Evaluation of Different Methods in Spatial Distribution Pattern of Trees Species in Kalkhani Forest in Kouhdasht, Lorestan - Zagros

In order to evaluate the efficiency of sampling indices in the spatial pattern of 4 wooden species (Quercus brantii, Crataegus aronia, Pistacia atlantica and Acer monspessulanum) an area of 500 hectares of Kalkhani forests of Koudasht city, Lorestan province was selected. The regular 100 m × 300 m grids in Arc GIS software were maked and taken with random starting point on the map of case study. The geographic position of 141 circle sample plots with area 1500 m2 (Which is the starting point for the distance-based methods) was entered in  Global Position System (GPS) set. The number, species, and crown cover of each base were recorded for spatial pattern analysis. The methods of study spatial distribution pattern were used density based indices (such as: Variance-to-Mean Ratio, Index cluster, Green, Moresita and Standardized moresita) and distance based indices (such as: Johnson and Zimmer, Eberhart, Hopkins, Hinez and C index) were accomplished by using of Ecological Methodology software. The results indicated that Quercus brantii and Pistacia atlantica have the highest and the lowest numbr of tree in case study, respectively. Also the basis of the results the highest and the lowest canopy cover area belong to Quercus brantii and Crataegus aronia, respectively. All of the density-based indices showed a clumped pattern for 4 trees species. Among the distance-based indices, Eberhart and Hinez presented better results than the other indices. In general, the density-based indices performed much better than the distance-based indices in this research. The comparison of the methods showed that each one can be applied, regarding the goal and available circumstances of future studies.