Comparing the Early Growth of Pure and Mixed Plantations of ＂Calocedrus formosana＂ and ＂Michelia formosana＂ at Lienhuachih, Central Taiwan

本報告目的是比較蓮華池試驗林2001年造林單一樹種之肖楠、烏心石人工林和兩樹種混淆人工林在2×1、2×2和2×3公尺三種栽植距離早期胸高直徑和林分斷面積之生長。試驗設計採用完全逢機設計、混淆人工林混淆比例為50和50%，以隔行混樹種方式進行混植，並在樣區內進行多年度林木屬性之調查。使用Canon 5D II全片幅機身，搭配Sigma 8 mm魚眼鏡頭進行冠層魚眼影像之拍攝和分析。研究結果顯示到2012為止，烏心石之胸徑總生長較肖楠生長快速，混淆效應雖會增加烏心石之胸徑總生長，但會減少肖楠胸徑總生長。兩期之胸徑生長量顯示烏心石在第一期之生長明顯優於肖楠，但在第二期則不如肖楠。混淆效應擴張烏心石之胸徑範圍，但對肖楠之胸徑範圍則無影響。對兩種樹種，純林和混淆林而言，肖楠胸徑生長均以在2×1公尺栽植距離下最小，隨者栽植距離增加，在純林和混淆林間呈現不同之差異。在2×1公尺栽植距離，由於單位面積林木株數最多，使得林分斷面積最多，隨者株數減少，兩樹種和兩種人工林形態之林分斷面積，均會因栽植距離增加，有降低之趨勢。混淆林內＂Michelia＂較高之斷面積組成比例，反映出＂Michelia＂在混淆林中之優勢地位。樹冠幅顯示2×1公尺栽植距離在2012年時樹冠已開始鬱閉，但在2×3公尺栽植距離則尚未鬱閉。

關鍵字

種間競爭；種內競爭；混淆效應；栽植密度

並列摘要

In this study, we compared the early growth, in terms of the diameter at breast height (DBH) and stand basal area of ＂Calocedrus formosana＂ and ＂Michelia formosana＂ (11 yr after planting) in both even-aged monoculture and mixed plantations with 3 planting spacings at distances of 2×1, 2×2, and 2×3 m in the Lienhuachih Experimental Forest. The mixed proportion was set at 50 to 50% in the mixed plantation. In each plot, stems were tagged and identified by species, and their sizes were measured annually. Stem location was recorded on a Cartesian coordinate system. A Canon 5D camera with a Sigma 8-mm lens was used to capture a fish-eye image for the canopy analysis. Results showed that ＂Michelia＂ grew significantly faster than ＂Calocedrus＂ in terms of DBH in 2012, and the mixed effect in the mixed plantation increased the total DBH growth of ＂Michelia＂ but decreased that of ＂Calocedrus＂. Two periods of DBH increment indicated the superiority of ＂Michelia＂ in the 1st period but the opposite in the 2nd period. The plantation mixed effect expanded the DBH range of ＂Michelia＂ but not that of ＂Calocedrus＂. The DBH increment was the least at the 2×1-m spacing for both species and plantation type, but there were different impacts with the wider spacing between monoculture and mixed plantations. The stand basal area in 2012 was the greatest for the 2×1-m spacing because of the larger number of trees involved, and it decreased with a declining number of trees with a wider spacing for both species and plantation types. In the mixed plantation, the proportion of the stand basal area in ＂Michelia＂ was greater reflecting the much-faster growth of ＂Michelia＂ in mixed plantations. The crown width revealed that the canopy with the 2×1-m spacing in 2012 had closed but had not closed with the 2×3-m spacing.

並列關鍵字

interspecific competition ； intraspecific competition ； mixture effect ； planting spacing

國際替代計量

Comparing the Early Growth of Pure and Mixed Plantations of ＂Calocedrus formosana＂ and ＂Michelia formosana＂ at Lienhuachih, Central Taiwan

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