The Amazon Fertilisation Experiment (AFEX)

亚马逊施肥实验（AFEX）

• 批准号: NE/L007924/1
• 负责人: Patrick Meir
• 金额: $ 37.63万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FL007924%2F1
• 关键词: Amazon; Fertilisation; Experiment; AFEX

Terrestrial ecosystems currently absorb one quarter of the carbon dioxide that Humankind releases into the atmosphere, thus reducing the rate of climate change. In this context, Amazon rainforest is extremely important, absorbing more than half a billion tonnes of carbon per year. This represents more than the combined emissions from the USA and China. However, we have limited understanding of how the productivity of Amazon forests is controlled, and this reduces our ability to predict what will happen in the future as atmospheric CO2 concentrations continue to rise and the climate changes.One of the main paradigms in ecology is that the productivity of tropical ecosystems, which occur on old, highly-weathered soils, is limited by the availability of phosphorus. This contrasts with more temperate ecosystems whose productivity has been shown to be limited by nitrogen availability. However, the phosphorus paradigm has not been tested in detail as there have been very few nutrient manipulation studies in tropical forests, and no large-scale study has been carried out in Amazon forest. This is a major issue because soil nutrient availability in most of Amazonia is substantially lower than in Panama, the location of the only ongoing fertilisation experiment in tropical lowland rainforest. Thus, the Panama findings may not be representative of large areas of Amazonia, and, therefore, our understanding of the role soil fertility plays in controlling tropical forest productivity is incomplete. Testing the phosphorus paradigm in Amazonia is critical for two reasons. Firstly, eastern and central Amazonia, the area which contains the lowest fertility soils, is considered to be at risk from the adverse effects of climate change, with widespread dieback predicted by some scientists. The resilience of these forests is considered to be highly dependent on whether trees are able to increase their growth in response to rising atmospheric CO2 concentrations, and this ability is likely to depend on the extent to which their growth is currently limited by soil nutrient availability. Secondly, there is growing evidence that the response of ecosystems to global change may differ depending on which nutrient limits their productivity. Therefore, establishing the first large-scale nutrient manipulation study in Amazonia should represent one of greatest priorities for ecosystem and climate change research. We will do just that, manipulating nitrogen, phosphorus and cation availability in central Amazon forest, at a site representative of the most common soil type in the Basin, and will quantify the response of key forest processes. We will determine the impacts on photosynthesis, plant respiration, biomass production and turnover, and decomposition, ultimately allowing us to take a full-ecosystem approach to establish how carbon storage has been affected. The new knowledge and understanding which we generate will be used to improve Amazon process representation in the Joint UK Land Environment Simulator (JULES). This will be the first time that multi-nutrient control of tropical forest function has been included in a dynamic global vegetation model, allowing for more realistic simulation of the response of the Amazon carbon cycle to environmental change. This will improve our ability to predict how the Amazon rainforest will change during the 21st century and what the implications will be for rates of regional and global climate change.In summary, our project will address a fundamental ecological question and will improve greatly our understanding of an issue that contributes substantially to uncertainty in predictions of rates of 21st century climate change; namely, how the productivity of one of the most important natural carbon sinks on the planet, the Amazon rainforest, is controlled.

