Hmmm Just theoretically, yes.

When carnivores feed on herbivores, granivores and omnivores, and all these groups are equally abundant?

Dr Linas Balciauskas thank you for your contribution to the discussion

Biomass decreases with each trophic level. There is always more biomass in lower trophic levels than in higher ones. Because biomass decreases with each trophic level, there are always more autotrophs than herbivores in a healthy food web. There are more herbivores than carnivores. As the trophic level go up its biomass decreases as the number of organisms decreases. So from the above discussion, we can say that in a natural ecosystem, the biomass of herbivore will be greater than the biomass of carnivore. Since only about 10 percent of energy available at one trophic level transfers to the next, an ecosystem cannot sustain a greater biomass of carnivores than herbivores. Terrestrial biomass generally decreases markedly at each higher trophic level. As of terrestrial producers are grasses, trees and shrubs. These have a much higher biomass than the animals that consume them, such as deer, zebras and insects. In most ecosystems, the biomass of carnivores is greater than the biomass of producer and dead organic matter. Primary producers form the base of all food chains. In all ecosystems, the biomass of primary producers is greater than the biomass of herbivores. Because energy is lost in the transfer from one level to the next, there is successively less total energy as you move up trophic levels. In general, we would expect that higher trophic levels would have less total biomass than those below, because less energy is available to them. Energy is lost with each trophic level, so it takes more of the sun's energy to ultimately produce a pound of meat to feed a carnivore than it does to produce a pound of plants to feed an herbivore. 10% of energy is passed from one trophic level to the next. Carnivores have higher consumption efficiency than herbivores, since more of their food source is consumed than enters into the detrital food chain. As the trophic level go up its biomass decreases as the number of organisms decreases. So from the above discussion, we can say that in a natural ecosystem, the biomass of herbivore will be greater than the biomass of carnivore.

In a closed system, no. But in an open system, where seasonal migration plays a role on what you find at a particular point in time, the carnivores could possibly appear to contribute more biomass than do the herbivores.

Dr A R Breisch thank you for your contribution to the discussion

No, there must be more herbivores because the herbivores provide food for the primary consumers. If the carnivores outnumbered the herbivores, the herbivores would die out and the carnivores would begin to starve. In most ecosystems, the biomass of carnivores is greater than the biomass of producers and dead organic matter. Primary producers form the base of all food chains. In all ecosystems, the biomass of primary producers is greater than the biomass of herbivores. Herbivores assimilate between 15 and 80 per cent of the plant material they ingest, depending on their physiology and the part of the plant that they eat. Carnivores generally have higher assimilation efficiencies than herbivores, often between 60 and 90 per cent, because their food is more easily digested. As the trophic level go up its biomass decreases as the number of organisms decreases. So from the above discussion, we can say that in a natural ecosystem, the biomass of herbivore will be greater than the biomass of carnivore. Biomass decreases with each trophic level. There is always more biomass in lower trophic levels than in higher ones. Because biomass decreases with each trophic level, there are always more autotrophs than herbivores in a healthy food web. There are more herbivores than carnivores. Hence, there can never be more carnivores than herbivores in an ecosystem, by mass, as too much energy is lost at each trophic level.With less energy at higher trophic levels, there are usually fewer organisms as well. Organisms tend to be larger in size at higher trophic levels, but their smaller numbers result in less biomass. When looking at biomass or energy pyramids, only about 10% of the energy/biomass is conserved as you move up a trophic level. Since herbivores are one trophic level above producers, the herbivore biomass will be about 10% of the producer biomass. Biomass decreases with each trophic level. There is always more biomass in lower trophic levels than in higher ones. Because biomass decreases with each trophic level, there are always more autotrophs than herbivores in a healthy food web. There are more herbivores than carnivores. This will create an imbalance in the food chain resulting in the reduction in population of herbivores as carnivores would feed on them and increasing the population of producers as there will be less herbivore to feed on plants. Energy is lost with each trophic level, so it takes more of the sun's energy to ultimately produce a pound of meat to feed a carnivore than it does to produce a pound of plants to feed an herbivore. 10% of energy is passed from one trophic level to the next. For each trophic level, only about 10 percent of energy passes from one level to the next. This is called the 10 percent rule. Because of this rule, herbivores only absorb around 10 percent of the energy stored by the plants they eat. Not all herbivores eat the same, however.Carnivores have food that runs away, so they have to be smaller and more energy efficient. This is broadly speaking: They have to be able to perform more effective actions-per-calorie than herbies, who can oftentimes just lazy around. Carnies rely on weapons and agility and strategy to consistently murder and eat prey. Energy decreases as it moves up trophic levels because energy is lost as metabolic heat when the organisms from one trophic level are consumed by organisms from the next level. When food energy is moved from farmers to herbivores to carnivores, only 10 percentages of the energy is transferred from one trophic stage to another trophic level. The right answer, therefore, is 'Herbivores have higher energy transfer performance than carnivores.

Unusual, but possible in communities where the herbivores have a very high turnover. Productivity is more important than biomass and it must be greater in the herbivorr population.

Dr David Robertson thank you for your contribution to the discussion

Energy is lost with each trophic level, so it takes more of the sun's energy to ultimately produce a pound of meat to feed a carnivore than it does to produce a pound of plants to feed an herbivore. 10% of energy is passed from one trophic level to the next. Carnivores have food that runs away, so they have to be smaller and more energy efficient. This is broadly speaking: They have to be able to perform more effective actions-per-calorie than herbier, who can oftentimes just lazy around. Carnies rely on weapons and agility and strategy to consistently murder and eat prey. Consumption Efficiency is the ratio Intake at level 2 to the Production at level 1. CE = C2/P1. This varies from very low in herbivores (1-5%) to higher in carnivores (up to 30%).Plants do not need to move from one place to another. Movements in a plant are usually at the cellular level and hence a far less amount of energy is required by plants. Animals, on the other hand, need to move from one place to another; in search of food. So, the energy need of animals is pretty higher than of plants. When food energy is moved from farmers to herbivores to carnivores, only 10 percentages of the energy is transferred from one trophic stage to another trophic level. The right answer, therefore, is 'Herbivores have higher energy transfer performance than carnivores. As the trophic level go up its biomass decreases as the number of organisms decreases. So from the above discussion, we can say that in a natural ecosystem, the biomass of herbivore will be greater than the biomass of carnivore. Hence, there can never be more carnivores than herbivores in an ecosystem, by mass, as too much energy is lost at each trophic level.In a typical ecological pyramid, the biomass of carnivores is less than the biomass of herbivores. This is because energy is lost at each trophic level as it is transferred from one organism to another. Biomass shrinks with each trophic level. That is because between 80% and 90% of an organism's energy, or biomass, is lost as heat or waste. A predator consumes only the remaining biomass.