應用SORTIE-ND模型模擬平地森林光臘樹林分的動態發展

A Simulation of the Stand Dynamic of Fraxinus Formosana Forest in Cultivated Land Using the SORTIE-ND Model

林金樹(Chin0-Su Lin) ； 馬曉恩(Siao-En Ma)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 24卷1期 (2010/03) Pp. 63-78

https://doi.org/10.6542/EFNTU.201003_24(1).0006

摘要

本研究以台南市白河區台糖所轄白河崁頂農場平地森林光臘樹（Fraxinus formosanaHayata）為研究對象， 依據林分直徑結構、直徑與樹高生長、林分枯損率等基本資訊，利用SORTIE-ND模型模擬光臘樹林分的發展趨勢，建立適合平地森林光臘樹林分的生長模型，並藉以評估性模型的適用性。研究結果顯示，50年生光臘樹林分密度即有反曲點出現，顯示林分因競爭而出現自我疏伐現象，林分胸高斷面積的變化趨勢受林分密度以及環境因子的影響出現不同的結果。第1、4、5樣區林分因競爭枯損或老化而疏開之後，會促進存留木的生長使得林分胸高斷面積維持上升狀態，第2、3、6樣區則因自我疏伐效果不彰使得存留木的生長維持平緩狀態。樣區現場資料與模擬資料的比對採用恆定面積增長定律（the constant areaincrement law, CAIL）以彌補數據間年分上的差距。結果顯示SORTIE-ND模型對於各樣區的模擬結果與實際值平均差距約為28%。孔隙模型為目前研究林分動態的主流，然而此類模型所建立的預測具有一定程度的不確定性，此種不確定性和模型的組成結構有關，因此各種參數推估方式與精細度將影響此類模型預測的準確程度。

關鍵字

林分動態 ； 光臘樹 ； SORTIE-ND

並列摘要

This study applied SORTIE-ND model to simulate the development of an afforestation hardwood forest in cultivated land. It also evaluated the suitability of this model in the simulation of forest development for local use in Taiwan. A stand of Fraxinus formosana Hayata on the Baihe farm managed by Taiwan Sugar Corporation was selected for this study. Diameter structure, growth of height and diameter, and mortality of the forest stand were measured and used for the SORTIEND modeling. Results showed that the stand density had inflection points in 50 years. It is shown that stand self-thinning happened due to competition. The increasing trend of stand basal area (BA) might be influenced by stand density and environmental factors and thus leaded to different results. BAs of trees in plots 1, 4, and 5 continuously increased after self-thinning, while the retained trees in plots 2, 3, and 6 had slower growth due to poor performance of self-thinning.A comparison of the field data and the simulation data was conducted based on the constant area increment law (CAIL) which is able to cover the time steps difference between yearly sampling intensity of the inventory and the simulator. Results showed that the predicted BA growth using SORTIE-ND model and the measured BA growth were around 28 percent deviation. Gap model is one of the main approaches for stand dynamic research, but its prediction has a certain degree of uncertainty mainly related to the model infrastructure. The exactness of model parameters applied in the simulation would affect the predict ability of SORTIE-ND model.

並列關鍵字

Stand dynamic ； Fraxinus formosana Hayata ； SORTIE-ND