Tajik, S., Sh. Ayoubi, J. Khajehali, and Sh. Shataee. 2019. Effects of tree species composition on soil properties and invertebrates in a deciduous forest. Arabian Journal of Geosciences

 Arabian Journal of Geosciences, 

(2019)

12(11), 1-11.

A comprehensive understanding of factors that influence soil properties and soil biota, such as tree composition, is essential for the management and conservation of biodiversity. This study was conducted to explore the effects of tree composition on a number of properties and invertebrates of soil in the forest ecosystem of northern Iran. Eleven plots were selected differing in the composition of the following tree species: Persian ironwood (Parrotia persica V.), maple (Acer velutinium B.), and hornbeam (Carpinus betulus L.). In each plot, we measured pH, particle size distribution, electrical conductivity (EC), calcium carbonate equivalent (CCE), organic carbon (OC), total nitrogen (TN), and soil microbial respiration rate (Resp), at depths of 0–10 cm and 10–20 cm. In addition, abundance, Shannon index, richness, and evenness of the soil invertebrates, at both depths, were determined. Accordingly, a total number of 636 and 312 invertebrates were recorded from the topsoil and subsoil, respectively. EC, pH, CCE, C/N, silt, sand, abundance, and richness of the soil invertebrates had a significant correlation with the tree abundance. The soil properties significantly differed among the plots having different tree species composition (P ≤ 0.05). The depths of the soil also had significant effects on the soil properties. The study revealed that the plot including single tree species (maple) had the highest invertebrate abundance (24.67), while the highest OC (6.06%), the greatest TN (0.40%), and the uppermost soil resp. (434 mg CO2 kg⁻¹ day⁻¹) were observed in the Persian ironwood-maple, which has two tree species. In addition, hornbeam-maple-Persian ironwood plot had the highest Shannon index (1.48) and the greatest richness of invertebrates (6.17), while the Persian ironwood-hornbeam-maple plot had the highest invertebrate evenness. However, the hornbeam plot had the lowest abundance, Shannon index, and richness of invertebrates (0.93). Overall, the results revealed that soil properties and soil invertebrate communities were affected by the dominant tree species, and their effects could be lowered or intensified by varying the proportion of different tree species.