Response of earthworm’s biomass and soil properties in different afforested type areas in the North Iran

The study was conducted to evaluate the effects of spruce ( Picea abies ), alder ( Alnus subcordata ), and spruce with alder and maple ( Picea abies with Alnus Subcordata and Acer cappadocicum ) plantations on the soil properties and earthworm’s abundance and biomass in the Lajim, north of Iran. Soil sampling with 50 × 50 cm samples to 50 cm depth in the studied stands was conducted in order to measure soil and earthworm abundance and biomass. Soil texture, C, N, pH, K, and P were measured in all samples in the laboratory. Earthworm’s abundance was measured by handpicked and dried for 48 h at 60 °C and then the biomass was measured per unit area. The results showed that the percentage of organic carbon, N, and C/N ratio reached the climax and acidity had the lowest value in spruce stand, and K was significantly higher in alder stand. The maximum and minimum abundance of earthworms was observed in alder and spruce stands, respectively. The results of this study support the effects of plantations on soil properties, earthworm abundance, and biomass.