Community level engineering effects of Triglochin maritima (seaside arrowgrass) in a salt marsh in northern New England, USA

• Published in: The Journal of ecology Vol. 92; no. 4; pp. 589 - 597
• Main Authors: Fogel, B.N, Crain, C.M, Bertness, M.D
• Format: Journal Article
• Language: English
• Published: Oxford, UK British Ecological Society 01.08.2004; Blackwell Science Ltd; Blackwell Science; Blackwell Publishing Ltd
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Artificial wetlands; Biological and medical sciences; Brackish; Community Assembly; Ecological engineering; Ecological zones; Ecology; ecosystem engineering; Ecosystems; Environmental impact; facilitation; flooded conditions; Fundamental and applied biological sciences. Psychology; General aspects; greenhouse experimentation; habitat modification; habitats; Human ecology; Marine; Marine ecology; Mud; physical stress; plant communities; Plant ecology; plant stress; Plants; reductive potential; root growth; salt marsh ecology; salt marsh plants; salt marshes; seed dispersal; seeds; soil salinity; species diversity; surface water level; Synecology; Triglochin maritima; waterlogging; Wetland ecology; United States; North America; America; New England states; Brackish water environment; Salt marsh; Monocotyledones; Triglochin maritima; Angiospermae; Juncaginaceae; Spermatophyta; Community
• ISSN: 0022-0477; 1365-2745
• DOI: 10.1111/j.0022-0477.2004.00903.x

1. Ecosystem engineers can influence other organisms indirectly by modifying their physical habitat and are common in all natural communities. We examined the mechanisms underlying the effects of engineering by seaside arrowgrass, Triglochin maritima (Juncaginaceae), in a northern New England forb panne. Within these waterlogged areas, T. maritima creates elevated rings that support high plant cover compared with nearly bare adjacent substrate. 2. The influence on vegetation patterns of ring height and facilitation by neighbouring vegetation were examined in the field with T. maritima rings (elevation + vegetation), experimentally lowered rings (vegetation only), artificially raised mud (elevation only) and bare mud. Transplants of four perennial species, along with naturally occurring seedlings, were followed to assess plant performance. We also monitored edaphic conditions, seed dispersal and plant cover in experimental plots over two growing seasons. 3. All transplanted species showed increased success in raised treatments (in which the substrate showed an increase in reductive potential and a decrease in waterlogging) while there was no significant relationship to the presence of neighbouring vegetation. Seed supply, however, was enhanced by both ring elevation and the presence of neighbours. 4. A glasshouse experiment to test the response of T. maritima to waterlogging showed an increased production of shallow roots, suggesting a mechanism that may contribute to ring formation. 5. Our results indicate that community consequences of engineering by T. maritima are predominantly due to raised ring formation that ameliorates waterlogging stress and thereby promotes increased species diversity. Consequently, T. maritima may be an important target species for conservation, as sea level rise is expected to increase waterlogging stress in marshes.