Vegetation colonization of abandoned agricultural land in Europe: impact on carbon sequestration

Abstract

In this study, we analyse the impact of plant colonisation on abandoned agricultural lands in Europe in terms of atmospheric CO₂ sequestration. Through a systematic revision, we selected 78 scientific articles in which we analysed which compartments of the ecosystem had been analysed for C fixation (soil, above-ground and below-ground biomass, dead wood and litter), and what the patterns and determining factors of this process had been. To this end, we used analysis of variance and linear and no linear regression. Our results indicate that C fixation in the soil has been studied much more than in living biomass, litter and dead wood, whereas carbon flows between compartments, have received little attention. After agricultural abandonment, soil organic carbon (SOC) generally showed an increasing pattern, but could also experience a decrease and more complex patterns. Carbon in above-ground biomass (CAGB) also increased throughout plant colonisation, but could become saturated from 60-80 years after abandonment onwards, due to self-thinning processes. The increase in SOC throughout succession was mainly explained by mean annual precipitation and temperature, which could be related to changes in microbial activity and litter degradation, and by soil N content. The latter variable also had a positive influence on CAGB, together with tree density in the initial stages. In order to promote carbon sequestration in new forests and shrubland areas developed on abandoned agricultural land, it is necessary to develop actions related to sustainable forest management and promote extensive land use.