水分對臺灣塔塔加地區雲杉與鐵杉土壤氮素礦化及硝化的影響

水分是影響土壤中氮素礦化及硝化作用的重要因素。本文透在實驗室中孵育的方法，研究臺灣塔塔加高山地區雲杉與鐵杉土壤中，水分對氮的礦化及硝化作用的影響。實驗採用雲杉與鐵杉生長地區的新鮮土壤與風乾土壤進行不同水量的添加，然後置於孵育箱中25˚C恒溫孵4週。結果顯示，水分增加會顯著降低雲杉新鮮0層土壤中氮的硝化作用，但對銨的含量影響不大，總礦化量則會隨水分增加而降低；在鐵杉新鮮土壤中，水分含量對其礦化及硝化作用的影響都不顯著。在風乾土壤的孵育實驗中，水分含量在0-30%範圍內，雲杉與鐵杉土壤礦化及硝化量大致上會隨水分含量增加而增加。當水分含量高於30%時，兩者的礦化皮硝化量均呈下降趨勢。水分含量的增加會降低雲層A層土壤的硝化比率，但對其他處理影響不大。不同的土壤性質是導致樹杉和鐵杉土壤礦化及硝化作用對水分回應差異的主要原因。

關鍵字

水分；雲杉土壤；鐵杉土壤；氮的礦化；硝化作用

並列摘要

Water is one of most important factors that influence soil nitrogen mineralization and nitrification. In this study, laboratory incubation experiments were performed to investigate the effects of water content on soil nitrogen mineralization and nitrification of spruce and hemlock forest soils from Tatachia, central Taiwan. Different amounts of water were added to fresh and air-dried soils from spruce and hemlock stands and subsequently, the samples were put in a incubation box at 25 for 4 week. The results showed that the nitrification of spruce fresh soil decreased significantly with increasing water content, while water content had no significant effect on ammonium content of spruce fresh soil. In the hemlock soil, the effect of water content was not significant on both nitrogen mineralization and nitrification. When the soils were air-dried, nitrogen mineralization and nitrification of both soils increased with the increasing of water content from 0% to 30%. When water content was higher than 30%, nitrogen mineralization and nitrification decreased with increasing water content. Water content had a significant effect on nitrification ratio of spruce A soil but not significant on other treatments. It was the different soil property that resulted in various responses of spruce and hemlock soils to water content.

並列關鍵字

water content, spruce soil, hemlock

國際替代計量

水分對臺灣塔塔加地區雲杉與鐵杉土壤氮素礦化及硝化的影響

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