Chung,C., Zak,D.R. and Reich,P.B.(2009): Microbial assimilation of new photosynthate is altered by plant species richness and nitrogen deposition. Biogeochemistry, 94, 233-242.

『新しい光合成産物の微生物同化は植物種が豊かであることと窒素沈積によって変わる』


Abstract
 To determine how plant species richness impacts microbial assimilation of new photosynthate, and how this may be modified by atmospheric N deposition, we analyzed the microbial assimilation of recent photosynthate in a 6-year-long field experiment in which plant species richness, atmospheric N deposition, and atmospheric CO2 concentration were manipulated in concert. The depleted δ13C of fumigaion CO2 enabled us to investigate the effect of plant species richness and atmospheric N deposition on the metabolism of soil microbial communities in the elevated CO2 treatment. To accomplish this, we determined the δ13C of bacterial, actinobacterial, and fungal phospholipid fatty acids (PLFAs). In the elevated CO2 conditions of this study, the δ13C of bacterial PLFAs (i15:0, i16:0, 16:1ω7c, 16:1ω9c, 10Me16:0, and 10Me18:0) and the fungal PLFA 18:1ω9c was significantly lower in species-rich plant communities than in species-poor plant communities, indicating that microbial incorporation of new C increased with plant species richness. Despite an increase in plant production, total PLFA decreased under N deposition. Moreover, N deposition also decreased fungal relative abundance in species-rich plant communities. In our study, plant species richness directly increased microbial incorporation of new photosynthate, providing a mechanistic link between greater plant detritus production in species-rich plant communities and larger and more active soil microbial community.

Keywords: Atmospheric N deposition; 13C; Grassland ecosystems; Phospholipid fatty acid (PLFA); Plant species richness; Soil microorganisms』

Abbreviations
Introduction
Methods
 Experimental design and sampling procedures
 Phospholipid fatty acid analysis
 Statistical analyses
Results
 Microbial assimilation of new photosynthate
 Total PLFA and relative abundance of microbial PLFAs
Discussion
Acknowledgments
References


ホーム