Analysis of Tree Stratum Vegetation in Sand Dune Core Zone in Parangtritis Village Kretek Sub-District Bantul Regency Yogyakarta As Learning Sources on Biodiversity for Grade X Senior High School

The research aims to know the species of tree stratum in the Sand Dune Core Zones of Parangtritis and their significant roles according to the Importance Value Index (IV). Besides, it is to examine the influence of abiotic environment (soil temperature, air temperature, light intensity, humidity, and soil pH) on the tree diversity in the sand dunes as well as the potential of the research results to be the learning materials for biology subject, particularly biodiversity, for Senior High School. The samples were taken using the Point Centered Quarter (PCQ) method in the Sand Dunes Core Zones that is spread through 141 Ha. The area was divided into three, 14 Ha for each. The vegetation parameter covers density, dominance, frequency, Importance Value Index, and Diversity Index. The influence of the abiotic environment was revealed using linear regression analysis. The results were then analyzed for the potentials to be used as the learning materials in biology subjects for grade x Senior High School. The study found six species of tree vegetation. The tree having the highest Importance Value Index is Acasia auricliformis (124.17%), while the lowest is Psidium guajava (3.26%). The measured abiotic environments do not influence the index of vegetation diversity in the sand dunes. The results are potential to use as learning materials for grade X senior high school. The aspects include object availability and the issues in question; suitability with the learning objectives; aims and purposes; information clarity; exploration guidelines; and the outcome