Above and belowground carbon stocks differ among meadow vegetation communities in the northern Sierra Nevada, California USA

Abstract

AbstractWhile they cover a relatively small geographic area, montane meadows are hotspots of soil carbon (C) and are characterized by diverse vegetation communities. Estimates of C stocks in meadows could be improved by linking vegetation communities to above- and belowground C stocks. Here, we explored the spatial distribution of above- and belowground C stocks associated with different vegetation communities from the center of a meadow to the forest edge in eight montane meadows in the Sierra Nevada mountains of California, USA. We found significant differences in belowground C stocks among vegetation communities within most meadows. Meadows that were adjacent to Pinus jeffreyi forest showed strong associations between belowground C stocks and vegetation communities, but meadows that were adjacent to mixed conifer forest did not. Belowground C stocks represented the dominant fraction of the total ecosystem C stock in all meadows. The presence of shrubs and establishing trees in meadows generally corresponded with lower belowground and total C stocks. The increase in aboveground C in communities with shrubs or establishing trees did not offset the decrease in belowground C relative to herbaceous plant communities. Though meadows are hydrologically dynamic ecosystems, vegetation communities exhibit strong controls over the quantity and location of C stocks within the ecosystem that may be identified by the composition of the surrounding forest. Our data provide a reference point for future efforts to manage C stocks in Sierra Nevada meadows.