Biogeochemical geography of peatlands from in-situ measurements to satellite imagery

从原位测量到卫星图像的泥炭地生物地球化学地理学

• 批准号: RGPIN-2017-06290
• 负责人: Kalacska, Margaret
• 金额: $ 3.42万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=654995
• 关键词: Biogeochemical; geography; peatlands; situ; measurements

Peatlands play a significant role in the global carbon cycle as well as in the maintenance of biodiversity and the protection of endangered species. Northern peatlands store one third of the terrestrial carbon derived from atmospheric carbon dioxide. Nevertheless, far less is known about their structure and function in comparison to other terrestrial ecosystems. Despite their resilience, peatlands are vulnerable to climate change, disturbance and land use change impacts. Precise information about their structure and functioning at landscape scales (and over time) is needed in order to inform policy regarding their management and conservation. Remote sensing and geospatial modelling offer the opportunity to better understand these ecosystems at large spatial scales through time. My research program aims to fill key knowledge gaps regarding the biogeochemical geography of peatlands from remotely sensed data. My long-term objectives are: 1) To determine the effect of scaling remotely sensed vegetation characteristics of peatlands from in-situ measurements to satellite imagery; and 2) To improve models of peatland carbon balance from imaging spectroscopy in light of projected climate change. Four scientific questions guide my proposed research program: 1) How is the anisotropic reflectance of peatlands affected by the illumination conditions (i.e. solar azimuth and zenith angle) during acquisition of airborne hyperspectral imagery? 2) Considering phenology, what is the spectral variability of peatland vegetation physiognomic classes? 3) With what precision can we determine the water table position (or a proxy) from optical imagery for peatlands as a means to model net ecosystem exchange at large spatial scales? and 4) Based on projected climate change, how will the extent of the different vegetation physiognomic classes change across the peatland? With 12% of its surface area estimated to be peatland, Canada has a clear stewardship obligation. The results from this research program would increase the understanding of the importance of this ecosystem as a climate change mediator and provider of fundamental ecosystem services.

泥炭地在全球碳循环以及维持生物多样性和保护濒危物种方面发挥着重要作用。北部泥炭地储存了来自大气二氧化碳的陆地碳的三分之一。然而，与其他陆地生态系统相比，人们对它们的结构和功能知之甚少。尽管泥炭地具有韧性，但它们很容易受到气候变化、干扰和土地利用变化的影响。需要关于它们在景观尺度上的结构和功能的准确信息(以及随着时间的推移)，以便为它们的管理和保护政策提供信息。遥感和地理空间建模提供了在大空间尺度上更好地了解这些生态系统的机会。我的研究计划旨在从遥感数据中填补有关泥炭地生物地球化学地理的关键知识空白。我的长期目标是：1)确定从现场测量到卫星图像的泥炭地遥感植被特征的缩放效果；2)根据预测的气候变化，改进从成像光谱学获得的泥炭地碳平衡模型。4个科学问题指导了我提出的研究计划：1)在获取航空高光谱图像时，泥炭地的各向异性反射率受光照条件(即太阳方位角和天顶角)的影响如何？2)考虑物候，泥炭地植被地貌类别的光谱变异性是什么？3)我们可以以多高的精度从泥炭地的光学图像中确定地下水位位置(或替代)，作为一种在大空间尺度上模拟净生态系统交换的手段？4)基于预测的气候变化，泥炭地不同植被地貌类别的程度将如何变化？据估计，加拿大12%的表面积是泥炭地，加拿大有明确的管理义务。这项研究计划的结果将提高人们对该生态系统作为气候变化调解人和基本生态系统服务提供者的重要性的理解。