Experimental evidence for indirect facilitation among invasive plants. (3rd December 2013)

• Record Type: Journal Article
• Authors: Flory, S. Luke; Bauer, Jonathan T.; Buckley, Yvonne
• Is Part Of: Journal of ecology. Volume 102:Number 1(2014:Jan.)
• Page Start: 12
• Page End: 18
• Publication Date: 2013-12-03
• Subjects: Plant ecology -- Periodicals; 577.05
• DOI: 10.1111/1365-2745.12186
• Languages: English
• ISSNs: 0022-0477

Abstract

<abstract abstract-type="main" id="jec12186-abs-0001"> <title>Summary</title> <p> <list id="jec12186-list-0001" list-type="order"> <list-item> <p>Facilitation among species may promote non‐native plant invasions through alteration of environmental conditions, enemies or mutualists. However, the role of non‐trophic indirect facilitation in invasions has rarely been examined.</p> </list-item> <list-item> <p>We used a long‐term field experiment to test for indirect facilitation by invasions of <italic>Microstegium vimineum</italic> (stiltgrass) on a secondary invasion of <italic>Alliaria petiolata</italic> (garlic mustard) by introducing <italic>Alliaria</italic> seed into replicated plots previously invaded experimentally by <italic>Microstegium</italic>.</p> </list-item> <list-item> <p> <italic>Alliaria</italic> more readily colonized control plots without <italic>Microstegium</italic> but produced almost seven times more biomass and nearly four times as many siliques per plant in <italic>Microstegium‐</italic>invaded plots. Improved performance of <italic>Alliaria</italic> in <italic>Microstegium‐</italic>invaded plots compared to control plots overwhelmed differences in total number of plants such that, on average, invaded plots contained 327% greater total <italic>Alliaria</italic> biomass and 234% more total siliques compared to control plots.</p> </list-item> <list-item> <p>The facilitation of <italic>Alliaria</italic> in <italic>Microstegium‐</italic>invaded plots was associated with an 85% reduction in the biomass of resident species at the peak of the growing season and significantly greater light availability in <italic>Microstegium‐</italic>invaded than control plots early in the growing season.</p> </list-item> <list-item> <p> <italic>Synthesis</italic>. Our results demonstrate that an initial plant invasion associated with suppression of resident species and increased resource availability can facilitate a secondary plant invasion. Such positive interactions among species with similar habitat requirements, but offset phenologies, may exacerbate invasions and their impacts on native ecosystems.</p> </list-item> </list> </p> </abstract>