Reed canary grass cultivation mitigates greenhouse gas emissions from abandoned peat extraction areas

Abstract

We studied the impact of reed canary grass (RCG) cultivation on greenhouse gas emission in the following sites of an abandoned peat extraction area in Estonia: a bare soil (BS) site, a nonfertilized Phalaris (nfP) plot, a fertilized Phalaris (fP) plot, and a natural bog (NB) and a fen meadow (FM) as reference areas. The C balance and global warming potential (GWP) were estimated by measuring CO 2 , CH 4 , and N 2 O emissions and aboveground and belowground biomass variations. The high CO 2 flux from the nfP and fP sites and the low CO 2 emission from the BS are due to the enhancement of mineralization by plant growth on planted sites and inhibited mineralization by the recalcitrant C of BS. The NB site emitted 24 kg CH 4 ha À1 yr À1 , whereas the almost zero CH 4 emission from the Phalaris plots and the BS site was due to the high S concentration in peat, which probably inhibited methanogenesis. The N 2 O flux varied from <0.1 kg on the Phalaris plots and the NB to 2.64 kg N 2 O ha À1 yr À1 on the FM. The highest yield of RCG was obtained in autumn (13.9 t and 8.0 t dw ha À1 on the fP and nfP, respectively). By spring, the biomass yield on the fP and nfP plot was 12.7 and 7.9 t dw ha À1 , respectively.The C balance of nfP and fP plots was negative in comparison to the BS (À3322, À5983, and 2504 kg CO 2 ha À1 yr À1 , respectively). This indicates that the cultivation of RCG transformed them from a net source of C into a net sink of C. The GWP for the fP and nfP sites was À5981 and À3885 kg CO 2 eq ha À1 yr À1, respectively. The BS site had a total GWP of 2544 kg CO 2 eq ha À1 yr À1 .

Carbon dioxide exchange of a perennial bioenergy crop cultivation on a mineral soil

“…On an annual basis, the average TER (+1000 g C m −2 ) for our study was within the range of what has been reported earlier for RCG cultivations at the comparison site (+480 g C m −2 , Shurpali et al, 2009), in cut-away peatland Estonia (+600 g C m −2 , 2-year study, Mander et al, 2012) and in the organic agricultural field in Denmark (+1900 g C m −2 , Kandel et al, 2013a). When compared to annual TER values for switchgrass, hybrid poplar and Scots pine forest (Skinner and Adler, 2010;Jassal et al, 2013;Kolari et al, 2009), the annual TER of the present study is higher.…”

Derivation of greenhouse gas emission factors for peatlands managed for extraction in the Republic of Ireland and the United Kingdom

“…Shurpali et al, 2008;Mander et al, 2012;Salm et al, 2012). While the addition of WT or VMC improved the performance of the R eco models at some of the sites, the improvement was only slight and this is likely due to the fairly narrow range of WT and VMC values recorded over the course of the 12-month study (e.g.…”

“…Järveoja et al, 2012;Mander et al, 2012;Salm et al, 2012;Strack et al, 2014), (c) no data from ROI or UK peatlands were included in the IPCC derivation, which might mean that the Tier 1 value may not be appropriate for these countries, and (d) no distinction is made between industrial or domestic extraction sites, despite large differences in their drainage, vegetation cover and management characteristics. In addition, previous studies of peatland fire EFs have focused on the boreal peatlands of Alaska (Yokelson et al, 1997) and Canada (Stockwell et al, 2014) and the temperate peatlands of Minnesota (Yokelson et al, 1997) and North Carolina (Stockwell et al, 2014).…”

“…The 10th and 90th percentile are indicated by the bars, the 25th and 75th percentiles with the top and bottom of the box and the median value by the centre line. (Data for Canada and Fennoscandia taken from the following studies; Tuittila and Komulainen, 1995;Sundh et al, 2000;Waddington et al, 2002;Glatzel et al, 2003;McNeil and Waddington, 2003;Tuittila et al, 2004;Cleary et al, 2005;Alm et al, 2007a;Shurpali et al, 2008;Waddington et al, 2010;Järveoja et al, 2012;Mander et al, 2012;Salm et al, 2012;Strack et al, 2014. ) Where studies reported seasonal fluxes (typically May to October), these were converted to annual fluxes by assuming that 15 % of the flux occurs in the nongrowing season soil moisture (Lindsay et al, 2014.…”

Alternative filter material removes phosphorus and mitigates greenhouse gas emission in horizontal subsurface flow filters for wastewater treatment

“…Pangala et al (2010) studied the impact of gypsum (CaSO 4 Á2H 2 O) and ochre on the CH 4 emission from a FWS CW treating farm wastewater in Scotland and found that the application of 10 tons of gypsum ha À1 to the sediment core reduced CH 4 emissions by 28%, whereas the addition of 5 tons of ochre ha À1 caused methane emission to decrease by 63% (Pangala et al, 2010). Similarly, Mander et al (2012) found a significant negative correlation between the CH 4 flux and the sulfate concentration in peat, and on SO 4 2À and Ca 2+ concentrations in soil water .…”