ABSTRACT Soil microbial biomass carbon (Cmic) and nitrogen (Nmic) dynamics were studied in five representative land use of Mediterranean agroecosystems over two consecutive years on a seasonal basis on the island of Lesvos, Greece. Soil samples from natural forests, olive groves, wheat cultivations, pasture, and annual crop rotation were collected from plots that had been managed conventionally according to local practices. The Cmic and Nmic values ranged from 86.8 to 565.1 and from 14.7 to 101.6 mg kg-1 dry soil, respectively, being affected by both land use and season. Their average values increased in the order of arable < forest ≤ pasture. Similar to all land uses, Cmic and Nmic showed a significant, land-use dependence with seasonal variation. Specifically, summer minima and autumn maxima highlighted how hot and dry Mediterranean summers affect the activity of soil micro-organisms. Cmic to organic C (Corg) and Nmic to total N (Ntot) ratios ranged from 1.3 to 4.0 and 2.0 to 11.2, respectively, and were also affected by land use and season. Seasonal variation of Cmic to Corg and Nmic to Ntot ratios followed the general trend of Cmic and Nmic only in the land uses that do not incorporate crop residues. The Cmic: Nmic average ratio was 6.86 and was the only one soil microbial biomass parameter studied where seasonal variability exceeded land-use variability.

中文翻译：

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地中海农业生态系统中受土地利用影响的土壤微生物生物质碳和氮的季节性变化。

摘要 连续两年在希腊莱斯沃斯岛按季节对地中海农业生态系统的五个代表性土地利用中的土壤微生物生物量碳 (Cmic) 和氮 (Nmic) 动态进行了研究。来自天然林、橄榄园、小麦种植、牧场和一年一度的作物轮作的土壤样本是从按照当地惯例进行常规管理的地块中收集的。Cmic 和 Nmic 值分别为 86.8 至 565.1 和 14.7 至 101.6 mg kg-1 干土，受土地利用和季节的影响。它们的平均值按照耕地<森林≤牧场的顺序增加。与所有土地利用类似，Cmic 和 Nmic 表现出显着的、具有季节性变化的土地利用依赖性。具体来说，夏季最低点和秋季最高点突出显示了炎热干燥的地中海夏季如何影响土壤微生物的活动。Cmic 与有机 C (Corg) 和 Nmic 与总 N (Ntot) 的比率范围分别为 1.3 至 4.0 和 2.0 至 11.2，并且还受到土地利用和季节的影响。Cmic 与 Corg 和 Nmic 与 Ntot 比率的季节性变化仅在不包含作物残留物的土地利用中遵循 Cmic 和 Nmic 的总体趋势。Cmic:Nmic 平均比率为 6.86，是唯一一项研究的季节性变异超过土地利用变异的土壤微生物生物量参数。Cmic 与 Corg 和 Nmic 与 Ntot 比率的季节性变化仅在不包含作物残留物的土地利用中遵循 Cmic 和 Nmic 的总体趋势。Cmic:Nmic 平均比率为 6.86，是唯一一项研究的季节性变异超过土地利用变异的土壤微生物生物量参数。Cmic 与 Corg 和 Nmic 与 Ntot 比率的季节性变化仅在不包含作物残留物的土地利用中遵循 Cmic 和 Nmic 的总体趋势。Cmic:Nmic 平均比率为 6.86，是唯一一项研究的季节性变异超过土地利用变异的土壤微生物生物量参数。