八種不同耐陰性樹種根系分布樣式之比較

Comparison on Root Distribution Pattern of Eight Tree Species with Different Shade Tolerance Classes

洪培翔(Pei-Xiang Hung)

指導教授 ： 郭耀綸

國立屏東科技大學/農學院/森林系所/碩士(2015年)

https://doi.org/10.6346/NPUST.2015.00214

摘要

林木的根系生長在地下，不易觀察其生長發育狀況，但瞭解不同樹種根系型態及分布樣式，在育林或水土保持上都有重要應用價值。本研究將8種台灣原生闊葉樹種一年生苗木栽植於長12 m，寬2 m，高1.0 m的大型容器內，目的是為了在收穫後觀察其根系生長及分布狀況。供試樹種包括苦楝、光臘樹、茄冬及樟樹等4種陽性樹種，以及烏心石、棋盤腳、恆春楨楠及蓮葉桐等4種中等耐陰樹種。栽植11個月後，發現苦楝樹高生長最大，達336 cm，其次為茄冬、光臘樹及樟樹，樹高在160-200 cm範圍。在根系生物量分配方面，蓮葉桐根部生物量為全株生物量的54%，苦楝約為40%，光臘樹、茄冬、樟樹、烏心石及棋盤腳約為30%，而恆春楨楠僅有11%。苦楝粗根佔全部根系重量的96%，茄冬、樟樹及棋盤腳則約80%，光臘樹、烏心石、恆春楨楠及蓮葉桐在50-70%範圍。在根系垂直深度方面，苦楝、茄冬、樟樹、棋盤腳及蓮葉桐可超過60 cm深，而光臘樹、烏心石及恆春楨楠只達45 cm。在根系水平分布方面，苦楝可長達331 cm，茄冬及樟樹可達100 cm以上，光臘樹、烏心石、棋盤腳及蓮葉桐在51-100 cm範圍，而恆春楨楠則少於50 cm。供試樹種根系垂直深度及水平分布，均與各樹種的樹高具顯著正相關。苦楝根系水平分布面積可高達8.81 m2，茄冬為2.33 m2，樟樹為1.06 m2，其餘樹種均未超過1 m2。供試樹種屬於主根性者為苦楝、樟樹、烏心石及蓮葉桐；根系無主根者為光臘樹、茄冬及恆春楨楠，但這些樹種的側根分枝較為發達；棋盤腳主根不明顯，但根系常有3-4個生長健壯的分枝。本研究於試驗後發現供試8樹種在根系型態及分布樣式會有不同差異，苦楝、茄冬、樟樹及蓮葉桐的根系生長較旺盛且分支較多；棋盤腳雖分支較少，但根系生長較其他樹種粗壯；光臘樹、烏心石及恆春楨楠根系生長並不旺盛。

關鍵字

生物量分配 ； 根系水平分布 ； 根系垂直深度 ； 根系形態

並列摘要

A tree root system grows under the ground, it is not easy to observe its growth and development. But, to understand the root types and distribution patterns of different species is important to applications in silviculture and soil and water conservation. I planted 8 kinds of one year-old seedlings of Taiwan native broadleaf species in large vessels with 12 m in length, 2 m in width, and 1 m in heigh. The objectives of this research was to observe the root growth and distribution after harvest. Experimental tree species included Melia azedarach, Fraxinus formosana, Bischofia javanica, and Cinnamomum camphora which are shade-intolerant species, and Michelia compressa, Barringtonia asiatica, Machilus obovatifolia and Hernandia Sonora which are medium shade-tolerant species. 11 months After planting I discovered that M. azedarach had the biggest growth height of 336 cm, followed by B. javanica, F. formosana and C. camphora with growth height of 160-200 cm. Regarding the biomass allocation in root againt the whole tree, it was 54% for H. Sonora, 40% for M. azedarach, 30% for F. formosana, B. javanica, C. camphora, M. compressa and B. asiatica and 11% for M. obovatifolia. Regarding the biomass allocation in coarse root against the whole root, it was 96% for M. azedarach, 80% for B. javanica, C. camphora and B. asiatica, and 50-70% F. formosana, M. compressa, M. obovatifolia and H. Sonora. Regarding the depth of root, it was over 60 cm for M. azedarach, B. javanica, C. camphora, B. asiatica and H. Sonora, and 45 cm for F. formosana, M. compressa and M. obovatifolia. Regarding the width of root, it was 331 cm for M. azedarach, over 100 cm for B. javanica and C. camphora, 51-100 cm for F. formosana, M. compressa, B. asiatica and H. Sonorain, and less than 50 cm for M. obovatifoliais. The depth and width of the experimental trees showed of significant positive correlation with the height. Regarding the horizontal area of the root distribution, it was 8.81 m2 for M. azedarach, 2.33 m2 for B. javanica, 1.06 m2 for C. camphora, 1 m2 for the other. Regarding the root type, M. azedarach, C. camphora, M. compressa and H. Sonora had one single major root; F. formosana, B. javanica and M. obovatifolia had no major root, but with more than 10 major branches, and B. asiaticais had 3-4 major roots. The 8 species had their different root types and distribution patterns. M. azedarach, B. javanica, C. camphora, and H. Sonora had heavier root growth. B. asiatica had less root branches but each larger than other. F. formosana, M. compressa, and M. obovatifolia had lighter roots.

並列關鍵字

biomass allocation ； root horizontal distribution ； root vertical distribution ； root morphology

參考文獻

廖宜緯、郭聖平、陳羽康、鍾玉龍 (2011) 台灣五種海岸防風林樹種根系之研究。華岡農科學報 26: 113-128。

林國銓、杜清澤、黃菊美、王巧萍 (2006) 亞熱帶闊葉樹林木粗根生物量和養分含量之估算。台灣林業科學 21(2): 155-166。

陳財輝、呂錦明 (1988) 苗栗海岸沙丘木麻黃人工林之生長及林分生物量。林業試驗所研究報告季刊 3(1): 333-343。

杜清澤、邱志明、林國銓(2011) 人倫地區柳杉人工林地上部與地下部生物量之估算。中華林學季刊44(3): 401-412。

林國銓、杜清澤、黃菊美 (2010) 光臘樹人工林碳貯存量和吸存量之估算。中華林學季刊 43(2): 261-276。