Multi-Level Interactions Arising from Herbivory: A Simulation Analysis of Deciduous Forests Utilizing Foret.

Area of Science:

• Ecology
• Forestry
• Ecosystem Dynamics

Background:

• Temperate forest ecosystems face herbivory pressure.
• Understanding long-term herbivory effects is crucial for forest management.
• Two dominant Southeastern U.S. tree species, white oak and tulip poplar, were selected.

Purpose of the Study:

• To examine the potential effects of herbivory on temperate forest ecosystems.
• To evaluate herbivory impacts across individual, phenotypic, interspecific, and community levels.
• To compare fixed versus facultative defense strategies in response to herbivore stress.

Main Methods:

• Utilized the FORET forest succession simulation model over a 500-year period.
• Stochastically varied annual herbivore incidence and energy allocation to growth vs. defense.
• Simulated two tree phenotypes: one with fixed defense allocation, another with facultative defense.

Main Results:

• White oak showed higher sensitivity to interspecific interactions, while tulip poplar was more sensitive to intraspecific interactions.
• Facultative defense strategies, which adjusted growth and defense tactics, were more influential on productivity than fixed strategies.
• Long-term herbivore stress significantly influences community dynamics, with interactions between herbivory and climate needing further investigation.

Conclusions:

• Forest ecosystem responses to herbivory depend on species-specific sensitivities and adaptive strategies.
• The ability to facultatively allocate resources to defense is a key factor in maintaining forest productivity under herbivore pressure.
• Future long-term studies should integrate herbivore and climate interactions for a comprehensive understanding of forest dynamics.