The source of energy in my food web is the sun. If either one of the either decomposer or producers goes extinct, the food chain would fall apart! It would first affect the primary consumer, there food would disappear. It would affect the secondary producer next, since the primary producers aren't eating food they slowly die out and then the secondary consumer's food is gone. A factor that may limit population growth in this food web is rain shortage. A possible case where an invasive species might disrupt the web would be if another worm species comes and takes over one of the two trees in the web and one of the worms actually in the web gets cut out, at least half the web would fall apart, and that could lead to many more problems including the whole biome!