Success
of restoration projects requires an understanding of the direction and rate of
natural and anthropogenic change within a dynamic ecosystem, as well as
understanding the best environmental conditions a target species requires for
persistence. Yet predicting future
states for optimal restoration is especially challenging for rare species in
ecosystems that are neither spatially nor temporally constant and may be
particularly vulnerable to fragmentation. Our experimental rare plant
reintroductions of U.S.
endangered Jacquemontia reclinata
and FL endangered Lantana canescens in two South Florida ecosystems revealed both species-specific
variables and general patterns impacting restoration in urban ecotones. Associated
with J. reclinata persistence in
coastal strand was topographic position from high tide line that was correlated
with salt exposure and significantly affected plant survival after hurricanes. Beyond the species-specific factors impacting
plant persistence, both ecotone species had optimal
habitats that are spatially wedged between stochastic disturbance and predictable succession
of woody vegetation. Human activities
including road building, beach raking, and fire suppression further constrain
the spatial dynamism of ecotones and may eventually
eliminate them and their species if trends continue. We present a general
conceptual model that incorporates disturbance and succession to predict
persistence of populations in ecotones, and suggests
management components for restoring and maintaining ecotones
to preserve diverse taxa.