Ecology Lecture Test (2)e

eating plants, mostly insects and mammals are herbivores

• 1]grazers-eat herbaceous plants
• 2]browsers-eat herbaceous "parts" of woody plants

preventative and responsive

• thorns and spines
• stinging hairs-nettle-has HCL on tips of hairs.
• Chemicals -such as tannins that make plant tissues unpalatable or hard to digest (example- toxic alkaloids)

overcompensation-grazers may eat the apical meristem which would have produced a seed head:compensate by growing 4 lateral meristems and actually increasing fitness.

• 1]obtain food source without competitors
• 2]use the plants poison as protection for the herbivore. example monarch butterfly
• 3]can use the defensive chemical as an indicator of food supply

• overgrazing results in fields of species with herbivore defenses because others are selected against.
• studies of exclosures (herbivores are excluded)... deer may vrowse new groth thus affect regeneration species composition.

fruit eating usually birds, mammals, insects

animals gets food(fruit), voids seeds elsewhere helping dispersal of plants

color vision

removes potential plants from the population

• Maybe because of climate(good year), it's able to store energy for burst.
• Or maybe it satiates the seed predator before all seeds are gone in a good year.

• The plants could alternate their years of seed production. Large one year, small the next. This would prevent seed predators from K-selecting.
• Or... they could synchronize their seed production with other trees.