communitites and ecosystems
essential questions
WHAT ROLES DO AUTOTROPHS PLAY IN THE COMMUNITY?
Autotrophs are organisms that produce their own food. They are called producers and are the basis of the food chain. No other organisms can convert the CO2 into organic molecules. They are critical to the world because all the other forms of life rely on the energy from organic molecules. Without autotrophs there would be no more usable energy (food) available for the world and for the food chain. Basically all life rely on autotrophs.
WHY IS THERE A LIMIT TO THE NUMBER OF TROPHIC LEVELS IN AN ECOSYSTEM?
Because toxins become more concentrated at higher trophic levels by biomagnification. Biomagnification is the process in which chemical substances become more concentrated at each trophic level. At each stage of the food chain the predator will accumulate higher concentrations of the toxin. The concentration of toxins in the higher trophic levels may be lethal even when the concentration in organisms at the start of the food chain are small given that organisms on each level pass about 10% of the energy to the next trophic level.
TO WHAT EXTENT ARE MODELS USEFUL REPRESENTATIONS OF THE REAL WORLD?
The process of making a model starts selecting a real-world situation, such as the feeding relationships in a community. But after a model is built, analyzed, and tested, it is often necessary to revise the model several times. In other words, when you look at the results of the model you usually find that your first attempt was a poor representation of what actually happens in the real world. Therefore, more than one trip around the modeling diagram may be needed in order to find a model that accurately describes the situation, but with observations and data from the real world situation which provide feedback in the modeling process can help us refine the models. I think that models are really useful representations of the real word, because they are done with detail and by group of scientific that really know what they are doing and try to make it the more similar to real world as they can.
Also there are several advantages to creating a model and one advantage is that it may not be possible to work with the real world environment all the time. There are many situations for which running an experiment would be too difficult, costly, or unethical. Food webs are one example of this it would be unethical (and dangerous) to make a species extinct just to see the effect it would have on the rest of the community.
Autotrophs are organisms that produce their own food. They are called producers and are the basis of the food chain. No other organisms can convert the CO2 into organic molecules. They are critical to the world because all the other forms of life rely on the energy from organic molecules. Without autotrophs there would be no more usable energy (food) available for the world and for the food chain. Basically all life rely on autotrophs.
WHY IS THERE A LIMIT TO THE NUMBER OF TROPHIC LEVELS IN AN ECOSYSTEM?
Because toxins become more concentrated at higher trophic levels by biomagnification. Biomagnification is the process in which chemical substances become more concentrated at each trophic level. At each stage of the food chain the predator will accumulate higher concentrations of the toxin. The concentration of toxins in the higher trophic levels may be lethal even when the concentration in organisms at the start of the food chain are small given that organisms on each level pass about 10% of the energy to the next trophic level.
TO WHAT EXTENT ARE MODELS USEFUL REPRESENTATIONS OF THE REAL WORLD?
The process of making a model starts selecting a real-world situation, such as the feeding relationships in a community. But after a model is built, analyzed, and tested, it is often necessary to revise the model several times. In other words, when you look at the results of the model you usually find that your first attempt was a poor representation of what actually happens in the real world. Therefore, more than one trip around the modeling diagram may be needed in order to find a model that accurately describes the situation, but with observations and data from the real world situation which provide feedback in the modeling process can help us refine the models. I think that models are really useful representations of the real word, because they are done with detail and by group of scientific that really know what they are doing and try to make it the more similar to real world as they can.
Also there are several advantages to creating a model and one advantage is that it may not be possible to work with the real world environment all the time. There are many situations for which running an experiment would be too difficult, costly, or unethical. Food webs are one example of this it would be unethical (and dangerous) to make a species extinct just to see the effect it would have on the rest of the community.