Christmas tree cultivation has shifted toward the production of higher-quality trees, increasing land quality expectations as well. Indeed, some species of tree, such as the Fraser fir, are unable to grow on low-quality, marginal farmland. Flat or gently rolling land is preferred to that with steep slopes and inclines, which is prone to erosion and fluctuations in fertility. Noticeable obstructions, such as rocks, fences or significant underbrush, are also undesirable. Like all crops and plants, Christmas trees require a specific set of nutrients to thrive. There are 16 elements crucial for growth; of those, three are obtained through air and water: hydrogen, carbon,
Douglas E. Noble at UC Berkeley. His dissertation focused on implementing an early computer-supported issue-based information system (IBIS), and he was a co-author on a research paper on IBIS with his dissertation chair Horst Rittel. Books: Edited Journals and Conference Proceedings: Catalog: Video: Douglas E. Noble Douglas E. Noble is an American architect and tenured faculty member at the USC School of Architecture. He is a fellow of the American Institute of Architects. He is known for his work in four overlapping arenas: Architectural Computing, Building Science, Architecture Education, and Design Theories and Methods. He received the ACSA/AIAS New Faculty Teaching Award in