孟宗竹林伐採後二年間地上部生物量與碳吸存量動態

Estimating Aboveground Biomass and Carbon Sequestration of Moso Bamboo Grown under Selection Cutting after Two Years

本研究係以惠蓀林場孟宗竹林分為樣區，調查樣區現有孟宗竹之DBH、竹齡，再依皆伐、擇伐和未處理等3組試驗處理，並於處理後連續調查2年，利用模式估算其林分年生長生物量，並配合碳含量，進而比較不同試驗處理對於孟宗竹碳吸存量之差異。研究結果顯示，處理後第1年，對照組孟宗竹林分碳吸存量為4.1±2.7Mg ha^(-1)year^(-1)、擇伐區為6.7±1.0Mg ha^(-1)year^(-1)、皆伐區則為2.2±0.4Mg ha^(-1)year^(-1)；第2年對照組孟宗竹林分碳吸存量為1.7±0.5Mg ha^(-1)year^(-1)、擇伐區為1.5±2.9Mg ha^(-1)year^(-1)、皆伐區則為5.8±2.0Mg ha^(-1)year^(-1)。對照組和擇伐處理的樣區，其單位時間內碳吸存量將隨時間增長而趨緩；皆伐處理將使次年碳吸存量大幅減少，但卻於隔年又漸恢復。擇伐處理並不會對新生孟宗竹胸徑造成顯著的影響，但卻會對年生長生物量與碳吸存量影響顯著。且擇伐處理後，隔年單位面積之竹林總生物量及碳吸存量會超越對照組。經營孟宗竹林分，應以連年擇伐成熟竹稈為主，若擇伐之竹可加以利用作為竹製產品將碳保存於其中，對碳替代的效果是正面的。而人工竹林適當經營，可使碳吸存量提升。 The effect of cutting treatments on the aboveground biomass and carbon sequestration of Moso bamboo (Phyllostachys pubescens) was studied by investigating diameter at breast height (DBH) for 2 years. The multiple regression model and carbon content were used to estimate aboveground biomass and carbon sequestration of Moso bamboo. The carbon sequestration in the first year after three treatments showed the following trend: selection cutting (6.7 Mg ha^(-1) year^(-1)) ＞ control (4.1 Mg ha^(-1) year^(-1)) ＞ clear cutting (2.2Mg ha^(-1) year^(-1)); after 2 years of treatments showed the following trend: clear cutting (5.8 Mg ha^(-1) year^(-1)) ＞ control (1.7 Mg ha^(-1) year^(-1)) ＞ selection cutting (1.5 Mg ha^(-1) year^(-1)). Varying selection cutting were no significant difference to the DBH of newborn bamboo, but actually attracted the net gross biomass and the carbon sequestration. And after selection cutting, the carbon sequestration of the Moso bamboo stand would exceed the control stand demonstrating that the Moso bamboo stand need suitable management to promote the carbon sequestration.

The effect of cutting treatments on the aboveground biomass and carbon sequestration of Moso bamboo (Phyllostachys pubescens) was studied by investigating diameter at breast height (DBH) for 2 years. The multiple regression model and carbon content were used to estimate aboveground biomass and carbon sequestration of Moso bamboo. The carbon sequestration in the first year after three treatments showed the following trend: selection cutting (6.7 Mg ha^(-1) year^(-1)) ＞ control (4.1 Mg ha^(-1) year^(-1)) ＞ clear cutting (2.2Mg ha^(-1) year^(-1)); after 2 years of treatments showed the following trend: clear cutting (5.8 Mg ha^(-1) year^(-1)) ＞ control (1.7 Mg ha^(-1) year^(-1)) ＞ selection cutting (1.5 Mg ha^(-1) year^(-1)). Varying selection cutting were no significant difference to the DBH of newborn bamboo, but actually attracted the net gross biomass and the carbon sequestration. And after selection cutting, the carbon sequestration of the Moso bamboo stand would exceed the control stand demonstrating that the Moso bamboo stand need suitable management to promote the carbon sequestration.