台灣中部蓮華池試驗林天然闊葉林與人工杉木林葉面積指數變動及其對初級生產力估算之影響

Variations in the Leaf Area Index and Its Effect on Estimations of Primary Production in a Natural Hardwood Forest and a Cunninghamia lanceolata Plantation at the Lienhuachi Experimental Forest, Centr

陳青香(Chin-Hsiang Chen) ； 林登秋(Teng-Chiu Lin) ； 黃正良(Jeen-Liang Hwong)

《台灣林業科學》 22卷4期 (2007/12) Pp. 423-439

https://doi.org/10.7075/TJFS.200712.0423

摘要

本研究於2005年在中部蓮華池試驗林3號（天然闊葉林）及4號集水區（人工杉木林），以LI-CORLAI-2000測量葉面積指數(LAI)，全年共測定LAI 6次。一年內天然闊葉林之平均LAI介於2.64~4.72，人工杉木林介於3.18~3.95，兩者之LAI在一年內皆有可觀的變動。測定期間3月低溫造成天然闊葉林LAI下降31%，而人工杉木林則至5月才下降且幅度較小(15%)，顯示異常低溫對杉木林的影響不若天然闊葉林立即而嚴重。7月18~19日海棠颱風過後，八月測得之天然闊葉林與人工杉木林LAI分別下降11及18%，海棠颱風對人工杉木林之影響似較對天然闊葉林之影響為大。天然闊葉林6次測量期間，3條樣線間LAI的差異最大達3.16（11月），該月B3樣線的LAI (6.34)幾乎是最低的B2 (3.18)的2倍。人工杉木林3條樣線間LAI的差異最大達3.12（3月），該月C3的LAI (5.74)，為C1 (2.62)的2倍以上。本研究中人工杉木林3條樣線間LAI的差異大於天然闊葉林。將本研究所測得之LAI套入一由LAI推估淨初級生產量的模式，結果顯示LAI之季節與空間變動，可使天然闊葉林與人工杉木林因為取樣時間不同而造成模式推估結果的變動達66及22%，而因取樣地點不同而造成模式推估結果的變動達45及49%。忽略LAI時空變動的特性，所得到的結果很可能依取樣的時間與地點而異，且此變異可能超過不同林分以及不同地區的同種林分。

關鍵字

天然闊葉林 ； 杉木林 ； 葉面積指數 ； 蓮華池試驗林

並列摘要

We set up 3 crest-to-valley transects each in watersheds no. 3 (a natural hardwood forest) and no. 4 (a Cunninghamia lanceolata plantation) at Lienhuachi Experimental Forest of central Taiwan in 2005. We measured the leaf area index (LAI) 6 times using a LI-COR LAI-2000 Plant Canopy Analyzer. The mean LAI measured during the sampled year ranged from 2.64 to 4.72 in the natural hardwood forest and from 3.18 to 3.95 in the C. lanceolata plantation. Both types of forests showed substantial intra-annual variation. Unusually low temperatures in March caused a 31% decrease in the LAI in the hardwood forest, but in the C. lanceolata plantation, the decrease was not detected until May and it was much smaller (15%). After typhoon Haitang passed nearby on July 18~19 LAI values decreased 11 and 18% in the hardwood forest and C. lanceolata plantation, respectively. Typhoon Haitang seemed to have a greater impact on the C. lanceolata plantation than on the natural hardwood forest. For the 6 samplings, the largest differences in LAI among the 3 transects reached 3.16 (November) in the hardwood forest in which the LAI of B3 (6.34) was approximately 2 times that of B2 (3.18). For the C. lanceolata plantation the largest difference reached 3.12 (March) with an LAI of C3 (5.73) being more than 2 times that of C1 (2.62). LAI differences among transects were greater in the C. lanceolata plantation than in the natural hardwood forest. Applying the measured LAI values to an ecological model showed that the temporal variation in LAI led to 66 and 22% differences in the estimation of the above-ground net primary production (ANPP) of the natural hardwood forest and C. lanceolata plantation, respectively, and spatial variations in LAI led to 45 and 49% differences in ANPP estimations. Without considering such temporal and spatial variations in LAI, estimations of ANPP will be dependent on both time and location, and such variations can be greater than differences among forests of different types and at different sites.

並列關鍵字

natural hardwood forest ； Cunninghamia lanceolata ； leaf area index ； Lienhuachi Experimental Forest