Final answer:
More productive ecosystems tend to have longer food chains than less productive ones due to higher levels of primary production supporting more trophic levels.
Step-by-step explanation:
The correct answer to the question “_______ ecosystems will likely have longer food chains than ______ ecosystems.” is c. More productive, less productive. More productive ecosystems tend to have higher levels of primary production, which supports a larger number of trophic levels and thus, longer food chains. In simpler terms, an ecosystem with plenty of energy and resources at the base can support more layers of consumers. An example of this would be a tropical rainforest compared to a desert. The rainforest has a vast array of plants (high net primary productivity) that support a wider range of herbivores, which in turn support many levels of carnivores. Conversely, less productive ecosystems, like deserts, have fewer plants and therefore support shorter food chains. It is also important to understand the distinction between the primary producers of different food webs. For instance, detrital food webs primarily rely on decomposers as their source of energy, whereas grazing food webs depend on photosynthetic organisms like plants and algae. Despite their differences, both types of food webs are essential in supporting ecosystem biodiversity and function.