Location: Invasive Plant Research LaboratoryTitle: Apparent tolerance of low water availability in temperate Asian bamboos
|MACK, RICHARD - Washington State University|
Submitted to: Journal of Environmental Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2018
Publication Date: 3/1/2018
Citation: Smith, M., Mack, R.N. 2018. Apparent tolerance of low water availability in temperate Asian bamboos. Journal of Environmental Horticulture. 36(1):7-13.
Interpretive Summary: Temperate Asian bamboos are a growing part of North American landscape material. While they boast cold tolerance and shade tolerance, their water needs have not been well studied. We investigated the effects of three watering regimes on five species of temperate Asian bamboos and one species of North American bamboo over a 30-day period during two different growing seasons. We looked at stomatal responses and internal water vapor pressure and intrinsic water use efficiency as measurements of leaf-level water response. Two species, Pleioblastus distichus and Pseudosasa japonica responded to the low watering treatment with significantly reduced stomatal conductance. Pleioblastus chino showed increased intrinsic water use efficiency in the mid and low irrigation treatments, and Arundinaria gigantea had significantly lower intrinsic water use efficiency than P. chino and S. palmata in the low irrigation treatment. No species altered internal water vapor pressure deficits to the point of drought. Temperate Asian bamboos, in addition to shade and freeze tolerance, also appear to tolerate low water inputs and should be able to withstand summer dry down without augmentive waterings.
Technical Abstract: Plant water dynamics and the ability to withstand periods of low moisture input facilitate establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia, but play only an incidental roll in North American forests and are altogether absent in Pacific Northwest forest. Many species are classified as mesic or riparian and none are described as drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and A. gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. Asian bamboo species tolerate low water availability and readily acclimate to various conditions.