Los Angeles has some of the strictest tree planting rules in the nation. These policies limit tree growth, worsen shade disparities and don't improve safety, researchers found. When researchers modeled looser planting restrictions in a lower-income neighborhood, potential tree space increased by nea rly 26%. But narrow sidewalks and dense infrastructure still limited where larger, shade trees could thrive. Many of L.A.'s strict tree-spacing rules are internal guidelines -- not laws -- meaning they could be updated more easily to allow for more trees. Closing L.A.'s shade gap, however, will require more than policy tweaks; infrastructure investments are also needed. ...read more read less