title: Input-output budget of nitrogen and the effect of experimentally changed deposition in the forest ecosystems in central Japan.
abstract: To evaluate the current nitrogen (N) status in Japanese forests, field measurements of rainfall, throughfall, litter layer percolation, and soil solution percolation were conducted in a red pine stand (Kannondai) and a deciduous stand (Yasato) located in central Japan. N input via throughfall was 31 and 14 kg ha(-1) year(-1) and output below rooting zone was 9.6 and 5.5 kg ha1 year(-1) in Kannondai and in Yasato, respectively. Two thirds of input N were retained in plant-soil systems. Manipulation of N input was carried out. Ionic constituents were removed from throughfall with ion exchange resin at removal sites and ammonium nitrate containing twice the N of the throughfall was applied at N addition sites periodically. SO4(2-) output below 20-cm soil layer changed depending on the input, while NO3- output was regulated mainly by the internal cycle and effect of manipulation was undetected. These Japanese stands were generally considered to have a larger capacity to assimilate N than NITREX sites in Europe. However, N output fluxes had large spatial variability and some sites in Kannondai showed high N leaching below rooting zone almost balanced with the input via throughfall.
authors.affiliation: National Institute for Agro-Environmental Sciences, Tsukuba, Ibakari, Japan. shindo@niaes.affrc.go.jp
authors.forename: J
authors.initials: J
authors.lastname: Shindo
authors.forename: T
authors.initials: T
authors.lastname: Fumoto
authors.forename: N
authors.initials: N
authors.lastname: Oura
authors.forename: H
authors.initials: H
authors.lastname: Toda
authors.forename: H
authors.initials: H
authors.lastname: Kawashima
mesh_terms: D000641:Ammonia / Q000032:analysis; D002118:Calcium / Q000032:analysis; D002712:Chlorides / Q000032:analysis; D004463:Ecology / Q000379:methods / Q000706:statistics & numerical data; D017753:Ecosystem; D007564:Japan; D008274:Magnesium / Q000032:analysis; D009566:Nitrates / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism; D011188:Potassium / Q000032:analysis; D011891:Rain; D012964:Sodium / Q000032:analysis; D012987:Soil / Q000032:analysis; D013431:Sulfates / Q000032:analysis; D013995:Time; D014197:Trees / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism
chemical_list: D002712:Chlorides; D009566:Nitrates; D012987:Soil; D013431:Sulfates; D000641:Ammonia; D012964:Sodium; D008274:Magnesium; D009584:Nitrogen; D011188:Potassium; D002118:Calcium; C006568:ammonium nitrate