Chinese tallow seed viability, resprouting capacity, and leaf litter flammability: consequences for restoring coastal pine forests

Abstract

Chinese tallow (Triadica sebifera) is an invasive tree that threatens the health and integrity of pine flatwoods and savannas along the USA Gulf of Mexico. These open forests historically experienced frequent, low-intensity surface fires, but tallow invasion likely threatens fire potential through ecosystem transformation. Here, we sought to better understand the mechanisms tallow uses to survive and proliferate in these threatened ecosystems by exploring three components of tallow invasion: seed viability, resprouting capacity, and litter flammability. In general, tallow seed viability declined rapidly after dispersal, and seedling establishment rates were similarly low. Tallow leaf litter drastically reduced fire ignition, rate of spread, and fuel consumption, a potential mechanism that could promote further tallow invasion in the absence of fire and drive ecosystem transformation. Although tallow can vigorously resprout, tree size, canopy closure, and soil EC reduced tallow survival following top-kill and subsequent resprouting.