报告题目1：When plants meet aerosols
报告题目2：Climatic and biotic drivers of tropical evergreen forest photosynthesis: integrating field, eddy flux, remote sensing and modeling
报告1摘要:Air pollutants, e.g., aerosols, largely contributed by anthropogenic activities, have been significantly affecting human and ecosystem health. The study in this talk developed a process-based integrated modeling framework to investigate the impact aerosol on global terrestrial ecosystem carbon dynamics over 2003 to 2010. The modeling framework simulates the detailed processes of how aerosol can affect the land-surface microclimate and plant physiology, which were poorly represented in previous studies. This presentation will discuss the features of the model development, design of the model simulations and the key results from the model simulations that quantify the impacts of aerosol on global terrestrial ecosystem carbon dynamics.
报告人1简介: Dr. Min Chen is Barbara McClintock Fellow of the Department of Global Ecology, Carnegie Institution for Science at Stanford University. Before joining Carnegie, he was a postdoctoral fellow at Harvard University. He received his PhD from Purdue University in 2013, and received Masters and Bachelor's degree both from Beijing Normal University. His research mainly focuses on the interactions between atmosphere, biosphere, and human dimension in the context of climate change, using mathematical modeling and remote sensing as the major approaches.
报告2摘要：Tropical evergreen forest photosynthetic metabolism is an important driver of large-scale carbon, water, and energy cycles, generating various climate feedbacks. However, questions remain about how best to represent evergreen photosynthesis in current terrestrial biosphere models (TBMs), especially its sensitivity to climatic vs. biotic variation. Here, we develop a new approach to partition climatic and biotic controls on tropical forest photosynthesis from hourly to inter-annual timescales. Our results show that climatic factors dominate photosynthesis dynamics at shorter-time scale (i.e. hourly), while biotic factors dominate longer-timescale (i.e. monthly and longer) photosynthetic dynamics. Focusing on seasonal timescales, we combine camera and ecosystem carbon flux observations of forests across a rainfall gradient in Amazonia to show that high dry season leaf turnover shifts canopy composition towards younger more efficient leaves. This seasonal variation in leaf quality (per-area leaf photosynthetic capacity) thus can explain the high photosynthetic seasonality observed in the tropics. Finally, we evaluated the performance of models with different phenological schemes (i.e. leaf quantity versus leaf quality; with and without within-canopy phenological variation). We found that models which represented phenology of leaf quality and its within-canopy variation performed best in simulating photosynthetic seasonality in tropical evergreen forests. This work highlights the importance of incorporating improved understanding of climatic and biotic controls in next generation TBMs to project future carbon and water cycles in the tropics.
报告人2简介：Dr Jin Wu is a broadly trained environmental scientist studying the interaction of forest ecosystems with climate. He got Ph.D. at the University of Arizona in 2015 working with Dr. Scott Saleska. He is recently a postdoc at Brookhaven National Laboratory. He shares a very broad research interest in plant physiology, ecosystem science, ecological strategies, biodiversity, and community assembly. Jin is especially keen to advance our understanding of these topics by using multi-discipline approaches (remote sensing, gas exchange measurements, biometry surveys, earth system modeling) undertaken across a wide range of scales (leaf, canopy, landscape, globe). His current research is focused on understanding and model representation of the processes that underlie the response of tropical forest ecosystems to global change. 具体信息请参见https://www.bnl.gov/envsci/bio/wu-jin.php.