The July 1994 edition of the Journal of Arboriculture published the results of a tree study conducted in Mexico City, Mexico by the Environmental Engineering Program at the Universidad Autonoma Metropolitana-Azcapotzalco. The study revealed disease and insect damage in more than 50% of the 1,261 trees in the study, revealing the results of poor species selection, inappropriate locations, and lack of planning and maintenance.

LASN asked James Urban, Landscape Architect and Urban Arboriculturist whose field studies have amassed a wealth of data on the effect of urban environments on tree performance, to comment. Asked how data from the recent Mexico City study might help determine precise planting and management criteria for healthy urban trees, Urban said that any data collection process is "time-consuming" and "subjective," but "gives us a data point to test against in the future." He favors methods which can provide large-scale information more quickly, stating that "meaningful data" is otherwise difficult to obtain. "It is even more difficult to measure the quality of biomass that is supported by open space," Urban added and recommended infrared technology, which is being used by skilled urban foresters to "identify individual sick trees in cities," to measure what is green and healthy.