Measurement and prediction of tree growth reduction from tree planting space design in established parking lots

Abstract

Five species of trees were measured in 12- to 27-year-old parking lots in north-central Florida, U.S. Tree species evaluated were Chinese elm (Ulmus parvifolia Jacq.), live oak (Quercus virginiana Mill.), sycamore (Platanus occidentalis L.), shumard oak (Q. shumardii Britton), and laurel oak (Q. laurifolia Michx.). Tree growth in the parking lot planting zones was reduced as the surface area of nonpaved surface was reduced for all trees except live oak. Regression models yielded significant relationships with prediction value between parking lot detail space openings and tree size, measured by diameter at breast height or by canopy radius. Normalization of the data within the site allowed for multiple site analysis. A method for generating similar data is introduced for development of regionally species-specific growth reduction multipliers. Those multipliers can be used to better meet long-term, canopy expectations or to advocate for larger planting zones.