云南藍果樹凋落物對其天然更新的影響1)

張珊珊　向振勇　康洪梅　楊文忠

(國家林業(yè)局云南珍稀瀕特森林植物保護和繁育重點實驗室(云南省林業(yè)科學院)，昆明，650201)

?

云南藍果樹凋落物對其天然更新的影響1)

張珊珊向振勇康洪梅楊文忠

(國家林業(yè)局云南珍稀瀕特森林植物保護和繁育重點實驗室(云南省林業(yè)科學院)，昆明，650201)

為了探討云南藍果樹(NyssayunnanensisW.C.Yin)瀕危機理，采用野外調查和室內控制相結合的方法，分析云南藍果樹凋落物對其天然更新的影響。結果表明：野外條件下，去除凋落物處理對云南藍果樹種子萌發(fā)率和幼苗都有顯著的影響。室內受控實驗發(fā)現(xiàn)，凋落物厚度和凋落物位置對云南藍果樹種子萌發(fā)和幼苗的影響差異顯著；不同質量分數(shù)的凋落物浸提液，顯著影響云南藍果樹的種子萌發(fā)率及幼苗的生長，抑制程度隨浸提液質量分數(shù)的增加而增強。云南藍果樹幼苗生長受限與其根部叢枝菌根真菌被浸提液抑制有關。因此，云南藍果樹凋落物對其天然更新具有物理阻礙作用和化感作用，應定期對天然林合理地清理林下凋落物，以促進云南藍果樹的天然更新。

云南藍果樹；凋落物；天然更新；種子萌發(fā)；幼苗生長

In order to explore the endangered mechanism ofNyssayunnanensisand make effective protection, we used in-situ experiment in field and manipulated greenhouse experiments to examine the physical and allelopathic effects of litter onN.yunnanensisnatural regeneration. The seed germination and seedling growth ofN.yunnanensiswere significantly inhibited by the litter in the field. Different thickness and different seed-sowing positions of litter had significant physical effects on seed germination and seedling growth. Allelochemicals in the litter also inhibited seed germination and seedling formation, which was evidenced by the fact of different concentrations of the litter extractions. Different concentrations of litter had significant negative allelopathic effects, and the inhibition degree of seed germination rate and seedling growth were aggravated with the increasing of the concentration. The inhibition ofN.yunnanensisseedling growth may be due to the inhibition of AMF symbiosis ion in theN.yunnanensisroot. Therefore, the litter in the forest has physical and chemical impacts on seed germination and seedling growth ofN.yunnanensis, and the conservation strategies should be dedicated to ameliorating the effects of litter and enhancing natural regeneration through regularly cleaning up the natural forest litter.

云南藍果樹(NyssayunnanensisW.C.Yin)為國家Ⅰ級重點保護野生植物，云南特有種和極危種[1]。云南藍果樹天然種群及幼苗數(shù)量都極少，已經(jīng)低于穩(wěn)定存活界限，瀕臨滅絕，屬于典型的極小種群物種。但迄今為止，對云南藍果樹瀕危機制的研究甚少，僅見于系統(tǒng)分類、形態(tài)修訂及種子萌發(fā)特性等方面的研究[2-3]。……