Species Composition, Size-Class Structure, and Diversity of the Lienhuachih Forest Dynamics Plot in a Subtropical Evergreen Broad-Leaved Forest in Central Taiwan

蓮華池常綠闊葉林動態樣區之物種組成、徑級結構與多樣性研究

張勵婉(Li-Wan Chang) ； 黃正良(Jeen-Lian Hwong) ； 邱少婷(Shau-Ting Chiu) ； 王相華(Hsiang-Hua Wang) ； 楊國楨(Kuoh-Cheng Yang) ； 張秀瑩(Hsiu-Ying Chang) ； 謝長富(Chang-Fu Hsieh)

《台灣林業科學》 25卷1期 (2010/03) Pp. 81-95

https://doi.org/10.7075/TJFS.201003.0081

摘要

依據CTFS長期進行永久樣區研究所發展而成之作業模式，進行木本植物普查，於蓮華池天然林內設置一處25公頃(500 m×500 m)之森林動態學研究永久樣區。調查項目包含每一棵樹的物種名稱、胸高直徑(DBH)與每一棵樹木的位置，調查結果區域內共計有144種木本植物，分屬於39科，86屬；其中DBH在1 cm以上的木本植物株數共計153,268株（6131株／公頃）。
以全樣區各科重要值指數而言，以樟科、殼斗科、茜草科最為優勢。統計數量最多的種類者為茜草樹，次多者為柏拉木。全樣區平均每公頃底面積為34.77平方公尺。南投石櫟底面積最大，佔全部底面積的8.38%，黃杞及鵝掌柴分別位居第二8.12%及第三7.23%。以重要值IV（相對密度及相對底面積加總）而言，樣區內最優勢的種類分別為茜草樹8.34%及柏拉木5.50%，其次為鵝掌柴5.41%，前30名物種累計可達83.06%。總體而言，優勢組成的集中於少數物種，而株數稀少之種類增加樣區物種的多樣性。
各種類徑級分佈呈現4型，分別為L型，倒J型、波動型及鐘型。前3型共98種，表此森林大部份的物種有足夠的幼苗，更新良好。以生物多樣性而言，與台灣其他低海拔動態樣區比較，蓮華池動態樣區為最為豐富；另與世界上島嶼動態樣區比較，其多樣性值低於其它熱帶的樣區，卻和波多黎各動態樣區相當。

關鍵字

物種組成 ； 徑級結構 ； 多樣性 ； 亞熱帶常綠闊葉林 ； 蓮華池動態樣區

並列摘要

The Lienhuachih Forest Dynamics Plot (FDP), measured 500 m by 500 m square, is located in central Taiwan. The collected data, followed a unified method adopted for the worldwide FDP network, were analyzed for floristic composition, size-class structure, and species diversity. In total, the censused trees and shrubs belonged to 144 species in 86 genera and 39 families. The most dominant families were the Fagaceae, Lauraceae, Rubiaceae, Euphorbiaceae, and Melastomataceae. In total, 153268 (6131 ha^(-1)) individuals were recorded, and the total basal area was 34.77 m^2 ha^(-1). Of the 144 species, the most abundant were Randia cochinchinensis and Blastus cochinchinensis. Pasania nantoensis had the highest basal area (8.38%), followed by Engelhardtia roxburghiana (8.12%) and Schefflera octophylla (7.23%). Calculation of the importance value (IV, incorporating relative values of abundance and basal area) showed that R. cochinchinensis, B. cochinchinensis, S. octophylla, Cryptocarya chinensis, and E. roxburghiana were the most dominant species with the highest IV values in the plot. The sum of the 30 top species' IV reached 83.06% of the whole. Although the 1st 2 species were understory and very dominant due to the large number of individuals, certain numbers of rare species however increased the floristic diversity in the plot. Based on the species composition, the forest is characteristic of the Machilus-Castanopsis forest zone of Taiwan, with certain dominant understory species and possessing 2 pioneer species in the major canopy composition.
For the size-class structure, 102 (each with total stems ≥ 25) species showed 4 patterns of size-class distribution: L-shaped, inverse J-shaped, fluctuating, and bell-shaped. The former 3 patterns in a total of 98 species, including a great number of small-sized individuals, imply that most current species in this study site can display good recruitment with rich resources of saplings. The woody plant richness of the Lienhuachih FDP is the highest among low-elevation FDPs in Taiwan. Compared to other Center of Ttropical Forest Science forest dynamics plots on islands, Fisher's alpha diversity (ha^(-1)) index of the subtropical Lienhuachih FDP was similar to that of the Luquillo FDP in Puerto Rico but much lower than that of other FDPs in the tropics.

並列關鍵字

species composition ； size class structure ； diversity ； subtropical evergreen broad-leaved forest ； Lienhuachih Forest Dynamics Plot