Plant tolerance to herbivory
Tolerance is the ability of plants to mitigate the negative fitness effects caused by herbivory. It is one of the general plant defense strategies against herbivores, the other being resistance, which is the ability of plants to prevent damage. Plant defense strategies play important roles in the survival of plants as they are fed upon by many different types of herbivores, especially insects, which may impose negative fitness effects. Damage can occur in almost any part of the plants, including the roots, stems, leaves, flowers and seeds. In response to herbivory, plants have evolved a wide variety of defense mechanisms and although relatively less studied than resistance strategies, tolerance traits play a major role in plant defense.
Ipomopsis aggregata
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material.
A deer and two fawns feeding on foliage
A sawfly larva feeding on a leaf
Tracks made by terrestrial gastropods with their radulas, scraping green algae from a surface inside a greenhouse
A fossil Viburnum lesquereuxii leaf with evidence of insect herbivory; Dakota Sandstone (Cretaceous) of Ellsworth County, Kansas. Scale bar is 10 mm.