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Native recolonization following control of invasive Ruellia simplex in a cypress floodplain forest
Author(s) -
Reinhardt Adams Carrie,
Wiese Christine,
Lee Leah C.
Publication year - 2015
Publication title -
applied vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.096
H-Index - 64
eISSN - 1654-109X
pISSN - 1402-2001
DOI - 10.1111/avsc.12187
Subject(s) - propagule , taxodium , perennial plant , introduced species , biology , invasive species , floodplain , plant community , vegetation (pathology) , native plant , agronomy , ecology , nutrient , species richness , medicine , pathology
Question What factors constrain establishment of native plant species after removal of a dominant invasive plant species? Specifically, we tested whether missing soil seed banks, elevated soil nutrients and invasion by other non‐native species explained the lack of recovery of native species. Location Bald‐cypress‐dominated ( Taxodium distichum ) floodplain forest. Paynes Prairie Preserve State Park, Alachua County, FL, US. Methods We assayed the plant composition of the soil seed bank to a depth of 5 cm and analysed soil nutrient levels in a floodplain forest invaded by Ruellia simplex . We measured percentage cover of vegetation 1 yr after herbicide application to control R. simplex . Results Many native species (largely perennials) and very few R. simplex emerged from the seed bank assay. Herbicide application reduced cover of R. simplex , but 1 yr post‐herbicide vegetation cover lacked native perennials, and instead was largely comprised of novel invaders and early successional (annual) natives. Across locations, levels of some soil nutrients (P, Mg) and pH were higher in R. simplex ‐invaded plots than in uninvaded plots. Similarly, R. simplex ‐invaded plots were significantly correlated with soil K and Ca levels at some locations but not others. Conclusion It seems most probable that watershed‐level factors, including soil nutrients and pH, as well as changes in hydrology are interacting with site‐level factors, such as remnant invasive non‐ Ruellia simplex plant propagules and vegetative propagules of R. simplex to constrain long‐term native plant community establishment. Propagule limitation from the soil seed bank is not likely a barrier to native plant recolonization in floodplain forests after removal of invasive R. simplex , as diversity and density of native species emerged from the soil seed bank was high and density of R. simplex in the soil seed bank was extremely low. It does seem likely that soil properties are influencing the plant community. A critical next step will be identification of native species tolerant of altered soil and water conditions if restoration efforts are to succeed. However, further research on all spatial levels is needed to effectively restore degraded floodplain forests, especially at the broader watershed level.