Final answer:
The statement that energy dissipates as heat and is not fully recycled in an ecosystem is true; approximately 10% of energy is passed on to the next trophic level, with the remainder lost during metabolic processes.
Step-by-step explanation:
The assertion that energy is stored at each link in a food web, but some energy used dissipates as heat into the community and is not recycled, is indeed true. In an ecosystem, energy is transferred through food chains or food webs from lower to higher trophic levels, but not all of this energy is efficiently passed on.
In each transfer, only about 10 percent of the energy is typically stored in the next step of the food chain, with the remaining 90 percent being utilized for metabolism, growth, and repair, which leads to energy being lost as heat. This is an essential reason why energy pyramids illustrate a decrease in energy at each step and why ecosystems generally have a limited number of trophic levels, commonly not more than four.
The concept of food webs, which unlike food chains, is non-linear, provides a more detailed and holistic view of energy transfer and consumption within an ecosystem. Energy loss through respiration and as heat also defines the net primary productivity, which is the total energy available to the primary consumers.