Soil nematode communities as indicators of soil health in different land use types in tropical area

The study of soil nematode communities is a powerful tool that has been widely used as an indicator of soil health. This study explored whether soil nematode composition of different land use types could be used as a baseline to indicate the soil health of both natural and anthropogenic ecosystems. The soil nematode community compositions were documented for five land use types in tropical China: bare land, secondary forest, old forest, eucalyptus plantation and litchi orchards. The first three land use types are natural ecosystems and considered as a vegetation succession, whereas the other two are anthropogenically managed ecosystems. The vegetation succession from bare land to secondary and old forests increased soil nematode abundance, diversity, diversity-weighted abundance and complexity of community structure. During the wet season, the abundances of the total nematodes, bacterivores. fungivores and herbivores were significantly lower in eucalyptus plantation and litchi orchards than in secondary and old forests. but higher than in bare land. During the dry season. the abundances of the total nematodes and each trophic group were greatest in orchards. The pattern of the diversity-weighted abundance of each nematode trophic group was similar to that of nematode trophic group abundance. The results indicate that soil nematode communities of different land use types could be used for comparison of soil health conditions in natural and managed ecosystems. Particularly, the soil health conditions as indicated through nematode communities of the two managed ecosystems were not as good as those of secondary and old forests, whereas litchi orchards might have better soil health conditions than eucalyptus plantations in tropical China.