东北黑土土壤磷的纬向分异

以中国东北的中纬度黑土区为样带，研究了有机磷浓度与有机质、全氮浓度的关系；全磷、有机磷、无机磷及有机磷和无机磷的比率与纬度分布的关系。结果表明，有机磷和有机质、全氮浓度具有良好的相关性，它们之间的相关系数分别为0.90和0.92，呈极显著正相关(P<0.01)。全磷、有机磷、无机磷、P_o/P_i在纬度上都存在不同程度的分异规律，即随着纬度的升高，其浓度或比率均有逐渐升高的趋势；其相关系数分别为0.68、0.77、0.26和0.60，相关分析表明，这些纬向分异规律都达极显著水平(P<0.01)。除了无机磷的纬向分异原因尚不明确之外，其他纬向分异的原因可能是由于黑土南北样带气候热量上的差异和人类活动的影响所致，从而造成南北样带之间有机质的矿化程度和速率产生差异。

Latitudinal differentiation of phosphorus in black soil in Northeast of China

Based on the region of black soil in Northeast of China, from Nenjiang County in Heilongjiang Province to Changtu County in Liaoning Province, studies were conducted to explore the relationship between the concentration of organic P and organic matter, organic P and total N; the relationship among the concentration of total P, organic P, inorganic P, the P_o/P_i ratio (ratio of organic P to inorganic P), and contribution of latitude. The results show that the relationship between the organic P and organic matter, organic P and total N are both close, their correlation coefficients are 0.90 and 0.92, respectively which indicate highly significant positive correlation (P<0.01). Along latitude, total P, organic P, inorganic P and the P_o/P_i ratio all show obvious differentiation characteristics, namely, the concentrations of total P, organic P, inorganic P and the P_o/P_i ratio all increase gradually with the increase of latitude. Their correlation coefficients 0.68, 0.77, 0.26, 0.60, respectively. The results of correlation analysis show that these latitudinal differentiations all have highly significant positive correlation(P<0.01). Except for the unclear cause of the latitudinal differentiation of inorganic P, the other latitudinal differentiations may be due to the difference of climate and effects of human activities between north and south, which lead to the difference of the mineralization velocity of organic matter.