Plant and Soil

, Volume 337, Issue 1, pp 151–165

Aboveground litter quality changes may drive soil organic carbon increase after shrub encroachment into mountain grasslands

Authors

    • Centre Tecnològic Forestal de Catalunya (CTFC)
  • Joan Romanyà
    • Departament de Productes Naturals, Biologia Vegetal i EdafologiaUniversitat de Barcelona
  • Pere Rovira
    • Centre Tecnològic Forestal de Catalunya (CTFC)
  • Pere Casals
    • Centre Tecnològic Forestal de Catalunya (CTFC)
Regular Article

DOI: 10.1007/s11104-010-0512-1

Cite this article as:
Montané, F., Romanyà, J., Rovira, P. et al. Plant Soil (2010) 337: 151. doi:10.1007/s11104-010-0512-1

Abstract

Shrub encroachment into grasslands is ubiquitous but its impact on soil organic C (SOC) remains unclear. In previous work we had observed that shrub encroachment into mesic mountain grasslands increased SOC content. Here we sought the mechanisms of this increase. To this end, we assessed aboveground and belowground production for a conifer shrub (Juniperus communis L), a legume shrub (Cytisus balansae ssp. europaeus (G. López & Jarvis) Muñoz Garmendia) and grass (Festuca eskia Ramond ex DC), together with decomposition rates for both aboveground litter and roots. Belowground C net inputs do not clearly explain SOC increase: grass root production was higher than that of either shrub and the decomposition rate of grass roots was the lowest. Aboveground C net inputs were only slightly greater in shrubs than in grass, but the decomposition rate of litter of both shrubs was much lower than that of grass. The decomposition of conifer litter was N-limited, whereas that of legume shrub litter was P-limited. Thus we conclude that the SOC increases after shrub encroachment into mesic grasslands probably as a result of higher recalcitrance of shrub aboveground litter relative to grass litter.

Keywords

Litter decompositionRoot decompositionLitter qualityLitter productionRoot productionIngrowth coresLegume shrubConifer shrubC sequestration

Copyright information

© Springer Science+Business Media B.V. 2010