primary resources maths

Ecological efficiency is the percentage of energy transferred from one trophic level to the next. Alternatively, it is the ratio of the net productivity, i.e., the biomasS, at one trophic level to the net productivity (biomass) at the level below. Ecological efficiency varies among organisms. Usually it is 10%. This means that 90% of the energy available at onp trophic level never transfers to the next. (There are number of ratios used to express the efficiency with which organisms exploit their food resources and convert the food into biomass. Important efficiency measures for producers are —1. Photosynthetic efficiency. It is the percentage ratio between gross primary productivity and incident total solar radiation. It generally varies from 1 to 5 per cent.Photosynthetic efficiency_ Gross primary productivity ^ Incident total solar radiation2. Net production efficiency. It is the percentage ratio between net primary productivity and gross primary productivity. It is around 50%.Net production efficiency_ Net primary productivity Gross primary productivityImportant efficiency measures for consumers include —1. Assimilation efficiency. It is the percentage ratio between food energy assimilated and food energy ingested at one trophic level.Assimilation efficiency_ Food energy assimilated ^ ^^ Food energy ingested2. Ecological efficiency. It is the percentage ratio between energy in biomass production at one trophic level and energy in biomass production at previous trophic level. It is also called trophic level efficiency.Ecological efficiency = Energy in biomass production at one trophic level Energy in biomass production at previous trophic level