Bilogical Pyramids/ Ecological Pyramid An ecological pyramid is a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem.
A pyramid is one graphical method that shows the quantitative relationship between organisms at each trophic level. Each trophic level is represented by rectangle, the lenth of which is proportional to the number of organism at that level. Ecological pyramids begin with producers on the bottom and proceed through the various trophiclevels. The highest level is the top of the food chain.
Example of a pyramid
Types of Pyramids There are different types of pyramid such as; Pyramid of Biomass Pyramid of Number Pyramid of Productivity
Pyramid of Biomass An ecological pyramid of biomass shows the relationship between biomass and trophic level by quantifying the amount of biomass present at each trophic level of an ecological community at a particular moment in time. Typical units for a biomass pyramid could be grams per meter2, or calories per meter2. One problem with biomass pyramids is that they can make a trophic level look like it contains more energy than it actually does.
Pyramid of Number An ecological pyramid of numbers shows graphically the population of each level in a food chain.
Pyramid of Productivity An ecological pyramid of productivity is often more useful, showing the production or turnover of biomass at each trophic level. Instead of showing a single snapshot in time, productivity pyramids show the flow of energy through the food chain. Typical units would be grams per meter2 per year or calories per meter2 per year. As with the others, this graph begins with producers at the bottom and places higher trophic levels on top.