臺灣中部三種針葉林土壤之有機氮型態對氮礦化作用之影響

Effects of Soil Organic Nitrogen Forms on Nitrogen Mineralization of Three Coniferous Forests Types in Central Taiwan

翁菁羚(Jing-Ling Weng) ； 關秉宗(Biing T. Guan) ； 江博能(Po-Neng Chiang) ； 王明光(Ming-Kuang Wang)

《中華林學季刊》 41卷4期 (2008/12) Pp. 493-501

https://doi.org/10.30064/QJCF.200812.0005

摘要

Nitrogen mineralization is the soil process which organic nitrogen converted to inorganic nitrogen. This study aimed to investigate the effects of soil organic N forms on N mineralization of three coniferous forests, Morrison spruce forest (Picea morrisonicola Hay.), Chinese hemlock forest (Tsuga chinensis var. formosana), and Taiwan red pine forest (Pinus taiwanensis Hay.) in the Tatachia area, central Taiwan. A short term laboratory incubation under 25℃ and 55% water holding capacity (WHC, i.e. 1/3 bars) was used to determine the potential of N mineralization of three forest soils. The content of different organic N forms, including total hydrolysable N, acid insoluble N, ammonium N, amino sugar N, amino acid N, hydrolysable unknown N, of three forest soils were analyzed. The relationship between different organic N forms with N mineralization under laboratory incubation was evaluated. Soil-organic N contents was highly correlated with inorganic N (r^2=0.77-0.87; p＜0.01) except hydrolysable unknown N showing negative correlation. The incubation results showed that NH4(superscript +)-N production was affected by composition of organic nitrogen. The mineralization rate and NH4(superscript +)-N concentration of spruce and pine forest soils were higher than that of pine forest soils.

關鍵字

氮礦化 ； 非線型混合效應模式 ； 氮劃分 ； 土壤有機氮

並列摘要

Nitrogen mineralization is the soil process which organic nitrogen converted to inorganic nitrogen. This study aimed to investigate the effects of soil organic N forms on N mineralization of three coniferous forests, Morrison spruce forest (Picea morrisonicola Hay.), Chinese hemlock forest (Tsuga chinensis var. formosana), and Taiwan red pine forest (Pinus taiwanensis Hay.) in the Tatachia area, central Taiwan. A short term laboratory incubation under 25℃ and 55% water holding capacity (WHC, i.e. 1/3 bars) was used to determine the potential of N mineralization of three forest soils. The content of different organic N forms, including total hydrolysable N, acid insoluble N, ammonium N, amino sugar N, amino acid N, hydrolysable unknown N, of three forest soils were analyzed. The relationship between different organic N forms with N mineralization under laboratory incubation was evaluated. Soil-organic N contents was highly correlated with inorganic N (r^2=0.77-0.87; p＜0.01) except hydrolysable unknown N showing negative correlation. The incubation results showed that NH4(superscript +)-N production was affected by composition of organic nitrogen. The mineralization rate and NH4(superscript +)-N concentration of spruce and pine forest soils were higher than that of pine forest soils.

並列關鍵字

N mineralization ； Nonlinear mix-effect model ； Nitrogen fraction ； Soil organic nitrogen