TY - JOUR
T1 - Dynamics of wetland vegetation under multiple stresses
T2 - A case study of changes in sawgrass trait, structure, and productivity under coupled plant-soil- microbe dynamics
AU - Muneepeerakul, Chitsomanus P.
AU - Muneepeerakul, Rachata
AU - Miralles-Wilhelm, Fernando
AU - Rinaldo, Andrea
AU - Rodriguez-Iturbe, Ignacio
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/11
Y1 - 2011/11
N2 - This paper quantifies wetland vegetation dynamics under drought, waterlogging, shading, and nutrient stresses within the coupled plant-soil-microbe system. A plant is characterized by three independent traits, namely leaf nitrogen (N) content, specific leaf area (SLA), and allometric carbon (C) allocation to rhizome storage, while plant growth is modelled through a dynamic plant allocation scheme. The modelling of N focuses on the internal cycle in which the aerobic and anaerobic processes are determined by the dynamics of oxygen controlled by plants, microbial aerobic processes, and hydrologic dynamics. The dynamics of water levels and soil moisture are described by a simple hydrologic model with stochastic rainfall and are decoupled from the plant-soil-microbe dynamics. Using the model to investigate the dynamics of sawgrass, the results, which are consistent with field observations in the southern Everglades, indicate that SLA decreases with increasing anaerobic condition. The lower SLA maintains high stomatal opening, while at the same time prevents cavitational collapse when sawgrass lowers its root:shoot ratio to reduce C cost in root anaerobic respiration. Given a naturally low but not too scarce level of phosphorus, net N mineralization is higher in the wetter hydrologic regimes because the increase in anaerobic decomposition and N mineralization compensate for the decline in those of aerobes; and the slower growing, more nitrogen efficient anaerobes compete less with plants for N. The optimal traits are the results of several counteracting trends of trade-offs in C and N economy differently influenced by trait combinations in different wetland environments.
AB - This paper quantifies wetland vegetation dynamics under drought, waterlogging, shading, and nutrient stresses within the coupled plant-soil-microbe system. A plant is characterized by three independent traits, namely leaf nitrogen (N) content, specific leaf area (SLA), and allometric carbon (C) allocation to rhizome storage, while plant growth is modelled through a dynamic plant allocation scheme. The modelling of N focuses on the internal cycle in which the aerobic and anaerobic processes are determined by the dynamics of oxygen controlled by plants, microbial aerobic processes, and hydrologic dynamics. The dynamics of water levels and soil moisture are described by a simple hydrologic model with stochastic rainfall and are decoupled from the plant-soil-microbe dynamics. Using the model to investigate the dynamics of sawgrass, the results, which are consistent with field observations in the southern Everglades, indicate that SLA decreases with increasing anaerobic condition. The lower SLA maintains high stomatal opening, while at the same time prevents cavitational collapse when sawgrass lowers its root:shoot ratio to reduce C cost in root anaerobic respiration. Given a naturally low but not too scarce level of phosphorus, net N mineralization is higher in the wetter hydrologic regimes because the increase in anaerobic decomposition and N mineralization compensate for the decline in those of aerobes; and the slower growing, more nitrogen efficient anaerobes compete less with plants for N. The optimal traits are the results of several counteracting trends of trade-offs in C and N economy differently influenced by trait combinations in different wetland environments.
KW - Coupled plant-soil-microbe dynamics
KW - Multiple stresses
KW - Stochastic
KW - Wetland
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U2 - 10.1002/eco.165
DO - 10.1002/eco.165
M3 - Article
AN - SCOPUS:81855182197
SN - 1936-0584
VL - 4
SP - 757
EP - 790
JO - Ecohydrology
JF - Ecohydrology
IS - 6
ER -