RISS 검색 - 국내학술지논문 상세보기

다국어 초록 (Multilingual Abstract)

Past work in recently deglaciated soils demonstrates that microbial communities undergo shifts prior to
plant colonization. To date, most studies have focused on relatively ‘long’ chronosequences with the ability
to sample plant-free sites over at least 50 years of development. However, some recently deglaciated soils
feature rapid plant colonization and questions remain about the relative rate of change in the microbial
community in the unvegetated soils of these chronosequences. Thus, we investigated the forelands of the
Mendenhall Glacier near Juneau, AK, USA, where plants rapidly establish. We collected unvegetated
samples representing soils that had been ice-free for 0, 1, 4, and 8 years. Total nitrogen (N) ranged from
0.00~0.14 mg/g soil, soil organic carbon pools ranged from 0.6~2.3 mg/g soil, and both decreased in concentration
between the 0 and 4 yr soils. Biologically available phosphorus (P) and pH underwent similar
dynamics. However, both pH and available P increased in the 8 yr soils. Nitrogen fixation was nearly undetectable
in the most recently exposed soils, and increased in the 8 yr soils to ~5 ng N fixed/cm2/h, a
trend that was matched by the activity of the soil N-cycling enzymes urease and β-1,4-N-acetyl-glucosaminidase.
16S rRNA gene clone libraries revealed no significant differences between the 0 and 8 yr soils;
however, 8 yr soils featured the presence of cyanobacteria, a division wholly absent from the 0 yr soils.
Taken together, our results suggest that microbes are consuming allochtonous organic matter sources in
the most recently exposed soils. Once this carbon source is depleted, a competitive advantage may be ceded
to microbes not reliant on in situ nutrient sources.

참고문헌 (Reference)

1 Xie, C.H, "Zoogloea oryzae sp. nov., a nitrogen- fixing bacterium isolated from rice paddy soil, and reclassification of the strain ATCC 19623 as Crabtreella saccharophila gen" 56 : 619-624, 2006

2 Hodkinson, I.D, "What a wonderful web they weave: spiders, nutrient capture and early ecosystem development in the high Arctic - some counter-intuitive ideas on community assembly" 95 : 349-352, 2001

3 Chin, C.C, "Urease.7. Some observations on assay method of Sumner" 17 : 60-65, 1966

4 Lozupone, C, "UniFrac - An online tool for comparing microbial community diversity in a phylogenetic context. BMC Bioinformatics 7. Martin, A.P. 2002. Phylogenetic approaches for describing and comparing the diversity of microbial communities" 68 : 3673-3682, 2002

5 Motyka, R.J, "Twentieth century thinning of Mendenhall Glacier, Alaska, and its relationship to climate, lake calving, and glacier run-off" 35 : 93-112, 2003

6 White, C.C, "The importance of marine-derived base cations and sulphur in estimating critical loads in Scotland" 177 : 225-236, 1996

7 Weintraub, M.N., "The effects of tree rhizodeposition on soil exoenzyme activity, dissolved organic carbon, and nutrient availability in a subalpine forest ecosystem" 154 : 327-338, 2007

8 Saiya-Cork, K.R, "The effects of long term nitrogen deposition on extracellular enzyme activity in an Acer saccharum forest soil" 34 : 1309-1315, 2002

9 Nemergut, D.R, "The effects of chronic nitrogen fertilization on alpine tundra soil microbial communities: implications for carbon and nitrogen cycling" 10 : 3093-3105, 2008

10 Schmidt, S.K, "The earliest stages of ecosystem succession in high-elevation (5000 metres above sea level), recently deglaciated soils" 275 : 2793-2802, 2008