闊葉樹於琉球松松材線蟲嚴重爲害林內的天然更新及其復育

Hardwood Natural Regeneration and Rehabilitation in a Seriously Nematode-damaged Luchu Pine (Pinus luchuensis) Plantation

馬復京(Fu-Ching Ma) ； 游漢明(Han-Ming Yu) ； 洪富文(Fu-Wen Horng) ； 張乃航(Nai-Hang Chang) ； 許原瑞(Yen-Ray Hsui)

《台灣林業科學》 17卷2期 (2002/06) Pp. 269-280

https://doi.org/10.7075/TJFS.200206.0269

摘要

台北縣坪林地區琉球松材線蟲(Bursaphelenchus xylophilus)爲害，致使上層的琉球松林木枯死殆盡，現今林分則是以陽性樹種白匏仔(Mallotus paniculatus)爲主要優熱種的次生闊葉林分，爲瞭解該次生闊葉林的樹種組成及更新潛力並考量維持林地的樹種組成及提升林地保育及生産能力，乃進行次生林更新潛力及復育造林的探討。本研究在坪林地區受害琉球松人工林進行下列處理：(1)不處理(control)，(2)清除灌叢(weeding)，(3)除草及增植作業(weeding with enrichment planting)。試區爲完全逢機區集設計，每一處理4重覆共4個區集。每一處理樣區面積爲40×25m合計1.2ha。次生闊葉林共調查得72個樹種，其中鳥心石、紅楠、香楠及江某具有良好的天然更新能力，可做爲林分經營的目標樹種。林慶整理後次生林分的胸高斷面積的生長效果不顯著，受害松林內天然更新幼木的發生，以林床整理的處理效果顯著，平均發生132株，對照區則平均發生34株，但在增植作業區平均發生不及1株，在發生幼木的樹種則仍以優勢種的白匏仔及野桐發生數量最多。林下栽植苗木平均成活率在82.6•，則顯示林床光度均維持在苗木可存活的等級以上，並非苗木存活的限制因子，而林下栽植的4個闊葉樹種以香楠的高生長表現最佳，連續4年平均累積淨高生長達199cm，而其他3個樹種累積高生長則在138cm以下。自此結果認爲利用既存的次生闊葉林再配合林下增植，可加速森林的復育。

關鍵字

高生長 ； 原生樹種 ； 增植 ； 成活率

並列摘要

A widespread nematode (Bursaphelenchus xylophilus) epidemic has occurred in northeastern Taiwan in the past 5-10 yr. Most of the Luchu pine plantations almost completely died back; this caused them to look like early developing secondary hardwood stands dominated by Mallotus paniculatus but interspersed with scattered standing dead Luchu pines. In order to estimate the potential natural regeneration capability of these nematode-damaged stands and determine rehabilitation measures, a typical plantation of this kind was selected in the Pinglin area, northern Taiwan and its stand structure was studied. Afterwards, a completely random block design with 3 treatments and 4 replicates was applied to the plantation. The 3 treatments included control, weeding, and weeding with enrichment planting. Each treatment area was 40×25 m. The total area was 0.1 ha. Within the plantation, 72 hardwood tree species were identified, and among them, good natural regeneration ability was found for important timber species, such as Michelia compressa, Machilus thunbergii, Mac. Zuihoensis and Schefflera significantly increase the basal area growth of the residual hardwood trees in the stand, which might have been affected by the disturbance of typhoons and damages caused by cutting practices of the nematode-damaged pines. However, weeding did increase the new occurrence of tree seedlings to an average of 132 seedlings/plot compared to 34 seedlings/plot in the control. As to the weeding with enrichment planting, the increase in new seedlings was lower than that in the control. The high weeding frequency in the treatment may have caused this result. The dominant naturally occurring seedlings were 2 pioneer tree species Mal. paniculatus and Mal. japonicus. For 4 native tree species used for enrichment planting, the net height growth of Machilus zuihoensis reached on average of 199 cm in 4 yr, but the net height growth of the remaining 3 tree species was still below 138 cm on average in the same period. The survival rates of seedlings were all above 82.6•, indicating the under-canopy bright is not a limiting factor in such stands. Weeding or weeding with enrichment planting can accelerate the restoration of this secondary forest.

並列關鍵字

height growth ； native species ； enrichment planting ； survival rate