Effects Of Prescribed Burning On Forest Ecosystem Multifunctionality Of Three Typical Forest Types In Hegang

Ecosystem multifunctionality as a comprehensive index to measure ecosystem functions and services,can simultaneously reflect the whole ecosystem function.Under the background of global warming,the frequency of extreme weather is increasing,which has a serious impact on terrestrial ecosystems and human life.Prescribed burning is widely used in forest management to reduce the accumulation of fuel and the occurrence of fire At the same time,Prescribed burning will also affect forest ecosystem and destroy ecosystem balance to a certain extent.Therefore,it is of great significance to study the impact of prescribed burning on ecosystem functions and services.In this study,three typical forest types of Pinus koraiensis,Larix gmelinii and Quercus mongolica,in Hongqi Forest Farm,hegang,Heilongjiang Province,were taken as research objects.Samples were collected at different recovery times after prescribed burning.By quantifying the ecosystem multifunctionality,This paper analyzes the influence of prescribed burning on the ecosystem multifunction of forest ecosystems of three typical forest types,reveals the influence mechanism of prescribed burning on ecosystems,enriches the application of ecosystem multifunction,and provides data reference and theoretical basis for future research on prescribed burning and ecosystem multifunction.The main results are as follows:(1)Prescribed burning significantly promoted the contents of soil SOC,TN,TP,MBN,DOC,DTN,RSOC,RTP and BG in the three typical forest types(p<0.001),but significantly inhibited the contents of soil NAG in the three typical forest types(p<0.001).The prescribed burning promoted the Pielou evenness of Pinus koraiensis forest and Quercus mongolica forest(p<0.001),and inhibited the Pielou evenness index of Larix gmelinii forest(p<0.001);The prescribed burning promoted the Simpson diversity of Quercus mongolica forest(p<0.001),and inhibited the Simpson diversity index of Pinus koraiensis forest and Larix gmelinii forest(p<0.001);Prescribed burning promoted Shannon-Weiner diversity index of Larix gmelinii forest and Quercus mongolica forest(p<0.001),and inhibited Shannon-Weiner diversity index of Pinus koraiensis forest(p<0.001).(2)Compared with the control plot(average method),the prescribed burning promoted the EMF of Pinus koraiensis forest and Quercus mongolica forest(5.45% and 3.91%)(p<0.001),and inhibited the EMF of Larix gmelinii forest(4.05%)(p<0.001).Compared with the control plot(threshold method),the prescribed burning promoted the effect of Simpson diversity index on EMF and inhibited the effect of soil p H on EMF in Pinus koraiensis forest;The prescribed burning promoted the effect of soil moisture content w on EMF in Larix gmelinii forest;Prescribed burning inhibited the effects of soil moisture content W and Pielou evenness index on EMF in Quercus mongolica forest.After the prescribed burning,the main driving factors of EMF of Pinus koraiensis forest and Larix gmelinii forest are Simpson diversity index and soil moisture content W,respectively.(3)By exploring the influence mechanism of prescribed burning and different forest types on EMF,the results showed that prescribed burning and different forest types did not show a significant correlation on EMF through direct effect,and different forest types significantly affected EMF through soil p H;Except that the interaction of soil layer,different forest types and prescribed burning had no significant effect on EMF,other factors significantly affected EMF(p<0.05).Soil layer and prescribed burning had a stronger explanation for EMF,accounting for 61% and 22% of its variation respectively.