Apparent Tolerance of Low Water Availability in Temperate Asian Bamboos1

Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant 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 role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered 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 irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.

Azumamiris vernalis: a new genus and species of Mirini from central Japan (Heteroptera: Miridae: Mirinae)

Azumamiris, a new genus of mirine plant bug, is established to accommodate a new species, A. vernalis, which has occasionally been found in central Honshu, Japan. This univoltine mirine was confirmed to be associated with a gramineous dwarf bamboo, Pleioblastus chino (Fr. et Sav.) Makino, and the adults appear only in early May. The final instar nymph is also diagnosed and described. The present new genus is assumed to be allied to Stenotus Jakovlev known from the Old World and to continental Chinese Elthemidea Zheng. A key to the genera under discussion is provided.