POST-FIRE RESPONSE OF BRYOPHYTES IN ASSOCIATION WITH UNDERSTORY VASCULAR PLANTS IN THE LOST PINES ECOSYSTEM OF CENTRAL TEXAS

Abstract

Bryophytes, which are usually early-responders to disturbance, have generally not been included in post-fire vascular plant research and may be an important element in the fire-recovery process. This study expands the work of past studies of forest succession after fire by combining vascular and non-vascular community fire-response interactions in a comprehensive evaluation of understory response to the Bastrop Fires of 2011. Approximately two years after the fire, I quantified herbaceous and non-vascular plant cover in both heavily burned and unburned riparian and upland areas in two adjacent watersheds of the unique Bastrop Lost Pines Ecosystem to identify recognizable post-fire plant assemblage patterns. I also measured soil moisture and estimated ground cover percentages of litter, bare ground and rock. Results demonstrate clear differentiation in species presence. Vascular plant species diversity and abundance was higher in burned areas while bryophyte presence in burned areas was primarily restricted to a limited number of early disturbance species. In unburned areas, bryophyte diversity was high while vascular plant diversity and abundance was low. Burned areas had low bryophyte diversity but were dominated by both vascular and non-vascular species commonly associated with disturbance. A significant finding is that soil moisture was higher in burned areas than unburned areas. Litter cover was not found to inhibit groundcover species regeneration, however litter composition and thickness may have an influence. Results of this study offer inferences into interactions between bryophytes and vascular plants and the role these interactions play in ecosystem recovery processes.