楓香人工幼齡林林分結構之量化及碳吸存能力之評估——以惠蓀林場為例

本研究目的在於分析楓香人工幼齡林之林分特性，研究區域位於南投縣仁愛鄉，為國立中興大學惠蓀林場第1林班第50號造林地，造林樹種為楓香，該林分原為孟宗竹林，但因竹林之生長衰退，林場於2011年將其剷除並栽植楓香，由於原竹林已有闊葉樹種入侵，林場在進行林相變更時，保留了具經濟價值之闊葉樹種，所以目前林分內除了楓香造林木外，也包含非楓香之其他闊葉樹種。本研究將林分區分為兩個層面進行分析，包含全林分及區別樹種（楓香與非楓香樹種），分別探討此兩個層面之林分性狀值、模擬林分結構及評估林分之碳貯存量。研究所得結果顯示，在林分性狀值方面，楓香之林分密度較非楓香樹種高，其餘林分性狀值非楓香樹種皆高於楓香。在林分結構方面，以Weibull機率密度函數分別模擬全林分、楓香與非楓香樹種之直徑分布，模擬結果經Kolmogorov-Smirnov統計檢定，顯示Weibull函數具良好的模擬結果，亦即此函數可有效的量化此三者之直徑分布。在林分之碳貯存量方面，整體林分之碳貯存量為60.09±31.07 Mg ha-1，其中楓香與非楓香樹種之貢獻比例約1：2，即非楓香樹種仍為此林分碳貯存量之主要貢獻者，此外，本研究根據碳貯存量之分析結果推估楓香樹種之碳吸存量，其碳吸存量為2.84±1.00 Mg ha-1 yr-1。 The purpose of this study was to explore the stand characteristics for a juvenile Liquidambar formosana plantation. This study was conducted at the No. 50 plantation area of the No.1 compartment of Huisun Forest Station. The study site belongs to National Chung Hsing University and is located in Ren'ai Township, Nantou County. The site was originally dominated by a moso bamboo (Phyllostachys pubescens) forest. Due to the decline of the bamboo forest, broadleaved trees have invaded in this bamboo forest. The Huisun Forest Station decided to eradicate the bamboo forest and L. formosana were planted in 2011. Some broadleaved trees with economic values were also kept. Consequently, this plantation contained L. formosana and broadleaved trees. We analyzed the stand characteristics, simulated stand structure and estimated carbon storage based at the whole stand level and tree species level (contain L. formosana trees and the other trees). The result showed that L. formosana had higher stand density than broadleaved trees while other stand characteristics showed the opposite results. The results of stand diameter distribution simulated with Weibull probability density function showed good fit by the Kolmogorov-Smirnov test for both whole stand and tree species levels, implying that this model can effectively describe the stand diameter distribution at different levels. Moreover, we evaluated the carbon storage, and found that the carbon storage of the entire stand was 60.09±31.07 Mg ha-1. The proportions of L. formosana trees and the other broadleaved trees was approximately 1:2, indicating that the other broadleaved trees were the main contributor in carbon storage for the entire stand. Furthermore, we calculated the carbon sequestration for L. formosana trees based on their carbon storage, and the value was predicted to be 2.84±1.00 Mg ha-1 yr-1.