This tutorial will cover the topic of ecology. We will discuss the various levels of organization of organisms within ecology, as well as explore several real world examples.
Our discussion breaks down as follows:
- What Is Ecology?
- Levels of Organism Organization
- Examples of Organism Organization
1. What Is Ecology?
Ecology, our key term for today, is a core subject of study within environmental science, and is therefore important for us to discuss. It is the study of the distribution and abundance of organisms, and their interactions with the living and nonliving parts of the environment.
- The study of the distribution and abundance of organisms, and their interactions with the living and nonliving parts of the environment.
2. Levels of Organism Organization
There are multiple levels of organization within ecology. The smallest is a single organism, and the levels go up to population, community, ecosystem, and finally, the biosphere.
At each new stage, there are emergent properties that can be observed that were unseen at the smaller level before it.
An organism is an individual living thing. When people talk about organisms, most people tend to think of animals. But organisms include fungi, animals, plants, as well as algae and bacteria.
The next level of organization above organisms is population, which is all the members of a single species in a given area.
Emergent properties of populations include:
Abundance: the number of organisms
Density: the number of individuals in the population per its specified area
Patterns of Dispersion: the spatial spread of species geographically
Age Structure: the relative number of different ages within a population
Sex Ratio: the number of females versus males within a population
Variability: the differences between organisms within a species
The next level in scale is the community. Community is all the populations of species within a given area and time.
Its emergent properties are:
Species Abundance: the number of species and relative abundance of species in that community
Species Composition: the exact species that exist in the community
Species Distribution: the way species are distributed geographically in relation to each other
Species Interactions: the observations of how species interact with each other
Above community is an ecosystem. Ecosystems are all of the communities and their relationships with the abiotic factors in a specific area. You may recall that abiotic factors are nonliving parts of an ecosystem such as weather, climate, and rocks, while biotic factors are the living, organic parts, like flora and fauna. Ecosystems are quite complex, and consist of hundreds and even thousands of species interacting.
Emergent properties at this level include:
Number of communities in an ecosystem
Interactions between those communities
Interactions between living organisms and the area's abiotic factors
Important to note is the concept of habitat, which is the area within an ecosystem that a particular species inhabits. Habitats are comprised of both biotic and abiotic factors.
Niche is another important concept, which is all the abiotic and biotic factors that affect and influence a particular species. It extends beyond a species' habitat because it deals with everything that impacts the species.
The biosphere is the highest level of ecology organization and includes all ecosystems on the planet, or all parts of the planet that contain life.
Emergent properties at this level include:
Number and types of ecosystems
Interactions between ecosystems
Global phenomena, such as climate and weather patterns
3. Examples of Organism Organization
Let's look at a couple of examples, and see what organism organization looks like in the bigger picture.
An ant is an example of the lowest level of organization —
the organism level. Different ant species prefer different habitats. This particular ant makes its home in a forest and lives in a tree. Its habitat includes the tree, the rain, the humidity that are in this area, and the food sources it consumes.
Its niche includes these things as well as other nearby species' actions that might impact this ant, such as a different nearby ant species who are competing for similar resources.
The ant's ecosystem would include a large region around it, filled with various species and other abiotic factors.
Another example would be a mushroom, like the one shown below. Its habitat would also be in a forest, perhaps at the base of a tree for protection. It would grow near the roots of the tree for resources, and its habitat would also include the local weather.
Its niche would be breaking down waste in the forest, such as leaf litter to eat. Its niche would also include how it is affected and distributed as a result of available nutrients and weather patterns, such as rainfall and sunlight.
Its ecosystem would include the forest and species around it, and the local weather, as well as any potential consumers that might want to eat it.
Today we learned about ecology and its various levels of organism organization: organisms, population, community, ecosystem, and biosphere. Important to note are the concepts of habitat, which is the area within an ecosystem that a particular species inhabits, and niche, which is all the abiotic and biotic factors that affect and influence a particular species. Our key term was ecology, which is the study of the distribution and abundance of organisms, and their interactions with the living and nonliving parts of the environment.