Spatiotemporal dynamics of trees distribution patterns following disturbance caused by decline in the oak forests of Lorestan province

The aim of this study was to investigate the spatiotemporal dynamics of trees distribution patterns in a ten-year period following disturbance caused by decline in the oak forests of Lorestan province in the west of Iran. For this purpose, the quantitative characteristics and the spatial patterns of trees in 5-hectare sample plots in four different regions without decline, which were surveyed in 2010, also surveyed in 2020 which three regions had conditions of decline and one region without decline). The results showed that the mean of density was decreased in declined areas and increased in the non-declined area during the period. During the ten-year period, there was a significant difference between the tree density and canopy percentage in the areas with and without decline. The spatial patterns of Persian oak (Quercus brantii) trees in the decline areas showed that during the period, the spatial patterns in the pure and low-density stands were clustered, while in the mixed stands with the dominance of oak with relatively high density, it was a random distribution pattern, which with increasing of distance, changed to clustered. The disturbance due to decline in the mixed stands caused the clustering occurred in a smaller radius (40 meters and more), but in the mixed stands without declined clustering observed in a radius of more than 60 meters. The results of this study showed that the trees decline affects the spatial patterns of trees which can be an effective guide in the management of decline stands.