Non-native liana Euonymus fortunei associated with increased soil nutrients unique bacterial communities and faster decomposition rate
Bray SR; Hoyt AM; Yang Z; Arthur MA
Invasive plants have wide-ranging impacts on native systems including reducing native plant richness and altering soil chemistry microbes and nutrient cycling. Increasingly these effects are found to linger long after removal of the invader. We examined how soil chemistry bacterial communities and litter decomposition varied with cover of Euonymus fortunei an invasive evergreen liana in two central Kentucky deciduous forests. In one forest E. fortunei invaded in the late 1990s but invasion remained patchy and we paired invaded and uninvaded plots to examine the associations between E. fortunei cover and our response variables. In the second forest E. fortunei had completely invaded the forest by 2005; areas where it had been selectively removed by 2010 were paired with an adjacent invaded plot. Where E. fortunei had patchily invaded E. fortunei patches had up to 3.5× nitrogen 2.7× carbon and 1.9× more labile glomalin in soils than uninvaded plots whereas there were no differences in soil characteristics between invaded and removal plots. In the patchily invaded forest bacterial community composition varied among invaded and non-invaded plots whereas bacterial communities did not vary among invaded and removal plots. Finally E. fortunei leaf litter decomposed faster (k = 4.91 year-1) than the native liana (k = 3.77 year-1) Vitis vulpina; decomposition of both E. fortunei and V. vulpina was faster in invaded (k = 7.10 year-1) than removal plots (k = 4.77 year-1). Our findings suggest that E. fortunei invasion increases the rate of leaf litter decomposition via high-quality litter alters the decomposition environment and shifts in the soil biotic communities associated with a dense mat of wintercreeper. Land managers with limited resources should target the densest mats for the greatest restoration potential and remove wintercreeper patches before they establish dense mats.