Wednesday, August 14, 2019: 1:30 PM-5:00 PM
M104, Kentucky International Convention Center
Co-organizer:
Monica Turner
The frequency, size, and severity of stand-replacing fires (which kill trees and initiate secondary succession) are increasing worldwide. Large, high-severity fires have burned recently in the western conterminous US, western Canada, Alaska, Australia, Portugal, and Greece. As rates of change in environmental drivers continue to accelerate, there is high uncertainty about successional trajectories following stand-replacing fire. The fate of obligate seeders (e.g., conifer trees) is especially unclear, and understanding patterns and controls on seed dispersal is fundamental to projecting the composition and structure of post-fire forests. Dispersal from ex situ sources is required for such taxa, but dispersal success may change along with fire regimes and climate. Although dispersal has been well studied within ecology, many questions remain about how dispersal plays out in recently burned forests given changing fire regimes in real-world burned landscapes. This session will focus on stand-replacing fires in forests where the role of ex situ dispersal will be most pronounced in determining postfire stand trajectories. Speakers will consider how dispersal is affected by increased fire frequency, size, and severity, and how climate warming may influence the timing, abundance, arrangement, delivery vector, and ultimately establishment and survivorship of dispersing propagules. Multiple dimensions of dispersal will be covered, including propagule sources (e.g., seed supply); environmental context (topography, patch size, distance to seed source); surface roughness within burned area (e.g., density and size of fire-killed snags); and interactions with other organisms (e.g., seed dispersers or predators). Questions will include: How are animal behaviors (dispersal and predation) sensitive to fire regime change? How is climate change altering seed supply? How much area in recent fires is beyond known dispersal distances? If young forests reburn before they recover, how do seed supply and release height influence dispersal success? How do topographic context and the density and size of postfire snags influence dispersal distance? Are interspecific interactions likely to enhance or reduce seed dispersal? This session will emphasize dispersal mechanisms given novel conditions and identify pressing questions that remain to be answered about dispersal into postfire landscapes.
1:30 PM
Cancelled
OOS 17-1