GSA Today最新文献_第6页

Predicting the Water Balance from Optimization of Plant Productivity 从植物生产力优化预测水分平衡

GSA Today Pub Date : 2020-11-01 DOI: 10.1130/gsatg471gw.1

A. Hunt, B. Faybishenko, B. Ghanbarian

{"title":"Predicting the Water Balance from Optimization of Plant Productivity","authors":"A. Hunt, B. Faybishenko, B. Ghanbarian","doi":"10.1130/gsatg471gw.1","DOIUrl":"https://doi.org/10.1130/gsatg471gw.1","url":null,"abstract":"How soil-water flows and how fast it moves solutes are important for plant growth and soil formation. The relationship describing the partitioning of precipitation, P, into run-off, Q, and evapotranspiration, ET, is called the water balance. Q incorporates both surface runoff and subsurface flow components, the latter chiefly contributing to soil formation. At shorter time intervals, soil-water storage, S, may change, dS/dt, due to atmosphere-soil water exchange; i.e., infiltrating and evaporating water and root uptake. Over sufficiently long time periods, storage changes are typically neglected (Gentine et al., 2012). Percolation theory from statistical physics provides a powerful tool for predicting soil formation and plant growth (Hunt, 2017) by means of modeling soil pore space as networks, rather than continua. In heterogeneous soils, solute migration typically exhibits non-Gaussian behavior, with statistical models having long tails in arrival time distributions and velocities decreasing over time. Theoretical prediction of solute transport via percolation theory that generates accurate full non-Gaussian arrival time distributions has become possible only recently (Hunt and Ghanbarian, 2016; Hunt and Sahimi, 2017). A unified framework, based on solute transport theory, helps predict soil depth as a function of age and infiltration rate (Yu and Hunt, 2017), soil erosion rates (Yu et al., 2019), chemical weathering (Yu and Hunt, 2018), and plant height and productivity as a function of time and transpiration rates (Hunt, 2017). Expressing soil depth and plant growth inputs to the crop net primary productivity, NPP, permits optimization of NPP with respect to the hydrologic fluxes (Hunt et al., 2020). Some remarkable conclusions also arise from this theory, such as that globally averaged ET is almost twice Q, and that the topology of the network guiding soil-water flow provides limitations on solute transport and chemical weathering. Both plant roots and infiltrating water tend to follow paths of least resistance, but with differing connectivity properties. Except in arid climates (Yang et al., 2016), roots tend to be restricted to the thin topsoil, so lateral root distributions are often considered twodimensional (2D), and root structures employ hierarchical, directional organization, speeding transport by avoiding closed loops. In contrast, infiltrating water (i.e., the subsurface part of Q) tends to follow random paths (Hunt, 2017) and percolates through the topsoil more deeply, giving rise to three-dimensional (3D) flow-path structures. The resulting distinct topologies generate differing nonlinear scaling, which is fractal, between time and distance of solute transport. On a bi-logarithmic space-time plot (Hunt, 2017), optimal paths for the different spatiotemporal scaling laws of root radial extent (RRE) and soil depth, z, are defined by their radial divergence from the same length and time positions. RRE relates to NPP, which is a key d","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"30 1","pages":"28-29"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46142433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Flooding Induced by Rising Atmospheric Carbon Dioxide 大气中二氧化碳上升引起的洪水

GSA Today Pub Date : 2020-10-01 DOI: 10.1130/gsatg427a.1

G. Retallack, G. Conde

引用次数: 2

Does Our Vision of Diversity Reduce Harm and Promote Justice? 我们的多样性愿景是否减少了危害并促进了正义？

GSA Today Pub Date : 2020-10-01 DOI: 10.1130/gsatg429gw.1

B. Keisling, R. Bryant, Nigel Golden, L. Stevens, Ellen Alexander

引用次数: 6

Learning from the Lockdown: The Silver Linings of a Virtual Conference 从封锁中学习：虚拟会议的一线希望

GSA Today Pub Date : 2020-09-01 DOI: 10.1130/gsatg468gw.1

L. Bailey, S. Portnoy, Alexander Prescott

{"title":"Learning from the Lockdown: The Silver Linings of a Virtual Conference","authors":"L. Bailey, S. Portnoy, Alexander Prescott","doi":"10.1130/gsatg468gw.1","DOIUrl":"https://doi.org/10.1130/gsatg468gw.1","url":null,"abstract":"BACKGROUND Due to COVID-19, scientists and students alike moved from hallway discussions and group debates to working in isolation and participating in online classes. Academic and professional communities around the world have experienced significant cancellations of critical in-person events, including a number of scientific meetings. The University of Arizona Department of Geosciences 48th annual conference, GeoDaze, was no exception. GeoDaze was originally scheduled for April 2020, but all in-person university events were cancelled a few weeks prior. As organizers of the conference, we were initially devastated that we would not see all of our hard work come to fruition this year. Within a few days of the cancellation, our heartbreak transitioned to problem solving as we decided to redevelop the conference into an innovative virtual event. Surprisingly, there were several silver linings in the online conference that enhanced the event for attendees. As GeoDaze concluded, we wondered: What can we learn from the unprecedented pandemic lockdown to enhance scientific meeting experiences? Here we outline the benefits of transitioning a conference to an entirely virtual format, and we argue that some elements of online meetings are worth incorporating into a post– COVID-19 world. GeoDaze is an annual university event inaugurated in 1972 that provides graduate and undergraduate students with the opportunity to present their latest geoscience research to the community. The entirely student-run conference draws in university alumni and geoscientists from industry, government, and academia. The ability for students to interact with professionals provides opportunities for career and academic growth through collaboration and guidance. This event often serves as the first opportunity for students to publicly present research, so there was a sense of urgency to maintain the annual tradition despite being met with initial hesitation and concern about moving GeoDaze to an entirely virtual format for the first time in history.","PeriodicalId":35784,"journal":{"name":"GSA Today","volume":"30 1","pages":"44-45"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45489802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Teaching with Digital 3D Models of Minerals and Rocks 矿物和岩石的数字三维模型教学

GSA Today Pub Date : 2020-09-01 DOI: 10.1130/gsatg464gw.1

G. Andrews, Gabrielle Labishak, S. Brown, S. Isom, Holly D. Pettus, Trevor Byers

引用次数: 6

Assembling Laurentia—Integrated Theme Sessions on Tectonic Turning Points 构造转折点的劳伦提亚整合主题会议

GSA Today Pub Date : 2020-07-01 DOI: 10.1130/gsatg459gw.1

Michael L. Williams, D. Kellett, B. Tikoff, S. Whitmeyer

引用次数: 0

Using Mobile Technologies to Enhance Accessibility and Inclusion in Field-Based Learning 利用移动技术提高实地学习的可及性和包容性

GSA Today Pub Date : 2020-06-17 DOI: 10.1130/gsat.s.12501404

S. Whitmeyer, C. Atchison, T. Collins