Will trees get enough nitrogen to sustain productivity in elevated CO2?

该项目建议通过研究土壤氮对植物的有效性和桉树对氮的利用来探索组织氮在未来二氧化碳(Eco2)升高的情况下如何下降。在几乎每一项在原生土壤上进行的大规模Eco2研究中，植物冠层的氮浓度都会下降。该项目计划探索生态系统氮平衡的变化是如何发生的，通过调查在Eco2下叶片氮是否由于植物活动和土壤氮素有效性的变化而下降。这一结果对于了解额外氮素在多大程度上“支持”Eco2施肥反应并维持生产力的长期增长至关重要。预期成果可能有助于制定管理备选办法，以维持未来的森林生产力。

The project proposes to explore how tissue nitrogen declines in future elevated carbon dioxide (eCO2) by studying the availability of soil nitrogen to plants and use of nitrogen by Eucalyptus woodland trees. Plant canopy nitrogen concentrations decline in nearly every large-scale eCO2 study done on native soils. The project plans to explore how changes in ecosystem nitrogen balance occur, by investigating if leaf nitrogen declines under eCO2 due to the balance of plant activity versus changes in soil nitrogen availability. The outcomes are central to knowing the extent to which extra nitrogen ‘feeds’ the eCO2 fertilisation response and sustains long-term increases in productivity. Expected outcomes may support the development of management options to sustain future forest productivity.