不同密度马尾松人工林枯落物输入对土壤理化性质的影响

为研究不同密度马尾松人工林枯落物输入对土壤理化性质和林分生长影响,选择适宜的人工林经营措施提供参考.以2 500,3 300,4 500,6 000株/hm2(分别记为M1、M2、M3和M4)4种造林密度的马尾松人工林为研究对象,利用结构方程探究不同密度马尾松林枯落物输入对土壤性质的影响.结果表明:林分密度对枯落物和土...

Effects of Litter Input on Soil Physical and Chemical Properties of Pinus massoniana Plantations with Different Densities

The purpose of this study was to study the influence of Pinus massoniana litter input with different densities on the soil physical and chemical properties and stand growth, and to improve the theoretical basis for selecting appropriate plantation management measures. Four planting densities, 2 500 trees/hm² (M1), 3 300 trees/hm² (M2), 4 500 trees/hm² (M3) and 6 000 trees/hm² (M4) of P. massoniana forests, were set up as research subject. The structure equation was used to explore the influence of litter input of P. massoniana forest with different densitieson soil properties. The result showed that forest density had a significant impact on litter and soil physical and chemical properties. The total storage and water holding capacity of litter were the highest under M2, which was significantly higher than others. The litter had the largest nutrient reserves of carbon, nitrogen, phosphorus, and potassium in M2, amongh which the orgainic carbon is the major, accounting for 96.98% of the total. The differences in soil physical and chemical properties decreased with the depth of the soil layer increased, and the litter layer had a greater impact on the physical and chemical properties in the surface soil. Soil water holding capacity, porosity, pH, total phosphorus, alkaline nitrogen and available phosphorus were all the highest in M2, whereas the organic matter and total nitrogen presented as M4>M2>M3>M1, and total potassium and available potassium had highest contents in M1. Litter accumulation and nutrient reserves were significantly positively correlated with soil silt, water holding capacity, porosity, organic matter, total phosphorus, and available nitrogen, while significantly negatively correlated with soil bulk density and permeability. The structural equation showed that the total storage of litter had a significantly positive correlation with soil physical and chemical properties, whereas soil water holding capacity had a significantly negative correlation with soil physical and chemical properties. Soil chemical properties had a significant positive correlation with forest volume, and a significant negative correlation was found between the forest stock and litter nutrients contents. In summary, the P. massoniana forest with M2 density had the more litter accumulation and nutrients reserves, which could reduce surface runoff, increase soil water holding capacity and porosity, reduce the loss of available nutrients, and promote root extension and extension, which should be the more appropriate forestation measures.