Spatial pattern analysis of Montpellier maple (Acer monspessulanum L.) on steep slopes in Zagros (Case study: Firoozabad, Fars province)

Topography is recognized as one of the effective drivers in spatial pattern of trees scattered on steep slopes. Topography influences spatial distribution of trees by changes in light availability, soil moisture and microclimate. This study was aimed to analyze spatial pattern of Montpellier maple (Acer monspessulanum L.) located on steep slopes in Zagros vegetation zone. For this purpose, a 200 m × 200 m plot was selected in Montpellier maple site close to Firoozabad, Fars province, with the minimum and maximum altitude of 1470 and 1540 meter above sea level, respectively. The spatial location of 288 maple trees with dbh ≥ 5 cm were registered by Leica TS06. Spatial pattern of trees was then investigated by structurally different summary statistics (pair correlation function, nearest neighbour distribution function, spherical contact distribution function). Spatial pattern analysis of the trees regardless of slope caused biased results. While the spatial pattern of maple trees in the study plot with slope of 35% was significantly clumped up to 29 m distance and the largest distance to nearest neighbour was 16.3 m. The largest empty space among the trees was observed at 40.8 m spatial scale. In general, it was concluded that spatial pattern analysis of Montpellier maples scattered on steep slopes should be investigated by summary statistics that consider distances among trees on slope instead of their distances on plain surface.