3.3 Organic carbon allocation in soil organic matter fractions
Both POC and MAOC declined along the gradient of ecosystem degradation,
whereas the POC/MAOC ratio was nearly constant across all forest states
and seasons except in arid land, where it was significantly higher (Fig.
4). POC content was significantly higher in natural and semi-natural
forest compared to other forest states by ca. 45% on average (Fig. 4a).
MAOC content followed the same pattern, with a reduction during the dry
season of 8, 33, 56 and 54% from natural forest to semi-natural forest,
simplified forest, shrub-dominated forest and arid land, respectively,
and a similar reduction of 21-55% during the rainy season.
Regarding changes in SOM fractions between seasons within the same
forest state, the greatest POC losses were detected in semi-natural
forest and simplified forest (~30%) followed by natural
forest (17%), shrub-dominated forest (14%) and arid land (12%).
Losses of MAOC between seasons were less intense and no significant,
showing a decrease of 7% for natural forest and 4% for shrub-dominated
forest and arid land, while reaching 26% for semi-natural and
simplified forest. POC/MAOC ratios remained constant across forest
states and seasons, with the exception of a slight but non-significant
decline of ca. 17% from the dry to rainy season in shrub-dominated
forest and a significant increase in arid land in both seasons.