[Effects of harvest disturbance on soil CH4 flux in a secondary hardwood forest in Northeast china].
From June, 2007 to October, 2009, a measurement with static chamber/gas chromatograph techniques was conducted on the soil CH4 flux in a typical secondary hardwood forest in Northeast China under the effects of different harvest disturbances, i.e., uncut (control), clear cutting (including both farming and reforestation after clear cutting), 50% stand volume removed, and 25% stand volume removed. In all of the four treatments, the soil was the sink of atmospheric CH4, but cutting decreased the soil CH4 uptake flux, with the order of uncut (-85.03 microg CH4 x m;(-2) x h(-1)) > 50% stand volume removed (-80.31 microg CH4 x m(-2) x h(-1)) > 25% stand volume removed (-70.97 microg CH4 x m(-2)h(-1)) > farming after clear cutting (-65.57 microg CH4 x m(-2) x h(-1)) > reforestation after clear cutting (-62.02 miocrog CH4 x m(-2) x h(-1)). During the study period, the seasonal patterns of the soil CH4 uptake flux in all treatments were similar, with a higher value in growth season and a lower one in winter. After the harvest disturbance, the soil temperature, humidity, and NO(3-)-N, and NH(4+)-N contents were all increased, and the soil CH4 flux had a significant quadratic correlation with soil temperature, and a negative linear correlation with soil moisture content. It was suggested that the increase of the soil moisture, NO(3-)-N, and NHa(4+)-N contents after the forest harvest was the main cause of the decrease of the soil CH4 uptake flux.
School of Forestry, Northeast Forestry University, Harbin 150040, China. shlong12@126.com
Sun
S
Hai-Long
D002681:China; D003247:Conservation of Natural Resources / Q000191:economics*; D016468:Forestry / Q000191:economics*; D065928:Forests; D008697:Methane / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D014197:Trees / Q000254:growth & development / Q000378:metabolism*; D014867:Water / Q000378:metabolism
D012987:Soil; D014867:Water; D008697:Methane