Ayres Abstracts
| María J. Lombardero, Matthew P. Ayres, Peter L. Lorio, Jr., and Jonathan J. Ruel. Environmental effects on constitutive and inducible resin defenses of Pinus taeda. Ecology Letters 3:329-339. Full text in pdf. |
| The ecological literature abounds with studies of environmental effects on plant anti-herbivore defenses. While various models have been proposed (e.g., plant stress, optimal allocation, growth-differentiation balance), each has met with mixed empirical support. One possible explanation for the mixed results is that constitutive and induced defenses are differentially affected by environmental conditions. In this study, constitutive oleoresin flow from Pinus tadea was least during periods of rapid tree growth and most when drought conditions limited growth; this is as expected if constitutive secondary metabolism is a function of the carbohydrate pool size after growth has been maximized. Induced increases in resin flow, however, were greatest in the fastest growing trees after the period of greatest growth. Apparently, resin production only becomes an allocation priority after wounding. Understanding environmental effects on plant anti-herbivore defenses requires physiological and evolutionary models that account for the differences between constitutive and induced secondary metabolism. |
| Pine, Pinus, plant defense, induced defense, bark beetles, Scolytidae, environmental effects, growth-differentiation balance |