Contribution of grazing to soil atmosphere CH4 exchange during the growing season in a continental steppe

Methane uptake by four land-use types in the agro-pastoral region of northern China

“…a Land-use type R 2 y 0 a b c d Tang et al, 2013). Seasonal CH 4 uptake was higher during the growing season than non-growing season with higher uptake during summer and autumn and lower uptake during late-autumn and winter, which was associated with a similar seasonal pattern in T s. These results were similar to those of others (Dise, 1992;Awasthi et al, 2005;Liu et al, 2007;Holst et al, 2008;Chen et al, 2010Chen et al, , 2011.…”

“…The destruction of grassland ecosystems and their conversion to croplands can result in severe desertification (Wu and Tiessen, 2002;Yang et al, 2005;Wang et al, 2011), which can reduce soil C storage (Xie et al, 2007;Klumpp et al, 2007), decreased soil fertility (Guo and Glifford, 2002;Xie and Wittig, 2004) and rapid decomposition of accumulated soil organic matter (Wang et al, 2011). A number of studies have evaluated CH 4 fluxes on grasslands in northern China (Wu et al, 2010;Chen et al, 2010Chen et al, , 2011Luo et al, 2013) and examined the influence of various management practices such as grazing (Chen et al, 2011;Wang et al, 2012;Tang et al, 2013) and fencing (Chen et al, 2011) on CH 4 fluxes. However, few studies have compared CH 4 fluxes of grazed and ungrazed grasslands to artificial perennial pastures and croplands throughout the entire year.…”

Carbon dioxide and methane fluxes in variably-flooded riparian forests

“…These rates (kg CH 4 -C ha −1 year −1 ) are comparable to those measured in the southern Ecuadorian Andes (−5.9;Wolf et al, 2012), Japanese larch (Larix kaempferi Sarg.) forest on volcanic soils (− 6.3; Ueyama et al, 2012), beech forest (Fagus sylvatica) in New Zealand (− 7.9; Price et al, 2004), desert steppe of Inner Mongolia (− 7.9;Tang et al, 2013), and deciduous forests in northwestern Pennsylvania (−8.9;Bowden et al, 2000). The flood-protected riparian forests exhibited CH 4 uptake capacity that ranks among the highest reported in the literature.…”

“…The inhibitory effect of atmospheric N deposition and fertilizer application on CH 4 uptake is thought to involve competition between CH 4 and NH 4 + for the CH 4 -monooxygenase enzyme in methanotrophic bacteria (Hanson and Hanson, 1996;Hütsch, 1998). Several studies have also documented the impact of physical land disturbance (surface mining, plowing, grazing) on CH 4 uptake and the long-lasting effect of that disturbance on soil methanotrophic activity in soils (Hütsch, 1998;Tang et al, 2013). Flood events can elicit significant change in the soil redox environment, and therefore can result in enhanced CH 4 emission during such events.…”

Methane Emission from Sheep Respiration and Sheepfolds During the Grazing Season in a Desert Grassland

“…Tang et al [16] reported that soil CH 4 flux varied during the growing season, and Jiang et al [17] studied the contribution of urine and dung patches from grazing sheep to CH 4 fluxes in the desert grassland. Our results indicate that CH 4 emissions from urine and dung were much lower than from sheep respiration and soil uptake over a grazing plot with a large area.…”