1. why do we (as scientists) bulid food webs?
Scientists need to find the balance of the food web to build it they need to know how one animal can affect the whole ecosystem. we build them to know what way is the energy going from animal to animal, we also build them to know what is the start of the food web, what is the main source of energy.
2. give an example of how one change might affect many other parts of the ecosystem.
if you remove a part of the ecosystem it collapses, for example lets say we remove a snake the snake eats mice so the mice don't have a predator any more so they over populate if the mice over populates what they eat, plants will be very low populated and mice will eventually die because they don't have what to eat any more, and what eats the snake the eagle the eagle will starve and die.
3. give an example on how one change in La Quebrada might affect the rest of the ecosystem
one change in la quebrada is in like any other ecosystem it collapses.
lets say we take out a fish out that swims in the creek bigger fishes might die because they feed of of that fish, and what does that fish eat aquatic insects and smaller fish the smaller fish and the aquatic insects over populate if that happens what the insects and the smaller fish will eat all theyr food and die.