Modelling of groundwater-vegetation interactions in a tidal marsh

Xin, Pei, Kong, Jun, Li, Ling and Barry, D. A. (2013) Modelling of groundwater-vegetation interactions in a tidal marsh. Advances in Water Resources, 57 52-68. doi:10.1016/j.advwatres.2013.04.005

Author Xin, Pei
Kong, Jun
Li, Ling
Barry, D. A.
Title Modelling of groundwater-vegetation interactions in a tidal marsh
Journal name Advances in Water Resources   Check publisher's open access policy
ISSN 0309-1708
Publication date 2013-07-01
Sub-type Article (original research)
DOI 10.1016/j.advwatres.2013.04.005
Volume 57
Start page 52
End page 68
Total pages 17
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon
Language eng
Abstract Wetting and drying due to tidal fluctuations affect soil conditions and hence plant growth in tidal marshes. Here, a coupled one-dimensional model was developed to simulate interacting groundwater flow and plant growth in these wetlands. The simulation results revealed three characteristic zones of soil conditions for plant growth along a cross-creek section subjected to the combined influences of spring-neap tides and evapotranspiration: (1) a near-creek zone affected by semi-diurnal tides over the whole spring-neap cycle, where the soil is well aerated although the plant growth could be slightly limited by the local water content dropping periodically below the wilting point on the ebb tide; (2) a less well-drained zone where drainage occurs only during neap tides (for which the daily inundation is absent) and plant growth is aeration-limited; and (3) an interior zone where evapotranspiration determines the soil-water saturation. Plant growth dynamics, which depend on these soil conditions, lead to spatial biomass distributions that are consistent with the characteristic zonation. The simulations shed light on the feedback mechanism for groundwater-vegetation interactions in the marsh system. It was demonstrated that the growth of pioneer plants can improve the soil aeration condition as a result of transpiration. The strength of this feedback varies spatially in accordance with the three characteristic zones of soil-water saturation. However, the development of another species in the marsh system is likely to be more complicated than suggested by the "positive feedback" mechanism proposed previously, due to the influence of inter-species competition. The feedback effects are generally more complex, involving both plant growth enhancement and inhibition depending on the combined influence of the intra- and inter-species competition, the ecosystem's carrying capacity and plant transpiration. These findings demonstrate the interplay of ecological and hydrological processes in tidal marshes, and provide guidance for future research, including field investigations that aim to establish the principle relationship between marsh morphology and plant zonation.
Keyword Salt marsh
Vegetation-groundwater interaction
Plant zonation
Soil aeration condition
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Civil Engineering Publications
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