INRA Grand-EST Nancy, UR 1138 Biogéochimie des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France.
Office National de Forêts (ONF), Unité Territorial de Darney-Bains, 6 rue des Rochottes, 88260, Darney, France.
Sci Rep. 2019 Jul 23;9(1):10687. doi: 10.1038/s41598-019-47042-6.
Douglas fir trees presumable stimulate nitrification in the soil. We studied in 21 French Douglas fir forests if and how nitrification is modulated by soil properties, past land use and current forest management. Soil (0-10 cm depth) was collected and initial concentrations of N-NH and N-NO, potential net nitrogen mineralization (PNM) and net nitrification (PNN) rates and microbial biomass were measured. At 11 of the 21 sites, annual nitrate fluxes in the soil were measured using anion exchange resin bags. Soils contained between 2.3 to 29.4 mg N-NO kg soil. About 86% (±14%) of mineral N was nitrate. The proportion of nitrate increased to almost 100% during incubation. PNN varied from 0.10 mg N kg soil day to 1.05 mg N kg soil day (21 sites). Neither the initial nitrate concentration nor PNN was related to soil chemistry (pH, % C, %N, P, CEC), microbial biomass, texture, past land use or thinning. In situ net nitrate accumulation (NNA) estimated with resins beds varied from 4 to 100 kg N-NO ha yr (11 sites). It was positively correlated with base saturation, clay content, ELLENBERG N, temperature and negatively with soil organic N, C/N ratio and precipitation.
花旗松树木可能会刺激土壤中的硝化作用。我们在 21 个法国花旗松林中研究了土壤特性、过去的土地利用和当前的森林管理如何调节硝化作用。采集了土壤（0-10cm 深度），并测量了初始 N-NH 和 N-NO 浓度、潜在净氮矿化（PNM）和净硝化（PNN）速率以及微生物生物量。在 21 个地点中的 11 个地点，使用阴离子交换树脂袋测量了土壤中的年硝酸盐通量。土壤中含有 2.3 至 29.4mg N-NO kg 土壤。约 86%（±14%）的矿质氮为硝酸盐。在培养过程中，硝酸盐的比例增加到几乎 100%。PNN 变化范围为 0.10mg N kg 土壤天至 1.05mg N kg 土壤天（21 个地点）。初始硝酸盐浓度或 PNN 均与土壤化学性质（pH、%C、%N、P、CEC）、微生物生物量、质地、过去的土地利用或间伐无关。用树脂床估计的原位净硝酸盐积累（NNA）变化范围为 4 至 100kg N-NO ha yr（11 个地点）。它与碱饱和度、粘粒含量、ELLENBERG N、温度呈正相关，与土壤有机氮、C/N 比和降水量呈负相关。
