Response Of Soil Faunal Community To Undergrowth Vegetation Removing And Different Fertilizing Modes In The Poplar Plantations In A Coastal Area Of Northern Jiangsu Province

Soil fauna is an important biological component in forest ecosystem. In order to explorethe response of soil faunal community to different fertilizing modes and undergrowth vegetationremoving, we selected different age poplar plantations in a coastal area of northern Jiangsu as theexperimental sites. The results indicate that:1. There were113994in total soil fauna found in the investigation, which belonged to3phyla,9classes and23orders.The dominanted groups were Oribatida and Prostigmata, thecommon ordinary group was Isoptera. A significant difference of soil fauna density (P<0.05)was observed in the three sites, while the taxonomic group number of soil fauna was notsignificant (P>0.05). The order of soil fauna density was4-years old poplar plantation,9-yearsold poplar plantation,20-years old poplar plantation. The dominant groups and ordinary groupsof soil faunal community were differnent across the different age Poplar plantations. Thedominant groups of4-years poplar plantation were Oribatida, Prostigmata, Orthoptera, andCollembola; the dominant groups of9-years old poplar plantation were Oribatida andProstigmata; the dominant groups of20-years poplar plantation were Oribatida, Prostigmata, andDipetera. The individual density and taxonomic number of soil fauna in0-20cm soil layer weresignificantly higher (P<0.05) than in litter layer in different age poplar plantations. Thediversity index of soil fauna was not significant (P>0.05) among different age poplar plantationsand different seasons. Jaccard index of soil fauna communities varied according to the changedseasons among different age poplar plantations.2. The significant difference(P<0.05) of soil fauna density was observed in differentfertilization treatments of different age poplar plantations, while the taxonomic group number ofsoil fauna was not significant (P>0.05).Under the same fertilization treatments, the effect of soilfauna individual density and group number in different concentration of different age poplarplantations were different. Application of organic fertilizer in poplar plantations could increasethe density and group number of soil fauna. Moderate NPK fertilizer would help the soil faunasurvive, but high concentration of NPK fertilizer was unsuitable to soil fauna breeding, contrary,would inhibit the soil fauna breeding.3. The density of soil fauna decreased significantly(P<0.05) after herb removed in poplarplantations of different ages. There were significant differences(P<0.05)in soil fauna densityand diversity index between undergrowth vegetation removing treatment and control check indifferent age poplar plantations. Among them, there were not significant difference(P>0.05)indensity and diversity index of soil fauna in spring between herb removal treatment and controlcheck in4-years old poplar plantation; there were not significant difference(P>0.05)in soil faunadensity in summer between herb removal treatment and control check in9-years old poplar plantation; there were not significant difference(P>0.05)in soil fauna diversity index in springbetween herb removal treatment and control check in20-years old poplar plantation.