In this study, soil organic matter (SOM), as well as the structure and function of soil microbial communities in three forest systems (holm oak, black pine and beech) widely distributed in the Mediterranean area, were analyzed to assess the effects of different canopies on microbial community. Fourier transform infrared (FTIR) spectroscopy, combined with Thermal analyses, was used to characterize SOM, in order to obtain information on its quality and stability. Soil microbial communities were analyzed through the phospholipid fatty acid (PLFA) profile, ergosterol, hydrolase, laccase and peroxidase activities, fungal and bacterial growth. Soil under pine and beech contained more recalcitrant SOM, in respect to the soil under holm oak, characterized by more labile SOM. The PLFA analysis showed a different structure of the edaphic microbial community of the three forests. Soils under pine was characterized by the greatest abundance of fungal biomass and high peroxidase activity likely in relation to the presence in this soil of more recalcitrant compounds, mainly decomposed by fungi. Overall, pine and beech forests represent important carbon sinks with larger amounts of recalcitrant organic matter in their soils.

在这项研究中，分析了土壤有机质（SOM）以及地中海地区广泛分布的三种森林系统（霍姆栎，黑松和山毛榉）中土壤微生物群落的结构和功能，以评估不同影响微生物群落的冠层。为了获得有关SOM的质量和稳定性的信息，使用了傅里叶变换红外（FTIR）光谱结合热分析来表征SOM。通过磷脂脂肪酸（PLFA）谱，麦角固醇，水解酶，漆酶和过氧化物酶活性，真菌和细菌生长分析土壤微生物群落。相对于木下的土壤，松树和山毛榉下的土壤含有更多的顽固性SOM，其特征是SOM较不稳定。PLFA分析表明，这三种森林的土壤微生物群落结构不同。松树下的土壤具有最大的真菌生物量和高的过氧化物酶活性，这可能与这种土壤中存在更多的难分解的化合物（主要是被真菌分解）有关。总体而言，松林和山毛榉林是重要的碳汇，土壤中含有大量顽固的有机物。