The development of Chinese fir plantations undergo significant changes in soil microbial metabolic function and enzyme activities

Comprehensive evaluation of soil enzyme activities, microbial community diversity can provide a theoretical basis for the sustainable management of the plantations. In this study, we analyzed soil enzyme activities and the metabolic functional diversity of the microbial communities of Chinese fir plantations aged 3 years, 12 years and 38 years. The results showed that the high-age (38 years old) was beneficial to soil microbial community diversity. The activities of catalase and urease, the average well colour development (AWCD) values for carbon sources used by microbial communities and five diversity indices all showed a gradual increase as trees aged from 3 years to 38 years. Sucrase activity decreased by 109% from 3- to 12-year-old plantations and increased by 139% from 12- to 38-year-old plantations. Overall, the stand age is an important factor for driving changes in soil properties of Chinese fir plantations, and high age may be more conducive to the improvement of soil properties, especially enzyme activities and microbial community diversity, which is of great significance to the screening of key indicators for the establishment of precision evaluation technology in Chinese fir sites.

全面评估土壤酶活性与微生物群落多样性，可为人工林的可持续经营提供理论依据。本研究针对树龄3年、12年及38年的杉木人工林，分析了其土壤酶活性与微生物群落的代谢功能多样性。研究结果表明，高树龄（38年生）有助于提升土壤微生物群落多样性。过氧化氢酶、脲酶活性，微生物群落利用碳源的平均颜色变化率（average well colour development, AWCD）值，以及5种多样性指数，均随树龄从3年增至38年而逐渐升高。蔗糖酶活性在3年生至12年生人工林内下降了109%，并在12年生至38年生人工林内提升了139%。总体而言，林分树龄是驱动杉木人工林土壤性质变化的重要因素，高树龄更有助于改善土壤性质，尤其是酶活性与微生物群落多样性，这对于筛选杉木立地精准评价技术的关键指标具有重要意义。