盐雾胁迫对舟山海岛7个造林树种存活和生长的影响

Effect of salt fog stress on survival and growth of seven afforestation tree species in Zhoushan islands

以普陀樟〔Cinnamomum japonicum var.chenii(Nakai)G.F.Tao〕、舟山新木姜子〔Neolitsea sericea(Bl.)Koidz.〕、红楠(Machilus thunbergii Sieb.et Zucc.)、全缘冬青(Ilex integra Thunb.)、石栎〔Lithocarpus glaber(Thunb.)Nakai〕、厚叶石斑木〔Raphiolepis umbellata(Thunb.)Makino〕和滨柃〔Eurya emarginata(Thunb.)Makino〕7个舟山海岛造林树种为研究对象,用浓度18 mg·g-1盐水通过盐雾发生装置每日喷雾0.0(对照)、0.5、1.0和2.0 h,并连续喷雾35 d,对翌年生长季各树种的形态特征、存活率和不同部位的干质量进行测定,并据此确定各树种的耐盐雾性。结果表明:随盐雾日处理时间及胁迫天数的延长,7个树种幼苗均表现出不同的受害症状并逐渐加重,但各树种的受害程度有差异。盐雾日处理0.5、1.0和2.0 h石栎幼苗的存活率,以及盐雾日处理2.0 h红楠、舟山新木姜子和滨柃幼苗的存活率均显著低于对照,但不同盐雾日处理时间对普陀樟、全缘冬青和厚叶石斑木幼苗的存活率均无显著影响。与对照相比,每日短时间的盐雾处理对普陀樟和全缘冬青幼苗的苗高和地径无显著影响,但随盐雾日处理时间延长二者的苗高和地径显著下降;盐雾日处理0.5、1.0和2.0 h,红楠、舟山新木姜子和滨柃幼苗的苗高总体上显著下降,厚叶石斑木幼苗的苗高则显著高于对照,但它们的地径总体上与对照无显著差异。每日短时间盐雾处理对普陀樟和滨柃幼苗单株的叶、根、茎干质量及总干质量均无显著影响,但随盐雾日处理时间的延长,二者单株的不同部位干质量及总干质量均逐渐下降;盐雾处理可导致舟山新木姜子、红楠、全缘冬青和石栎幼苗单株的不同部位干质量及总干质量显著或极显著下降,且降幅总体上随盐雾日处理时间的延长而增大,其中石栎幼苗单株的不同部位干质量及总干质量均最低;盐雾处理对厚叶石斑木幼苗生长则有一定的促进作用,使其单株的不同部位干质量及总干质量不同程度增加,但随盐雾日处理时间的延长增幅减小。盐雾处理对供试各树种叶、茎和根的质量比以及根冠比有不同的影响效应,其中盐雾胁迫造成各树种不同程度落叶,使多数树种根冠比增大,但全缘冬青和厚叶石斑木的根冠比则有所下降。根据实验结果,结合供试树种在舟山海岛的生长环境,初步确定厚叶石斑木的耐盐雾性最强,全缘冬青、普陀樟和滨柃的耐盐雾性次之,红楠和舟山新木姜子的耐盐雾性较弱,石栎的耐盐雾性在7个树种中最弱。

Taking seven afforestation tree species of Cinnamomum japonicum var. chenii （Nakai） G. F. Tao, Neolitsea sericea （Bl.） Koidz., Machilus thunbergii Sieb. et Zucc., Ilex integra Thunb., Lithocarpus glaber （ Thunb.） Nakai, Ra_phiolepis umbellata （Thunb.） Makino and Eurya emarginata （Thunb.） Makino in Zhoushan islands as researched objects, by means of device of generating salt mist, daily spraying 18 mg·g^-1 salt solution for 0.0 （ the control） ,0.5, 1.0 and 2.0 h , and continuously spraying for 35 d , morphological characteristics, survival rate and dry weight of different parts of all tree species in growing season of the next year were measured,and accordingly,salt fog resistance of all tree species were determined. The results show that with prolonging of daily treating time of salt fog and stressing day, seven tree species seedlings appear different injury symptoms and the damage increasing gradually, but injury degree of different tree species is various. Survival rate of L. glaber seedling in daily treatment of salt fog for 0.5, 1.0 and 2. 0 h , and survival rates of M. thunbergii, N. sericea and E. emarginata seedlings in daily treatment of salt fog for 2 . 0 h are significantly lower than those of the control, but different daily treating times of salt fog have no significant effect on survival rate of C. japonicum var. chenii, I. integra and R. umbellata seedlings. Compared with the control, short daily treating time of salt fog has no significant effect on height and basal diameter of C. japonicum var. chenii and I. integra seedlings, while with prolonging of daily treating time of salt fog, their heights and basal diameters decrease significantly. Daily treatment of salt fog for 0.5, 1.0 and 2. 0 h , height of M. thunbergii, N. sericea and E. emarginata seedlings totally decreases significantly, and height of R. umbellata seedling is significantly higher than that of the control, but their basal diameters totally have no significant difference with those of the control. Short daily treating time of salt fog has no significant effect on dry weights of leaf, root, stem and total seedling per plant of C. japonicum var. chenii and E. emarginata, while with prolonging of daily treating time of salt fog, their dry weights of different parts and total seedling per plant decrease gradually. Salt fog treatment can significantly or extremely significantly reduce dry weights of different parts and total seedling per plant of N. sericea, M. thunbergii, I. integra and L. glaber, and their decreasing ranges totally increase with prolonging of daily treating time of salt fog, in which, dry weights of different parts and total seedling per plant of L. glaber is the lowest. While salt fog treatment has a certain promotion effect on growth of R. umbellata seedling, and leads to increasing of dry weights of different parts and total seedling per plant with different degrees, while their increasing ranges reduce with prolonging of daily treating time of salt fog. Salt fog treatment has different effects on weight ratios of leaf, stem and root and root/shoot ratio of all tree species tested, in which, salt fog stress induces defoliation of all tree species with different degrees, so, it makes root/shoot ratio of most tree species increase, but root/shoot ratio of I. integra and R. umbellata slightly decreases. Based on experiment result and combined with growth environment of tree species tested in Zhoushan islands, it is determined preliminarily that salt fog resistance of R. umbellata is the strongest, that of I. integra, C. japonicum var. chenii and E. emarginata is the second, that of M. thunbergii and N. sericea is weaker, and that of L. glaber is the weakest among seven tree species.