The effect of different poplar clones on soil biological characteristics in north of Iran

For several years, soil quality assessment has been focused solely on determining the soil physical and chemical properties, but recently, the measurement of soil biology has also been considered. Present study was conducted in the east of Guilan province on the poplar lands of the Safrabasteh Poplar Research Station. The plan of soil samplings were conducted in a random-systematic grid with 4 plantation stands including Populus euramericana 45.51, Populus euramericana Triplo, Populus deltoides 69.55 and Populus deltoides 77.51, which are about 25 years old as well asnatural forest, Populus caspica as control area. Soil sampling was taken at a depth of 0-20 cm, then some microbial indices and soil chemical properties were analyzed. The results revealed biological and chemical indices have significant differences among the treatments and the majority of these variables in Populus deltoides 77.51are higher compared to the other treatments. According to the results, it can be stated that due to the importance and economic value of poplar cultivation and the interactions between them and soil, in choosing the best clones, both growth and economic benefits and their impact on the environment and especially the soil must be taken into account. It is declared that the variations of soil properties and the diversity of trees indices are proportional to forest site productivity. Different poplar clones and species have different ability to return nutrients to soil and affect soil. Based on the results, Populus deltoides 77/51 compared to the other treatments showed appropriate conditions to improve microbial respiration activities.