compete for them.

Cooperation

An interaction where both species benefit from the relationship.

Parasitism

An interaction where one species benefits while the other is harmed.

Generalist

A species that can live in many habitats and eats many different foods; flexible.

Specialist

A species that needs a very specific habitat and food source; not flexible.

Biome

A general type of habitat that has a specific type of climate and special types of plants/animals.

Trophic interactions

Interactions that involve feeding relationships among organisms.

Non-trophic interactions

Interactions that do not involve feeding, such as competition and cooperation.

Seal diet

Seals eat dogfish, herring, and cod.

Plankton consumers

Animals that eat plankton include herring, krill, and scallop.

Food chain example

Plankton → krill → mackerel → Tuna.

Cod competitor

Krill competes with cod for food.

Mackerel classification

The mackerel is a specialist; it only eats krill.

Desert ecosystem

A desert is very dry and hot, and is a harsh place to live.

Rattlesnake diet

Rattlesnakes prey mostly on mice and lizards.

Gila Woodpecker

A bird that uses its beak to make nest cavities in the Saguaro cactus without harming it.

Exponential Population Growth

Occurs when space and resources are unlimited.

Logistic Population Growth

Occurs when space and resources are limited and population levels off at a carrying capacity.

Carrying Capacity

The maximum population size that an environment can sustain indefinitely.

Trumpeter Swan

A species that was reintroduced to Minnesota in the 1980s after being wiped out due to hunting and habitat loss.

Human Impacts on Ecosystems

Changes to systems caused by human activity that can lead to the expansion of some species while causing others to decline or go extinct.

Specialists

Species that are more likely to be harmed by human activities due to their specific habitat and food requirements.

Generalists

Species that are more adaptable and flexible, allowing them to handle changes in their environment better than specialists.

HIPPCO

An acronym for the six ways humans impact ecosystems: Habitat Loss, Invasive Species, Population Growth, Pollution, Climate Change, and Overharvesting.

Habitat Loss

The destruction of natural environments due to human construction, leading to loss of homes for wildlife.

Invasive Species

A species that rapidly grows in population and negatively impacts native species in the area.

Population Growth of Humans

The increasing number of humans, which leads to habitat loss and increased hunting of animals.

Pollution

The introduction of harmful substances into the environment, often caused by human activities like transportation and industrial processes.

Climate Change

Long-term changes in temperature and weather patterns, often exacerbated by human activities.

Overharvesting

The excessive harvesting of resources, leading to waste and depletion of those resources.

Biodiversity Loss

The decline in the variety of life in a particular habitat or ecosystem, which can lead to the loss of ecosystem services.

Ecosystem Services

The benefits that humans derive from ecosystems, which can be diminished by biodiversity loss.

Leopard Seals

Predators in the Antarctic food web that, if declined, would lead to an increase in the population of zooplankton.

Zooplankton

Small aquatic organisms that are part of the food web and can be affected by changes in predator populations.

Population Growth Rate

The rate at which a population increases or decreases over time.

Point of Fastest Population Increase

The point on a growth graph where the population is increasing at the fastest rate.

Point of Carrying Capacity

The point on a growth graph where the population has reached the maximum sustainable level.

Example of Biodiversity Loss

The decline of wolf populations leading to less biodiversity and a decrease in food sources.