2011 Fiscal Year Final Research Report
Complete understanding of the nitrogen missing link in boreal forest ecosystems and evaluation of nitrogen provision and loss
| Project/Area Number |
20255002
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 海外学術 |
|---|
| Research Field |
Environmental dynamic analysis
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HARAGUCHI Akira 北九州市立大学, 国際環境工学部, 教授 (50271630)
KOIKE Takayoshi 北海道大学, 農学研究院, 教授 (10270919)
HATANO Ryusuke 北海道大学, 農学研究院, 教授 (40156344)
TAMAI Yutaka 北海道大学, 農学研究院, 准教授 (50281796)
|
|---|
| Co-Investigator(Renkei-kenkyūsha) |
HORIUCHI Junichi 北見工業大学, 工学部, 教授 (30301980)
MIYAMOTO Toshizumi 北海道大学, 農学研究院, 講師 (00343012)
|
|---|
| Project Period (FY) |
2008 – 2011
|
| Keywords | 北方森林 / 高緯度森林限界 / 窒素ミッシングリンク / Spodosol / 低温耐性土壌細菌 / フェザーモス / コンソーシアム形成 / カンパ林 / シアノバクテリア共生 / VBNC |
|---|
| Research Abstract |
Nitrogen imbalance of the boreal forest ecosystem has long been a mystery, called missing link of nitrogen in boreal forest. We challenged to this mystery, to practically understand the effects of climate change on forest biomass productivity in several types of boreal forests. Precise investigation of optimal culture conditions including compositions of the medium were obviously close to the reported conditions of the forest bed soil in summer seasons. The 16S rRNA gene-targeting DGGE analysis combined with gellan gum medium revealed the presence of Dugnella (class y-Proteobacteria) and Clostridiumin (phylum Firmicutes) in the A-horizon of the subarctic tundra soil, and also showed the aboveground vegetation affect on bacterial activity in soil. Thus, it was strongly suggested that scale of the elemental circulation in the boreal forests near the forest limit highly regulates acetylene reducing activity of free-living nitrogen-fixing bacteria. Also it was speculated that the low acetylene reduction in the forest bed soil would be highly regulated as corroborative events together with ericoid mycorrhizal and/or ectomycorrhizal fungi, leading to effective nitrogen supply to the forest ecosystem.
|
