钟山论坛-学术汇报

发布者:gjdq发布时间:2011-08-26浏览次数:44

南京大学气候与全球变化研究院  
“钟山论坛”第三期  
主题: Carbon Cycle and Global Change  
Understanding the magnitude and mechanisms of carbon exchange between the land and atmosphere has emerged as a crucial component of reliably projecting climate change. It remains unclear whether a warmer land surface will continue to remove a share of anthropogenic CO2 emissions or act as a carbon source in the future. Answering this fundamental global change question requires traversing disciplinary boundaries and transcending multiple space and time scales.
 
时间:2011年8月26日14:30 – 17: 00
地点:南京大学科技馆二楼报告厅
 
 
报告1: Chasing Carbon through the Earth System 
Kevin Gurney, Ph. D.
Associate Professor, School of Life Sciences, Arizona State University
Adjunct Associate Professor, Department of Earth and Atmospheric Sciences, Purdue University
 
 
 
He is a mixture of atmospheric scientist and ecologist working in the broad arena of “global change”. In particular, He interested in quantification and characterization of the global carbon cycle with emphasis on exchanges of CO2 with the terrestrial biosphere and the fossil fuel sources of CO2 to the atmosphere. The future evolution and mechanistic underpinnings of the global carbon cycle are fundamental to climate change research and decisionmaking on climate change mitigation and adaptation. In addition to his scientific research, he has also continued work in the area of climate change policy through research on those aspects of domestic and international policy that relate to the carbon cycle.
 
Abstract: 
In this talk he will describe his current research activities and how they evolved from his attempt to answer the aforementioned central global change question. The first research theme he will discuss utilizes atmospheric CO2 to understand the global biosphere. Often referred to as an “inverse approach”, this branch of biogeochemistry combines knowledge of atmospheric transport with space/time patterns of atmospheric CO2 to infer net biome productivity. He will demonstrate that there is far more ecological knowledge embedded in the inverse “signal” than previously thought.
Reliable results to the inverse approach rely on accurate quantification of another important carbon flux – that due to the combustion of fossil fuels. Though traditionally considered a “known”, the advent of satellite CO2 monitoring and increasing in situ carbon measurement density, have put considerable pressure on improving this portion of the global carbon cycle. Hence, his second research theme – high resolution quantification of fossil fuel CO2 emissions. Known as the “Vulcan Project” (after the Roman god of fire), this effort has expanded and is now utilized in a variety of disciplinary research settings and as a decision support tool at multiple scales. A pilot effort, called “Hestia” has achieved building/street level quantification across the city of Indianapolis.
Exploring the relationship between climate and terrestrial carbon exchange with increasingly powerful simulation models has illuminated a suite of important biophysical feedbacks. This is the focus of his third theme in which he will describe their attempt to simulate realistic tropical deforestation within an Earth System Model by incorporating human decisionmaking into the middle of the climate-deforestation feedback.
 
  
报告2: Exploring the mechanisms of C accrual in grassland systems 
Helen Rowe, Ph. D.
Director, Ecosystem Conservation and Resilience Initiative (ECRI)
Assistant Professor, School of Life Sciences, Arizona State University
 
 
 
 
His current research interests can be described as the study of conservation in human dominated landscapes. Given the pressure of urbanization and agriculture, how do we maintain viable natural and critical habitats to preserve biodiversity? While his recent research uses tallgrass prairie as the system of interest, similar questions can be applied to other systems. Current projects include: 1) evaluating the effect of restoring parcels with high or low diversity plant communities on native prairie remnants as compared to adjacent crops or roads; 2) quantifying ecosystem services of native prairie as well as restorations of varying quality in an agroecosystem context; and 3) testing specific restoration techniques in support of improving ecological restoration management practices.
 
Abstract: 
Carbon in soils accounts for approximately two-thirds of the global terrestrial C pool, therefore its protection is important to limit climate change. In order to effectively protect or restore soil C, we need to improve our understanding of the mechanisms of C accrual.   Many factors affect the accrual of carbon in soils including climate, plant growth, plant chemistry, soil biota, soil nutrient levels, soil type and texture, and plant richness.   The relative importance of these different drivers is the topic of considerable study and is as yet unresolved. One way to study the rates of C accrual is through “chronosequence” of prairie restorations.   Other studies compare soil C pools and dynamics under different types of plant communities. The author provides an overview and describes her own research and preliminary results regarding the mechanisms of soil C accrual.