Many people view urban areas as hostile for plants – concrete stifles root growth, and pollution from vehicles makes it difficult to gain nutrients. A study conducted by The Earth Institute at Columbia University not only discredits those theories, however, but suggests that urban environments have a lot to offer plants to promote growth. To conduct the research, The Earth Institute researchers planted seedlings in the spring of 2007 and 2008 in three sites around New York, urban, suburban and rural. Over a five-year period, researchers observed an eight-fold increase in biomass in the urban-grown seedlings. Researchers attribute the increased growth to high temperatures (particularly at night), carbon dioxide concentrations and atmospheric nitrogen deposition. Saplings planted in Central Park developed a lower root-to-shoot ratio, which reduced below-ground carbon costs to the plant. To compensate for the root development, urban seedlings allocated more growth to leaves than the rural-grown seedlings. This resulted in a ten-fold greater photosynthetic area but the same photosynthetic capacity of foliage as the rural plants. The findings mark a step toward understanding how nature and urban environments mix. With human influence spreading across the globe, nature and urban environments are inseparable. The key is that plants can adapt to these changes in their environments, and in this case, really thrive in a human environment. http://www.gizmag.com/urban-trees-earth-insitutue/22304/
