摘要
本文以山西太岳山3个林龄(18、35和51年生)华北落叶松林为对象,研究其土壤微生物生物量、土壤真菌群落结构多样性特征,并利用通径分析,探讨土壤和凋落物养分含量对土壤微生物的影响。结果表明:随着华北落叶松林年龄的增加,土壤微生物生物量碳逐渐增加,微生物生物量碳占其与可溶性有机碳之和的比例也逐渐增加;土壤微生物生物量碳/氮比在51年生华北落叶松林中最大(13),约为其他两个林龄华北落叶松林的1.6倍;土壤微生物碳熵在35年生华北落叶松林中最低(1.5%),在18年生华北落叶松林中最高(2.8%)。土壤微生物生物量氮、真菌Shannon指数、土壤和凋落物碳/氮比在不同林龄华北落叶松林中的变化趋势均为35年生>18年生>51年生。通径分析结果表明,真菌群落结构多样性对土壤微生物生物量碳有较大的直接作用,凋落物自身化学组成对土壤微生物生物量氮有显著影响,土壤碳/氮比和微生物生物量碳/氮比是调控真菌群落结构多样性的直接因素。总的来说,35年生华北落叶松林的土壤有机碳活性最小,土壤碳库稳定性较好,养分状况优于另外两个林龄华北落叶松林。
Soil microorganisms play an important role in carbon and nitrogen cycling. Changes in litterfall and soil properties due to stand age can have important implications to soil carbon （C） and nutrient cycling via microbial pathway. Soil degradation has widely occurred in Larix princip- is-rupprechtii plantation because of its simple forest structure; however, little is known about how soil nutrients are related to soil microbial properties. Here we determined soil microbial responses to different aged L. principis-rupprechtii plantations （ 18-, 35-, and 51-year-old） in Taiyue Moun- tain of Shanxi Province. The results showed that soil microbial biomass C and the proportion of microbial biomass C to the sum of microbial biomass C and dissolved organic C increased with the increase of stand age. Soil microbial biomass C/N ratio in the 51-year-old L. principis-rupprechtii plantation was the highest （ 13）, being 60% higher than that in the 18- and 35-year-old L. prin- cipis-rupprechtii plantations. The microbial carbon entropy ranged from 1.5% in the 35-year-old L. principis-rupprechtii plantation to 2.8% in the 18-year-old L. principis-rupprechtii plantation. Soil microbial biomass N, fungal Shannon diversity, soil and litter C/N ratios decreased in the follow- ing order： 35-year-old 〉 18-year-old 〉 51-year-old plantations. Fungal community structure di- versity had a direct effect on soil microbial biomass C, while litter C/N had a significant effect on soil microbial biomass N, and soil and microbial biomass C/N ratios were the direct factors regu-lating soil fungal community structure diversity. In general, the active organic 35-year-old L. principis-rupprechtii plantation was lower than those in the other and its carbon pool was more stable and nutrient situation was better. C content in the two plantations,
出处
《生态学杂志》
CAS
CSCD
北大核心
2016年第12期3183-3190,共8页
Chinese Journal of Ecology
基金
林业公益性行业科研专项(201404213)资助
