Energy flow rates

Total energy flow is measured as the sum of all energy flows through all trophic compartments of an ecosystem (Buzhdygan et al. 2020). Flow and storage of energy is not necessarily correlated, therefore energy flows should be measured as well as standing biomass. Calculation of energy flows requires information on population density for all species, knowledge of diet/feeding behaviour, estimation of net primary productivity (Malhi et al. 2022).

Buzhdygan et al. 2020 measured energy flows across multiple trophic levels in grassland by measuring:

• Dry plant biomass in May and August – clipped aboveground biomass (0.2 x 0.5 m rectangle) and root biomass to 40 cm depth
• Aboveground invertebrate fauna sampled from May to September by pitfall trap
• Aboveground invertebrate fauna sampled by suction sampling in June and July
• Aboveground invertebrates were sorted to order and into trophic groups (herbivore, carnivore, omnivore, decomposer)
• Belowground mesofauna (5cm diameter, 5cm depth core) and macrofauna (22cm diameter, 10cm depth core) were sampled
• Body mass of each species was estimated from the mean length of males and females using allometric equations
• Microbial biomass was measured using substrate-induced respiration
• Dry mass of surface litter from a 50 x 20 cm frame
• Soil organic matter was estimated from soil carbon and bulk density
• Energy flows were represented as dry mass per area per day

See Invertebrate biomass, Mammal biomass, Vegetation biomass, Species diversity for relevant methodologies.