Question

visual reading tool: food webs

1. find a food chain that connects algae to the alligator. then find another food chain from the saltmeadow grass to the alligator. use two pencils of different colors to highlight the two food chains.
2. how are primary producers important to the alligators energy supply?
3. how could decomposers be added to the diagram? which parts of the food web do they affect?

food webs and disturbance changes to a food web can cause a variety of effects. these effects are hard to predict because food webs are complex. sometimes the effects of changes are minor. some animals can adjust well to changes in food webs, for example, if they eat a variety of foods. other times a change can have dramatic effects throughout a food web.
reading tool
academic words
adjust to adjust is to change slightly, often to meet a need. some animals adjust their diets when food sources change.
look at the food web above. suppose that the population of pelicans declined. how might bobcats have to respond to this change?
ecological pyramids
key question how do ecological pyramids help analyze energy flow through trophic levels?
each step in a food chain or food web is called a trophic level. primary producers make up the first trophic level. consumers occupy the other levels. ecological pyramids are models of trophic levels in a food chain or food web. the shape of the pyramid shows the relative amount of energy or matter in each level.
34 chapter 3 ecosystems
copyright © savvas learning company llc. all rights reserved.

Explanation:

1. For the first part, we trace the paths in the food - web. Algae is eaten by killifish which is eaten by raccoon which is eaten by alligator. So the food - chain is Algae→Killifish→Raccoon→Alligator. Saltmeadow grass is eaten by shrimp which is eaten by catfish which is eaten by alligator. So the food - chain is Saltmeadow Grass→Shrimp→Catfish→Alligator.
2. Primary producers like algae and saltmeadow grass are the base of the food - web. They convert solar energy into chemical energy through photosynthesis. Other organisms in the food - web, including the alligator, ultimately depend on this energy as they eat organisms that either directly or indirectly consume primary producers.
3. Decomposers can be added at the end of the food - web, breaking down dead organisms (from all levels of the food - web). They recycle nutrients back into the ecosystem, affecting all parts of the food - web by making nutrients available for primary producers again. For the pelican - bobcat situation, if pelican population declines, bobcats may have to rely more on other prey like raccoon as their food source.

Answer:

1. Algae→Killifish→Raccoon→Alligator; Saltmeadow Grass→Shrimp→Catfish→Alligator
2. Primary producers convert solar energy into chemical energy through photosynthesis, which is the base energy source for the alligator's food - web.
3. Decomposers can be added at the end, breaking down dead organisms from all levels; they affect all parts by recycling nutrients. If pelican population declines, bobcats may rely more on other prey like raccoon.