User:Tuj54739/sandbox

"The efficiency of energy transfer through food chains [food chain efficiency (FCE)] is an important ecosystem function. It has been hypothesized that FCE across multiple trophic levels is constrained by the efficiency at which herbivores use plant energy, which depends on plant nutritional quality. Furthermore, the number of trophic levels may also constrain FCE, because herbivores are less efficient in using plant production when they are constrained by carnivores."

from https://www-pnas-org.libproxy.temple.edu/content/105/47/18408.abstract

The amount of energy lowing to top trophic levels depends on primary production and the efficiency at which it is converted to production at each trophic level. In aquatic systems, algal production is often limited by light and nutrients, and the nutritional quality of algae depends on the relative balance of these two resources. In this study, we used a mesocosm experiment to examine how light and nutrient variation affected food chain efficiency (FCE, defined as the proportion of primary production converted to top trophic level production), using a food web with benthic and pelagic food chains. We also related variation in benthic and pelagic efficiencies to the nutritional quality of primary producers, i.e. carbon:nitrogen:phosphorus stoichiometry. As predicted, pelagic and benthic FCEs were highest under low light/high nutrient conditions, the treatment with the best algal food quality, i.e. the lowest C:nutrient ratios. Pelagic FCE and pelagic herbivore efficiency (HEP) were more responsive than benthic FCE to variation in light and nutrients. Furthermore, pelagic FCE and HEP were highly correlated with algal C:P, suggesting 'carryover effects' of algal food quality on carnivores (larval fish) via effects on herbivore (zooplankton) quality. Benthic (tadpole) production was primarily explained by primary production rate, suggesting food quantity rather than quality drives their production. However, benthic FCE was also highest at low light/high nutrients and was significantly correlated with food quality. The stronger effect of food quality in mediating pelagic compared to benthic efficiencies, is consistent with differences in the stoichiometric mismatches between algae and consumers. Pelagic FCE and HEP were more likely to be P-limited, whereas benthic FCE was more likely N-limited. This study is the first to examine both pelagic and benthic FCE within the same system, and highlights the importance of differential consumer needs in determining how food quality affects energy transfer efficiency.

https://onlinelibrary-wiley-com.libproxy.temple.edu/doi/full/10.1111/oik.02106

food-chain efficiency The ratio between the energy value (the nutritional value, discounting indigestible parts such as hair or feathers) of prey consumed by a predator and the energy value of the food eaten by that prey. Maximum food-chain efficiency (gross ecological efficiency) occurs when the yield of prey to the predator is such that the surviving prey just consume all the available food: this implies that the food of the prey is being exploited to the best advantage by the predator.

https://www.encyclopedia.com/science-and-technology/biology-and-genetics/environmental-studies/food-chain

10% rule source https://www.ck12.org/biology/food-chain/lesson/Food-Chains-and-Food-Webs-Advanced-BIO-ADV/

"Energy consumption in the various stages of the food chain, provides a reasonable indicator for the environmental impact in the production of food."

from https://www-jstor-org.libproxy.temple.edu/stable/4315006?sid=primo&seq=1#metadata_info_tab_contents

My Stuff

In food chains, one important aspect is the transfer of energy flowing throughout the organisms. Energy decreases as trophic level increases, with the Primary Producers having the most. This concept is called the 10% rule. Because of this rule, there are usually no more than five tropic levels in a food chain. The excess energy passed is used for the metabolic process. Humans are able to receive more energy by going back a level in the chain and consuming the food before. A prime example is getting more energy from consuming a salad, rather than consuming the animal that ate the lettuce.

Food chain efficiency is based upon the energy first consumed by the primary producers. It is a subject often experimented with when determining the quality of the food eaten.