中文摘要：

这研究的目的是调查根围的角色器官的在半干旱的森林和 rihizosphere 上的树种类的效果里的土壤 P 供应的磷 P 器官的 P。我们在根围和单音特定的西蒙白杨 Populus simonii 和蒙古的松 Pinus sylvestris var 的体积土壤检验了器官的 P 部分。在在东北中国的 Horqin 沙的土地的半干旱的沙的土壤的 mongolica 种植园。全部的器官的 P TPo 越过二个看台说明了 76% 全部的 P。器官的 P Po 部分的集中在 NaOH-Po 的顺序减少了 > Res-Po > HCl-Po > NaHCO < 潜水艇 class= “ a-plus-plus ” > 在两种植园的 3 -Po。NaHCO 的集中 < 潜水艇 class= “ a-plus-plus ” > 3 -Po 是 38% 和 43% 比大批分别地在西蒙白杨和蒙古的松种植园玷污在根围土壤降低。相反，总计显著地在西蒙白杨种植园在根围土壤积累的 P， TPo 和 NaOH-Po，但是不在蒙古的松种植园变化。土壤不顺从的器官的 P 部分断然与土壤被相关器官的碳。结果建议易变的器官的 P 是的那根围在这个半干旱的区域的植物可得到的 P 的重要来源，但是不顺从的器官的 P 部分与树种类改变了的根围动态并且被相关到器官的碳动力学。

英文摘要：

The aim of this study was to investigate the role of rhizosphere organic phosphorus （P） in soil P supply in semiarid forests and the effects of tree species on rihizosphere organic P. We examined organic P fractions in rhizosphere and bulk soils of mono-specific Simon poplar （Populus simonii） and Mongolian pine （Pinus sylvestris var. mongolica） plantations in a semiarid sandy soil of Horqin Sandy Land in Northeast China. Total organic P （TPo） accounted for 76% of total P across the two stands. The concentration of organic P （Po） fractions decreased in the order of NaOH-Po〉Res-Po〉HCI-Po〉NaHCO3-Po in both plantations. The concentration of NaHCO3-Po was 38% and 43% lower in rhizosphere soil than in bulk soil in Simon poplar and Mongolian pine plantations, respectively. In contrast, total P, TPo and NaOH-Po significantly accumulated in rhizosphere soil in Simon poplar plantations, but no change in Mongolian pine plantations. Soil recalcitrant organic P fractions were positively correlated with soil organic carbon. The results suggest that rhizosphere labile organic P was an important source of plant-available P in this semiarid region, but the dynamic of rhizosphere recalcitrant organic P fractions varied with tree species and was correlated to organic carbon dynamics.