University of Tehran Forest and Wood Products 5052-2008 77 3 2024 11 21 Structure analysis of juniper (Juniperus excelsa M.B.) stands in the Irano-Touranin vegetation zone (Case study: Parvar protected area, Semnan province) Structure analysis of juniper (Juniperus excelsa M.B.) stands in the Irano-Touranin vegetation zone (Case study: Parvar protected area, Semnan province) 301 312 99813 10.22059/jfwp.2024.381531.1310 FA Parisa Panahi Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Khosro Sagheb Talebi Forest Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Hooman Ravanbakhsh Forest Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Morteza Moridi Department of Forestry and Forest Economics, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Mehdi Pourhashemi Forest Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Yousef Ajani Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Maryam Hasaninejad Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Maedeh Fadaei Khojasteh Botany Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran, Iran. Journal Article 2024 08 31 The dynamics of spatial structure play a major role in understanding the mechanisms of forest structure and the formation of biodiversity, and largely determine the sustainability of the forest and its productivity. As part of a long-term monitoring project, the present study was conducted to assess the structure of juniper (Juniperus excelsa M.B.) stands in the Parvar protected area of Semnan province in the Irano-Touranian vegetation zone. Two permanent sample plots, each one hectare, were randomly selected, and the quantitative characteristics of woody species were measured and recorded using the full calipering inventory method. The structural characteristics of the stands were calculated based on the nearest neighbor indices. In sample plot one, juniper was the most abundant species, accounting for 49.7% (94 stems), while Rosa canina was the least abundant, with 4.8% (9 stems). Berberis integerrima and Cerasus microcarpa accounted for 39.7% and 5.8% of abundance, respectively. Sample plot two, with 75 stems per hectare, consisted of only two species: juniper (54 stems, 72%) and barberry (21 stems, 28%). The Clarke and Evans index and uniform angle indices indicated a clustered spatial distribution pattern of trees. The species mingling index for the entire stand in sample plots one and two was 0.46 and 0.38, respectively, indicating moderate mixing. The combined structural diversity index value was 0.47 and 0.48 in sample plots one and two, respectively, suggesting high diversity in the investigated stands. This study demonstrated the effectiveness of these indices in estimating the horizontal structure of forest stands, providing valuable information essential for management and decision-making processes. The dynamics of spatial structure play a major role in understanding the mechanisms of forest structure and the formation of biodiversity, and largely determine the sustainability of the forest and its productivity. As part of a long-term monitoring project, the present study was conducted to assess the structure of juniper (Juniperus excelsa M.B.) stands in the Parvar protected area of Semnan province in the Irano-Touranian vegetation zone. Two permanent sample plots, each one hectare, were randomly selected, and the quantitative characteristics of woody species were measured and recorded using the full calipering inventory method. The structural characteristics of the stands were calculated based on the nearest neighbor indices. In sample plot one, juniper was the most abundant species, accounting for 49.7% (94 stems), while Rosa canina was the least abundant, with 4.8% (9 stems). Berberis integerrima and Cerasus microcarpa accounted for 39.7% and 5.8% of abundance, respectively. Sample plot two, with 75 stems per hectare, consisted of only two species: juniper (54 stems, 72%) and barberry (21 stems, 28%). The Clarke and Evans index and uniform angle indices indicated a clustered spatial distribution pattern of trees. The species mingling index for the entire stand in sample plots one and two was 0.46 and 0.38, respectively, indicating moderate mixing. The combined structural diversity index value was 0.47 and 0.48 in sample plots one and two, respectively, suggesting high diversity in the investigated stands. This study demonstrated the effectiveness of these indices in estimating the horizontal structure of forest stands, providing valuable information essential for management and decision-making processes.

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