Ecology of Phreatophytes

Abstract

Phreatophytes are plants with temporary or permanent access to groundwater. Despite distinct interspecific differences, many phreatophytes share the following traits: (1) rapid vertical root growth; (2) vigorous vegetative regeneration; (3) a significant fraction of xylem conduits with large diameters; (4) high hydraulic conductance; (5) relatively high vulnerability to xylem embolism; (6) high foliar conductance to water vapour; (7) high rates of biomass production; and (8) low water use efficiency. Phreatophytes can be considered a hydro-ecological plant type, and put in a line with hydrophytes, hygrophytes, and xerophytes. In subdividing phreatophytes according to their dependence on groundwater, it is suggested to replace the conventional term “obligate” with “permanent”, and “facultative” with “temporary” as the fraction of the water demand that is covered by uptake of groundwater seems to be determined by environmental conditions rather than by inherent traits of the plants.