PLFA profiling of microbial community structure and seasonal shifts in soils of a Douglas-fir chronosequence
PLFA profiling of microbial community structure and seasonal shifts in soils of a Douglas-fir chronosequence
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DOI：
10.1007/s00248-007-9295-1
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发表时间：
2008-04-01
影响因子：
3.6
通讯作者：
Dick, Richard P.
中科院分区：
文献类型：
--
作者：
Moore-Kucera, Jennifer;Dick, Richard P.
森林采伐的影响和频率对土壤微生物群落的结构和功能有显著影响。土壤微生物进行生物地球化学过程的能力对维持森林生产力至关重要，并对分解动态和碳储存潜力有直接影响。在西澳西南部的风河树冠鹤研究森林，提供了一个独特的机会来研究森林的时间序列和采伐对SMC的残余影响，并与原生林进行比较。本研究的目的是利用磷脂脂肪酸（PLFA）谱分析确定砍伐和林龄对SMC时间动态和生理应激标志物的影响。在22个月内（11月02日至9月04日），对300-500年的原始针叶林林分和8 (CC8)-或25 （CC25）年的补种伐伐地的土壤微生物PLFA谱进行了7次测定。林分的PLFA模式因采伐而发生变化，但季节变化大于林龄差异。微生物生物量（总PLFA）、细菌、真菌和选定的其他PLFA在CC8位点显著减少，但在CC25位点相对于老生长位点没有显著减少。夏末胁迫指标[饱和/不饱和PLFA比值和(cy17: 0+cy19: 0)/(16:1 ω - 7+ 18:1 ω - 7)]的增加与水分胁迫有关。尽管25年采伐后的冠层和凋落物输入与原始原生林有很大不同，但我们得出结论，在采伐25年后，微生物群落的组成已经恢复到足以与原生林相似的程度，而不是最近采伐的太平洋西北森林遗址。该研究显示了PLFA分析在野外条件下分析微生物群落及其压力状态的潜力，但广泛的时间变化强调了需要跨季节采样以充分解释生态系统管理对微生物种群的影响。
The impact and frequency of forest harvesting could significantly affect soil microbial community (SMC) structure and functioning. The ability of soil microorganisms to perform biogeochemical processes is critical for sustaining forest productivity and has a direct impact on decomposition dynamics and carbon storage potential. The Wind River Canopy Crane Research Forest in SW, WA, provided a unique opportunity to study a forest chronosequence and the residual effects of harvesting on the SMC in comparison to old-growth forests. The objective of this study was to determine the effect of clear-cutting and stand age on temporal dynamics of SMC and physiological stress markers using phospholipid fatty acid (PLFA) profiling. Soil microbial PLFA profiles were determined seven times over 22 months (Nov. 02 to Sep. 04) in old-growth coniferous forest stands (300-500 years) and 8 (CC8)- or 25 (CC25)year-old replanted clear-cuts. PLFA patterns of the SMC shifted because of clear-cutting, but seasonal temporal changes had greater shifts than differences among stand age. The microbial biomass (total PLFA) and bacterial, fungal, and selected other PLFAs were significantly reduced in CC8 but not in CC25 sites relative to the old-growth sites. An increase in stress indicators [PLFA ratios of saturated/monsaturated and (cy17: 0+cy19: 0)/(16: 1 omega 7+18: 1 omega 7)] in late summer was related to water stress. Although the canopy and litter input are quite different for a 25-year clear-cut compared to virgin old-growth forest, we conclude that the composition of the microbial communities, 25 years after clear-cutting, has recovered sufficiently to be much more similar to old-growth forests than a recent clear-cut at this Pacific Northwest forest site. The study shows the potential of PLFA analysis for profiling microbial communities and their stress status under field conditions, but wide temporal shifts emphasize the need for sampling over seasons to fully interpret ecosystem management impacts on microbial populations.