Patrones en las defensas de las plantas: ? Porque los herbivoros prefrieren ciertas especies?

Patterns of heitmory and plant defenses arc presented lor 47 tree species studied on Barro Colorado Island, Panama. Species growing In comparable microhabitats differ in the rates of herbivore damage by 4 orderi of magnitude. Over 70%QT these between-specles differences in herbivory can be explained by defenses measured in mature leaves. Species with little herbivore damage had tough, fibrous leaves with low nitrogen and water contents. Measures of phenolic compounds were not significantly correlated with herbivory. Since species appeal to be protected from herbivores in proportion to their investment tn defenses. 1 ask why species differ in the amounts and type of defense. Fust It is hypothesized that the optimal amount of defense is determined by the intrinsic growth rate of a species: plants with low intrinsic growth rates should have a Urge investment in defenses and a high resistance to herbivores. Secondly, it is hypothesised that type of defense is directly related to the average leaf lifetime of a specie! Evidence from lowland forests m Central and South America are in agreement with these ideas.