Distribution and abundance of plant species under the shade of Pinus mercusii, Acacia auriculiformis and Eucalyptus alba in Gama Girimandiri Forest, Yogyakarta.
The purpose of this research was to study distribution and abundance of (shrubs, herbs, and rumput) under the three stands,i.e. Pinus mercusii, Acacia auriculiformis and Eucalyptus alba and environmental factors influencing them in Gama Girimandiri Forest. Data were collected in April-May 2011, using square plots. Plots were located in three locations by following a stratified random sampling method. We administered 10 repetitions, and plot size 5×5 m for shrubs and herbs, and 1×1 m forgrass. The species found in each stand were identified and calculated for their density, frequency, domination, important value, diversity index, and those parameters' correlation with the measured environmental factors. The study shows that 59 species of herbs and shrubs, and 12 species of grass. In the three stands, it could be shown various domination of grass, meanwhile there is no dominant species at the level of herbs and shrubs. The highest density, measured by diversity index,was observed at the stand of Pinus (3,13), followed by Acacia (3,12) and Eucalyptus (2,8). The distribution and density of Memecylon sp and Oplismenus burmanni were observed at their highest value under the stand of Pinus, Lantana camara Linn (37.2). At the same fashion, Paspalum conjugatum (58.3) does under the stand of Acacia, and Desmodium triflorum (64,2) and Ischaemum magnum (122) under Eucalyptus. Lantana camara could always be found under the three stands, it had high important value, categorized as r strategy species and invasive. Light density and pH significantly influenced the diversity index of shrubs and herbs. In addition, only soil temperature gave an effect to grass.