Influence Of Soil Fauna To Litter Decomposition In Central Guizhou Karst Forest

To reveal the role of soil fauna in litter decomposition in karst forests,deepen the understanding of nutrients recycling in the plant-soil system in the ecologically fragile karst region.A two-year field litterbag experiment,with local dominant herbaceous and woody species litter,i.e.,Imperata cylindrica(IC),Platycarya longipes(PL),and Cladrastis platycarpa(CP),was carried out to study the influence of different groups of soil fauna to litter decomposition,based on random forest model.(1)Results showed that a total of 35033 individuals of soil fauna,which belonged to 24 groups,were captured in litterbags.Acarina and Collembola were the dominant groups.Random forest model identified that Prostigmata,Entomobryomorpha,Araneae,Lepidoptera larva,Neelipleona,Mesostigmata,Oribatida,Symphypleona,Pseudoscorpiones,Scolopendrelidae,Hymenoptera played a vital role in litter decomposition in central Guizhou karst forests.(2)Total organic carbon,total potassium content and C/N ratio decreased,while total nitrogen,total phosphorus and total calcium content increased.The release of each element under the action of soil fauna was promoted,and the promoting effect of macrofauna on the release of elements was greater than that of meso-,and micro-fauna.(3)On average,soil fauna contributes 21.56% to forest litter decomposition,of which the contribution rate of meso-,and micro-fauna to litter decomposition was 11.71%,higher than that of macrofauna(9.85%),Soil fauna mainly contributed to litter mass loss in the early stage of decomposition..In the central Guizhou karst forest,soil fauna had a positive effect on litter decomposition,especially in the early stage of decomposition.The promoting effect of macrofauna on element release was obvious.