Impact of Spacing on Juvenile Wood and Mature Wood Properties of White Spruce (Picea glauca)

植樹間距對白雲杉幼齡木及成熟木的影響

楊恭志(Kang-Chi Yang)

《台灣林業科學》 17卷1期 (2002/03) Pp. 13-29

https://doi.org/10.7075/TJFS.200203.0013

摘要

此研究針對植枓間距對白雲杉幼齡木成熟木的生長率、比重、及假導管長度的影響加以研討。樣本是從一個38年生的人工林取採。此人工林座落在安大略省雷灣市附近30km處。此人工林有3個植樹間距，亦即是1.8，2.7和3.6m，在每一個間距區內隨機取樣十棵樹木，研究的木材樣本是用一個12mm直徑的木材抽出機在每一棵樣本樹南邊胸高處抽出，取得的資料是用Contrast test加以統計分析，幼齡木及成熟木的區域分界點是利用假導管長度的變異而訂定之標準。幼齡木的寬度是介於8個年輪和20個年輪之間，在所有三個植樹間距中，幼齡木的生長率皆較成熟木的生長率來的高，而幼齡木的假導管長度皆較成熟木的假導管長度來的短。幼齡木及成熟木假導管的平均長度分別是1.8-2.0mm和2.9-3.0mm。幼齡木及成熟木的比重極相近，在最窄的間距，幼齡木及成熟木的比重分別爲0.38和0.37。在兩個較寬的間距，其平均比重介於0.33和0.35。從統計分析得知假導管的長度不受間距的不同而異，不過有例外，幼齡木在較寬的間距有較長的假導管，雖然在統計上顯示假導管的長度不受間距所影響，但是假導管的平均長度在較寬的植樹間距則有增加長度的傾向。這增加的傾向和已知的發表資料迥異，此差異價得進一步的研討。

關鍵字

幼齡木 ； 成熟木 ； 植樹間距 ； 木材性質 ； 白雲杉

並列摘要

The impact of spacing on the growth rate, relative density, and tracheid length of juvenile and mature wood was evaluated. Ten plantation-grown white spruce (Picea glauca Moench. Voss) trees 38 years old grown at each of 3 spacings, i.e., 1.8×1.8 m, 2.7×2.7 m, and 3.6×3.6 m at Stanley, 30km west of Thunder Bay, Ontario were randomly selected for this study. Samples consisting of 12-mm-diameter increment cores were extracted at breast height from the south aspect of each tree. A contrast test was applied statistically to test the difference between spacings. Boundaries of juvenile and mature wood were demarcated with an earlywood tracheid length variation method. The juvenile-mature transition period of P. glauca ranged from 8 to 20 years. For all 3 plantation spacings, the growth rate in juvenile wood was greater than that of mature wood. In contrast, the mean earlywood tracheid length in juvenile wood, ranged from 1.8 to 2.0 mm which is shorter than those of mature wood which ranged from 2.9 to 3.0 mm. The relative densities (acetone extractive free) of juvenile and mature wood were found to be very similar for each spacing. The highest mean relative densities which occurred at the narrowest spacing were 0.38 to 0.37 for juvenile and mature wood, respectively. The mean relative densities of trees at the 2 wider spacings ranged from 0.33 to 0.35. Results of the contrast test indicated that there was no statistically significant impact of spacing on tracheid length, except in juvenile wood at the widest spacing which has long tracheids. However, arithmetically, a trend of increasing tracheid length with increasing spacing was discerned. This observation does not agree with most in the reports literature. Further studies are needed to clarify these contradictory results.

並列關鍵字

plantation spacing ； growth rate ； relative density ； tracheid length ； white spruce