Have a question about trophic levels, biomass?

Question

I have a project about a self-sustained imaginary space station. it is basically a mini-earth. Everything is the same as Earth except that it has no fish, and fewer animals/plants/etc.

For details look at my other questions :)

For this project I have to describe and illustrate the path of energy and matter through living systems and the physical environment . <--- I do not get this part... What does this mean??? energy and matter ??

The things I need are the foob web/chain (know this) , trophic levels (what is this?? Do not get this), and biomass(What is this)..

and how should I draw out a trophic level, biomass............ plz help

I also have to compare different energy pathways.. What does this mean?

For biomass = recently dead creatures.. but how is it a path?? Can someone describe it and link a site where there is like a picture for the path?(cycle?)

Answer 1

When they talk about pathways for energy and matter, here's what they mean:
1. Energy is a one-way path. It starts with sunlight, captured by producers to make their own food during photosynthesis, passed to consumers when they eat producers, and so on.
2. Matter travels in cycles. Matter is passed through the food chain like energy is, but dead organisms and waste materials are broken down by decomposers so the matter can be recycled back through the system.

Trophic levels are "feeding levels" or steps in a food web or food chain. The first trophic level is "producers", second is "herbivores" or "primary consumers", third is "carnivores" or "secondary consumers", and so on.

Biomass is the total mass of material in a certain trophic level. In the space station, the biomass of the producers will be all the kilograms of plant or algae material. The biomass of the primary consumers will be 1/10 as much as the producers. The biomass of the secondary consumers will be 1/10 as much as the primary consumers.

Usually trophic levels and biomass are drawn out on an ecological pyramid. See some examples here:
http://www.altavista.com/image/results?itag=ody&q=ecological+pyramid&kgs=1&kls=0

Answer 2

Think of a food pyramid, the higher you are the more biomass is under you, so the most biomass is at the base and the least is at the top. A is the best answer in an ideal system as the greater the difference in biomass between levels the less disturbance to the food chain since there will be ample food for each level