Photosynthesis and respiration of <i>Pinus pumila</i> needles in relation to needle age and season

  • Takuya Kajimoto
    Laboratory of Silviculture, Faculty of Agriculture Nagoya University Nagoya 464‐01 Japan

抄録

<jats:title>Abstract</jats:title><jats:p>Rates of net photosynthesis and dark respiration were measured for detached needles of <jats:italic>Pinus pumila</jats:italic> trees growing on the Kiso mountain range in central Japan in 1987. Dependency of photosynthesis on light and temperature was examined in relation to needle age and season. The light saturation point of net photosynthesis was lower in 3‐ and 4‐yr‐old needles than that in current (flushed in 1987), 1‐ and 2‐yr‐old needles. <jats:italic>P</jats:italic><jats:sub>nmax</jats:sub>, net photosynthetic rates at 1000 μmol m<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> and 15°C, of needles from 1‐ to 4‐yr‐old generally decreased with needle age. <jats:italic>P</jats:italic><jats:sub>nmax</jats:sub> of 1‐ to 4‐yr‐old needles became higher in August than in other months, and <jats:italic>P</jats:italic><jats:sub>nmax</jats:sub> of current needles did so in September. Current needles showed high respiration rates (at 15°C) only in August. Optimum air temperatures for net photosynthesis at 1000 μmol m<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup> were between 10 and 15°C for current and 1‐yr‐old needles. The temperature coefficient of dark respiration rates was 2.3–3.3 for current needles from August to October, and 2.2 for 1‐yr‐old needles in mid‐July.</jats:p>

収録刊行物

被引用文献 (9)*注記

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