title: Burial depth and stolon internode length independently affect survival of small clonal fragments.
abstract: Disturbance can fragment plant clones into different sizes and unstabilize soils to different degrees, so that clonal fragments of different sizes can be buried in soils at different depths. As a short-term storage organ, solon internode may help fragmented clones of stoloniferous plants to withstand deeper burial in soils. We address (1) whether burial in soils decreases survival and growth of small clonal fragments, and (2) whether increasing internode length increases survival and growth of small fragments under burial. We conducted an experiment with the stoloniferous, invasive herb Alternanthera philoxeroides, in which single-node fragments with stolon internode of 0, 2, 4 and 8 cm were buried in soils at 0, 2, 4 and 8 cm depth, respectively. Increasing burial depth significantly reduced survival of the A. philoxeroides plants and increased root to shoot ratio and total stolon length, but did not change growth measures. Increasing internode length significantly increased survival and growth measures, but there was no interaction effect with burial depth on any traits measured. These results indicate that reserves stored in stolon internodes can contribute to the fitness of the A. philoxeroides plants subject to disturbance. Although burial reduced the regeneration capacity of the A. philoxeroides plants, the species may maintain the fitness by changing biomass allocation and stolon length once it survived the burial. Such responses may play an important role for A. philoxeroides in establishment and invasiveness in frequently disturbed habitats.
authors.affiliation: College of Nature Conservation, Beijing Forestry University, Haidian District, Beijing, China.
authors.forename: Bi-Cheng
authors.initials: BC
authors.lastname: Dong
authors.forename: Rui-Hua
authors.initials: RH
authors.lastname: Liu
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Li
authors.forename: Ming-Xiang
authors.initials: MX
authors.lastname: Zhang
authors.forename: Guang-Chun
authors.initials: GC
authors.lastname: Lei
authors.forename: Fei-Hai
authors.initials: FH
authors.lastname: Yu
mesh_terms: D027703:Amaranthaceae / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D000704:Analysis of Variance; D018533:Biomass; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology; D018520:Plant Shoots / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology; D018547:Plant Stems / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D012098:Reproduction; D012987:Soil; D013997:Time Factors
chemical_list: D012987:Soil