森林環境暨資源學系林增毅副教授參與Tropical Forestry 2021國際研討會
馬來西亞沙巴大學熱帶林業學院(Faculty of Tropical Forestry, Universiti Malaysia Sabah)於2021年12月14-15日舉辦熱帶林業2021(Tropical Forestry 2021 ) 線上國際會議。森林環資學系林增毅副教授參與會議並發表有關模擬撫育更新回收農地林木樹種樹高直徑關係。臺灣擁有長久之撫育造林政策，主要目的在於保持森林生態服務系統。造林政策鼓勵混合樹種造林以增加更新林分之潛力。然而，較少論文探討造林樹種之生長狀況。本研究主要找海拔250至2500公尺設立樣區測量造林苗木之胸高直徑以及樹高。樣區設置與前身為果園、檳榔園及竹林。模擬樹高直徑關係中，發現有些樹種之樣本量極少，因此採用混合式回歸模式模擬稀少物種之關係。初步結果發現林分潛力及苗木之間的競爭影響樹高直徑關係。探討此關係有助於規劃更完善之育林措施。此分享得到以會研究學者之共鳴，討論也許能套用混合式回歸模式分析馬來西亞物種豐富之熱帶雨林。
Associate Professor Tzeng Yih Lam Presentation at Tropical Forestry 2021
The Faculty of Tropical Forestry, Universiti Malaysia Sabah organized Tropical Forestry 2021 Online International Conference on 14-15 December 2021. Associate Professor Tzeng Yih Lam from the School of Forestry and Resource Conservation, National Taiwan University participated in the conference and presented on a topic about height-diameter relationships of tree species planted on reclaimed agricultural land. Taiwan has a long history of reforesting degraded forest lands and reclaimed agricultural lands to improve forest ecosystem services. While the effort has been ongoing since 1950’s, very few studies attempted to understand how tree species planted on these lands are growing. To fill the knowledge gap, we established plots across elevation from 250 to 2500 m above sea level on reforested fruit orchards, betel nut farms, and bamboo plantations. Diameter and height of 15 plantation tree species were measured. Mixed effects modelling framework was applied to model tree height and diameter relationship of the 15 species with the Wykoff model. Random effects were added to species so that species with few observations could share information from species with abundant information. Preliminary results show that stand productivity and tree-level competition have potential effects on height-diameter relationship. Studying height-diameter relationship could assist decision making for better management of ecosystem services of reclaimed agricultural lands.
Figure 1. Group photo of the session
Figure 2. Screenshot of Associate Prof. Lam Presentation