Water status of bare-root seedlings of Chinese fir and Masson pine

Abstract

Water relation parameters of bare-root seedlings of Chinese fir (Cunninghamia lanceolata Hook.) and Masson pine (Pinus massoniana Lamb.) were measured and changes of root growth potential as well as field survival rate of both species were studied after the bare-root seedlings were exposed in a sunny field conditiory. The results showed that Masson pine had a lower osmotic potential (−2.07Mp_a) at turgor loss point and at, full turgor (−1.29Mp_a), compared with Chinese fir (−1.80Mp_a and −1.08Mp_a respectively). The parameter V_p/V₀ (63.27%) of Masson pine was higher than that of Chinese fir (58.03%). This means that Masson pine has a stronger ability to tolerate desiccation, compared to Chinese fir according to analysis of above water relation parameters. Root growth potential and field survival rate decreased with prolonging duration of exposure. The field survival rate of both species was reduced to less than 40% after the seedling being exposed only two hours. Water potentials of −1.60 Mpa and −1.70 Mpa were suggested to be critical values for Chinese fir and Masson pine respectively in successful reforestation.

Keywords

Chinese fir / Masson pine / Water relations / Seedling desiccation / Water potential / Root growth potential / S791.27 / S791.248 / A