Quinquennial (half-decadal) carbon and nutrient dynamics in temperate forests: Implications for carbon sequestration in a high carbon dioxide world

温带森林五年（半十年）碳和养分动态：对高二氧化碳世界中碳封存的影响

• 批准号: NE/S015744/2
• 负责人: Douglas Clark
• 金额: $ 51.8万
• 依托单位: UK CENTRE FOR ECOLOGY & HYDROLOGY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FS015744%2F2
• 关键词: Quinquennial; half; decadal; carbon; nutrient

Having more carbon dioxide (CO2) in the atmosphere has increased rates of photosynthesis, promoting greater tree growth and carbon storage in forests. This process is called 'CO2 fertilisation' and results in 2-3 billion tonnes of carbon being removed from the atmosphere each year, which is 25-30% of the carbon put into the atmosphere by human activity annually. CO2 fertilisation, thus, greatly reduces rates of global warming. The fight against climate change relies on CO2 fertilisation continuing into the future; the Paris climate agreement emphasises that global efforts are required to limit the amount of carbon we release to that which trees, soil, and oceans can absorb naturally. Increased carbon storage in mature forests, due to CO2 fertilisation, is considered to be the most important reason for the current carbon uptake. But, looking forward, it is highly uncertain whether such high rates of uptake will continue, because the production of plant biomass also requires the uptake of nutrients from soils. The availability of key nutrients (especially nitrogen and phosphorus) may severely limit the ability of trees in mature forests to continue to grow more rapidly. Studying mature forests is particularly important when determining whether nutrient availability may limit future carbon uptake by land ecosystems. Firstly, as discussed above, mature forests are likely the most important absorbers of carbon on land; secondly, nutrient availability is generally low in mature forests because the roots of mature trees may have already fully explored their soils in their search for key nutrients. If mature forests are unable to access more nutrients in the future and maintain their carbon uptake, then this would have major implications for our society. It would mean that we would have to reduce our carbon dioxide emissions by a greater extent, and more rapidly than currently expected, if we are to avoid the most serious consequences of climate change. Temperate forests currently absorb almost as much carbon as the emissions from all EU nations. While tropical rainforests are, of course, important, mature temperate forests are calculated to be fourfold more efficient at absorbing carbon, and so merit special attention. To be able predict how mature temperate forests will respond in the future, it is critical that we determine whether greater carbon dioxide concentrations in the atmosphere will allow mature trees in temperate forest to:1) take up more nutrients from soils, and/or,2) increase the efficiency with which they use available nutrients to produce new plant tissue.Manipulating CO2 for whole stands of mature forest is challenging and expensive, and until now there has been no experiment that would have allowed us to address the uncertainties discussed above. All this has changed with the establishment of a new experimental facility in mature oak forest in central England. Leveraging a £15m philanthropic gift and an equivalent University of Birmingham investment, a whole-ecosystem free-air carbon dioxide enrichment (FACE) experiment has been set-up, which is successfully forest patches to CO2 concentrations more than one third higher than current levels. In the FACE ecosystem, the canopy trees are at least 160 years old and the site has been forested for the last 400 years. QUINTUS aims to carry out the detailed measurements of nutrient cycling (more than 20,000 analyses) that are required to answer the two key processes outlined above and, thus, determine how a mature temperate forest responds to rising atmospheric CO2. This new experimental understanding will then be used to develop and test the next generation of the computer models which are used to predict future rates of climate change. QUINTUS will deliver a foundational change in our understanding of future C uptake in temperate forests, and in mature forests generally. Such an advance is urgently required and has major societal relevance.

在大气中具有更多的二氧化碳（CO2）的光合作用率提高，从而促进森林中的树木生长和碳储存率更高。该过程称为“二氧化碳受精”，每年从大气中清除了2-3亿吨碳，这是人类活动每年将碳放入大气中的25-30％。因此，二氧化碳受精大大降低了全球变暖的速度。与攀岩变化的斗争依赖于二氧化碳的施肥持续到未来。巴黎气候协议强调，需要全球努力将我们释放的碳量限制为自然可以吸收的树木，土壤和海洋。由于二氧化碳受精，成熟森林中的碳储存增加被认为是当前碳摄取的最重要原因。但是，展望未来，高度不确定摄入率是否会继续下去，因为植物生物量的产生也需要从土壤中吸收养分。关键营养素的可用性（尤其是氮和磷）可能严重限制了成熟森林中树木的能力继续增长。在确定养分的可用性是否可能限制土地生态系统的未来碳吸收时，研究成熟的森林尤为重要。首先，如上所述，成熟的森林可能是陆地上最重要的碳吸收剂。其次，成熟森林中的营养利用率通常很低，因为成熟树木的根可能已经完全探索了它们的土壤，以寻找关键营养素。如果成熟的森林将来无法获得更多的营养并保持其碳吸收，那么这将对我们的社会产生重大影响。这意味着如果我们要避免气候变化最严重的后果，我们将不得不更大程度地减少二氧化碳的排放，并且比目前预期的要快。温带森林目前吸收的碳几乎与所有欧盟国家的排放一样多。当然，尽管热带雨林是重要的，但成熟的温度森林被计算为吸收碳的效率更高，因此值得特别注意。为了预测未来成熟的温度森林将如何反应，我们必须确定大气中的二氧化碳浓度较高，是否会使温度森林中的成熟树木允许：1）从土壤中吸收更多的营养成分，以及/或/或，/或2）提高他们使用可用的营养物质来产生新的植物组织的效率。上面讨论的不确定性。随着在英格兰中部成熟的橡树森林建立新的实验设施，所有这些都发生了变化。已经设置了一项全生态系统的二氧化碳（FACE）实验，利用1500万英镑的慈善礼物和同等的伯明翰大学投资，这是成功的二氧化碳实验，这成功地将森林化森林化为CO2的浓度超过三分之一。在面部生态系统中，顶篷树至少160年，并且该地点在过去的400年中一直在森林中进行森林。 Quintus的目的是进行营养循环的详细测量（超过20,000个分析），这些测量需要回答上面概述的两个关键过程，从而确定成熟温度森林如何响应大气上升的二氧化碳。然后，这种新的实验理解将用于开发和测试下一代计算机模型，这些计算机模型用于预测未来的气候变化速度。 Quintus将在我们对温度森林以及成熟森林中未来的C摄取的理解方面进行基本变化。迫切需要这样的进步，并且具有重要的社会意义。

项目成果

Representation of the phosphorus cycle in the Joint UK Land Environment Simulator (vn5.5_JULES-CNP)

英国联合陆地环境模拟器 (vn5.5_JULES-CNP) 中磷循环的表示

• DOI: 10.5194/gmd-15-5241-2022
• 发表时间: 2022
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: Nakhavali M

Representation of phosphorus cycle in Joint UK Land Environment Simulator (vn5.5_JULES-CNP)

• DOI: 10.5194/gmd-2021-403
• 发表时间: 2021-12
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: M. Nakhavali;L. Mercado;I. Hartley;S. Sitch;Fernanda V. Cunha;Raffaello di Ponzio;L. F. Lugli;C. Quesada;K. Andersen;S. Chadburn;A. Wiltshire;D. Clark;G. Ribeiro;Lara Siebert;A. M. Moraes;Jéssica Schmeisk Rosa;R. Assis;J. Camargo