NI: Network for Monitoring Canopy Temperature of Forests - netCTF

森林是全球碳循环的关键组成部分，因为它们通过光合作用将二氧化碳从大气中带走，并将碳储存在木材和土壤中。森林中的所有生物也通过呼吸产生二氧化碳，这是维持自身和生长的必然结果。目前，森林吸收的二氧化碳多于释放的二氧化碳，有助于减少大气中存在的二氧化碳，但在气候变化的情况下，森林的这种免费礼物并不能保证以目前的速度无限期地持续下去。除了碳循环，森林在水循环中也是至关重要的，因为树木将土壤中的水分输送到大气中。树叶是植物调节与大气交换气体(水、二氧化碳)的关键部分。叶表面(气孔)中的气孔对于失水和温度控制以及二氧化碳的进入都是重要的。树叶暴露在阳光直射下的温度可能比空气高十多度，即使在温带地区也是如此。叶片温度很重要，因为许多生物过程，包括光合作用和呼吸作用，对温度都很敏感；非常高的温度会立即对叶片造成严重的损害。在接下来的一个世纪里，我们预计二氧化碳浓度和气温将继续上升。当树木生长在二氧化碳浓度较高的环境中时，气孔关闭并限制水分损失；这可以防止植物脱水，但也减少了树叶可以降温的程度。然而，对森林冠层温度的监测有限，对不同气候带的不同物种和森林如何应对气候变化的了解也有限。该项目将建立一个使用热红外相机测量森林冠层温度的全球研究人员网络，这将提供更多的了解，也是其他学科的科学家可以使用的重要数据来源。该网络将确保不同小组收集的数据具有可比性，并通过提供明确的指导和工具来帮助数据处理和分析。这将鼓励其他研究人员使用热红外相机，而热红外相机的分析可能具有挑战性。我们的网络将在英国、中国、印度、澳大利亚、巴西、秘鲁、巴拿马、美国和加纳的热带和温带森林和大草原的14个地点监测树冠温度。在英国和秘鲁的网站将由该项目新建立。10个站点已经建立了数据收集，而最后两个站点(澳大利亚、加纳)正在开发中。使用摄像头收集数据将使我们不仅能够了解不同地点的森林是如何行为的，而且还可以了解不同地点的不同物种是否以及如何做出反应。该项目的长期性意味着将包括季节性变化，并将量化森林对热浪和干旱等极端事件的反应。未来的工作将更详细地确定树冠温度的变化如何与森林碳循环和水循环的变化相联系。我们的工作提供了对森林树冠对气候变化的反应的洞察，将为评估温室气体排放对地球的影响而制作的模型提供信息，这些模型被用于为全球气候变化政策提供信息。此外，当前全球对通过植树缓解气候变化的重视使得评估这些树木在未来条件下将如何应对至关重要。

Forests are a critical component of the global carbon cycle because they take carbon dioxide out of the atmosphere through photosynthesis, and store the carbon in wood and soil. All living things in forests also produce carbon dioxide through respiration as an inevitable consequence of sustaining themselves and growing. At present, forests take in more carbon dioxide than they release, helping to reduce the amount of carbon dioxide present in the atmosphere, but this 'free gift' from forests is not guaranteed to continue at its current rate indefinitely under climate change. As well as the carbon cycle, forests are also crucial in the water cycle as trees pump water from the soil into the atmosphere.Leaves are the key part of the plant that regulates the exchange of gases (water, carbon dioxide) with the atmosphere. The pores in the leaf surface (stomata) are important for water loss and temperature control as well as the entry of carbon dioxide. Leaves exposed to direct sunlight can be more than ten degrees hotter than the air, even in temperate latitudes. Leaf temperature is important because many biological processes, including photosynthesis and respiration, are sensitive to temperature; very high temperatures can cause immediate and acute damage to leaves. Over the coming century, we expect carbon dioxide concentrations and air temperatures to continue to rise. When trees are grown in higher carbon dioxide concentrations, stomata close and limit water loss; this prevents the plant dehydrating but also reduces how much leaves can cool down. However, there is limited monitoring on forest canopy temperatures, and limiting understanding on how different species and forests in different climate zones are responding to climate change. This project will build a global network of researchers working to measure forest canopy temperatures using thermal infrared cameras, which will provide both greater understanding and also a crucial data resource for scientists in other disciplines to utilise.The network will ensure that the data collected by separate groups are comparable, and aid data processing and analysis by providing clear guidance and tools. This is will encourage other researchers to take up use of thermal infrared cameras, the analysis of which can be challenging. Our network will monitor canopy temperatures at fourteen sites in tropical and temperate forests and savannah, in UK, China, India, Australia, Brazil, Peru, Panama, USA, and Ghana. The sites in the UK and Peru will be newly established by this project. Ten sites already have established data collection, while the final two sites (Australia, Ghana) are in development. Having data collected using cameras will allow us to understand not only how forests in different locations are behaving, but also whether and how different species within sites respond. The long-term nature of the project means that seasonal variation will be included, and the forest response to extreme events such as heat waves and droughts will be quantified. Future work will establish in more detail how changes to canopy temperature link to changes in forest carbon and water cycling. Our work providing insight into the response of forest canopies to climate change will inform models produced to assess the impacts of greenhouse gas emissions on the planet, which are used to inform global climate change policies. Further, the current global emphasis on mitigating climate change through tree planting makes it crucial to assess how these trees will cope under future conditions.