論文

査読有り
2017年

Nitrogen flux patterns through Oxisols and Ultisols in tropical forests of Cameroon, Central Africa

SOIL SCIENCE AND PLANT NUTRITION
  • Makoto Shibata
  • ,
  • Soh Sugihara
  • ,
  • Antoine David Mvondo-Ze
  • ,
  • Shigeru Araki
  • ,
  • Shinya Funakawa

63
3
開始ページ
306
終了ページ
317
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1080/00380768.2017.1341285
出版者・発行元
TAYLOR & FRANCIS LTD

We lack an understanding of nitrogen (N) cycles in tropical forests of Africa, although the environmental conditions in this region, such as soil type, vegetation, and climate, are distinct when compared with other tropical forests. Herein, we simultaneously quantified N fluxes through precipitation, throughfall, and 0-, 15-, and 30-cm soil solutions, as well as litterfall, in two forests with different soil acidity (Ultisols at the MV village (exchangeable Al3+ in 0-30 cm, 126 kmol(c) ha(-1)) and Oxisols at the AD village (exchangeable Al3+ in 0-30 cm, 59.8 kmolc ha(-1))) over 2 years in Cameroon. The N fluxes to the O horizon via litterfall plus throughfall were similar for both sites (MV and AD, 243 and 273 kg N ha(-1) yr(-1), respectively). Those values were remarkably large relative to other tropical forests, reflecting the dominance of legumes in this region. The total dissolved N flux from the O horizon at the MV was 28 kg N ha-1 yr-1, while it was 127 kg N ha(-1) yr(-1) mainly as NO3- -N (similar to 80%) at the AD. The distinctly different pattern of N cycles could be caused by stronger soil acidity at the MV, which was considered to promote a superficial root mat formation in the O horizon despite the marked dry season (fine root biomass in the O horizon and its proportion to the 1-m-soil profile: 1.5 Mg ha(-1) and 31% at the MV; 0.3Mg ha(-1) and 9% at the AD). Combined with the published data for N fluxes in tropical forests, we have shown that Oxisols, in combination with N-fixing species, have large N fluxes from the O horizon; meanwhile, Ultisols do not have large fluxes because of plant uptake through the root mat in the O horizon. Consequently, our results suggest that soil type can be amajor factor influencing the pattern of N fluxes from the O horizon via the effects of soil acidity, thereby determining the contrasting plant-soil N cycles in the tropical forests of Africa.

リンク情報
DOI
https://doi.org/10.1080/00380768.2017.1341285
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000407175700011&DestApp=WOS_CPL
URL
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85021954519&origin=inward
ID情報
  • DOI : 10.1080/00380768.2017.1341285
  • ISSN : 0038-0768
  • eISSN : 1747-0765
  • SCOPUS ID : 85021954519
  • Web of Science ID : WOS:000407175700011

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