| Trees planted in containers or along sidewalks lack necessary nutrients and water to satisfy their needs due to the compaction of limited soil volumes. This results in restricted tree growth and development and eventually death. In order to determine the response of tree species established in compacted soils, a study was carried out with three tree species commonly used in urban forestry in Puerto Rico. Same-size saplings of three ornamental tropical tree species: trumpet brush (Tecoma stans), bottle brush ( Callistemon citrinus), and pink trumpet (Tabebuia rosea) were transplanted in pots of sandy clay loam or clay at three levels of compaction: control (without compaction), ≈1.15, and 1.4 g/cm3. Plant height and stem diameter, number and color of leaves, leaf area, and dry weights of roots, stems and leaves were measured on two plants every two months for six months. Data was analyzed as a 3 x 2 x 3 x 3 (species x soil type x compaction x time) factorial arrangement in a completely randomized design with two replications. No leaf color differences were observed between species. All species exhibited better growth in sandy clay loam at a 1.15 g/cm3 bulk density and, after six months, a reduced root-shoot ratio was observed. All trumpet brush saplings died within two months when planted in clay at the 1.4 g/cm 3 bulk density. Bottle brush had better growth than pink trumpet and trumpet brush for all compaction levels and both soil types. |
