The N₂O Flux Characteristics Of Different Forest Land Types In Larix Gmelinii Ecosystem

Climate warming caused by rising N2O content in the atmosphere has become an important issue of global concern,and forest soil has become one of the important emission sources of N2O.This paper takes the three types of forest land in the Larix gmelinii ecosystem as non-forested land,forested land,and marsh wetland as the research object.The dynamic air chamber method is used to determine the soil N2O net exchange flux,and the characteristics of soil N2O flux of different forest land types And analyzed the effects of soil environmental factors(soil temperature,soil moisture)and soil chemical properties on soil N2O flux.The research results can provide theoretical basis and data support for N2O emission reduction and forest land greenhouse gas emission contribution assessment in the region.The main findings are as follows:(1)The soils without forest land,forest land and marsh wetland are all sources of N2O,and the fluxes are in order of no forest land(16.01?g/m2/h)>marsh wetland(12.02?g/m2/h)>forest land(0.464?g/m2/h).The soil N2O fluxes of the three forest land types showed obvious monthly changes,that is,they showed a high-low-high change trend with time,but the daily change had no obvious trend.(2)The soil temperature and humidity of the three types of forest land show a certain time-varying characteristic.The daily and monthly temperature changes of the soils without forest land,forest land,and marsh wetland showed strong temporal dynamic characteristics,which showed that they gradually decreased with time.Or dynamic characteristics;the monthly humidity changes of soils without forest land,forest land,and marsh wetlands show strong temporal dynamic characteristics.With the passage of time,soil moisture is gradually decreasing and decreasing.(3)Soil microenvironment and soil chemical properties will have different effects on the N2O flux of different forest types.The N2O flux of the forestless and swamp wetlands is affected by the dual effects of soil temperature and soil moisture,both of which are significantly or extremely significantly related.The nitrogen ratio was significantly negatively correlated.The N2O flux in forest land was significantly positively correlated with soil temperature,not corrciated with soil moisture,and significantly negatively correlated with soil nitrate...