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.