An Assessment of the Potential to Produce Commercially Valuable Lipids on Highway Right-of-Way Land Areas Located Within the Southeastern United States

Right-of-way (ROW) land areas are required for all publicly owned transportation roadways representing over 40 million acres within the US alone. These relatively unused land assets could support potential farming land for plants and algae that contain high levels of lipids that could be used in the energy industry as an alternative fuel source. This process would offer many benefits including more efficient use of public land, eliminating mowing maintenance, increasing the bioenergy use in the US, providing visually appealing viewscapes, and helping to naturally reduce localized carbon dioxide. This paper analyzed the feasibility and potential optimization strategies of using this concept in the South-Eastern United States by scaling and comparing many of the benefits and risks associated with the selected lipid sources (soybeans, flax, sunflowers, Tung trees, Chinese tallow tree, and microalgae). Based on this assessment, the most attractive option appears to be growing flax in the winter and sunflowers in the summer with Tung Trees grown year-round as an alternative option. This would maximize lipids output while preserving and enhancing right-of-way land areas.

Tallow tree allocates contrasting secondary chemicals in response to varying environments along elevational gradients

Aims Understanding how tree species regulate multiple types of secondary chemicals along elevational gradients is critical for elucidating the physiological and ecological strategies of plants in response to varying biotic and/or abiotic environments. This study aims to examine how Chinese tallow tree (Triadica sebifera) allocates resources to the production of different secondary chemicals in response to varying environments across elevational gradients. Methods We conducted field surveys of different herbivore feeding guilds and their damage rates on Chinese tallow trees along an elevational gradient in China and measured secondary chemicals (tannins and flavonoids) in damaged and undamaged leaves. Important Findings The odds of a leaf being damaged (chewing or scarring) decreased with elevation. Flavonoid concentrations increased with elevation in undamaged leaves but decreased with elevation in damaged leaves, with quercitrin contributing most strongly to this pattern, likely as results of plant responding to changing biotic or abiotic stresses along elevational gradients. Tannin concentrations did not vary with elevation, so undamaged leaves had relatively lower tannin to flavonoid ratios at high elevation than at low elevation. Our study reveals variation in herbivory and contrasting trends in plant secondary metabolism along an elevation gradient and highlights the importance of simultaneously considering multiple types of secondary chemicals in plant physiological and ecological strategies.