美国栎属种源引种、变异研究:幼树年高生长节律和物候期的变异

Studies on the variations of provenances and families in the Genus Quercus of American:variations in the annual height growth rhythm and phenological phase in two year old saplings

对定植在江苏省林业科学研究院苗圃 (南京 )内的美国栎属 3个树种 ,19个种源、家系 (包括柳叶栎 9个种源、家系 ,北方红栎 6个家系 ,红栎 4个种源 )的 2年生幼树进行了年高生长节律和物候期 (包括展叶期、叶变色期和落叶期 )的定期观测 (分别每 3～ 15d观测 1次 )。结果表明 :(1) 3个树种在南京年高生长节律差异显著。柳叶栎在生长期内抽梢次数较多 ,在 5次以上 ,基本呈连续生长趋势。生长节律呈快 (5月 )—慢 (6月 )—最快 (7,8月 )—慢 (9月 )。种内种源、家系间生长节律差异较小 ,但年净生长量差异大。北方红栎和红栎生长不连续 ,呈间隙周期性生长 ,有明显生长和停止期。一般年抽梢 2次 ,少数抽梢 3,4次或 1次。生长节律呈生长—停止—生长—停止。种内种源、家系间生长节律差异大 ,其中红栎 9813号种源全年抽梢仅 1次 ,但红栎 9819号和 982 1号全年抽梢 3次。 (2 )春季萌叶期以柳叶栎较早 ,北方红栎最迟 ;秋季叶变色以红栎较早 ,红叶期长 ,柳叶栎最迟 ;落叶期以北方红栎最迟 ;秋季叶变色以红栎较早 ,红叶期长 ,柳叶栎最迟 ;落叶期以北方红栎较早 ,红栎最迟。物候期在种内不同种源、家系间亦有较大差异。

Two year old saplings of American Oak 3 species and 19 provenances and families (including 9 provenances and families of Quercus phellos, Wellow Oak;6 families of Q rubra L., Northern Red Oak;4 provenances of Q.coccinea, Scarlet Oak)were grown for observation of annual height growth rhythem and phenological phase in March 1999 on a nursery in Jiangsu Academy of Forestry,Nanjing China.Sapling annual height growth,leaves expansion,leaves colour changes and leaves fall were recorded every 3 to 15 days during growing seasons(from April to November in 1999).The results of observation showed that there were significant differences among species,provenances and families.(1)Annual height growth rhythm:Wellow Oak has more than 5 times of shoot growth flush and growth is continual.The growth rhythm was fast(in May) to slow (in June) to most fast(in July to August) to slow(in September).Shoot growth of Northern Red Oak and Scarlet Oak is episodic and has 1 to 4 times of shoot growth flush.The growth rhythm was growth to rest to growth to rest.(2)Phenological phase:leaves expansion in Wellow Oak is more early than Scarlet Oak and Northern Red Oak is latest.Leaves turning red in Scarlet Oak in autumn is most early and longest and Wellow Oak is latest.Leaves fall in Northern Red Oak is more early than Wellow Oak and Scarlet Oak is latest.