4.2. Carbon stocks in the different riparian vegetation cover types
In this study, biomass C stocks ranged from 49 to 160 t/ha in
natural woodlots, 33e110 t/ha in hybrid poplar buffers, and only
3e4 t/ha in herbaceous buffers (Fig. 1). These field measurements
are within the range of published biomass C stocks for different
agricultural land uses in Canada, including poplar plantations and
farm woodlots (Arevalo et al., 2009). Our biomass C stock estimates
for riparian woodlots also fall in the range of mean biomass C stock
estimates for managed forests of the Mixedwood plains ecozone
(Stinson et al., 2011). Furthermore, our belowground (root) biomass
C stock amounts for poplar buffers (4.8e13 t/ha) and riparian
woodlots (5.2e36.8 t/ha) (Table 3) are in the same order of
magnitude than national scale estimates for managed forests of
Eastern Canada, which are 10e17.5 t/ha (Smyth et al., 2013).
Results from this study put in perspective the high potential of
hybrid poplar riparian buffers to increase C storage within a decade.
Site level comparisons between agricultural buffer types suggest
that 9-year-old poplar buffers store 9e31 times more biomass C
than herbaceous buffers (Fig. 1). On a mean annual basis, planting
poplar buffers in replacement of non managed herbaceous buffer
could increase biomass C storage by 3.2e11.9 t/ha/yr (Table 5).
Biomass C stocks of poplar buffers were in the range of what was
observed in most riparian woodlots (Fig. 1), which suggest that
planting poplar buffers in agricultural landscapes can accelerate the