never mind it was producers
@philcua Yep. For future references, around 90% of energy is lost at each trophic interaction. This is in the form of metabolic heat for the most part. So, from grass to say cow, 90% of the possible energy in the plant that the cow eats is lost.
I would say decomposers. They gain most of the energy because a producer (sun, for example) will give energy to consumers such as a grasshopper. A bird could eat the grasshopper, a snake eats the bird, and a fox eats the snake. The fox dies and the decomposers consume the fox, gaining the energy from the fox's consumptions. Hopefully this makes sense :p
@tarantulagirl98, No, all energy in the system comes from whatever source a autotroph is using, and most of that is from photosynthesis. Things that are not autotrophs cannot get energy from anything but other organisms, whether that is a autotroph or another heterotroph. This means that the only energy that is put into the system that is not from another organism is from the sun and a couple other things that are not important for our discussion. That is it, that is the max. No reaction is 100% efficient and the processes in cells and organisms are no different. Think of it this way: If we make a new currency and call it Bio-dollars and print a total of 100 Bio-dollars and no more or less. Say photosynthesis of our made-up autotrophs is often around 30% efficient, so of the 100 Bio-dollars they are exposed to they capture 33.33. Now, that piece of autotroph is consumed, and 90% of the energy is lost through various means, but primarily through heat. So, our primary consumer has managed to capture 3.33 Bio-dollars, add another consumer and it drops to 0.33. Now say that last consumer dies and is eaten by a decomposer. Only 0.03 Bio-dollars are left in our system. Does that help? Also, think of all the waste our bodies produce from food, not to mention we are constantly expending energy to maintain a certain temperature. If you look at top-tier predators, you'll be shocked on how much and how often they need to eat. Lions need to eat an average of 8 to 9 kg (1 kg = 2.2 lbs). https://www.cbs.umn.edu/research/labs/lionresearch/faq In the Fall, when brown bears are trying to pack on as much weight as possible, they may eat up to 90 kg of food a day. http://animals.nationalgeographic.com/animals/mammals/brown-bear/ What do plants need? Not much. The can get carbon from CO2 in the air and use energy from light to create glucose molecules. These molecules are used for energy and building new plant cells. Many other nutrients that are needed enter the cell due to osmosis and very little or even no energy is expended during this process.
Oh, that is per day for the lions and bears.