Efleet Of Simulated Nitrogen Deposition On Soil Respiration In Betula Platyphylla Forest In South Of Daxing’anling Moorltains

Since the industrial revolution, atmospheric nitrogen deposition has been derived from fossil-fuel combustion and biomass burning,consequently it is occurring over almost the whole world, with the serious influence of the global nitrogen cycle and Carbon; Forest soil is the huge carbon pool in terrestrial ecosystems. So studied the soil respiration in Betula platyphylla forest with the treatments of Control(CK, no nitrogen fertilization), low nitrogen(LN,10kg·hm-2·a-1), medium nitrogen(MN,25kg-hm-2·a-1) and high nitrogen(HN,50kg·hm-2·a-1) is very urgent. The main conclusions are as follow:1. The basic characteristics on soil respiration in Betula platyphylla forest were in the growing season (May-September) average soil respiration rate was3.42±0.09μmol· m-2s-1, and the soil respiration rate was July (4.55)> August (4.48)> June (3.30)> September (2.68)> May (2.08); Soil respiration and temperature showed positive significant associated (P<0.001.), and with the soil moisture was significantly associated (P<0.05), with soil temperature and moisture showed positive significant associated (P<0.001); and two-factor mode is better than single-factor; The Q10was2.43.2. The diurnal variation of soil respiration and the seasonal average soil respiration in different nitrogen deposition treatments all was HN>MN>LN>CK, The seasonal average soil respiration rates under HN、MN and LN treatments increased by34.79%、24.56%and13.74%compared with the values under CK. Nitrogen deposition promoted the soil respiration rates and the soil respiration rates was positively correlated with the magnitude of nitrogen deposition.3. Simulated nitrogen deposition have no significant influence on soil temperature sensitivity and soil moisture relationship; Under the HN、MN and LN different nitrogen deposition treatments between soil respiration rate and soil temperature(P<0.001), the Q10were2.13、2.53and2.31; There were significantly exponential relationship between soil respiration rate and soil moisture (P<0.05); There were significantly positive exponential relationship of soil temperature and moisture on soil respiration rates (P<0.001).