Ecology: Definition, Types, and Examples from Study.com

Ecology Definition and Examples

Study.com® Plans Courses v Ecology | Definition, Types & Examples Lessonre viering this lesson on a parent account. Please log in to your student account to track your progress. Author Instructor Marta Toran View bio What is ecology? Learn about ecology definition and ecological system and see ecology examples. Understand community ecology, microbial ecology, population ecology, etc.

Table of Contents

Table of Contents > Ecology Definition > Importance of Ecology in Our Lives > Types of Ecology > Lesson Summary

Ecology Definition

From crowded cities to remote wilderness areas, every environment hosts a complex network of interactions among living things. Additionally, they support complex interactions between living things and the environments themselves. Ecology is the study of how organisms and the environment interact with one another and how those interactions affect the abundance and distribution of various species. Studying ecology allows scientists to understand how different living and nonliving things impact one another and clarifies how human activity affects the natural world. Ecologists are scientists who study ecology, and they focus on a wide range of topics. They may work in forests, aquatic habitats, deserts, or Report an Error You are viewing lesson 19 in chapter 28 of the course: Lauren Scott View biohuman-made environments like farms and cities. They may focus entirely on one animal or plant species or study multiple species and their interactions with the physical environment.

Biotic and Abiotic Components

Biotic, or living, factors, and abiotic, or nonliving, factors play essential roles in ecology. Biotic factors that impact species abundance and distribution include:

• Predator species
• Food abundance
• Competing organisms
• Microbes
• Pollinators
• Parasites

An abundance or scarcity of any biotic factor sends a ripple effect through the ecosystem, which is the entirety of the abiotic and biotic factors in a designated area. For example, an abundance of plants often leads to an increase in herbivore populations. In turn, predators that hunt the herbivores may also increase in population due to the increased food availability. On the other hand, if a disease killed a significant percentage of the herbivore population, predator populations might decrease while plant species become overabundant. Abiotic factors form the basis of the physical environment. All impact an organism's survival and reproductive success, but not all are affected by living things themselves. Examples of abiotic factors include:

• Sunlight
• Water availability
• Air temperature
• Water temperature
• Soil nutrients
• Oxygen
• SalinityForest ecosystems illustrate the influence of abiotic factors. Tall trees prevent sunlight from reaching the soil; therefore, only plants adapted to low light conditions survive on the forest floor. Oxygen is an important factor in aquatic habitats. If decaying algae or plant matter consumes too much oxygen, other organisms cannot survive. This lack of oxygen leads to fish kills, often seen in coastal areas in warm weather.

Ecology Examples

Ecology involves several types of interactions among organisms and abiotic factors. Interaction complexity depends on the ecosystem. Regions with high biodiversity, meaning a greater number of different species, tend to have more complex ecological relationships than areas with low biodiversity.

Food Webs

A food web is a system of connected food chains that encompasses all food production and predator-prey interactions in an ecosystem. Organisms belong to trophic levels depending on their roles in the food web. For example, photosynthetic organisms like algae and plants are in the primary producer trophic level because they use energy from sunlight to produce their food. The next trophic level includes primary consumers, which are herbivores like grasshoppers, ducks, and deer. Secondary consumers are often omnivores that consume plants and animals, but some are strict carnivores that eat primary consumers. Tertiary consumers eat secondary consumers, and quaternary consumers eat tertiary consumers. Organisms can occupy more than one trophic level. Quaternary consumers are the apex predators, or top predators, in their environments.A food web shows the flow of energy through aquatic and terrestrial habitats.

Symbiotic Relationships

Symbiotic relationships are long-term interactions between organisms of two different species that usually benefit at least one of the organisms involved. The interaction between pollinators and flowers is a typical example. Pollinators like butterflies and bees gather pollen on their bodies as they feed on flower nectar and then carry that pollen to other plants. The pollinating insects gain nourishment from the flowers while helping the plants reproduce. Both organisms benefit from the interaction. Another commonly observed symbiotic relationship is the one between epiphyte plants and their host trees. In this case, the epiphyte plants benefit from the interaction while there is no benefit or harm to the trees.Epiphyte plants live on the surface of trees. The plants gain nutrients and moisture access without harming the supporting tree.

