Changes in stable nitrogen isotopes of plants, bulk soil and soil dissolved N during ecosystem retrogression in boreal forest

Stable nitrogen isotope ratios (δ15N) of plants and soil have been used to study changes in the N cycle during ecosystem succession retrogression. However, little is known about how δ15N mineral dissolved organic (DON) change retrogression, despite their potential inform on processes contributing loss. Here, we examined NH4+ DON together with dominant plant species bulk across a 5,000-year-old retrogressive chronosequence forested islands northern Sweden. The N, did not greatly suggesting that there are no major losses from system. was significantly correlated islands, indicating an important determinant N. higher than those probably because inclusion microbial fraction. Despite lack as retrogression proceeded, most increased. These results suggest relative importance three underlying mechanisms involved unclear, resources response retrogression: they increasing reliance DON, decreasing dependence transferred mycorrhizal fungi reduced surface layers proceeds.