Reproductive and seedling ecology of cane (Arundinaria gigantea), a native North American bamboo

Canebrakes were an integral part of the bottomland hardwood forest ecosystem in the southeastern U.S.  They were vast, monodominant stands of the bamboo called cane (Arundinaria gigantea [Walt.] Muhl.). Canebrakes have declined by an estimated 98% since European settlement.  Virtually all efforts to restore canebrakes have used transplanted rhizomes.  Cane is believed to be semelparous, and little is known about its reproductive phase.  We sought to elucidate cane reproductive and seedling ecology.  We observed cane flowering, and performed experiments on cane seeds and seedlings with two restoration-related goals: 1) to identify and describe critical stages in cane sexual reproduction and 2) to determine the effects of post-disturbance conditions on cane reproduction.  Based on our previous studies of “adult” cane, we expected cane seedlings to perform better in previously disturbed, high light environments.  We tested germination and establishment of cane seeds and seedlings in a 2 x 2 factorial design with repeated measures.  We planted seeds into either forested or large canopy gap sites, half of which were recently burned.  During our two-year study, high among-plot variability swamped treatment effects on cane seed germination, establishment, and seedling survival with the exception that burned sites had a marginally significant (P = 0.09) negative effect.  We observed that seeds with the highest overall survival rates were those we planted into leaf-litter in partial sunlight.  Based on differential mortality between our four different censuses, we conclude that seed germination and seedling establishment are critical stages, but that once established, seedlings are robust.