白桦和落叶松苗木对其纯林土壤养分的生物检测

利用35年生白桦、落叶松纯林土壤分别栽植白桦、落叶松1年生苗木,通过对苗木生长、生物量、叶片养分及土壤养分变化的研究,对两种土壤的肥力进行评价,探讨白桦、落叶松混交林种间互作机制.结果表明:白桦纯林土壤全氮、碱解氮含量显著高于落叶松纯林土壤(P<0.05),落叶松纯林土壤全磷、全钾、速效磷含量显著高于白桦纯林土壤(P<0.05).盆栽第1年,白桦纯林土壤上的白桦苗木苗高、地径和生物量分别比在落叶松纯林土壤上增加69%、52%和65%(P<0.05),落叶松苗木分别增加12%、8%和37%(P>0.05).以白桦纯林土壤为基质时,白桦、落叶松苗木叶片氮浓度高于落叶松纯林土壤,而磷浓度低于落叶松纯林土壤.白桦凋落量大且分解速度快,落叶松对土壤磷具有活化作用,导致白桦纯林土壤氮素有效性较高,落叶松纯林土壤有效磷含量较高.推测两树种混交时,土壤氮、磷的互补作用可能对林分产量产生有益的作用.

Soil nutrient status of pure birch and larch plantations based on their seedlings bioassay

One-year-old birch(Betula platyphylla) and larch(Larix olgensis) seedlings were respectively planted in pots with the soils taken from 35-year-old pure birch and larch plantations,and the seedlings growth,biomass increment,foliar nutrient content,and soil nutrient status were monitored,aimed to evaluate the fertility levels of the two soils and the possible interspecific interaction in mixed larch-birch forest.Birch soil had significantly higher contents of total N and available N than larch soil,while larc...