Investigating the use of a leaf trait-based approach to remotely measure tropical forest productivity

热带森林和热带草原占陆地碳循环的60%。因此，了解这些地区的碳固存速率，以及预测的变化，对于预测未来的气候至关重要。MODIS卫星提供了两种产品来测量植被覆盖地区的总初级生产力(GPP)和净初级生产力(NPP)。然而，人们对这些产品准确估计热带森林上GPP和NPP的规模和空间模式的能力产生了严重的怀疑(克利夫兰等人。2015年)。显然，在这些地区需要一种新的方法。这项提议旨在调查一种新的基于树叶特征的方法来遥感热带森林生产力的使用。利用叶片光谱、航空高光谱数据和偏最小二乘回归分析(PLSR)，它将在现有文献的基础上表明，通过根据野外收集的值校准哨兵卫星数据，可以准确地估计碳循环过程，如叶片光合作用、呼吸作用和木本植物生产力。最终，它打算在谷歌地球引擎(一个处理卫星图像的云计算平台)中创建热带森林生产力地图，供公众和科学使用。我的硕士学位论文在这一领域进行的初步研究非常有前途，在北亚利桑那大学担任研究学者一年后，我与Chris Doughty教授合作扩展了这项工作，我相信我处于独特的位置来承担这项研究，并推动这一新颖和新兴的领域。

Tropical forests and savannahs account for 60% of terrestrial carbon cycling. Thus, understanding rates of carbon sequestration in these areas, along with projected changes, is vital for predicting future climate. MODIS satellites offer two products to measure gross primary productivity (GPP) and net primary productivity (NPP) across vegetated areas. Yet significant doubt has been cast on the ability of these products to accurately estimate the magnitude and spatial patterns of GPP and NPP over tropical forests (Cleveland et al. 2015). It is clear that in these regions a new methodology is required. This proposal aims to investigate the use of a novel leaf trait-based approach to remotely sense tropical forest productivity. Using leaf spectroscopy, airborne hyperspectral data and partial least square regression analysis (PLSR), it will build on existing literature to show that carbon cycling processes, such as leaf photosynthesis, respiration and woody productivity, can be accurately estimated by calibrating SENTINEL satellite data on field-collected values. Ultimately, it intends to create maps of tropical forest productivity in Google Earth Engine (a cloud computing platform for processing satellite imagery) for public and scientific use. Initial research carried out for my MSc dissertation in this area was very promising, and, following a year-long position as Research Scholar at Northern Arizona University, where I collaborated with Prof. Chris Doughty to expand this work, I believe I am uniquely placed to undertake this research and advance this novel and emerging field.