應用存活分析方法於山胡椒(Litsea cubeba)苗木生長與存活率之研究

The study of Litsea cubeba seedling growth and survival rate using survival analysis

山胡椒 (Litsea cubeba) 全株具芳香氣味，為樟科 (Lauraceae) 木薑子屬 (Litsea)，雌雄異株，多年生落葉小喬木。其為重要的傳統民俗植物，成分在醫療方面具有多種重要的醫療價值，是新興的木本油料植物資源，具有潛在可開發價值的多功能樹種。山胡椒苗木繁殖困難與生長勢弱，使得山胡椒的育苗具有一定挑戰性。掌握山胡椒發芽後的生長與存活動態是瞭解山胡椒生態與育苗作業基礎，但目前對於山胡椒發芽後的苗木生長狀況並無太多的資料，因此是必須面對的重要課題。本研究探討山胡椒自種子發芽後，觀察苗木發展階段的植株生長與存活率變化，以提供生態與育苗做為參考。研究目標為 (1) 蒐集與監測山胡椒苗木基徑、苗高生長變化，與存活率變化；(2) 探討不同的培養介質對於山胡椒生長的適應性與影響。研究結果顯示，山胡椒苗木的基徑與苗高生長緩慢，且會受到不同土壤介質處理影響相對生長率表現。6個月的培育過程，山胡椒苗木有明顯的死亡發生，由存活分析結果顯示僅適用泥炭土的處理的存活時間中位數最短約91天，適當加入森林土調整後可延長存活時間中位數達183天。配適參數型回歸模型的結果顯示，在苗木發展初期基徑有較大的相對生長，可以顯著的提升苗木存活時間，自初期的1.950倍至中期的5.317倍；苗木相對高度生長則在6個月內對於苗木存活率無顯著影響。研究結果顯示山胡椒的苗木培育初期，必須注意使用之土壤介質，以及基徑的相對生長，可提高山胡椒苗木培育的成效。

Litsea cubeba is a small- to medium-sized deciduous tree or shrub of Lauraceae in the mountainous regions. It is one of the most valuable multipurpose ethnobotany tree that are used as medicine and production of essential oil. The Litsea cubeba seedlings are weak and difficult to propagate. Therefore, it is a challenging to cultivate Litsea cubeba seedlings. In this study, we evaluated the seedling growth and survival rate of 6-month old Litsea cubeba seedlings after germination to provide the basic knowledge for nursing operation. The research objectives were (1) to collect and monitor the data of seedling base diameter, height, and survival rate, and (2) to explore the effects of three different soil mixture treatments on the growth and survival rate. The results showed that the seedling base diameter and height grew slowly, and the relative growth rate was affected by different soil treatments. The survival time of the seedlings were significantly different among soil treatments during the 6-month cultivation period. Survival analysis showed that survival rates were significantly different, with the lowest survival time of 91 days for cultivated medium and the highest survival time of 183 days for mixed soil medium. The base diameter relative growth of the seedling significantly increased with the increasing survival time from 1.950 times in the early stage to 5.317 times in the middle stage. The relative seedling heights were not significantly affected by survival rate . The results of this study showed that the soil media and relative growth of base diameter were important factors affected growth and survival rate of Litsea cubeba seedlings in the early stage of cultivation. These findings provide references for the cultivation of Litsea cubeba seedling.