Competition in Ecology

Competition occurs when two or more species depend on the same limited resource in an environment. They may compete for shelter and breeding space, food, or water, reducing the reproductive fitness of both or all species. Foxes and lynxes, for example, compete for the same food source in Alaska and Canada, limiting the reproduction and survival of each. In human environments, garden plants and farm crops compete with weeds for water and soil nutrients. People typically remove the weeds to give the favored plants an advantage.

Importance of Ecology in Our Lives

Understanding ecology is critical to controlling the impact of human activity on the environment. By learning how different species interact and how abiotic resources cycle through various ecosystems, people can better understand how to harvest natural resources and utilize space without causing extensive damage to habitats or populations. If a population is already threatened or habitat is degraded, applying ecological principles can help slow or reverse the damage. Some applications of ecology include:

• Sustainable development-Resource harvesting and other economic activities are conducted in ways that allow future generations to meet their needs.
• Restoration ecology- Restoration ecologists repair damage caused by invasive animal and plant species by restoring native species.
• Fisheries management- Harvesting of target species is reduced to keep the population healthy. Fishing methods that harm non-target species are modified or replaced.
• Climate change research- Scientists monitor and predict long-term changes in temperature and precipitation that affect species distribution and human health.
• Endangered species protection- Species in danger of extinction are protected via harvesting regulations and habitat preservation.
• Renewable energy- Energy is harnessed for human use through renewable sources like sunlight and wind instead of nonrenewable fossil fuels.

Types of Ecology

The field of ecology includes many research areas and subdisciplines. Some of the major types or levels of ecology include ecosystem, community, population, organismal, microbial, and global.

Ecosystem Ecology

Ecosystem ecology concerns the interaction of all organisms and abiotic factors in an area. Instead of just looking at individual species or how two species interact, scientists study how organisms impact their physical environment and vice versa. For example, an ecosystem ecologist might learn how beaver dams affect water flow through a forest ecosystem and how that impacts the survival of aquatic species or the distribution of sediment. A coral reef ecologist might study how changes in water temperature impact coral survival.A coral reef ecosystem includes biotic components, like fish and coral, along with abiotic factors like salinity and water temperature.

Community Ecology

A biological community is a group of different species populations that live close enough to interact. Community ecology looks at how those species interact with one another and with other environmental factors. Researchers study competition relationships that limit species abundance and also examine symbiotic relationships and predator- prey interactions.

Population Ecology

Population ecology is the study of organism populations in relation to the environment. A population is a group of organisms of the same species that live in the same area. The area can be small or large but generally has similar resources throughout. The organisms in that population are likely to breed and interact in other ways. Population ecologists study the density of the organisms, which is the number of individuals per unit area, and their dispersion, or how they space themselves out within their population boundaries.

Organismal and Behavioral Ecology

Organismal ecology examines how an organism's adaptations impact its distribution and survival. Studying a species's physical structures or morphology can help scientists understand its feeding behaviors, habitat usage, and social interactions. Beak shape, for example, gives ecologists and animal scientists knowledge of what foods a bird may eat in its local environment. Characteristics like horns tell them that aggression may be observed when defending territories or choosing mates. Behavioral ecology is a branch of organismal ecology that studies an organism's behavioral adaptations and how they impact species survival and evolution.

Microbial Ecology

Microbial ecology is the study of how microorganisms interact with animals, plants, the environment, and each other. Microbes are essential to the movement of nutrients through food webs, and they also affect oxygen levels in an environment. Microbes can have positive interactions with some organisms, aiding in processes like digestion and infection control. In other cases, microbes can cause diseases to spread through a population, potentially upsetting the balance of an entire ecosystem.

Global Ecology (Biosphere)

Global ecology involves the interactions of all living and nonliving things on the planet, considering the total of all ecosystems. It examines the effects of material and energy movement on organism distribution around the world. This field is also called biosphere ecology because it addresses every place that life exists on Earth. The three spheres of the biosphere are:

• Lithosphere- the terrestrial component
• Hydrosphere- all the Earth's water systems
• Atmosphere- the air layers surrounding the planet

Global ecologists study topics like the effects of ocean currents, air currents, climate, and geological processes on species survival and distribution.

Lesson Summary

Lesson Summary