title: Carbon dynamics and budget in a Zoysia japonica grassland, central Japan.
abstract: The ecosystem carbon budget was estimated in a Japanese Zoysia japonica grassland. The green biomass started to grow in May and peaked from mid-July to September. Seasonal variations in soil CO(2) flux and root respiration were mediated by changes in soil temperature. Annual soil CO(2) flux was 1,121.4 and 1,213.6 g C m(-2) and root respiration was 471.0 and 544.3 g C m(-2) in 2007 and 2008, respectively. The root respiration contribution to soil CO(2) flux ranged from 33% to 71%. During the growing season, net primary production (NPP) was 747.5 and 770.1 g C m(-2) in 2007 and 2008, respectively. The biomass removed by livestock grazing (GL) was 122.1 and 102.7 g C m(-2), and the livestock returned 28.2 and 25.6 g C m(-2) as fecal input (FI) in 2007 and 2008, respectively. The decomposition of FI (DL, the dry weight loss due to decomposition) was very low, 1.5 and 1.4 g C m(-2), in 2007 and 2008. Based on the values of annual NPP, soil CO(2) flux, root respiration, GL, FI, and DL, the estimated carbon budget of the grassland was 1.7 and 22.3 g C m(-2) in 2007 and 2008, respectively. Thus, the carbon budget of this Z. japonica grassland ecosystem remained in equilibrium with the atmosphere under current grazing conditions over the 2 years of the study.
authors.affiliation: River Basin Research Center, Gifu University, Yanagido 1-1, Gifu, 501-1193, Japan. ddhital@green.gifu-u.ac.jp
authors.forename: Deepa
authors.initials: D
authors.lastname: Dhital
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yashiro
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ohtsuka
authors.forename: Hibiki
authors.initials: H
authors.lastname: Noda
authors.forename: Yoko
authors.initials: Y
authors.lastname: Shizu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Koizumi
mesh_terms: D000818:Animals; D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D002417:Cattle; D019069:Cell Respiration; D017753:Ecosystem; D005243:Feces; D007564:Japan; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism*; D011891:Rain; D012621:Seasons; D012987:Soil / Q000032:analysis; D013696:Temperature
chemical_list: D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon