University:
York University
Course:
SC/BIOL 2021 | Cell Biology
Academic year:

2019
Views:

436

Pages:

2
Author:

Nick T.

Secondary Production, Chapter 4. 2/4/19 Production by heterotropns. * production of biomass by consuming other organisms. herbivores and carnivores Units g, energy/area, volume/time. →Secondary production allows ecologists to understa- nd carrying capacity. "Too many cows w/ not enough grass. La Production usually devoted to growing somatic (tissue) and gonads (eggs + sperm) production. Amount of Production varies with Young ones grow more rapidly age: (P/B) Production to biomass ratio is used to under- stand the importance of an organism in a food web. usually, Small organisms have high P/B. Measuring 2nd Production Need to understand growth rate and mortality rate. Cohort individuals born around the same time. Lo Based method • Track Death Loss of biomass due to mortality • Track Growth: Production of biomass growth Both methods should have the same growth rate. * Incremental Summation Method # of samples Nt Aug. body mass: Mt t=1, 2, 3, 4. Production (N + N₂)/2* (M2-M) Elimination = (M + M₂)/2+(N-N₂) *Allometric Method: Estimation of production of whole community can be very useful. →Method depends on the correlation between (P/B). • Determine P/B ratio of all species in Sample. (biomass-B) Bx P/B P → Benthic production also varies by depth and Temp. Allometric is used to estimate production OF whole community. Drivers of 2nd Production. Temp Depth "There's always bigger Fish P.P. Trophic level. Efficiency Ecosystem + Organism. If blue whales ate Fish that ate krill, they'd have to eat more fish Since there's a trophic level in there.