Lipid Analysis of Sediments for Microbial Biomass and Community Structure

Abstract. The unique and fragile High Arctic ecosystems are vulnerable to global climate warming. The elucidation of factors driving microbial distribution and activity in arctic soils is essential for a comprehensive understanding of ecosystem functioning and its response to environmental change. The goals of this study were to investigate microbial biomass and activity, microbial community structure (MCS), and their environmental controls in soils along three elevational transects in the coastal mountains of Billefjorden, central Svalbard. Soils from four different altitudes (25, 275, 525 and 765 m above sea level) were analyzed for a suite of characteristics including temperature regimes, organic matter content, base cation availability, moisture, pH, potential respiration, and microbial biomass and community structure using phospholipid fatty acids (PLFAs). We observed significant spatial heterogeneity of edaphic properties among transects, resulting in transect-specific effects of altitude on most soil parameters. We did not observe any clear elevation pattern in microbial biomass, and microbial activity revealed contrasting elevational patterns between transects. We found relatively large horizontal variability in MCS (i.e., between sites of corresponding elevation in different transects), mainly due to differences in the composition of bacterial PLFAs, but also a systematic altitudinal shift in MCS related to different habitat preferences of fungi and bacteria, which resulted in high fungi-to-bacteria ratios at the most elevated sites. The biological soil crusts on these most elevated, unvegetated sites can host microbial assemblages of a size and activity comparable to those of the arctic tundra ecosystem. The key environmental factors determining horizontal and vertical changes in soil microbial properties were soil pH, organic carbon content, soil moisture and Mg2+ availability.

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Microbial biomass, activity, and community structure in horticultural soils under conventional and organic management strategies

European Journal of Soil Biology ◽

10.1016/j.ejsobi.2013.07.005 ◽

2013 ◽

Vol 58 ◽

pp. 122-128 ◽

Cited By ~ 27

Author(s):

Tida Ge ◽

Xiaojuan Chen ◽

Hongzhao Yuan ◽

Baozhen Li ◽

Hanhua Zhu ◽

...

Keyword(s):

Community Structure ◽

Microbial Biomass ◽

Management Strategies ◽

Organic Management ◽

Biomass Activity

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The restoration age of Robinia pseudoacacia plantation impacts soil microbial biomass and microbial community structure in the Loess Plateau

CATENA ◽

10.1016/j.catena.2018.02.001 ◽

2018 ◽

Vol 165 ◽

pp. 192-200 ◽

Cited By ~ 22

Author(s):

Dong Liu ◽

Yimei Huang ◽

Hanyin Sun ◽

Shaoshan An

Keyword(s):

Community Structure ◽

Microbial Community ◽

Microbial Biomass ◽

Loess Plateau ◽

Microbial Community Structure ◽

Soil Microbial Biomass ◽

Robinia Pseudoacacia ◽

The Loess Plateau ◽

Soil Microbial ◽

Restoration Age

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Nitrogen Addition Affects Soil Respiration Primarily through Changes in Microbial Community Structure and Biomass in a Subtropical Natural Forest

Forests ◽

10.3390/f10050435 ◽

2019 ◽

Vol 10 (5) ◽

pp. 435 ◽

Cited By ~ 3

Author(s):

Jiacong Zhou ◽

Xiaofei Liu ◽

Jinsheng Xie ◽

Maokui Lyu ◽

Yong Zheng ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Microbial Biomass ◽

Soil Respiration ◽

Forest Soil ◽

Microbial Community Structure ◽

N Deposition ◽

N Addition ◽

C Cycling ◽

Total Plfa

Forest soil respiration plays an important role in global carbon (C) cycling. Owing to the high degree of C and nitrogen (N) cycle coupling, N deposition rates may greatly influence forest soil respiration, and possibly even global C cycling. Soil microbes play a crucial role in regulating the biosphere–atmosphere C exchange; however, how microbes respond to N addition remains uncertain. To better understand this process, the experiment was performed in the Castanopsis kawakamii Hayata Nature Reserve, in the subtropical zone of China. Treatments involved applying different levels of N (0, 40, and 80 kg ha−2 year−1) over a three-year period (January 2013–December 2015) to explore how soil physicochemical properties, respiration rate, phospholipid fatty acid (PLFA) concentration, and solid state 13C nuclear magnetic resonance responded to various N addition rate. Results showed that high levels of N addition significantly decreased soil respiration; however, low levels of N addition significantly increased soil respiration. High levels of N reduced soil pH and enhanced P and C co-limitation of microorganisms, leading to significant reductions in total PLFA and changes in the structure of microbial communities. Significant linear relationships were observed between annual cumulative respiration and the concentration of microbial biomass (total PLFA, gram-positive bacteria (G+), gram-negative bacteria (G−), total bacteria, and fungi) and the microbial community structure (G+: G− ratio). Taken together, increasing N deposition changed microbial community structure and suppressed microbial biomass, ultimately leading to recalcitrant C accumulation and soil C emissions decrease in subtropical forest.

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