A forest ecosystem can support a limited number of bears. This is because available energy is lost from one trophic level to the next. (flies, trout, then bears)
<span>Not only does topsoil erosion lead to loss of soil fertility, it can also cause water pollution. Water pollution is a result of the downpour of the fertilizer chemicals to the water contaminating the water in terms of sulfur content, halogen content, and other possible metals.</span>
Fossil molds and casts preserve a three-dimensional impression of remains buried in sediment. Cast fossils occur when mold fossils are filled in with minerals that harden over time, creating a fossilized replica of the original organism. Mold fossil-A fossil formed when an animal, plant, or other organism dies and is covered by sediment, its flesh decays and bones deteriorate due to chemical reactions, and a cavity remains below the ground surface.
