C. Edward Proffitt
Steven E. Travis
J. Egerova
2003
<p><span>Coastal wetland loss is a major environmental issue in the Mississippi Delta region of the southern United States, where grasses such as </span><i>Spartina alterniflora</i><span> may play a critical role both as early colonizers on created sites and as facilitators of other marsh grasses and shrubs, particularly at high intertidal elevations. We explored the potential role of </span><i>S. alterniflora</i><span> as a facilitator of the colonization and growth of the shrub </span><i>Baccharis halimifolia</i><span> at two created wetlands in southwestern Louisiana through a combination of plant surveys and experimentation. Surveys for the presence of </span><i>B. halimifolia</i><span> inside and outside the bare centers of </span><i>S. alterniflora</i><span> clones that had begun to senesce inwardly were conducted at a 4-yr-old site originally created in 1993. The percent of clones containing </span><i>B. halimifolia</i><span> and the number of individual </span><i>B. halimifolia</i><span> plants per clone increased with increasing </span><i>S. alterniflora</i><span> clone size and decreased with increasing distance from an adjacent containment berm. Two experiments conducted at a second 4-yr-old site that was originally created in 1996 were designed to assess seed capture and growth of seedlings of </span><i>B. halimifolia</i><span> inside </span><i>S. alterniflora</i><span> clones. These experiments revealed that while significantly fewer seeds settle inside clones, those seedlings that grow in such areas gain a clear advantage in terms of both survival and rate of growth, which helps to explain the results of the initial survey and testifies to the role of </span><i>S. alterniflora</i><span> as a nurse plant in newly-created high intertidal marshes.</span></p>
application/pdf
10.1672/4-20
en
Springer
Facilitation of survival and growth of Baccharis halimifolia L. by Spartina alterniflora Loisel. In a created Louisiana salt marsh
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