Feedbacks between forest structure and an opportunistic fungal pathogen

Abiotic stresses, physiological dysfunction, forest stand dynamics, and primary tree attackers (native and non-native) are all recognized as important contributors to both anomalous tree mortality and background tree mortality, and thus as important influences on biogeochemical cycling and habitat for associated terrestrial organisms. Opportunistic and latent tree pathogens and insect pests have largely been left out of this discussion, probably because they are difficult to monitor and their effects sometimes more diffuse, yet they play important roles in tree mortality scenarios.

We know very little about the influence of biotic gradients, e.g., forest dynamics and forest structure, on the occurrence and effects of these opportunistic biotic enemies. To better understand the influence of an important biotic gradient—forest structure as represented by tree density and competition—on the occurrence and distribution of a typical opportunistic pathogen, we analyzed the relationship bet...