Nitrogen Fixation,Soil Nitrogen Availability,and Biomass in Pure and Mixed Plantations of Alder and Pine in Central Korea |
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Authors: | Yowhan Son Yoon Young Lee Chon Young Lee Myong Jong Yi |
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Institution: | 1. Division of Environmental Science and Ecological Engineering, Korea University , Seoul, Korea;2. Forest Research Institute , Seoul, Korea;3. Division of Forest Resources, Kangwon National University , Chunchon, Korea |
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Abstract: | ABSTRACT Rates of nitrogen (N) fixation, soil N availability, and aboveground biomass were measured in 27-year-old pure and mixed Alnus hirsuta and Pinus koraiensis plantations in central Korea. Nodule biomass and N fixation were 179.3 kg ha? 1 and 46.6 kg ha? 1yr? 1 for the pure A. hirsuta plantation (PA) and 95.2 kg ha? 1 and 41.1 kg ha? 1yr? 1 for the mixed A. hirsuta + P. koraiensis plantation (MAP), respectively. A. hirsuta seemed to provide more than two thirds of annual N requirement for P. koraiensis.Rates of acetylene reduction were significantly related to soil temperature (R2 = 0.51, P < 0.001), but not to soil moisture content. Total inorganic N ammonium (NH4 +)plus nitrate (NO3 ?)] availability measured using ion exchange bags were significantly higher under PA (27.91 μ g-N bag? 1) and MAP (31.34 μ g-N bag? 1) than under the pure P. koraiensis plantation (PP) (14.31 μ g-N bag? 1). Especially soils under the influence of A. hirsuta showed at least 2 fold increase in resin total inorganic N concentrations. Total aboveground biomass (Mg ha? 1) was 147.3 for PA, 145.8 for MAP, and 174.8 for PP, respectively, and was not significantly different among plantations. A. hirsuta significantly increased soil N availability; however, the influence of N fixation on aboveground biomass was not significant for the study plantations. |
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Keywords: | aboveground biomass A hirsuta nitrogen availability nitrogen fixation P koraiensis |
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