Sarkar Sudip, Das Dipty Kumar, Singh Abhinandan, Laik Ranjan, Singh Santosh Kumar, van Es Harold M, Krishnan Kavya, Singh Amit Kumar, Das Anup, Singh Utkarsh, Elansary Hosam O, Mahmoud Eman A
ICAR Research Complex for Eastern Region, Patna, 800014, India.
Department of Forestry, Dr. Rajendra Prasad Central Agricultural University, Pusa, 848125, India.
Heliyon. 2024 Aug 3;10(16):e35593. doi: 10.1016/j.heliyon.2024.e35593. eCollection 2024 Aug 30.
Seasonal variations directly impact the biochemical and microbial properties of the soil, influence carbon and nutrient cycling within the soil system. Soils under tree plantation (TP) are rich in organic matter and microbial population, making them more susceptible to seasonal variation. We studied the effect of seasonal variations in soil chemical properties (pH, electrical conductivity (EC), total organic carbon (TOC), total nitrogen (TN), C/N ratio etc) and microclimate (moisture and temperature) on microbial respiration (SR), biomass, and carbon (C) utilization efficiency under 13 years old Kadamb ( Miq.), Simaraubha ( DC), and Litchi ( Sonn.) based TPs in middle Gangetic region. In contrast to higher SR and metabolic quotient (qCO) in winter, the microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) in fall > summer > spring > winter, irrespective of TPs. The positive relationship between qCO and C/N ratios strongly supports the dependence of microbes on soil carbon for respiration. qCO had a significantly positive relationship with soil moisture (MC) and Electrical conductivity (EC), but a significantly negative relationship with temperature and pH. Higher MBN/TN and MBC/TOC ratios fall under simaraubha, and litchi-based TPs indicated more nitrogen (N) and carbon accumulation into microbial biomass. The seasonal variation of MBC/MBN ratios signifies the changes in microbial communities and fungi dominate over bacteria during winter, as bacteria have a lower C/N ratio than fungi. Stepwise regression analysis suggested that soil properties and micro-climate regulated microbial biomass and SR differ with TPs. Thus, the study indicates that microbial activities and biomass production can significantly influence by soil properties and seasonal variations under TPs.
季节变化直接影响土壤的生化和微生物特性，影响土壤系统中的碳和养分循环。人工林（TP）下的土壤富含有机质和微生物种群，使其更容易受到季节变化的影响。我们研究了恒河中游地区基于13年树龄的乌檀（Miq.）、麻疯树（DC）和荔枝（Sonn.）人工林土壤化学性质（pH值、电导率（EC）、总有机碳（TOC）、总氮（TN）、碳氮比等）和小气候（湿度和温度）的季节变化对微生物呼吸（SR）、生物量和碳（C）利用效率的影响。与冬季较高的SR和代谢商（qCO）相反，无论人工林类型如何，秋季的微生物生物量碳（MBC）和微生物生物量氮（MBN）均为秋季>夏季>春季>冬季。qCO与碳氮比之间的正相关强烈支持微生物呼吸对土壤碳的依赖性。qCO与土壤湿度（MC）和电导率（EC）呈显著正相关，但与温度和pH呈显著负相关。麻疯树和荔枝人工林的MBN/TN和MBC/TOC比值较高，表明微生物生物量中氮（N）和碳的积累更多。MBC/MBN比值的季节变化表明微生物群落的变化，冬季真菌占主导地位，因为细菌的碳氮比比真菌低。逐步回归分析表明，土壤性质和微气候对微生物生物量和SR的调节因人工林类型而异。因此，该研究表明，人工林下的微生物活动和生物量生产会受到土壤性质和季节变化的显著影响。
