Source: Earth PD http://bit.ly/1ESoBKp Ant CC http://bit.ly/1xc91Ki Ants PD http://bit.ly/1xvANMt Food Web CC http://bit.ly/1MFN5ZI Map of China CC http://bit.ly/1O3sK41 Earth Clipart PD http://bit.ly/1ESoBKp Mushroom CC http://bit.ly/1GSNA0w
Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is ecology. So let's get started.
We're going to talk about ecology and the various levels of organization of organisms within ecology. Ecology 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. It is our key term for today.
There are multiple levels of organization within ecology. The smallest is a single organism, like this ant here, and goes 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.
So this ant is an organism, or an individual living thing. When people talk about organisms, most people tend to think of animals. But organisms include fungi, animals, and plants as well.
Above organisms, population, which is all the members of a single species in a given area. For example, this photo here shows all the ants of a single species in a small area. Emergent properties of populations include abundance, which is the number of organisms, density, which is the number of individuals in the population per its specified area, patterns of dispersion, which is what the spatial spread of species is geographically, age structure, which is the relative number of different ages within a population, sex ratio, which is how many females versus males there are in a population, and variability, which is the differences between organisms within a species.
Next up in scale is community. Community is all the populations of species within a given area and time. Its emergent properties are species abundance, which is the number of species and relative abundance of species in that community, species composition, which is what exact species exist in the community, species distribution, which is the way species are distributed geographically in relation to each other, and species interactions, which is observations of how species interact with each other.
Above community is ecosystem. Ecosystems are all of the communities and their relationships with the abiotic factors in a specific area. If you remember, 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.
An example of an ecosystem would be a particular region in China and the relationship between abiotic factors and living communities in that area. Ecosystems are quite complex, and consist of hundreds and even thousands of species interacting. Emergent properties at this level include the number of communities in an ecosystem, interactions between those communities, and interactions between living organisms and the areas abiotic factors.
Important to note is the concept of habitat, which is the area within an ecosystem that a particular species inhabits. They are comprised of both biotic and abiotic factors. And 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.
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 the number and types of ecosystems, the interactions between ecosystems, and global phenomena such as climate and weather patterns. Let's take a couple examples, and see what it looks like in the bigger picture.
Earlier, we mentioned how an ant was an example of the lowest level of organization-- the organism level. Different ant species prefer different habitats. But this one is an ant that makes its home in a forest, and lives in a tree.
Its habitat includes the tree, the rain and 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 is 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 this one. 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, the local weather, as well as any potential consumers that might want to eat it.
Now let's have a recap. We talked about ecology and its various levels of organism organization. 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.
Well, that's all for this tutorial. I look forward to next time. Bye.