How are living things connected? They are connected bye food chains because if one animal dies then the others would die or over populate then their would be to much or to less.
This is a predator it eats consumers
The second question is what happens if there are changes in an ecosystem or if one thing is removed from the food web? This is what would happen lets say the plants were removed then the plant eaters would die then after that the things that eat the plant eaters would die then there would be no more animals in that food web.
here is an other example.
Another thing for question two is if there are less plants and more deer they would eat plants then have no food but since Colorado has more plants then deer it works out perfectly. pg. 333 On pg 332 and 333 the energy pyramid, if one part died then the thing that eats it would die then plants, animals and predictors one would survive but then die or over populate.