Nitrogen mineralization in the ruderal sub-alpine communities in Mount Uludag, Turkey

Nitrogen mineralization and nitrification in the soil of sub-alpine ruderal community of Mount Uludag, Bursa, Turkey was measured for 1 year, under field conditions with Verbascum olympicum and Rumex olympicus being the dominant pioneer species under dry and wet sites, respectively. Seasonal fluctuations were observed in N mineralization and nitrification. The net N mineralization and nitrification were high in early summer and winter, due to high moisture. The annual net N mineralization rate (for the 0-15 cm soil layer) was higher under R. olympicus (188 kg N ha(-1) yr(-1)) than under V. olympicum (96 kg N ha(-1) yr(-1)). A significant positive correlation between net N mineralization and soil organic C (r(2) = 0.166), total N (r(2) = 0.141) and water content (r(2) = 0.211) was found. Our results indicate that N mineralization rate is high in soils of ruderal communities on disturbed sites and varies with dominant species and, a difference in net N mineralization rate can be attributed to organic C, total N and moisture content of soils. (C) 2008 Elsevier Masson SAS. All rights reserved.