While cities provide vital habitat for human beings to thrive, it appears U.S. cities have been built on the most fertile soils, lessening contributions of these lands to Earths food web and human agriculture, according to a study by NASA researchers and others.
Comparing Post-Urban U.S. to Pre-Urban U.S., Difference in Total Annual Net Primary Production
This graphic compares modern U.S. annual Net Primary Production (NPP) to a computer-derived estimate of what the annual NPP would be in the absence of urbanization. The graphic shows areas with reductions or gains in NPP as a result of urban development. NPP measures plant growth by describing the rate at which plants use carbon from the atmosphere to build new organic matter through photosynthesis. Units are in grams of carbon per meter squared. Credit: Marc Imhoff/NASA
U.S. Urbanization and Net Primary Production
a) The top map depicts urbanized areas across the continental U.S. The map was generated from nighttime satellite images from the Defense Meteorological Satellites Operational Linescan System (DMSP/OLS) collected from October 1994 to March 1995. Red indicates urban areas; yellow marks those smaller towns, and suburbs on the peripheries of cities, or peri-urban areas; and black represents non-urban or rural areas. b) The lower map shows simulated total annual NPP for the U.S. at 1x 1km horizontal resolution. Units for NPP are in grams of carbon per square meter. Credit: Marc Imhoff/NASA
Though cities account for just 3 percent of continental U.S. land area, the food and fiber that could be grown there rivals current production on all U.S. agricultural lands, which cover 29 percent of the country. Marc Imhoff, NASA researcher and lead author of a current paper, and co-author Lahouari Bounoua, of NASA and University of Maryland, College Park, added that throughout history humans have settled in areas with the best lands for growing food.
"Urbanization follows agriculture -- its a natural and important human process," said Imhoff.Throughout history, highly productive agricultural land brought food, wealth and trade to an area, all of which fostered settlements.
Krishna Ramanujan | GSFC
Goldilocks principle in biology -- fine-tuning the 'just right' signal load
15.10.2018 | Aarhus University
Food for the city – from the city
03.09.2018 | Fraunhofer-Institut für Arbeitswirtschaft und Organisation IAO
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
New measurement method allows researchers to precisely follow the movement of individual molecules over long periods of time
The function of proteins – the molecular tools of the cell – is governed by the interplay of their structure and dynamics. Advances in electron microscopy have...
16.10.2018 | Event News
02.10.2018 | Event News
01.10.2018 | Event News
16.10.2018 | Life Sciences
16.10.2018 | Physics and Astronomy
16.10.2018 | Event News