Structure, Photosynthesis and Light In Canopy Environments (SPLICE)

树冠环境中的结构、光合作用和光 (SPLICE)

• 批准号: NE/W006596/1
• 负责人: Tristan Quaife
• 金额: $ 81.76万
• 依托单位: University of Reading
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW006596%2F1
• 关键词: Structure; Photosynthesis; Light; Canopy; Environments

The SPLICE project (Structure, Photosynthesis and Light In Canopy Environments) seeks to improve our understanding of global photosynthesis and hence our ability to model climate change, by considering the way in which the three-dimensional structure of plants interacts with light and how this in turn impacts on the uptake of carbon. We will employ state-of-the-art techniques to measure the three dimensional structure and photosynthesis of forests and construct detailed computer simulations to create a virtual laboratory that we can use to improve simulations from climate models. The process of photosynthesis is fundamental to life on Earth. In this project we are concerned with its role in the terrestrial carbon cycle, which in turn is important for understanding climate change. The land surface absorbs around 25% of anthropogenic CO2 emissions and this proportion has remained remarkably constant despite increasing emissions. Whether or not this will continue is unknown. Earth System Models (ESMs), which are essentially climate models that include climate-relevant biological process, include the uptake of carbon by plants via photosynthesis so that they can model (a) the influence of this process on atmospheric carbon dioxide concentrations and (b) the impact of climate change on global vegetation. There have been significant advances made in the modelling of photosynthesis inside these models in recent decades, for example the interaction with the nitrogen cycle, but they still include some very simple assumptions. We argue that chief amongst these is the way in which the three dimensional structure of vegetation is represented - something that has not been improved for nearly four decades.The equations in ESMs that govern the interception of light by plants, which in turn drives photosynthesis, make the simplifying assumption that leaves are randomly arranged in space, not clustered into tree crowns or around branches. This allows relevant equations in physics to be solved in such a way that results in computationally efficient computer code, but does not represent reality very closely. Recent research from the University of Reading has shown that the impact of including even a simple representation of these effects into an ESM can have large impacts on the global carbon cycle. In particular we showed an enhancement in the modelled estimates of global photosynthesis of 5 billion tonnes of carbon per year, or more than half of CO2 released from burning fossil fuels. Most of this occurs in the tropics, an area of the Earth likely to be especially vulnerable to the impacts of climate change.SPLICE will measure the 3D structure of 26 forests around the world using a combination of terrestrial Lidar scanning and airborne Lidar surveys. Lidar uses scattered laser light to infer structure of forests and information from it can be used to reconstruct a branch-by-branch simulation of the forest. We will take these data and build detailed 3D models of the forest light environment and resulting photosynthesis. The photosynthetic flux will be measured using a variety of techniques, including observations of solar induced fluorescence (SIF) from drones. These observations will be used to test our 3D models. SIF occurs as part of photosynthesis and although it has been known about for some time the technology to observe it remotely is relatively new. It provides a close proxy for the amount of carbon being taken up by photosynthesis.Our final step will be to use the detailed 3D models to develop a modified version of the computer codes used in ESMs to represent the interaction of light with vegetation canopies. These modified codes will be used in the land surface component of UKESM - the UK's new Earth System Model - to assess the impact of these changes globally and the magnitude of their impact on the carbon cycle and hence climate change.

剪接项目（结构，光合作用和冠层环境中的光）试图通过考虑植物的三维结构与光线相互作用以及对碳摄取的影响如何影响我们对气候变化的能力，从而提高我们对全球光合作用的理解，从而对气候变化进行建模。我们将采用最先进的技术来衡量森林的三维结构和光合作用，并构建详细的计算机模拟，以创建一个虚拟实验室，我们可以用来改善气候模型中的模拟。 光合作用的过程是地球生命的基础。在这个项目中，我们关心其在陆地碳周期中的作用，这反过来对于理解气候变化很重要。土地表面吸收了大约25％的人为二氧化碳排放，尽管排放量增加，但该比例仍然非常恒定。这是否会继续是未知的。地球系统模型（ESMS）本质上是包括气候相关的生物学过程的气候模型，包括植物通过光合作用摄入碳的摄入，以便它们可以对（a）（a）该过程对大气二氧化碳浓度的影响以及（b）气候变化对全球植被的影响。近几十年来，在这些模型内部的光合作用建模中取得了重大进展，例如与氮循环的相互作用，但它们仍然包含一些非常简单的假设。我们认为，其中的主要是代表植被的三维结构的方式 - 近四十年来一直没有改善。ESMS的方程式控制植物对光的拦截的方程式，这反过来驱动了光合作用，这会使叶子的简化假定在太空中随机排列，而不是在太空中随机排列，而不是在树冠上群或周围的树冠或周围的树冠。这允许求解物理学方程，以导致计算有效的计算机代码，但并不能非常紧密地表示现实。阅读大学的最新研究表明，即使将这些效果简单地表示为ESM的影响也会对全球碳循环产生很大的影响。特别是，我们显示了每年50亿吨碳的全球光合作用估计值的增强，或者是燃烧化石燃料释放的CO2的一半以上。其中大部分发生在热带地区，地球的一个地区可能特别容易受到气候变化的影响。Splice将使用陆地激光雷达扫描和机载激元的Surveys结合使用世界各地26个森林的3D结构。激光雷达使用散射的激光来推断森林的结构及其信息可用于重建对森林的分支分支模拟。我们将获取这些数据并构建森林光环境的详细3D模型和产生的光合作用。光合通量将使用多种技术测量，包括从无人机中观察到太阳能诱导的荧光（SIF）。这些观察结果将用于测试我们的3D模型。 SIF作为光合作用的一部分出现，尽管已经知道了一段时间以来，远程观察的技术是相对较新的。它为光合作用所吸收的碳量提供了密切的代理。我们的最后一步将使用详细的3D模型来开发ESMS中使用的计算机代码的修改版本，以表示光与植被檐篷的相互作用。这些修改后的代码将用于UKESM的陆地表面成分（英国新的地球系统模型），以评估全球变化的影响以及它们对碳循环的影响幅度以及因此气候变化的影响。