目前，陆地生态系统吸收了人类排放到大气中的二氧化碳的四分之一，从而减缓了气候变化的速度。在这方面，亚马逊雨林极为重要，每年吸收超过5亿吨碳。这比美国和中国的排放量总和还要多。然而，我们对亚马逊森林的生产力是如何控制的了解有限，这降低了我们预测未来大气中二氧化碳浓度持续上升和气候变化会发生什么的能力。生态学的一个主要范例是，热带生态系统的生产力，发生在古老的，高度风化的土壤上，受到磷的可用性的限制。这与更温和的生态系统形成对比，后者的生产力已被证明受到氮供应的限制。然而，磷的范例还没有得到详细的测试，因为在热带森林中很少有营养操纵研究，在亚马逊森林中也没有进行过大规模的研究。这是一个主要问题，因为亚马逊河流域大部分地区的土壤养分供应量大大低于巴拿马，而巴拿马是唯一正在进行的热带低地雨林施肥实验的地点。因此，巴拿马的调查结果可能不能代表亚马逊河流域的大片地区，因此，我们对土壤肥力在控制热带森林生产力方面所起作用的理解是不完整的。在亚马逊河流域测试磷范例至关重要，原因有二。首先，亚马孙河东部和中部是土壤肥力最低的地区，被认为有可能受到气候变化的不利影响，一些科学家预测会出现大范围的枯死。据认为，这些森林的复原力在很大程度上取决于树木是否能够增加其生长以应对大气中二氧化碳浓度的上升，而这种能力很可能取决于其生长目前受到土壤养分供应限制的程度。第二，越来越多的证据表明，生态系统对全球变化的反应可能会有所不同，这取决于哪些养分限制了它们的生产力。因此，在亚马逊河流域建立第一个大规模的营养操纵研究应该是生态系统和气候变化研究的最优先事项之一。我们将这样做，操纵亚马逊森林中部的氮，磷和阳离子的可用性，在该盆地最常见的土壤类型的代表性网站，并将量化关键森林过程的响应。我们将确定对光合作用，植物呼吸，生物量生产和周转以及分解的影响，最终使我们能够采取全生态系统方法来确定碳储存如何受到影响。我们产生的新知识和理解将被用来提高亚马逊过程表示在联合英国陆地环境模拟器（JULES）。这将是第一次将热带森林功能的多营养控制纳入动态全球植被模型，从而能够更真实地模拟亚马逊碳循环对环境变化的反应。这将提高我们预测亚马逊雨林在21世纪世纪将如何变化以及对区域和全球气候变化率的影响的能力。总之，我们的项目将解决一个基本的生态问题，并将大大提高我们对一个问题的理解，这个问题在很大程度上导致了对21世纪世纪气候变化率的预测的不确定性;也就是说，地球上最重要的自然碳汇之一亚马逊雨林的生产力是如何被控制的。

项目成果

Scaling leaf respiration with nitrogen and phosphorus in tropical forests across two continents.

• DOI: 10.1111/nph.13992
• 发表时间: 2017-05
• 期刊: The New phytologist
• 作者: Rowland L;Zaragoza-Castells J;Bloomfield KJ;Turnbull MH;Bonal D;Burban B;Salinas N;Cosio E;Metcalfe DJ;Ford A;Phillips OL;Atkin OK;Meir P
• 通讯作者: Meir P

Respiration in wood: integrating across tissues, functions and scales.

木材的呼吸：跨组织、功能和尺度的整合。

• DOI: 10.1111/nph.16354
• 发表时间: 2020
• 期刊: The New phytologist
• 作者: Meir P

Effects of natural and experimental drought on soil fungi and biogeochemistry in an Amazon rain forest

• DOI: 10.1038/s43247-021-00124-8
• 发表时间: 2021-03-10
• 期刊: COMMUNICATIONS EARTH & ENVIRONMENT
• 影响因子: 7.9
• 作者: Buscardo, Erika;Souza, Romulo C.;Nagy, Laszlo
• 通讯作者: Nagy, Laszlo

Climate Warming and Soil Carbon in Tropical Forests: Insights from an Elevation Gradient in the Peruvian Andes.

• DOI: 10.1093/biosci/biv109
• 发表时间: 2015-09-01
• 期刊: Bioscience
• 影响因子: 10.1
• 作者: Nottingham AT;Whitaker J;Turner BL;Salinas N;Zimmermann M;Malhi Y;Meir P
• 通讯作者: Meir P

Convergence in phosphorus constraints to photosynthesis in forests around the world.

世界各地森林中磷对光合作用的限制趋同。

• DOI: 10.1038/s41467-022-32545-0
• 发表时间: 2022-08-25
• 期刊: Nature communications
• 影响因子: 16.6