Soil microarthropod-plant community relationships in alpine moss- sedge heath

- Data on Oribatida, Prostigmata, Mesostigmata & Collembola in alpine moss-sedge heath.
- The relationship between the plant community and soil microarthropods was studied.
- We found a strong relationship between the plant and the microarthropod community.
- Relationship with plant community strongest for herbivores/fungivores/detritivores.
- Relationship stronger with plant composition than plant growth form or chemistry.

Above-ground vegetation has long been acknowledged as an important driver of below-ground decomposer communities. Here we compare the relationship between the plant community and four microarthropod groups (oribatid, mesostigmatic and prostigmatic mites and Collembola) in alpine moss-sedge heath. We assess the relative importance of plant growth forms (PGF), mean vegetation chemistry and plant community composition in influencing the microarthropod community composition. Microarthropod and plant community composition was recorded at 15 alpine Racomitrium lanuginosum heath sites in the UK. The correlation between the microarthropod community and the plant community was 0.76, 0.44, 0.34 and 0.59 for Oribatida, Prostigmata, Mesostigmata and Collembola, respectively (Procrustes analysis). Plant species composition was more important in determining community composition for microarthropods that are herbivores/fungivores/detritivores (Oribatida and Prostigmata and Collembola) than PGF or vegetation chemistry. Predatory microarthropods (Mesostigmata) were influenced by PGF, but not plant species composition or vegetation chemistry. This may reflect the importance of physical habitat structure for these species. We conclude that there is a strong relationship between the plant community composition and the soil microarthropod community but measures such as PGF or mean vegetation chemistry are too coarse to be useful in predicting the microarthropod community composition, because mites respond strongly to heterogeneity between plant species.