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題 名 | 極點分布序列終端樣區選擇之研究=The Study on the Selection of Terminal Plots for Polar Ordination |
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作 者 | 呂金誠; | 書刊名 | 國立中興大學實驗林研究彙刊 |
卷 期 | 19:1 1997.03[民86.03] |
頁 次 | 頁125-144 |
分類號 | 436.12 |
關鍵詞 | 極點分布序列; 終端樣區; 相異性指數; 相關係數; Polar ordination; Terminal stands; Dissimilarity indicescorrelation coefficient; |
語 文 | 中文(Chinese) |
中文摘要 | 極點分布序列是植群分析上最常被應用的一種分析方法,本研究利用三個研究地 區的植群調查資料及9種X軸,135種Y軸及2﹐025種Z軸的決定方式,探討本方法 在應用上的一些問題。結果顯示,各終端樣區選擇方法所決定的各軸,均會發生嚴重的重複 現象,因此不同的分析過程將導致不同的結果。同時這種重複現象在環境變異越大的地區, 亦越明顯。而各軸與相異性指數間的相關係數,與調查地區內的環境變異程度呈反比,故當 調查區域之環境變異過大時,要將過多的變異用低向度的平面或空間,來加以表達有其困難 。而在終端樣區的選擇上,植群分化不過於明顯時,宜採用較為嚴苛的終端樣區選擇方法; 反之,則宜採用較為中間型的選擇法來決定各軸,所得的分析結果表達性較佳。終端樣區選 擇不當,將使極點分布序列各二維及三維空間與相異性指數間的相關係數低至不具代表性, 這時使用極點分布序列來分析植群,表面上亦能獲得分析結果,但這些結果卻沒有任何價值 與意義可言,實值得使用本法進行分析的研究者加以留意。 |
英文摘要 | The polar ordination (PO) is one vegetation analysis method widely used by plant ecologists. Vegetation data investigated from three areas and 9 determined methods of the X axis, 135 determined methods of the Y axis and 2,025 determined methods of the Z axis of PO was studied in this paper to understand some problems of PO. The results reveals the repeatbility of all axes may occur by any selected methods of terminal plots. Due to different terminal plots determine different axes of PO, and lead to different results. The repeatability of axes is also more serious at vegetation on more differentiated areas. The correlation coefficient between the axis of PO and the dissimilarity indices is negatively related to the environment gradient of studied area, and it is difficult to present the multi-dimensional data with low dimensional space when the environmental gradient is sharp. To obtained the best analyzed results, the terminal plots must be selected by more strict methods in less environment variance and less vegetation differentiated area. By contrast, it is adequate to select by more medium methods. It is worthy for the researchers to note that not suitable selected methods will product the low correlation coefficients between the 2 or 3 dimensional space with dissimilarity indices, and may be not representative for investigation data. |
本系統中英文摘要資訊取自各篇刊載內容。