title: Dynamics of carbon pools in post-agrogenic sandy soils of southern taiga of Russia.
abstract: BACKGROUND
  Until recently, a lot of arable lands were abandoned in many countries of the world and, especially, in Russia, where about half a million square kilometers of arable lands were abandoned in 1961-2007. The soils at these fallows undergo a process of natural restoration (or self-restoration) that changes the balance of soil organic matter (SOM) supply and mineralization.
  
  
  RESULTS
  A soil chronosequence study, covering the ecosystems of 3, 20, 55, 100, and 170 years of self-restoration in southern taiga zone, shows that soil organic content of mineral horizons remains relatively stable during the self-restoration. This does not imply, however, that SOM pools remain steady. The C/N ratio of active SOM reached steady state after 55 years, and increased doubly (from 12.5 - 15.6 to 32.2-33.8). As to the C/N ratio of passive SOM, it has been continuously increasing (from 11.8-12.7 to 19.0-22.8) over the 170 years, and did not reach a steady condition.
  
  
  CONCLUSIONS
  The results of the study imply that soil recovery at the abandoned arable sandy lands of taiga is incredibly slow process. Not only soil morphological features of a former ploughing remained detectable but also the balance of soil organic matter input and mineralization remained unsteady after 170 years of self-restoration.
authors.affiliation: Dept, Soil Sci, C-v-O, University of Oldenburg, Oldenburg, Germany. oykalinina@mail.ru.
authors.forename: Olga
authors.initials: O
authors.lastname: Kalinina
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Goryachkin
authors.forename: Nina A
authors.initials: NA
authors.lastname: Karavaeva
authors.forename: Dmitriy I
authors.initials: DI
authors.lastname: Lyuri
authors.forename: Luise
authors.initials: L
authors.lastname: Giani