Biocomplexity: Carbonshed Studies of Carbon Sequestration in Complex Terrain

MonsonRecent对美国碳汇的分区估计表明，很大一部分碳汇在美国西部，出现在丘陵到山区的生态系统中。我们利用卫星数据和生态系统模型表明，美国西部山地地区对美国碳汇的贡献不成比例；我们估计，美国大陆碳汇的25%至50%，以及美国西部高达75%的碳汇发生在山区。我们用测量来验证这些预测，或者用改进的机械模型来建立这些预测的能力是有限的。尽管生物地球化学过程的尺度是在山区流域率先进行的，但最近的研究更多地集中在“塔足迹”范式上，而不是分水岭方法；不幸的是，我们目前基于塔的测量能力不足以在复杂地形学中发展准确的质量平衡预测，这减少了理解土壤中生物地球化学通量的努力。在这项建议中，我们发展了一种“碳棚”方法来研究山地景观的生态系统碳平衡。我们将同一背景下的碳化带定义为分水岭--山坡和山谷形成的复杂地形格局，直接影响二氧化碳的排放和积累，以及能量和水的再分配格局，间接影响整个景观中二氧化碳的交换。我们认为碳棚尺度对于将当地生态系统层面的二氧化碳通量与区域景观层面的二氧化碳通量联系起来是至关重要的。在这项建议中，我们提出了一项在科罗拉多州落基山脉前缘测量碳棚二氧化碳通量的计划。认识到在复杂的地形中使用大气技术直接测量碳收支是不可能的，我们专注于模型数据集成，使用测量来校准和约束模型，并使用模型来内插观测。我们还认识到碳和水交换是紧密耦合的，特别是在这个半干旱的西部环境中，我们将重点放在将碳和水的测量联系起来。我们将用多个时间和空间尺度的测量来挑战过程模式，利用季节到年际通量测量、碳棚尺度运动放大(10‘S公里)和区域(1000’S公里)空中测量。2002年的大火将使我们能够对最近燃烧的系统中的碳动态进行空中测量，这是对基于扰动的模型中通量提升的独特测试。该项目的建模将使用一个耦合的生态系统-大气模型，允许将模拟的通量转化为浓度模式，以便与地面和空中观测进行比较。该提议通过以下方式解决智力上的优势标准：1)确定碳科学中的一个新现象：由于气候和土地利用模式的相互作用，碳汇在高起伏的生态系统中发展的趋势；2)提出衡量这一现象的创新和跨学科方法；3)组建一个包括生物物理学家、气象学家、生态学家和教育工作者在内的团队来研究这个问题。博士后研究将为两名研究生和两名博士后提供培训机会。资助的活动将成为开发一门关于人与环境耦合的新课程的催化剂，该课程将包括分析土地利用历史、水资源、灭火和生物物理控制对山区碳的综合作用。这项研究将支持由科罗拉多大学CIRES教育和外联办公室协调的一个重要的K-12和教师培训计划。拟议的研究将极大地增强NCAR ATD的NSF设施的碳循环仪器能力，从而为科学基础设施做出贡献，这一能力可供普通科学界使用。此外，一个大大改进的分析区域碳汇活动的四维模型将提供给一般科学和公共政策团体，用于分析美国的碳汇及其与全球碳循环问题的相关性。

0321918MonsonRecent estimates that regionalize the US carbon sink suggest that a significant fraction is inthe Western US, in ecosystems that occur in hilly to mountainous regions. We have usedsatellite data and ecosystem models to show that Western US montane regions contributedisproportionately to the US carbon sink; we estimated that 25 to 50% of the total continental UScarbon sink, and up to 75% of Western US carbon sink occurs in mountainous terrain. Ourability to validate these predictions with measurements, or to build on them with improvedmechanistic models, is limited. Although the scaling of biogeochemical processes waspioneered in mountain watersheds, recent research has focused more on the "tower footprint"paradigm than the watershed approach; unfortunately, our current capabilities with tower-basedmeasurements are not adequate to develop accurate mass balance predictions in complextopography, and this has diminished efforts to understand biogeochemical fluxes in themountains. In this proposal, we develop a "carbonshed" approach for the study of theecosystem carbon balance of montane landscapes. We define a carbonshed within the samecontext as a watershed - a mountainous tract in which the slopes and valleys cause complextopographic patterns, which directly influence the drainage and accumulation of CO2, as well aspatterns in the redistribution of energy and water, which indirectly influence the exchange of CO2across the landscape. We make the case that the carbonshed scale is crucial for linking local,ecosystem-level CO2 fluxes to regional, landscape-level CO2 fluxes.In this proposal, we present a plan to measure carbonshed CO2 fluxes in the Front Range ofthe Rocky Mountains in Colorado. Recognizing that direct measurement of carbon budgetsusing atmospheric techniques will be impossible in complex landscapes, we focus on modeldataintegration, using measurements to calibrate and constrain models, and models tointerpolate observations. Recognizing also that carbon and water exchange are closely coupled,especially in this semi-arid Western environment, we focus on linking carbon and watermeasurements. We will challenge process models with measurements at multiple time andspace scales, utilizing seasonal to interannual flux measurements, carbonshed scale campaignsto scale up (10's of km), and regional (1000's of km) airborne measurements. Large fires in2002 will allow us to make airborne measurements of carbon dynamics in recently burnedsystems, a unique test of the upscaling of fluxes in disturbance-based models. The project'smodeling will use a coupled ecosystem-atmosphere model, allowing simulated fluxes to betranslated into concentration patterns for comparison to surface and airborne observations.The proposal addresses the intellectual merit criteria by 1) identifying a new phenomenon incarbon science: the tendency for carbon sinks to develop in high-relief ecosystems, as a result ofthe interaction of climate with land use patterns, 2) proposing innovative and cross-disciplinarymethods to measure this phenomenon, and 3) assembling a team including biophysicists,meteorologists, ecologists and educators to study this problem.Broader ImpactsThe studies will provide training opportunities for two graduate students and two,postdoctoral students. The funded activities will serve as the catalyst to develop a new courseon human-environment coupling that will include an analysis of the combined roles of land usehistory, water resources, fire suppression and biophysical controls over carbon in the mountains.The research will support a significant K-12 and teacher training program coordinated by theUniversity of Colorado CIRES Office of Education and Outreach. The proposed research willcontribute to scientific infrastructure by adding a greatly enhanced carbon cycle instrumentalcapability to the NSF Facilities at NCAR ATD, which are available to the general scientificcommunity. Additionally, a greatly improved 4-dimensional model for analyzing regional carbonsink activity will be made available to the general scientific and public policy communities for usein analyzing US carbon sinks and their relevance to global carbon cycle issues.