Research On Nutrient Return Dynamics Of Liquidambar Formosana

This paper made a study of the amount of nutrient return and the amount of canopy leaching, and explores the characteristics of Liquidambar formosana return nutrients, to further Liquidambar formosana plantation management and to provide the scientific basis for nutrient cycling studies. The main results are as follows:(1) The amount of annual litter Liquidambar formosana plantation was 4935.6 kg·hm-2, the order of the amount of litter was leaf> branches> fruit> debris, leaf litter accounted for 55.83%of total litter, to 2755.7 kg·hm-2. Litterfall peaked at 12 months, up to 1055 kg·hm-2, accounting for 21.38%the amount of litter throughout the year. Litter layer dry weight of total biomass was 4028.215kg·hm-2.(2) Leaves, flowers and fruits of Liquidambar formosana litter of the nutrient content of the same order as:N> Ca> K> Mg> P, branches of the order of Ca> N> Mg> K> P, debris was:N> Ca>> Mg> K> P. Each component in the N and Ca content were higher, P content have the lowest. Liquidambar formosana plantation litter nutrient content in return for was 111.849 kg·hm-2. Liquidambar formosana plantation litter size of each element of return in the order of N> Ca> K> Mg> P, the total size of each component of the return of leaves> branches> fruit> debris, fallen leaves on the return of total nutrient return in 63.6%. Liquidambar formosana plantation N, P, K, Ca, Mg monthly return in the five elements of both appear in the December peak, respectively,9.221 kg·hm-2,0.379kg·hm-2,1.966kg·hm-2, 10.286kg·hm-2 and 1.98kg·hm-2, with the highest amount of litter appeared the same month, the lowest value in March.(3) Litter of Liquidambar formosana decomposited 50%of the time required for 412 days,95%of litter decomposition time is 1851 days. Litter, in addition to K, Mg, N, P, Ca appeared the phenomenon of nutrient enrichment, but the overall downward trend in litter decomposition in 546 days, N, P, K, Ca, and Mg-concentration of the initial concentration of their respective 85.02%,91.35%,40.46%,79.23%and 65%.(4) Outside the forest precipitation, through-fall and stem-flow in the relatively large concentration of each element, the highest concentration of both Ca elements were 4.783mg·L-1,12.888mg·L-1 and 12.924mg·L-1, the lowest concentration of both P elements were 0.1mg·L-1,0.162mg·L-1 and 0.192mg·L-1. Precipitation outside the forest nutrient concentrations in the order:Ca> N> K> Mg> P, while the penetration of water and stem flow in the order:Ca> K> N> Mg> P. Liquidambar formosana plantation stemflow nutrient contents were higher than outside the forest through the water and precipitation.(5) For the full year, N, P, K, Ca, Mg elements through leaching coefficients were 1.371,1.62,3.283,2.695,4.181 water, nutrient enrichment significantly, the annual average leaching concentrations were:0.773 mg·L-1,0.062mg·L-1,3.588mg·L-8.106mg·L-1,1.344mg·L-1. Liquidambar formosana Plantation stemflow nutrient leaching coefficients are greater than 1, showing the incremental leaching, stemflow nutrient enrichment significantly. Leaching of K elements of which the largest coefficient of 5.095, the average annual leaching concentration of 6.435 mg·L-1, P leaching coefficient of the smallest, the average annual leaching concentration of 0.092mg·L-1; N, Ca, Mg annual leaching concentrations were:2.908mg·L-8.141mg·L-1,1.463mg·L-1.N, P, K, Ca and Mg leaching were in 0.151kg·hm-2, 0.249kg·hm-2,30.308kg·hm-2,63.232kg·hm-2 and 11.883kg·hm-2, The total leaching volume 105.823kg·hm-2. Leaching of Ca, which the largest, accounting for 59.8%of the total.(6) Liquidambar formosana plantation annual nutrient return, N, P, K, Ca and Mg were 47.645kg·hm-2,2.009kg·hm-2,40.269kg·hm-2,107.855kg·hm-2 and 19.894kg·hm-2, arranged in order of size as:Ca> N> K> Mg> P. Among them, a large amount of litter is the return of N and Ca, their litters were returned to the percentage of the total accounted for 42.5%and 39.9%, while the Ca and K in the return of the amount of rainfall leaching accounted for a large proportion of, respectively,59.8%and 28.6%. Liquidambar plantation total annual nutrient return to 217.672kg·hm-2, the return of nutrients through litter leaching and rainfall total return less the same amount of nutrients were 111.849kg·hm-2 and 105.823kg·hm-2, visible return of rainfall leaching of nutrients can not be ignored.