Monthly Production Pattern Of Fine Root In Litter Layer And Its Influential Factors In A Mytilaria Laosensis Plantation

The experimental site is set in a 21-year-old M.laosensis plantation,located at Xiayang forest farm(26° 48'N,117°58'E),northwest Fujian Province,South-Eastern China.In March 2014,four 10 m×10 m plots were established in the M.laosensis plantation.Tree 0.5 m×0.5 m sub-plots were set in each plot,with three treatments(CK,LN,HN).Morphology,order-branch structure,nutrient contents and ?15N of fine root in litter layer were measured.The results showed that:(1)In M.laosensis plantation,monthly pattern of fine root production in litter layer was 0.07-0.36 g·m-2.There were significant differences between two kinds of fine root(in litter layer and in 0-10 cm soil layer)in morphology,order-branch structure,nutrient contents and ?15N.Fine root in litter layer had higher SRL,SRA,percentages of fine root in the first and secondary order than fine root in the 0-10 cm soil layer.Fine root in litter layer had lower RTD,diameter,percentages of fine root in the third and other orders than fine root in the 0-10 cm soil layer.There were higher C,N,P,K,Mg,Na concentrations and lower ?15N of fine root in litter layer,compared to the fine rot in 0-10 cm soil layer.(2)There were significant differences in production and order-branch structure of fine root in litter layer,but not in fine root morphology,among different treatments.Fine root production presented:HN>LN>CK.Percentage of fine root in the first order in HN treatment was higher than that in other treatments.The results showed that:nitrogen is one of most important nutrient to drive fine root grown into leaf layer.(3)There were significant differences in fine root N,P,K,Ca contents among different treatments.There were no significant differences in fine root C,C/N,C/P,N/P,Mg,Na contents and ?15N among different treatments.