Different management of larch grasslands in the European Alps shows low impact on above- and belowground carbon stocks

Larch (Larix decidua) grasslands represent a traditional agro-forest system in the montane and subalpine belts of the European Alps, combining fodder and timber production. Due to socio-economic reasons, large parts of those dual-purpose grasslands have either been abandoned or intensified over the last 60 years. While their associated benefits such as high biodiversity and space for human recreation has recently been acknowledged, the carbon sequestration potential of larch grasslands is still unknown. In this study, we quantified belowground organic carbon stocks (i.e. in roots and 0-20 cm topsoil) and aboveground biomass carbon (i.e. trees and understory vegetation) of three differently managed larch grasslands - namely intensively, extensively and pastured - as well as of abandoned larch grasslands. Data obtained from 166 study sites show that larch grasslands store between 184 and 265 t C ha−1. Below- and aboveground carbon stocks are similar in the managed larch grasslands but increase with abandonment due to enlarged tree-biomass.