title: Sediment type affects competition between a native and an exotic species in coastal China.
abstract: Different types of sediments in salt marsh have different physical and chemical characters. Thus sediment type plays a role in plant competition and growth in salt marsh ecosystems. Spartina anglica populations have been increasingly confined to upper elevation gradients of clay, and the niche sediment has changed. Because the niches of S. anglica and the native species Scirpus triqueter overlap, we conducted a greenhouse experiment to test the hypothesis that plant competition has changed under different types of sediments. Biomass and asexual reproduction were analyzed, and inter- and intraspecific competition was measured by log response ratio for the two species in both monoculture and combination under three sediment types (sand, clay and mixture of sand and clay). For S. anglica, biomass, ramet number and rhizome length in combination declined significantly compared with those in monoculture, and the intensity of interspecific competition was significantly higher than that of intraspecific competition under all sediments. For S. triqueter, the intensities of intra- and interspecific competition were not significantly different. This indicates that S. triqueter exerts an asymmetric competitive advantage over S. anglica across all sediments, but especially clay. Thus the sediment type changes competition between S. anglica and S. triqueter.
authors.affiliation: School of Nature Conservation, Beijing Forestry University, Beijing 100083, China.
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Li
authors.affiliation: School of Nature Conservation, Beijing Forestry University, Beijing 100083, China.
authors.forename: Yong-Yang
authors.initials: YY
authors.lastname: Wang
authors.affiliation: The State Key Laboratory of Pollution Control and Resource Reuse, School of Life Science, Nanjing University, Nanjing 210093, China.
authors.forename: Shu-Qing
authors.initials: SQ
authors.lastname: An
authors.affiliation: College of Environment and Resource, Inner Mongolia University, Hohhot 010021, China.
authors.forename: Ying-Biao
authors.initials: YB
authors.lastname: Zhi
authors.affiliation: School of Nature Conservation, Beijing Forestry University, Beijing 100083, China.
authors.forename: Guang-Chun
authors.initials: GC
authors.lastname: Lei
authors.affiliation: School of Nature Conservation, Beijing Forestry University, Beijing 100083, China.
authors.forename: Ming-Xiang
authors.initials: MX
authors.lastname: Zhang
mesh_terms: D000538:Aluminum Silicates; D018533:Biomass; D000077215:Clay; D017753:Ecosystem; D019015:Geologic Sediments; D006109:Poaceae / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D027343:Rhizome / Q000502:physiology; D012492:Salts / Q000378:metabolism; D053833:Wetlands
chemical_list: D000538:Aluminum Silicates; D012492:Salts; D000077215:Clay