Music Our big, beautiful, blue planet is in a complicated balance of life and death, predator and prey, friend and foe. The word ecology literally translates to the study of home, our home, planet Earth. The word ecology literally The more specific definition of ecology is the study of the relations of organisms to one another and to their physical environment.
It answers questions like, how do living things interact and rely on each other, or on their surroundings? The survival of any species is dependent on other living organisms and non-living components. This is called interdependence. For example, humans could not survive without plants to produce oxygen, and the plants need carbon dioxide from humans and other organisms, or even from volcanic eruptions. Ecology is extremely complex and difficult to study.
So one way that ecologists deal with this complexity is to use ecological models to represent or describe the components of an ecological system. This model is called an ecosphere. The largest ecological system we know of is the biosphere, planet Earth.
This is the only biosphere we study because, so far, it's the only place in the universe that we know has life. The biosphere is the thin veil on Earth that goes from above the ground to the deepest parts of the ocean. All life on Earth is in the biosphere.
If you zoom in to one ecosystem, it's a little easier to see all the parts working together. An ecosystem is all the organisms in a non-living environment found in a particular place. The living things in this pond ecosystem include fish, turtles, aquatic plants, algae, insects, birds, and bacteria.
These organisms interact in ways that affect their survival. For instance, insects and fish eat aquatic plants, and the turtles eat the fish. The nonliving, or physical and chemical things, include the chemical composition of the pond, its pH, its levels of dissolved oxygen and carbon dioxide, and its supply of nitrogen, which all help to determine what kinds of organisms live in the pond and how abundant they are. A community is all of the interacting organisms in an area.
It does not include the nonliving factors. A population is all of the organisms of one type of species in the area, and an organism refers to an individual animal. In order, the levels of organization from the most broad to the narrowest are the biosphere, ecosystem, community, population, and organism. When we talk about where an organism lives, instead of saying ecosystem, which might still be a fairly large area, we could talk about its habitat. It's just a word that means the place where an organism lives.
A habitat includes both biotic and abiotic factors. Biotic factors are the living parts of the habitat, and when you add the letter A in front of the word, it means not living, so abiotic factors are the non-living parts of the habitat. Using the pond ecosystem as an example, Biotic factors include grasses, algae, fish, birds, and insects. The abiotic factors include the pH of the water, rocks, soil, the sunlight, and temperature.
Now you may sometimes hear people try to use the word habitat and the word niche interchangeably. And that's not quite how they should be used. A niche is the job or role of the organism within its environment. So habitat is a home and niche is a job.
For example, A redwood tree takes energy from the sun and turns it into sugar using photosynthesis. Redwood trees are often found in foggy coastal areas like Santa Cruz, California. The habitat is the foggy coastal areas like California, and the niche is converting the sun's energy into sugar by photosynthesis. Now, some organisms fill a very broad niche and some a very specific one.
Generalists eat a variety of foods and specialists eat few or even just one type of food. Pigs are an example of a generalist. They'll eat lots of different foods very happily.
This can be beneficial to them because they could survive on a variety of foods and fill a niche in many different habitats. The panda, on the other hand, is a specialist because they only eat bamboo. If bamboo is unavailable, the panda population may die off.
This species has a much higher risk of becoming extinct, so it's often beneficial for organisms to be generalists. Thanks for watching this episode of Teacher's Pet. Don't forget to like and subscribe and follow me on Twitter at Science Pet.