關渡自然保留區1986-1998年植群變遷

Vegetation Changes at the Kuantu Nature Reserve during 1986-1998

李建堂(Cheing-Tung Lee) ； 鄭育斌(Yu-Pin Cheng) ； 邱文良(Wen-Liang Chiou) ； 林則桐(Tzer-Ton Lin) ； 陳建文(Chien-Wen Chen) ； 王儀臻(I-Chen Wang)

《台灣林業科學》 17卷1期 (2002/03) Pp. 41-50

https://doi.org/10.7075/TJFS.200203.0041

摘要

本研究利用系統調查關渡自然保田區於1998年的植物社會。全區共設置16條南北向樣線，紀錄每一樣線的植物組成及相對覆蓋度，並沿樣線每隔20m取2×2m的小樣區，紀錄植物組成、覆蓋度、水筆仔數量及胸高自徑。同時沿各樣線每隔10m紀錄所在的生育地類型，並量測高程。調查結果用來和1986年的結果比較，以瞭解關渡自然保留區植物社會在1986-1998年間的變遷情形，並推估研究區的平均堆積速率。研究結果顯示，在1986年以單葉鹹草、蘆葦和水筆仔爲優勢植物社會的草澤地，已轉變成以水筆仔和蘆葦儿優勢的林澤。水筆仔、蘆葦和裸露地的樣線覆蓋度分別爲61.3、25.5和13.2%,而單葉鹹草則已完全消失，水筆仔的相對覆蓋度約佔1998年植群總而積的70.6%。樣區調查得到水筆仔的總株數爲3666株，其中樹木與苗木數量的比例約偽1:3.8，而其胸徑分布與1986年時相同，皆呈反J型，顯示其更新良好，仍其有擴展的空間。植物社會的海拔高程量測結果顯示，水筆仔和蘆葦的海拔分布幅度分別在0.2-1.3m和0.3-1.6m之間，而裸地高程則在1.2m以下。蘆葦生育地的海拔高程分布高於水筆仔，且兩者之間呈顯著的差異(α=0.05)，與1986年的結果相同。在1986-1998年間，研究區每年的平均堆積速率約2.0cm。

關鍵字

關渡自然保留區 ； 水筆仔 ； 堆積速率

並列摘要

A systematic survey was used to investigate the vegetation structure of the Kuantu Nature Reserve, northern Taiwan in 1998. In totals 16 transects were carried out in the study area to investigate vegetation types and relative coverage. Meanwhile, along with each transect, a 2 x 2-m quadrat was sampled with 20-m intervals to record vegetation type, coverage, numbers of Kandelia, and the diameter of Kandelia at breast height. Additionally, field elevation surveys were conducted along with each transect at 10-m intervals. The results were used to compare with findings from 1986 in order to understand how the vegetation has changed during 1986-1998 and to estimate the accretion rate in the study area. The results revealed that the marsh habitat in 1986, dominated by Cyperus, Phragmites, and Kandelia, had changed into a swamp habitat dominated by Kandelia and Fhragmites by 1998. Transect coverages of Kandelia, Fhragmites, and bare land were 61.3, 25.5, and 13.2%, respectively, and Cyperus had disappeared. Relative coverage of Kandelia in the study area was approximately 70.6% of the total vegetation area. The total number of Kandelia was 3666, of which the ratio of samplings and trees to seedlings was about 1:3.8. The size-class distribution of the Kandelia population showed a reversed J-shape which is similar to the results from 1986. The elevation range for Kandelia and Fhragmites was 0.2-1.3 and 0.3-1.6 m, respectively. Elevation of bare land was below 1.2 m. The elevation range of Kandelia significantly differented from that of the Fhragmites (a=0.05), a result similar to that from 1986. On average, the accretion rate in the study area during 1986- 1 998 was about 2.0 cm/yr.

並列關鍵字

Kuantu Nature Reserve ； Kandelia ； accretion rate