Effects of Soil Removal and Flooding on Leaf Cell Structure of Quercus Falcata Var. Pagodaefolia and Qurecus Nigra

Extract

Soil removal and flooding are serious problems for many urban trees. The main purpose of this paper is to outline some changes which occur in leaves of cherrybark oak (Quercus falcata var. pagodaefolia) and water oak (Quercus nigra) during soil removal and flooding treatments. There has not been any prior documentation of leaf tissue of trees under these conditions. Two-year-old saplings of cherrybark oaks and water oaks were randomly planted in twenty-four experimental plots. Trees were randomly subjected to a combination of soil removal and flooding treatments for one year. Leaf tissues were collected from trees in controlled and treated plots. Tissues were fixed overnight at 4° C in 4% glutaraldehyde buffered with 0.07M cacodylate at pH of 7.2 and post-fixed for one hour in 1% osmium tetroxide in the same buffer. After washing thoroughly in the buffer, tissues were dehydrated in a graded ethanol series and embedded in Eponate 12 resin. Thin sections of 75nm thick were cut with a MT-6000 ultratome and placed on 300 mesh copper grids. Sections were then positive stained with uranyl acetate followed by lead citrate. All examinations of the cell structure were made using a Zeiss EM 10C transmission electron microscope.