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Articles 1 - 5 of 5
Full-Text Articles in Social and Behavioral Sciences
Trends In Land Surface Phenology Across The Conterminous United States (1982-2016) Analyzed By Neon Domains, Liang Liang, Geoffrey M. Henebry, Lingling Liu, Xiaoyang Zhang, Li-Chih Hsu
Trends In Land Surface Phenology Across The Conterminous United States (1982-2016) Analyzed By Neon Domains, Liang Liang, Geoffrey M. Henebry, Lingling Liu, Xiaoyang Zhang, Li-Chih Hsu
Geography Faculty Publications
Tracking phenological change in a regionally explicit context is a key to understanding ecosystem status and change. The current study investigated long-term trends of satellite-observed land surface phenology (LSP) in the 17 National Ecological Observatory Network (NEON) domains across the conterminous United States (CONUS). Characterization of LSP trends was based on a high temporal resolution (3-d) time series of the two-band enhanced vegetation index (EVI2) derived from a long-term data record (LTDR) of the Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS). We identified significant trend patterns in LSP and their seasonal climate and land …
Detecting Recent Crop Phenology Dynamics In Corn And Soybean Cropping Systems Of Kentucky, Yanjun Yang, Bo Tao, Liang Liang, Yawen Huang, Christopher J. Matocha, Chad D. Lee, Michael Sama, Bassil El Masri, Wei Ren
Detecting Recent Crop Phenology Dynamics In Corn And Soybean Cropping Systems Of Kentucky, Yanjun Yang, Bo Tao, Liang Liang, Yawen Huang, Christopher J. Matocha, Chad D. Lee, Michael Sama, Bassil El Masri, Wei Ren
Geography Faculty Publications
Accurate phenological information is essential for monitoring crop development, predicting crop yield, and enhancing resilience to cope with climate change. This study employed a curve-change-based dynamic threshold approach on NDVI (Normalized Differential Vegetation Index) time series to detect the planting and harvesting dates for corn and soybean in Kentucky, a typical climatic transition zone, from 2000 to 2018. We compared satellite-based estimates with ground observations and performed trend analyses of crop phenological stages over the study period to analyze their relationships with climate change and crop yields. Our results showed that corn and soybean planting dates were delayed by 0.01 …
Global Pattern And Change Of Cropland Soil Organic Carbon During 1901-2010: Roles Of Climate, Atmospheric Chemistry, Land Use And Management, Wei Ren, Kamaljit Banger, Bo Tao, Jia Yang, Yawen Huang, Hanqin Tian
Global Pattern And Change Of Cropland Soil Organic Carbon During 1901-2010: Roles Of Climate, Atmospheric Chemistry, Land Use And Management, Wei Ren, Kamaljit Banger, Bo Tao, Jia Yang, Yawen Huang, Hanqin Tian
Plant and Soil Sciences Faculty Publications
Soil organic carbon (SOC) in croplands is a key property of soil quality for ensuring food security and agricultural sustainability, and also plays a central role in the global carbon (C) budget. When managed sustainably, soils may play a critical role in mitigating climate change by sequestering C and decreasing greenhouse gas emissions into the atmosphere. However, the magnitude and spatio-temporal patterns of global cropland SOC are far from well constrained due to high land surface heterogeneity, complicated mechanisms, and multiple influencing factors. Here, we use a process-based agroecosystem model (DLEM-Ag) in combination with diverse spatially-explicit gridded environmental data to …
Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang
Mapping Temperate Vegetation Climate Adaptation Variability Using Normalized Land Surface Phenology, Liang Liang, Mark D. Schwartz, Xiaoyang Zhang
Geography Faculty Publications
Climate influences geographic differences of vegetation phenology through both contemporary and historical variability. The latter effect is embodied in vegetation heterogeneity underlain by spatially varied genotype and species compositions tied to climatic adaptation. Such long-term climatic effects are difficult to map and therefore often neglected in evaluating spatially explicit phenological responses to climate change. In this study we demonstrate a way to indirectly infer the portion of land surface phenology variation that is potentially contributed by underlying genotypic differences across space. The method undertaken normalized remotely sensed vegetation start-of-season (or greenup onset) with a cloned plants-based phenological model. As the …
Networks Of European Cities In Worlds Of Global Economic And Environmental Change, Stanley D. Brunn, Lomme Devriendt, Andrew Boulton, Ben Derudder, Frank Witlox
Networks Of European Cities In Worlds Of Global Economic And Environmental Change, Stanley D. Brunn, Lomme Devriendt, Andrew Boulton, Ben Derudder, Frank Witlox
Geography Faculty Publications
Geographers have a long tradition of classifying cities using a number of criteria. Population size, industrial production, capital city functions, airline connections, sites of sporting events and major headquarters and banks are among them. While these studies are useful in looking at cities in an economy and population at a given point of time, they are less useful in assessing rapidly occurring changes within a regional or global system. Our research represents a new approach to classify cities and urban systems; we use the volume and networks/linkages or flows associated with electronic Information or “Knowledge worlds.” We argue that in …