Comparatively Study On The Characteristics Of Litter Of Different Natural Forests In Wuyishan Scenery District

The Wuyishan is nature of the world and cultural heritage,it has the most completely with the same latitude,the most typical,and the largest in the subtropical area of original forest ecosystems in the world.It also is the key area of protect the world's biological diversity,so it has important academic value and ecological value.In order to find out the rules of litter characteristics,such as amount,component,seasonal dynamics,nutrient content and return, decomposition of four natual forsts in Wuyishan Scenery District were studied,the results showed as follows:1)The litter amount in the year of broadleaf leaf forest,pinus massoniana forest,Chinese fir forest and Phyllostachys heterocycla cv.Pubescens forest were:4913.11,3976.40,3546.42,2574.40 (unit:kg·hm^-2),the litter amount difered in four natural forests,but leaf hold the absolutcontent,the range from 69.71%to 86.50%;the total litter peak of chinese fir,broadleaf leaf,pinus massoniana and Phyllostachys heterocycla cv.Pubescens forests were in may and november,april and november,may.In april,forest on the changing patterns of the total litter and leaf litter in the same model,without broadleaf leaf forest in which the of single peak change pattem,the other forests were all two peaks patterns.2)The litter ofpinus massoniana forest various components nutrient content were in sequence of N＞Ca＞K＞Mg＞P.The nutrient content of leaf and branch in Chinese fir forest were in sequence of Ca＞N＞K＞Mg＞P,flowers and fruit and Miscellany were:N＞Ca＞K＞Mg＞P. Leaf and branch of Phyllostachys heterocycla cv.Pubescens forst,the nutrient content order was: N＞Ca＞K＞Mg＞P,the Miscellany was:N＞K＞Ca＞Mg＞P;the leaf,branch and Miscellany of broadleaf leaf forest were in sequence of N＞Ca＞K＞Mg＞P,Miscellany was N＞K＞Ca＞Mg＞P.3)The annual total amount in litter returning to soil were can be ranked in a decreasing order as Pinus massoniana＞Chinese fir＞broadleaf leaf＞Phyllostachys heterocycla cv.Pubescens.The amounts of five nutrients were in the sequence of N＞Ca＞K＞Mg＞P,N variation range was 15.85～40.07 kg·hm^-2,P was 1.21～6.93 kg·hm^-2,K was 7.23～20.43 kg·hm^-2,Ca was 14.30～27.68 kg·hm^-2,Mg was 2.26～7.68 kg·hm^-2.Leave litter and twig litter with the five elements(N,Ca,K, Mg,P)on the nutrient return of the dynamic ranges with different patterns,there are three modes: single peak,a two peaks and more peaks,the high peak has different time in four natural forests.4)The ratio annual initial mass of decomposing litter remaining can be ranked in a decreasing order aspinus massoniana twig litter(82.81%)＞chinese fir twig litter(78.18%)＞phyllostachys heterocycla cv.Pubescens twig litter(75.70%)＞broadleaftwig litter(72.84%)＞chinese fir leaf litter(66.41%)＞pinus massoniana leaf litter(66.33%)＞phyllostachys heterocycla cv.Pubescens leaf litter(49.85%)＞broadleaf leaf litter(46.90%).The annual decomposition ratio of the eight kinds of litter were in sequence of broadleaf leaf litter＞phyllostachys heterocycla cv.Pubescens leaf litter＞pinus massoniana leaf litter＞chinese fir leaf litter＞broadleaf twig litter＞pinus massoniana twig litter＞phyllostachys heterocycla cv.Pubescens twig litter＞chinese fir twig litter.The time of decomposing 50%and 95%litters were different,the T_0.5 variety range was 1.8275～2.6263a,T_0.95range was 3.3346-11.3681a.5)During the course of decomposition,release dynamics of nutrients differed in four natural forests and also by different decomposition periods,N and P content in leave and twig litter were fluctuantly,K content has the same changes tendency,always descreased with the passage of time,organic C content was fluctuations,but slowly decreased in the all course,the annual change of Ca,Mg content were not stablely,at the end of the decomposition time,other litters all have the released tendency but pinus massoniana twig litter.There were different nutrient concentrations in different of litters in four natural forsts.N concent was increasing in a certain degree with the passage of time,and in the decreased tendency at the last decomposition.P concentwas fluctuantly increasing slowly,after one year,chinese fir leaf litter was bigger than others,phyllostachys heterocycla cv.Pubescens leaf litter was smallest.There were different changes tendency during Ca content,after one year,phyllostachys heterocycla cv.Pubescens twig litter was bigger thanpinus massoniana twig litter(53.89%).Mg and K content have the same changes tendency,always descreased with the passage of time,organic C content also has released change tendency in others litter,but pinus massoniana twig litter was fluctuantly in the July.