研究了不同土壤水分条件对黄土高原 4个乡土树种幼苗生长及干物质分配的影响。结果表明,中度干旱(50%~55% θf)下虎榛子(Ostryopsis davidiana Decne. )和白刺花 (Sophora viciifolin Hance)的生物量比适宜水分下(70% ~75% θf)增加 20.23%和3.93%,而大叶细裂槭(Acer stenolobum Rehd. var. megalophyllum Fang et Wu)和辽东栎(Quercus liaotungensis Koidz. )生物量分别降低 13.59%和 35.25%;重度干旱(40% ~45% θf)对幼苗生长均有明显抑制作用。白刺花地上部与地下部的生长受水分胁迫影响较小,较其他树种具有更强的耐旱性;干旱对辽东栎地上部生长的影响较地下部大,重度干旱下其生长明显受抑制。随干旱程度加剧幼苗的根冠比增大,在重度干旱下大叶细裂槭根冠比达2以上。虎榛子整体生长速度较慢,对干旱的适应可能更多表现在生理上的耐旱。

Effects of different soil water contents on growth and dry matter allocation of four native tree species seedling on Loess Plateau were studied. The results showed that seedlings of Ostryopsis davidiana Decne. and Sophora viciifolin Hance had higher biomass under medium drought(50% -55%θf) than that of under normal water(70% -75% θf), increasing 20.23% and 3.93% respectively, Quercus liaotungensis Koidz. and Acer stenolobum Rehd. var. megalophyllum Fang et Wu were on the contrary and their biomass decreased 13.59% and 35.25% respectively. The growth of four tree species seedlings had been inhibited significantly under severe drought(40% -45%θf). The growth of above- and under-ground parts of S. viciifolin was decreased slightly, it had the strongest drought resistance than other tree species. The growth of above-ground part of Q. liaotungensis was decreased higher than that of under-ground part under soil drought and its growth was significantly decreased under severe drought. Root-shoot ratio of seedling had increased with descending soil water content and root-shoot ratio of A. stenolobum var. megalophyllum added up to 2 under severe drought. The growth speed of O. davidiana is slow and it probablely hasmore physiological drought resistance to adapt stress condition.