2017年
Nitrogen flux patterns through Oxisols and Ultisols in tropical forests of Cameroon, Central Africa
SOIL SCIENCE AND PLANT NUTRITION
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- 巻
- 63
- 号
- 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
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- 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
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- DOI : 10.1080/00380768.2017.1341285
- ISSN : 0038-0768
- eISSN : 1747-0765
- SCOPUS ID : 85021954519
- Web of Science ID : WOS:000407175700011