Temporal dynamics and variation with forest type of phospholipid fatty acids in litter and soil of temperate forests across regions
Temporal dynamics and variation with forest type of phospholipid fatty acids in litter and soil of temperate forests across regions
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DOI：
10.1016/j.soilbio.2015.08.035
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发表时间：
2015-12-01
影响因子：
9.7
通讯作者：
Scheu, Stefan
中科院分区：
文献类型：
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作者：
Pollierer, Melanie M.;Ferlian, Olga;Scheu, Stefan
微生物构成土壤食物网的基础，是碳循环和固存的关键控制点。几乎所有中欧森林都得到管理，土地使用制度可能影响微生物丰度和群落组成。因此，需要了解土地利用强度和非生物变量，如pH值、C/N比、湿度状况以及随之而来的不同压力水平如何影响微生物群落。我们调查了磷脂脂肪酸（PLFA）配置文件的落叶和土壤从四个森林类型不同的树叶，年龄和管理强度，复制在三个地区在德国。为了说明时间变化，在同一季节取样两次，但间隔三年。总微生物生物量和微生物群落组成在不同年份之间不同，可能是由于不同年份之间的天气条件变化。枯落物层更容易干燥的影响，减少了近30%的总PLFA在干燥的一年。在土壤中，天气条件的影响取决于土壤类型，因此不同地区之间，微生物在桑迪土壤的Schorfheide更容易受到水胁迫，证明了10倍增加的应力指标CY/前比在干燥的一年。尽管微生物生物量和群落组成的时间变化，真菌和细菌的能量通道之间的平衡，如真菌-细菌的比例，保持相当恒定，特别是在土壤中。虽然总的微生物生物量没有不同的森林类型，微生物群落组成显着不同的山毛榉和针叶林。尽管更酸性的条件下，真菌的能量通道是不太明显的针叶林落叶比阔叶林，而细菌脂肪酸的比例是最高的针叶林。增加管理强度可能会促进暴露凋落物层中的细菌能量通道。支持这一假设针叶林功能显着较高的值的应力指标cy/前和SAT/MONO比。细菌群落结构和生物量与pH密切相关，特别是PLFA占主导地位，在高和低pH值，分别指示pH值特定的微生物群落。与此相反，真菌丰度与C-到-N比的落叶。结果表明，落叶和土壤需要单独考虑时，调查微生物群落组成的变化，因为这些层之间的微生物对环境压力的敏感性显着不同。在调查与气候变化有关的微妙影响时，这一点以及重复取样事件可能特别重要。(C)2015爱思唯尔有限公司版权所有。
Microorganisms form the basis of soil food webs and represent key control points of carbon cycling and sequestration. Virtually all central European forests are managed and land-use regimes likely impact microbial abundance and community composition. Consequently, knowledge on how land-use intensity and abiotic variables, such as pH, C-to-N ratios, moisture regimes and concomitantly different stress levels, affect microbial communities is needed. We investigated phospholipid fatty acid (PLFA) profiles of leaf litter and soil from four forest types differing in foliage, age and management intensity, replicated in three regions across Germany. To account for temporal variation, samples were taken twice in the same season, but with an interval of three years. Total microbial biomass and microbial community composition differed between years, presumably due to between year variations in weather conditions. The litter layer was more prone to effects of drying, with a reduction of almost 30% of total PLFAs in the drier year. In soil effects of weather conditions depended on soil type and therefore differed between regions, with microorganisms in the sandy soils of the Schorfheide being more susceptible to water-stress, as evidenced by a ten-fold increase of the stress indicator cy/pre ratio in the drier year. Despite temporal variations in microbial biomass and community composition, the balance between the fungal and bacterial energy channel, as measured by fungal-to-bacterial ratios, remained rather constant in particular in soil. While total microbial biomass did not differ between forest types, microbial community composition differed significantly between beech and coniferous forests. Despite more acidic conditions, the fungal energy channel was less pronounced in leaf litter of coniferous forests than in broad-leaved forests, whereas the proportion of bacterial fatty acids was the highest in coniferous forests. Increasing management intensity presumably fosters the bacterial energy channel in the exposed litter layer. Supporting this assumption coniferous forests featured significantly higher values of the stress indicators cy/pre and SAT/MONO ratio. Bacterial community structure and biomass closely correlated with pH, with particular PLFAs dominating at high and low pH, respectively, indicating pH-specific microbial communities. In contrast, fungal abundance in leaf litter was correlated with C-to-N ratio. The results suggest that leaf litter and soil need to be considered separately when investigating changes in microbial community composition, since susceptibility of microorganisms to environmental stressors differs markedly between these layers. This, and repeated sampling events, may be particularly important when investigating subtle effects such as those related to climate change. (C) 2015 Elsevier Ltd. All rights reserved.