Effects of elevated tropospheric ozone and fluctuating moisture supply on loblolly pine seedlings inoculated with root infecting ophiostomatoid fungi

Abstract

Southern Pine Decline is a cause of premature mortality of Pinus species in the Southeastern United States. While the pathogenicity of ophiostomatoid fungi, associated with declining Pinus species, has been observed both in the laboratory and the field the driving mechanisms for success of fungal infection, as well as the bark-beetle vectors is less understood. The goal of this research is to provide insight into the role of future climatic conditions, specifically elevated tropospheric ozone and altered precipitation patterns, in the progression of Southern Pine Decline on loblolly pine (Pinus taeda L.). Two key questions were addressed: (1) will predicted concentrations of tropospheric ozone affect loblolly pine vigor and increase susceptibility to fungi associated with Southern Pine Decline?; and (2) will predicted precipitation patterns affect loblolly pine vigor and increase susceptibility to fungi associated with Southern Pine Decline? Our results indicate seedlings selected for susceptibility to root infecting ophiostomatoid fungi were more sensitive to elevated ozone than tolerant seedlings, however, neither ozone nor fluctuating moisture supply resulted in seedlings to becoming more susceptible to root infecting ophiostomatoid fungi.