نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار بخش تحقیقات منابع طبیعی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی ایلام
2 دانشیار موسسه تحقیقات جنگلها و مراتع کشور
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Monitoring the nutrients of tree leaves is done to know how they change in the physiological response of trees to environmental stresses. In the present study the status of leaf nutrients of crown dieback affected Persian oak trees during the years 2019- 2021 was monitored. Two northern and southern sites were selected in Mele-Siah area and five healthy trees and five declining trees were determined in each. From each tree, 20 mature and healthy leaves were separated and collected in bags. Leaf samples were taken to the laboratory to measure the concentration of nitrogen, phosphorus, potassium, calcium and magnesium elements. Leaf sampling was done during three years in August. A hole was dug on the southern side of each tree crown and soil sampling was done in the two horizons in order to measure soil moisture. Soil sampling was done during three years in the months of growing season. The results showed that the amount of leaf nitrogen was the highest in 2019 and the lowest in 2020, and also it was more in healthy trees. The amount of phosphorus in all years was higher in the northern site. The amount of potassium was the highest in 2019 and the lowest in 2020. The amount of leaf calcium and magnesium was the highest in 2019 and the lowest in 2021. Also, the amount of calcium was higher in the northern site. The highest amount of calcium was found in declining trees of northern site and in healthy trees of southern site. The results showed that the soil moisture was higher in the northern site in all the sampling years. In addition, soil moisture was associated with annual changes and this has affected the changes of leaf nutrients in different years.
کلیدواژهها [English]
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