How important are ecosystem disturbances in maintaining complexity of trophic networks, and do post disturbance plant communities provide deviation-from-neutrality topographies that determine diversity of associated trophic levels? For all forests, fire is a key disturbance that influences plant diversity and the structure of trophic networks, including diversity of interactions at multiple spatial scales. We examined the relationship between fire frequency and chemically mediated trophic interaction diversity in longleaf pine within the Gulf Coastal Plain of the Florida panhandle. Simulation models, experimental plots, and long-term monitoring data were utilized to test hypotheses about the relationships between time since fire, plant chemistry, and tri-trophic interaction diversity.
Inferences from simulated communities demonstrate potentially strong effects of both disturbance and scale on tritrophic interaction diversity, driven by changes in plant diversity, plant chemistry, and rare species. The effects of fire on network parameters in longleaf pine are also scale dependent, but stratified sampling at small scales within longleaf pine forests can be used to estimate diversity at broader scales. Finally, a great deal about plant diversity dynamics and associated upper trophic levels can be learned by examining the role of plant chemistry in affecting fire intensity, plant recolonization, and diversity of biotic interactions.