Wetlands, carbon, and climate change

The Effects of Organic Matter Amendments on Greenhouse Gas Emissions from a Mitigation Wetland in Virginia’s Coastal Plain

“…Despite making up only five to eight percent of world land cover (Mitsch and Gosselink 2007), wetland ecosystems play an important role in regulating the Earth's climate. Wetland soils contain 16 to 33 % of the earth's soil carbon (C) pool of 2,500 Pg (Lal 2005;Bridgham et al 2006) and emit 20 to 40 % of methane (CH 4 ) (Bloom et al 2010), an important greenhouse gas (GHG) (Myhre et al 2013).…”

“…Others have claimed that because wetlands are sustainable ecosystems and persistent as C sinks, the widely-used 100-year time horizon is too short, and that: B…wetlands can be created and restored to provide C sequestration and other ecosystem services without great concern of creating net radiative sources on the climate due to methane emissions^ (Mitsch et al 2013). But errors in both the math and reasoning underpinning this latter view have been exposed (Bridgham et al 2014;Neubauer 2014), which reaffirms the potential century-scale impact of restored and created wetland CH 4 emissions on regional climate budgets.…”

Validation of the ecosystem services of created wetlands: Two decades of plant succession, nutrient retention, and carbon sequestration in experimental riverine marshes

“…Other studies of restored wetlands have also shown high carbon sequestration rates in the range of 280-305 g-C m À2 yr À1 (Euliss et al, 2006;Hendriks et al, 2007). In all of these cases including the Olentangy River wetlands, carbon sequestration rates are almost an order of magnitude higher than the much more studied boreal peatlands that have carbon sequestration rates reported to be 10-46 g-C m À2 yr À1 (Turunen et al, 2002) and 29 AE 13 (Mitsch et al, 2013). The data are clear that created and natural temperate wetlands sequester considerably more carbon than boreal peatlands.…”

“…We can conclude that these wetlands Table 7 Comparison of carbon sequestration in the Olentangy River wetlands to a reference site and other temperate, boreal, and tropical created and natural freshwater wetlands (from Mitsch et al, 2013 andGosselink, 2015) Wetland sequester in the range of 180-270 g-C m À2 yr À1 . The average rate from the two independent studies is 215 g-C m À2 yr À1 , 53% higher than a natural flow-through wetland in Ohio that we used as a reference (Table 7).…”

Sources and preservation of organic matter in soils of the wetlands in the Liaohe (Liao River) Delta, North China

“…It is estimated that 20-30% of the Earth's soil pool of 2500 Pg of carbon is stored in wetlands (Roulet, 2000;Bridgham et al, 2006), although wetlands comprise only about 5-8% of the terrestrial land surface (Mitsch and Gosselink, 2007). Wetlands are also a source of greenhouse gas emissions, especially methane (Mitsch et al, 2012). Thus, wetland ecosystems play a significant role in the global carbon cycle and climate change.…”