Final answer:
Biomass and the number of species decrease as one ascends the ecological pyramid due to energy loss at each trophic level. Producers have the highest biomass and energy, which diminishes through primary, secondary, and tertiary consumers.
Step-by-step explanation:
In an ecological pyramid, biomass and the number of individuals in a species typically decrease as you move up through the trophic levels, from producers to primary consumers, to secondary consumers, and so on. This phenomenon is due to the fact that energy is lost at each trophic level, mainly through metabolic processes and as heat.
Producers, such as green plants, form the base of the pyramid and have the largest biomass and number of individuals because they convert solar energy into organic matter through photosynthesis. Primary consumers, which are herbivores, consume the producers and thus have less energy available to them—typically around 10% of the energy received from their food source is converted into their own biomass, as 90% is lost. As a result, there are fewer primary consumers in terms of biomass and numbers compared to producers. This pattern continues up the pyramid, leading to even smaller biomass and fewer numbers among secondary consumers (carnivores that eat herbivores) and tertiary consumers (carnivores that eat other carnivores).
Considering the example provided, if producers have 1,000,000 kilocalories of energy, primary consumers would have significantly less because of the energy transferred inefficiency, typically around 10%, resulting in approximately 100,000 kilocalories of energy available at that level.