Plants growing on karst soils, which are characterized by high pH (>7.5–8.0) and low phosphorus availability, often exhibit phosphorus deficiency. However, little is known about the soil nutrient availabilities and foliar nutrient concentrations of trees in karst ecosystems with lower soil pH (<7.0). In this study, we analyzed soil properties and nutrient concentrations of leaf litter from two secondary forests in the Asian monsoon temperate region of Japan, one on karst (limestone) soil and the other on non-karst (sandstone) soil. We also compared the live leaf nutrient concentrations of four dominant tree species (Carpinus tschonoskii, Cornus macrophylla, Neolitsea sericea, and Quercus variabilis) found in both sites. The karst soil had a higher pH (6.5) than the non-karst soil (5.6), as well as higher phosphorus concentrations and calcium availability, but lower potassium availability. The phosphorus concentrations measured using Truog ([NH₄]₂SO₄) and Olsen (NaHCO₃) extraction methods were both higher in the karst soil. The availabilities of ammonium and nitrate in the soil did not differ significantly between the sites. The concentrations of calcium, potassium, and phosphorus in the live leaves and leaf litter reflected their availability in the soil, and the litter nitrogen concentration was higher in the karst forest. Overall, this karst soil with a relatively low pH (6.5) was rich in phosphorus but poor in potassium. Karst soil may provide a large quantity of phosphorus for trees at low pH. Future research should investigate the change in phosphorus availability of karst soils at different degrees of weathering.

中文翻译：

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日本伊吹山温带季风喀斯特和非喀斯特森林生态系统土壤养分有效性和树木叶面养分浓度的变化

喀斯特土壤上生长的植物具有高pH值（>7.5-8.0）和低磷利用率的特点，通常表现出磷缺乏。然而，对于土壤 pH 值较低（<7.0）的喀斯特生态系统中的土壤养分有效性和树木叶面养分浓度知之甚少。在这项研究中，我们分析了日本亚洲季风温带地区两处次生林的土壤性质和凋落物养分浓度，其中一处位于喀斯特（石灰岩）土壤，另一处位于非喀斯特（砂岩）土壤。我们还比较了两个地点发现的四种主要树种（Carpinus tschonoskii、Cornus macrophylla、Neolitsea sericea和Quercus variabilis ）的活叶养分浓度。喀斯特土壤的pH值（6.5）高于非喀斯特土壤（5.6），磷浓度和钙利用率也较高，但钾利用率较低。_{使用Truog ([NH 4} ] ₂ SO ₄ ) 和Olsen (NaHCO ₃ ) 提取方法测得的喀斯特土壤中磷浓度均较高。土壤中铵和硝酸盐的有效性在不同地点之间没有显着差异。活叶和凋落物中钙、钾、磷的浓度反映了它们在土壤中的有效性，喀斯特森林中凋落物氮的浓度较高。总体而言，这种pH值相对较低（6.5）的喀斯特土壤磷含量丰富，钾含量贫乏。喀斯特土壤可以为低 pH 值的树木提供大量的磷。未来的研究应该调查不同风化程度下喀斯特土壤磷有效性的变化。