The Dynamic Of Litterfalls In Broad-leaved Korean Pine Mixed Forest In Changbai Mountain

Forest litterfall is organic matter in forest ecosystems produced by aboveground plant communities and eventually returned to the soil surface.Litterfall is the link between plant and soil,which deeply affects the carbon and nutrient cycle and energy flow of forest ecosystem.The carbon cycle of forest ecosystem is restricted by many factors,and the speed of litterfall cycle in forest ecosystem is very important.Litterfalls affect the carbon sink of forest ecosystem by affecting the rate of carbon cycle.At the same time,litterfall is also an important source of forest soil nutrients,which plays an important role in forest water and soil conservation,biodiversity maintenance and natural forest renewal.Therefore,the yield,composition and spatio-temporal dynamic characteristics of forest litterfalls are one of the important contents in the study of global change.Studying the data changes of litterfalls will provide new ideas for understanding the material circulation and energy flow of forest ecosystem.The broad-leaved Korean pine mixed forest in Changbai Mountain is the typical zonal forest vegetation in Northeast China.It has the highest community type and rich species diversity,playing an important role in absorbing CO2 and mitigating climate warming.In this paper,the litterfalls(branches,leaves,flowers and fruits,bark,sundries,etc.)of broad-leaved Korean pine mixed forest in Changbai Mountain were collected from 2003 to 2014 for 12 consecutive years.We analyzed that the production of litterfalls and their composition,monthly,interannual,spatial pattern as well as relationships between litterfall production and climatic factors(temperature and rainfall).The main conclusions were as follows:(1)From 2003 to 2014,the litterfall production of broad-leaved Korean pine mixed forest in Changbai Mountain ranged from 4683.39 to 8595.83 kg hm-2 from April to October,with the average value of 6380.63 kg hm-2.(2)The proportion of each component in broad-leaved Korean pine mixed forest in Changbai Mountain was that leaves(59%)> branches(13%)> sundries(11%)> fruits(10%)> barks(4%)> lichen(3%).(3)The forest litterfalls of broad-leaved Korean pine mixed forest in Changbai Mountain showed obvious monthly and interannual dynamics,and the peak values of total litterfalls and leaf litterfalls appeared in September and October.(4)From 2003 to 2014,there was the heterogeneous spatial pattern of total litterfalls in broad-leaved Korean pine mixed forest in Changbai Mountain.(5)There were significant non-linear relationships between the total litterfall amount and monthly rainfall as well as monthly mean temperature in broad-leaved Korean pine mixed forest in Changbai Mountain.With the increasing monthly rainfall,the average monthly total litterfalls significantly decreased at first,then maintain stable;with the increasing monthly average temperature,the average monthly total litterfalls firstly decreased and then increased.However,there was no significant relationship between total litterfall amount and total rainfall and temperature from April to October.(6)Branch of the litterfall and skin litterfall is significantly positive correlation,leaf litterfall and fruit and flower litterfall is significantly positive correlation,debris and moss and other components of the litterfall is not significantly correlated.