Lecture 10: Trophic relationships in communities
Detritivores eat dead organic matter.
The world is green because carnivores keep herbivore pop down so they don’t
limit plant growth. Trophic cascades, one level affecting the next and so on. Indirect
effects can be as strong as direct effects.
Monarch butterfly larva = specialist at eating milkweed. Cuts leaf midrib to reduce sap
pressure before eating. They don’t detoxify the poison, they put it in their cuticle, making
Hard for herbivores to digest plants. Eating animals is easy to digest since it’s animal
material like you.
Graminoids (grasses, sedges) have meristem below the plant so can still grow
right back even when eaten e.g. lawn mowing. Also are defended by mechanical defense
(silica in them since it’s abrasive/like eating sandpaper).
Forbs = not grasses. They’re broad-leafed and have chemical defenses using
Cattle = ruminants = highly developed mammals to break down leaf material. Cow eats
brings back to mouth, grind and swallow again. Horses not the same, grind in mouth and
lets microbial digestion in cecum (appendix in humans).
Break/chew food for high SA for digestive enzymes.
Veratrum (corn lily) makes cyclopami