Record ID No. |
1136 |
Author(s) |
van Diepen LTA, Lilleskov EA, Pregitzer KS, Miller RM , 2007 |
Affiliation |
van Diepen, LTA, Michigan Technol Univ, Sch Forestry & Environm Sci, Ecosyst Sci Ctr, Houghton, MI 49931 |
Title |
Decline of arbuscular mycorrhizal fungi in northern hardwood forests exposed to chronic nitrogen additions |
Source. Vol.(no):Page |
NEW PHYTOLOGIST. 176(1):175-183p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry |
Sub-subjects |
Nitrogen metabolism |
Host |
Acer spp. |
Organism |
AMF |
Country |
USA, N. America |
Abstracts |
Arbuscular mycorrhizal (AM) fungi are important below-ground carbon (C) sinks that can be sensitive to increased nitrogen (N) availability. The abundance of AM fungi (AMF) was estimated in maple (Acer spp.) fine roots following more than a decade of experimental additions of N designed to simulate chronic atmospheric N deposition. Abundance of AMF was measured by staining and ocular estimation, as well as by analyzing for the AMF indicator fatty acid 16:1 omega 5c in phospholipid (biomass indicator) and neutral lipid (lipid storage indicator) fractions. Arbuscular mycorrhizal fungal biomass, storage structures and lipid storage declined in response to N addition measured by both methods. This pattern was found when AM response was characterized as colonization intensity, on an areal basis and in proportion to maple above-ground biomass. The phospholipid fraction of the fatty acid 16:1 omega 5c was positively correlated with total AMF colonization and the neutral lipid fraction with vesicle colonization. Decreased AMF abundance with simulated N deposition suggests reduced C allocation to these fungi or a direct soil N-mediated decline. The fatty acid (phospholipid and neutral lipid fractions) 16:1 omega 5c was found to be a good indicator for AMF active biomass and stored energy, respectively. |