High water level impedes the adaptation of Polygonum hydropiper to deep burial: Responses of biomass allocation and root morphology

Abstract

Many studies have investigated the individual effects of sedimentation or inundation on the performance of wetland plants, but few have examined the combined influence of these processes. Wetland plants might show greater morphological plasticity in response to inundation than to sedimentation when these processes occur simultaneously since inundation can negate the negative effects of burial on plant growth. Here, we evaluate this hypothesis by assessing growth of the emergent macrophyte Polygonum hydropiper under flooding (0 and 40 cm) and sedimentation (0, 5, and 10 cm), separately and in combination. Deep burial and high water level each led to low oxidation-reduction potential, biomass (except for 5-cm burial), and growth of thick, short roots. These characteristics were generally more significant under high water level than under deep burial conditions. More biomass was allocated to stems in the deep burial treatments, but more to leaves in the high water level treatments. Additionally, biomass accumulation was lower and leaf mass ratio was higher in the 40-cm water level + 10-cm burial depth treatment than both separate effects. Our data indicate that inundation plays a more important role than sedimentation in determining plant morphology, suggesting hierarchical effects of environmental stressors on plant growth.

Effects of sedimentation on soil physical and chemical properties and vegetation characteristics in sand dunes at the Southern Dongting Lake region, China

“…A high rate of sedimentation inhibits the growth and colonization of all but highly specialized species13, which might be attributed to the low availability of oxygen and light in buried soils41113. In this study, only a few sedimentation-tolerant species were able to successfully colonize (e.g.…”

“…As a result, only a few sedimentation-tolerant species can successfully colonize under heavy sedimentation. However, slight sedimentation may not inhibit or even stimulate the growth of some sand dune species because the deposited sediments can reduce water evaporation and temperature fluctuations1113. Therefore, vegetation characteristics will differ depending on the sedimentation rate in sand dunes.…”

Responses of eastern Chinese coastal salt marshes to sea-level rise combined with vegetative and sedimentary processes

“…Moreover, the model was calibrated based on previous field observations and empirical assumptions, ignoring the plasticity of coastal vegetation. Pan et al 35. demonstrated that wetland plants can display morphological plasticity in response to inundation.…”

Competition between two wetland macrophytes under different levels of sediment saturation

“…Dongting Lake (28°30'-30°20' N, 111°40'-113°10' E), the second largest freshwater lake in China with an area of 2620 km 2 , is located in the northern Hunan Province in a basin south of the Yangtze River, to which it is connected by three distributary channels (Pan et al, 2014; Fig. 1).…”