Tree diameter determines where the cross-sectional area is measured. Regardless of the method, determining the adjustment factors for species, condition, and location requires technical competence and experience. A tree valuation is only as credible as the arborist who makes the determination. The value of a particular species or variety can be looked up in an established tree listings or judged by a local arborist. Value is often affected by local usage.
Physical condition is also a factor' regardless of the kind or size of the plant.
Parts deformed by crowding, storm damage, fire, insect damage, disease or other cause are primary concerns when judging condition. Careful inspection should reveal these and other factors. Plant location also affects value, especially when it is near buildings, utility lines or other plants. Plants used in planned landscapes often have higher appraised values than those growing wild. Appraising a landscape plant requires considerable time on the site for looking at the tree, its environment, measuring and examining its parts, collecting samples, taking photo graphs, and asking questions of people living nearby.