Insights into the mechanism of diurnal variations in methane emission from the stem surfaces of Alnus japonica.

Recent studies have suggested that in certain environments, tree stems emit methane (CH ). This study explored the mechanism of CH emission from the stem surfaces of Alnus japonica in a riparian wetland. Stem CH emission rates and sap flux were monitored year-round, and fine-root anatomy was investigated.

Diurnal variations in the thickness of the inner bark of tree trunks in relation to xylem water potential and phloem turgor.

The inner bark plays important roles in tree stems, including radial exchange of water with the xylem and translocation of carbohydrates. Both processes affect the water content and the thickness of the inner bark on a diurnal basis. For the first time, we simultaneously measured the diurnal variations in the inner bark thickness of hinoki cypress () by using point dendrometers and those of local xylem potential by using stem psychrometers located next to the dendrometers to determine how these variations were related to each other, to phloem turgor and carbohydrate transport.

Nitrogen Availability and Microbial Communities of Canopy Soils in a Large Cercidiphyllum japonicum Tree of a Cool-Temperate Old Growth Forest.

Canopy soils on large trees are important for supporting the lives of many canopy plants, and thereby increasing regional biodiversity. However, because of the less accessibility to canopy soils, there is insufficient knowledge on how canopy soils produce available nitrogen (N) for canopy plants through the activity of canopy soil microbes. Canopy soils usually have different soil properties from ground soils, so we hypothesized that canopy soils would have unique microbial communities compared to ground soils, but still provide available N for canopy plants.

Water Adsorption to Leaves of Tall Tree Analyzed by Infrared Spectroscopy under Relative Humidity Control.

Leaf water storage is a complex interaction between live tissue properties (anatomy and physiology) and physicochemical properties of biomolecules and water. How leaves adsorb water molecules based on interactions between biomolecules and water, including hydrogen bonding, challenges our understanding of hydraulic acclimation in tall trees where leaves are exposed to more water stress. Here, we used infrared (IR) microspectroscopy with changing relative humidity (RH) on leaves of tall trees.

Height-related variations of leaf traits reflect strategies for maintaining photosynthetic and hydraulic homeostasis in mature and old Pinus densiflora trees.

Because tree size and age co-vary, it is difficult to separate their effects on growth and physiological function. To infer causes for age-related height-growth decline, we compared various leaf traits between mature (ca. 100 years) and old (ca.

Water retained in tall Cryptomeria japonica leaves as studied by infrared micro-spectroscopy.

Recent studies in the tallest tree species suggest that physiological and anatomical traits of tree-top leaves are adapted to water-limited conditions. In order to examine water retention mechanism of leaves in a tall tree, infrared (IR) micro-spectroscopy was conducted on mature leaf cross-sections of tall Cryptomeria japonica D. Don from four different heights (51, 43, 31 and 19 m).

Leaf water maintains daytime transpiration in young Cryptomeria japonica trees.

Compared with stem water storage, leaf water storage is understudied although it may be important for alleviating water stress by contributing quickly and directly to transpiration demand. To quantify the relative contribution of stem versus leaf water storage to daily water deficit, we measured diurnal changes in transpiration rate, sap-flow velocity and stem radius of 10-year-old Cryptomeria japonica D. Don trees.

Physiological and morphological acclimation to height in cupressoid leaves of 100-year-old Chamaecyparis obtusa.

Cupressoid (scale-like) leaves are morphologically and functionally intermediate between stems and leaves. While past studies on height acclimation of cupressoid leaves have focused on acclimation to the vertical light gradient, the relationship between morphology and hydraulic function remains unexplored. Here, we compared physiological and morphological characteristics between treetop and lower-crown leaves of 100-year-old Chamaecyparis obtusa Endl.