Tissue water relations of 20 tree species growing in a cool temperate forest

Using the pressure-volume technique, leaf tissue water relations of twenty tree species growing in a cool temperate forest of the Ashiu Kyoto University Forest were studied. Acer micranthum Sieb. et Zucc., Ilex sugerokii Maxim., Sorbus commixta Hedl. and, Hamamelis japonica S. et Z. var. obtusata Matsumura growing in xeric habitats had less than -1.8 MPa in water potential at turgor loss (φWtlp) and -0.7 MPa in osmotic potential at full turgidity (φSsat). Subxeric and submesic and mesic tree species such as Swida controversa Hemsl., Carpinus tschonoskii Maxim., C. laxiflora Bl. and Betula grossa S. et Z. had more than -1.4 MPa in φWtlp and -0.6 MPa in φSsat. Ilex sugerokii Maxim. and Hamamelis japonica S. et Z. var. obtusata Matsumura had thick and watery leaves. All Carpinus and Acer species had thin leaves with low moisture content. The species growing in xeric habitats had similar characteristics in tissue water relations. Those species such as Carpinus and Acer showed a tendency of genus-specific characteristics in tissue water relations independently of their living habitats.