人工造林與天然林對溪流水質之影響

Impact on Stream Water Quality by Plantation and Natural Forest

余瑞珠(Rei-Ju Yu) ； 王亞男(Ya-Nan Wang) ； 蕭英倫(Ing-Luen Shiau) ； 林法勤(Far-Ching Lin) ； 柯淳涵(Chun-Han Ko)

《中華林學季刊》 42卷4期 (2009/12) Pp. 529-539

https://doi.org/10.30064/QJCF.200912.0005

摘要

本研究目的在探討人工造林與天然林對溪流水質之影響。實驗地點選在南投縣信義鄉台大實驗林人工造林集水區（內茅埔營林區轄區內茅埔溪、坪瀨溪）以及天然林集水區（和社營林區沙里仙溪），於2004年進行水質監測，並比較不同林份對溪流水質之影響。經2004年的水質監測並分別分析水量、水中總溶解固體(TSS)、懸浮固體(SS)、總氮(TN)、水中總磷(TP)以及水中生化需氧量(BOD)等變化。結果顯示天然林集水區（沙里仙溪）水量只有在颱風季節較人工造林集水區大，其它月份並沒有差異。而人工造林集水區TSS及SS相較於天然林只有在颱風季節有較高的濃度，而其它月份並沒有差異，這可能因為颱風帶來雨水沖蝕土壤並將有機質帶入水體所致。而人工林集水區TN略高於天然林集水區，這可能是農地耕作以及施肥所影響，但仍在未達污染範圍。坪瀨溪與內茅埔溪集水區中BOD略高於沙里仙溪的含量，如不考慮降雨等因素，BOD、SS、TN、TP在水中的含量相差不多。由此可推測人工造林的成效並不亞於天然林。若能有效減少裸露地面積與比例，亦可有效降低水中有機物質的含量，達到潔淨水源之效益。

關鍵字

人工林 ； 天然林 ； 水質監測 ； 總有機碳量

並列摘要

The objective of this study is to investigate the impact on stream water quality by plantation and natural forests. The sites were located at two watersheds in NTU experimental forest, Shin-yi township, Nan-tou county: Nei-mao pu and Ping-lai creeks in Nei-mao-pu section with plantation forest stand; Shai-Li shien creek in Ho-sheh section with all natural forest stand. A yearround water quality monitoring program was conducted in 2004. Stream flow rates, total soluble solid (TSS), suspended solid (SS), total nitrogen, total phosphorus and biological oxygen demand (BOD) were analyzed monthly. The result demonstrated that the stream flow rates for natural forest, Shai-Li shien creek were higher just in the typhoon season. Stream flow rates were similar for both watersheds in other months. TSS and SS values of the stream from watershed with plantation forest were just higher in typhoon seasons. The above findings may be due to rainfall erosion and organics brought to the streams. TN values of the stream from watershed with plantation forest were higher than of the stream from the natural forest, probably due to farming and fertilization; although TN values did not reach any extent of pollution. BOD values of Nei-mao pu and Ping-lai creeks were slightly higher the values of Shai-Li shien creek. Without the aspect of rainfall, there were not a lot of difference for SS, TN, TP and BOD values in all creeks. Hence, it is assumed that the benefit of plantation forest is not less than one of natural forest. If the area and coverage of barren land could be effectively reduced, organic contents in the streams could be reduced. And the benefit of water quality purification will be achieved.

並列關鍵字

plantation forest ； natural forest ； water quality monitoring ； total organic carbon