凋落物对2针叶树种种子萌发和幼苗生长的影响

Effects of litter on seed germination and seedling growth of two coniferous tree species

通过研究华北落叶松云杉混交林下凋落物对2优势树种种子萌发及幼苗生长的影响表明:1)4种凋落物水浸液抑制华北落叶松和云杉种子的萌发,50.0 g/L的华北落叶松和云杉针叶水浸液的抑制作用较强;2)华北落叶松针叶和白桦树皮的水浸液促进华北落叶松幼苗生长,云杉针叶水浸液起抑制作用;3)白桦树皮水浸液抑制云杉幼苗生长,其他3种凋落物水浸液低质量浓度时促进云杉幼苗生长,高质量浓度抑制其生长;4)5.0和12.5 g/L的白桦树皮水浸液促进华北落叶松幼苗生物量,25.0和50.0 g/L时起抑制作用;5)4种水浸液均强度抑制云杉幼苗生物量;6)4种凋落物水浸液对华北落叶松和云杉种苗的影响以抑制作用为主,对云杉的作用强于华北落叶松。

In this paper,effects of litter aqueous extracts on seed germination and seedling growth of two dominant tree species were investigated in the mixed stand of Larix principis-rupprechtii and Picea wilsonii （Picea meyeri）.The results were as follows.1） Germination of two species were both inhibited by all types of aqueous extracts.The most obvious inhibition was presented by 50.0 g/L aqueous extracts of L.principis-rupprechtii or P.wilsonii （P.meyeri）.2） Seedlings of L.principis-rupprechtii were promoted by aqueous extracts of L.principis-rupprechtii needles or Betula platyphylla barks,while they were inhibited by aqueous extracts of P.wilsonii （Picea meyeri） needles.3） Seedlings of P.wilsonii （Picea meyeri） were inhibited by aqueous extracts of B.platyphylla barks,while they were enhanced by lower concentrations and inhibited by higher concentrations of aqueous extracts by other three litter types.4） Biomass of L.principis-rupprechtii was improved by aqueous extracts of B.platyphylla barks at concentrations of 5.0 and 12.5 g/L,but not at concentrations of 25.0 and 50.0 g/L.5） Biomass of P.wilsonii was inhibited by all types of the aqueous extracts.6） Four types of litterfall aqueous extracts totally inhibited seeds germination and seedling growth of both species,but the effect on P.wilsonii was stronger than that on L.principis-rupprechtii.