Low tolerance to simulated herbivory in Hawaiian seedlings despite induced changes in photosynthesis and biomass allocation.

摘要: BACKGROUND AND AIMS Seedling herbivory is an important factor underlying plant community diversity and structure. While considerable research has characterized seedling defence in terms of resistance, very little known about tolerance herbivory. Moreover, few studies have attempted to identify mechanisms across a range species. METHODS simulated was tested diverse pool ten Hawaiian species, including several lobeliad species (family Campanulaceae), grass, herb common woody trees shrubs. Tolerance measured as the relative survival growth damaged plants receiving 50 % defoliation with simultaneous jasmonic acid application compared undamaged control plants, assessed 1·5 5 weeks after damage. Putative were measured, photosynthetic parameters, light use efficiency, biomass allocation reflecting priorities, analysed using species-level regression analyses on indices. KEY RESULTS No fully tolerated at either harvest date, significantly reduced shoot well root biomass. Lobeliad had particularly low tolerance. Species varied considerably size, parameters their constitutive (pre-damage) induced (post-damage) parameters. However, only levels non-photochemical quenching related tolerance, indicating that more efficient (and less heat dissipation) are better tolerating damage than high dissipation. CONCLUSIONS Native expressed conservative level Root decreased response damage, but this not associated greater suggesting may be due constraints following adaptive plasticity. Conservation native island threatened by invasive herbivores should prioritize protection for seedlings improved regeneration persistence disturbed habitats.