نوع مقاله : علمی - پژوهشی
نویسندگان
1 دانشآموخته کارشناسی ارشد جنگلداری، دانشکده منابع طبیعی، دانشگاه ارومیه، ارومیه، ایران
2 استاد گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه ارومیه، ارومیه، ایران
3 دانش اموخته دکتری جنگلداری، دانشکدۀ منابع طبیعی، دانشگاه ارومیه، ارومیه
4 دانشیار گروه مرتع و آبخیزداری، دانشکده منابع طبیعی، دانشگاه ارومیه، ارومیه، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: Understanding the functional role of woody species in natural ecosystems is essential for evaluating ecosystem service production and achieving sustainable management. In forest ecosystems, there is a dynamic interaction between two key components: trees and soil. While tree growth and productivity are influenced by soil characteristics, the type and quantity of organic matter and nutrients returned by trees also play a significant role in shaping soil properties. This study examined three species—Montpellier maple (Acer monspessulanum), azarole hawthorn (Crataegus azarollus), and wild pistachio (Pistacia atlantica)—with respect to their quantitative traits (diameter at breast height, collar diameter, height, and number of shoots), qualitative traits (health status and origin), and their effects on selected soil properties (pH and electrical conductivity), as well as key regulatory (soil carbon sequestration, soil water holding capacity) and supporting (soil nutrient content) ecosystem services.
Material and Methods: In the study area, 30 individuals of each species were selected using fixed-count plot sampling. Selected trees were required to have a single, distinct main trunk, crowns isolated from neighboring trees, and be in healthy condition with no visible signs of disease, wounds, or decline. If the required number of individuals was not achieved along a sampling transect, an additional randomly oriented transect was established 50 meters away, following the dominant slope direction. For each selected tree, quantitative traits—including diameter at breast height, collar diameter, tree height, number of shoots, and crown diameter—along with qualitative traits such as origin, health condition, and stem angle, were measured and recorded. Soil samples were collected from beneath the canopy of 10 randomly selected trees per species, taken from a depth of 0–20 cm. Additionally, an undisturbed soil core was extracted from the same depth to determine soil water holding capacity. The analyzed soil parameters included pH, electrical conductivity (EC), available phosphorus, available nitrogen, available potassium, and organic carbon.
Results: Analysis of the quantitative characteristics revealed significant differences in the mean number of shoots (P = 0.04), crown diameter (P = 0.00), and tree height (P = 0.00) among the three studied species. Additionally, soil properties beneath the tree canopies showed significant differences in pH (P = 0.01) and EC (P = 0.00). Regarding regulatory services, soil carbon sequestration and water holding capacity differed significantly among the species. Likewise, for supporting services, significant differences were observed in the mean concentrations of available nitrogen and potassium. The highest average organic carbon content was recorded in the soil beneath A. monspessulanum, while the greatest water holding capacity was observed in the soil beneath P. atlantica. Furthermore, the soils under A. monspessulanum had the highest levels of available nitrogen and potassium.
Conclusion: The results of this study highlight that different tree species exert distinct and significant influences on litter quality and the physical, chemical, and biological properties of the soil. Among the species studied, A. monspessulanum, with its higher average quantitative values (number of shoots, crown diameter, and height), contributed most to ecosystem services related to nutrient cycling and soil carbon sequestration. Meanwhile, Pistacia atlantica demonstrated the highest soil water holding capacity. Overall, species ranking indicated that A. monspessulanum was better adapted to the environmental conditions of the study area and provided superior ecosystem services compared to the other two species.
کلیدواژهها [English]
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