| 要旨トップ | 目次 | 日本生態学会第65回全国大会 (2018年3月、札幌) 講演要旨
ESJ65 Abstract


一般講演(口頭発表) E02-07  (Oral presentation)

Soil microbial communities associated with each step in nitrogen transformation along a rainfall gradient in semiarid forests

*Chikae Iwaoka(Kyoto University), Takeshi Taniguchi(Tottori University), Sheng Du(Chinese Academy), Norikazu Yamanaka(Tottori University), Ryunosuke Tateno(Kyoto University)

Nitrogen (N) as well as water is the most limiting resources for plant growth in drylands. However, it is unknown how soil N transformation is limited by rainfall amount and which step is the rate-limiting step of N transformation in drylands. For mechanistically and comprehensively understanding soil N transformation process, it’s very useful to focus on soil microbial communities associated with each step of N transformation. Here, we briefly divided N transformation process into three steps, i.e. organic matter degradation step, mineralization step and nitrification step, which are primarily driven by fungi, prokaryote and ammonia-oxidizers, respectively. Microbial response to drought is various depending on the taxa, so we expected each step show different change along a rainfall gradient. We collected soil samples from three black locust forests along a rainfall gradient and analyzed extractable N and microbial communities. As a result, fungal, prokaryotic and ammonia-oxidizers community composition all dramatically changed along the rainfall gradient, as strong decomposers and nitrifiers increased. Accordingly, dissolved organic N, ammonium N and nitrate N content increased along the rainfall gradient. Thus, the rainfall gradient did not create a specific rate-limiting step, but almost equally affected every step of N transformation by controlling important microbial groups.


日本生態学会