屏東萬隆農場櫸木之生長及CO_2吸存量

Assessment of Growth and CO_2 Sequestration of ＂Zelkova serrata＂ in the Wan-Long Farm, Pingdong

陳忠義(Chung-I Chen) ； 王亞男(Ya-Nan Wang) ； 葉玲薇(Ling-Wei Yeh) ； 謝忠諺(Chung-Yen Hsieh) ； 余瑞珠(Jui-Chu Yu) ； 吳宗賢(Chung-Shien Wu)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 26卷3期 (2012/09) Pp. 191-199

https://doi.org/10.6542/EFNTU.201209_26(3).0003

摘要

林木利用光合作用將碳吸存於體內，是自然界的碳貯存源之一。林木的固碳作用可緩和全球暖化，因此估算林木的CO_2吸存量，為現今的重要議題。臺灣以往的林木CO_2吸存量之研究，以山區的造林地為主，對平地造林的林木CO_2吸存狀況，仍缺乏完善的資料。本研究以屏東縣萬隆農場平地造林為試驗地，調查試驗地在2002及2003年廣泛栽植的櫸木（6－8年生）之生長量，並計算其材積及CO_2吸存量。結果顯示6年生櫸木之平均胸徑為3.86 cm，7年生為4.07 cm（2002年栽植）、5.29 cm（2003年栽植）、8年生為6.42 cm。比較胸徑與冠幅的生長趨勢顯示本試驗地櫸木尚未鬱閉。CO_2吸存量8年生櫸木為26.60 Mg／ha，7年生為24.50 Mg／ha。與前人研究比較，其CO_2吸存量較樟樹、楓香等闊葉樹種為低，表示萬隆農場的櫸木造林木之生長量不佳，可能是初期生長不良或其他環境因子所致，因而有較低的材積及CO_2吸存量。各項生長參數與碳吸存量的回歸式顯示，單以胸徑加入回歸式（Y = -0.00902+0.00254 × DBH）即可達相當的準確率，而加入樹高的參數後，R2可達0.917（Y = -0.01054+0.00069211 × H+0.00227 × DBH），可供將來迅速推估本試驗地櫸木碳吸存量之參考。整體而言，萬隆農場的櫸木生長較其他平地造林地區的造林樹種差，死亡率也高於本試驗地的其他樹種，且其葉片常有病害的症狀，較不適合栽植於本試驗地。

關鍵字

人工林 ； 櫸木 ； 生長表現 ； 碳吸存量 ； 平地造林

並列摘要

Trees sequestrate carbon of CO_2 via photosynthesis, which greatly alleviates the global warming. As a result, assessing CO_2 sequestrations becomes an important issue. Related study in Taiwan is focusing on plantations in mountain areas. However, assessing CO_2 sequestrations from trees of plain areas remains limited. In this study, we estimated the growth and CO_2 sequestrations of ＂Zelkova serrata＂, the most extensively planted species in the Wan-Long farm in Pingtung. Our results showed that the average DBH values of 6-year-old, 7-year-old and 8-year-old ＂Z. serrata＂ were 3.86 cm, 4.07 cm (planted in 2002), 5.29 cm (planted in 2003), and 6.42 cm, respectively. The DBH values and canopy diameters were well correlated, suggesting that the canopies of ＂Z. serrata＂ were keeping expansion in 2010. For CO_2 sequestrations, 8-year-old trees of ＂Z. serrata＂ have sequestrated CO_2 of 26.60 Mg/ha, and 7-year-old trees have sequestrated CO_2 of 24.50 Mg/ha. Apparently, the amount of sequestrated CO_2 in sampled ＂Z. serrata＂ trees was relatively low when compared with those in other trees species in previous studies. This indicates that ＂Z. serrata＂ trees afforested in Wan-Long farm are not good in growth, possibly due to bad growth at the early stage of afforestation. Our regression analysis yielded a good-fit model (Y = -0.01054+0.00069211 × H+0.00227 × DBH; R^2 = 0.917) when parameters of growth, carbon sequestration, and height were taken into account. This model facilitates to rapidly estimate the carbon sequestrations of ＂Z. serrata＂ in the Wan-Long farm. In conclusion, the low growth and survival rates of ＂Z. serrata＂ in the Wan-Long farm imply that this area is not suitable for ＂Z. serrata＂.

並列關鍵字

Plantation ； ＂Zelkova serrata＂ ； Growth ； CO_2 sequestration ； Lowland plantation