Rule of organic phosphorous and microbial on phosphorous supply for vegetation in forest soil

利用Hedley法和微生物生物量P （MBP）对日本普通森林、热带森林和喀斯特地区森林土壤的磷组分进行了研究，以阐明森林植被的磷和磷供应特征。结果总结如下：1。有效磷（Ion part -P + Bicarb-P）浓度极低（低于30 μg P/g），低于森林植被年吸收量。可矿化磷在一般日本森林中含量较多。有机磷矿化速率对森林植被磷供应具有重要意义。3 .在印度尼西亚东加里曼丹热带森林强风化土壤中，全磷量、有效磷比和矿化磷比随着森林植被的减少而降低。MBP浓度大于有效磷（有效磷加矿化磷）浓度，因此MBP库对热带森林磷供应具有重要意义。在长江上游喀斯特森林土壤中，速效磷和矿化磷均与土壤pH和全碳- 6呈较强的正相关。Hedley法测定的有效磷浓度与Bray II法和Olsen法测定的有效磷浓度呈正相关。海德利的Available-P几乎等于布雷ii - p - 7。MBP浓度与稳定磷浓度基本相等，可作为喀斯特地区森林磷供应评价指标。在三宅岛厚而坚硬的火山灰沉积区，由于火山灰层氮供应不足，白杨带根瘤生长旺盛。10.日本的热带天然林和关东地区的森林，在氮供应丰富的情况下，相对于N条件，存在P极限条件。本文讨论了三宅岛热带退化森林和酸性土壤中根系磷供应是森林恢复的关键。

Phosphorus fractions by Hedley method and microbial biomass P (MBP) have been investigated in general Japanese forest, tropical forest and karst region forest soils to clarify the characteristics of P and P supply to forest vegetation. The results are summarized as follows.1. Available-P (Ion fraction-P + Bicarb-P) concentrations were remarkable low (under 30 μg P/g), and their values were lower than the annual uptake P by forest vegetation.2. Mineralizable-P is much in general Japanese forest. Phosphorus mineralization rate from organic P is important for P supply to forest vegetation.3. In tropical forest soil with strong weathering in East Kalimantan in Indonesia, total-P amount, available-P ratio and mineralizable-P ratio decreased with decreases of forest vegetation.4. MBP concentrations were greater than labile-P (available plus mineralizable-P) concentrations, so MBP pool is important for P supply to tropical forest.5. In forest soils in a karst region of the upper Yangtze River in China, both available-P and mineralizable-P have strong positive correlation with soil pH and total-C.6. Available-P concentrations by Hedley method have positive correlation with P concentrations by Bray II and Olsen methods. Available-P by Hedley is nearly equal to Bray II-P.7. MBP concentrations were nearly equal as labile-P concentrations, so MBP is index of P supply evaluation in karst region forest.8. In the region of the thick and very hard volcanic ash sedimentation in Miyake Island, Alnus sieboldiana grew a lot with their root nodule because of poor N supply in the ash layer.9. The tropical natural forest and Kanto region forest in Japan, which have rich N supply, had P limit condition compared to N condition.10. We discuss that P supply to root noble is the key to forest recovery in tropical degradation forest and in acid soil on Miyake Island.