第127回地球研セミナー
生態系機能にかかる栄養塩制限と地球規模での気候変動
- 開催日時
- 2016年4月28日（木）16:00 - 17:00
- 場 所
- 総合地球環境学研究所 セミナー室３・４（⇒アクセス)
- 講 演 者
- Benjamin Houlton
(Associate Professor and Chancellor's Fellow, Associate Director:
UC Davis John Muir Institute of the Invironment)
- 要 旨
- Nutrients have a long-standing and demonstrated importance is controlling many different aspects of ecosystem structure and functioning, on both land and in the sea and over paleo- to modern-time scales. Disagreements exist, however, over role of terrestrial nutrient availability in determining the fate of the land CO2 sink, particularly in a world of multiple interacting global changes, such as rising CO2, climate change, and nitrogen and phosphorus pollution. In this talk I will examine key issues and opportunities associated with nutrient-carbon-climate interactions in terrestrial ecosystems. First, I will examine evidence for plant nutrient stoichiometric responses to elevated CO2 via global data synthesis. This work reveals widespread adaptive capacity for plant P, but not N, concentrations across an array short term free-air CO2 experiments (FACE). Simulated N deposition appears to increase plant P concentrations, but elevated P inputs do not alter plant P concentrations in return. Second, I will present results from a new satellite-based biogeochemical model, which indicates that that terrestrial P cycle is exceedingly closed with respect to new nutrient inputs, thus pointing to an important role for P limitation of plant productivity over decadal to century time scales. Finally, I will discuss results from several Earth system models, which suggest that terrestrial nutrient limitation could result in an additional 2 degrees C of global warming by year 2100. This result is highly uncertain however; our recent work on plant paleo-nitrogen isotopes over glacial-interglacial time scales could help to improve models of terrestrial biosphere response to modern climate change.
- 連絡担当者
- 研究基盤国際センター 乙川 真理
