温度、水分和森林演替对中亚热带丘陵红壤氮素矿化影响的模拟实验

研究了温度、水分和演替阶段及其交互作用对中亚热带丘陵红壤区森林土壤氮素矿化过程及其矿化速率的影响.结果表明：温度和演替阶段对土壤氨化速率影响显著，其中12 ℃<24℃<36 ℃，灌丛林和马尾松(Pinus massoniana)林低于常绿阔叶林(P＜0.05)；而水分的影响不显著.水分和演替阶段对土壤硝化速率有显著影响，土壤半饱和含水量高于自然含水量及饱和含水量，且马尾松林高于灌丛林(P＜0.05)；而温度的影响不显著.温度、水分和演替阶段对土壤氮净矿化速率的影响均显著，其中12 ℃<24 ℃<36 ℃，土壤半饱和含水量高于自然含水量和饱和含水量，灌丛林<马尾松林<常绿阔叶林(P＜0.05).温度升高有利于提高土壤氨化速率和净矿化速率，温度过高则抑制土壤硝化速率；土壤含水量适中有利于土壤氮素矿化过程；顺行演替将提高土壤供氮能力，且抑制过强的硝化作用.

Effects of temperature, moisture and forest succession on nitrogen mineralization in hillside red soils in mid-subtropical region, China

Effects of temperature, moisture and forest succession, as well as their interaction on nitrogen mineralization in hillside red soils in mid-subtropical region were investigated. The results showed that effects of temperature and succession stage on soil ammonification rate were significant with rate at 12 ℃<24 ℃<36 ℃, and rate in shrub and Masson pine forest being lower than that in evergreen broad-leaved forest (P＜0.05), while the impact of moisture was not significant. Moisture and succession stage significantly affected the soil nitrification rate, with that of half-saturation being higher than natural and saturation moisture levels, and that in Masson pine forest being higher than in shrubs (P＜0.05), while temperature had no significant impact. The effects of temperature, moisture and succession stage on soil net N-mineralization rate were all significant, with 12 ℃<24 ℃<36 ℃, half-saturation higher than natural and saturation, and shrubs