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Title: ABUNDANCE OF GLOMALIN, A GLYCOPROTEIN PRODUCED BY ARBUSCULAR MYCORRHIZAL FUNGI, ALONG A TROPICAL SOIL CHRONOSEQUENCE ON THE HAWAIIAN ARCHIPELAGO

Author
item RILLIG, MATTHIAS - CARNEGIE INST. WASHINGTON
item Wright, Sara
item TORN, MARGARET - LAURENCE BERKLEY NATL LAB
item FIELD, CHRISTOPHER - CARNEGIE INST. WASHINGTON

Submitted to: Soil Ecology Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Glomalin is a glycoprotein produced by the hyphae of arbuscular mycorrhizal fungi, which appears to be stabilized in soil and involved in soil aggregate stability. In order to test the hypothesis that soil mineralogy is important in stabilization of glomalin, and to explore the role of glomalin through timescales of ecosystem development, we measured glomalin concentrations along a soil development chronosequence. The chronosequence consists of six sites (0.3 kyr, 2.1 kyr, 20 kyr, 150 kyr, 1,400 kyr, 4,100 kyr) across the Hawaiian archipelago that show little variation in precipitation, temperature and vegetation. During the first 150,000 yrs non-crystalline minerals are dominant, thereafter, non-crystalline minerals decline and crystalline minerals accumulate. We found very high glomalin concentrations of over 50 mg/g soil along the chronosequence. Whereas, the easily extractable glomalin (EEG) concentration did not change distinctly across the sites, the total glomalin (TG) concentration followed a pattern closely resembling the accumulation of intermediate-cycling carbon, except for the oldest site (4.1 Mio yrs). EEG may represent the most recently deposited fraction of glomalin. The turnover time of extracted and purified glomalin TG was estimated by radiocarbon dating (C-14 was measured by accelerator mass spectrometry) and was in the range of decades. This confirms the idea that glomalin may be stabilized in soil through organomineral associations, and highlights the potential importance of this fungal protein in nutrient cycling, at least in iron rich tropical soils.