SGER: New Methods for Study of Nitrification in Microenvironments of Forest Soils

新的方法有望为微生物生态学中以前难以解决的问题提供答案。该项目将开发确定酸性森林土壤中硝化作用发生地点所需的新技术：(A)聚合酶链式反应，使用基于氨单加氧酶染色体基因和氨氧化菌株特有的16S核糖体DNA区域的引物，量化小土壤样本中的硝化菌种群；(B)微电极，测量土壤中的pH值梯度。在赤杨(Alnus Rubra)下发育的酸性森林土壤中，自养硝化作用可能发生在碱性微环境中。将确定pH值和硝化菌种群的微梯度(通过聚合酶链式反应)。所开发的方法将适用于林业和农业实践的改进以及土壤养分动态的基础研究。

New methods hold the promise for providing answers to previously intractable problems in microbial ecology. This project will develop new technologies needed to determine where nitrification occurs in acidic forest soils: (a) polymerase chain reaction (PCR) to quantify nitrifier populations in small soil samples using primers based on the ammonium monooxygenase chromosomal gene and regions of 16S ribosomal DNA specific to ammonia- oxidizing strains and (b) microelectrodes to measure pH gradients in the soil. Autotrophic nitrification may occur in alkaline microenvironments within an acid forest soil developed under red alder (Alnus rubra). Microgradients of pH and populations of nitrifiers (by PCR) will be determined. Methods developed will be applicable to improvements in forestry and agricultural practices as well as to the fundamental study of nutrient dynamics in soils.