Stoichiometry of microbial indicators shows clearly more soil responses to land cover changes than absolute microbial activities

摘要: Abstract Land cover changes are recognized to affect the organic matter fractions and other soil properties with a consequence for microbial enzyme activities involved in nutrient cycling. The topsoil (0–10 cm depth) C, N, P [i.e., basal respiration (BR), substrate inducted (SIR), biomass-C, -N, -P (MBC, MBN MBP)] ratios, (i.e., urease, invertase, acid phosphatase arylsulfatase) activities, as well of particulate (POC PON) dissolved (DOC DON) were measured virgin natural forest dominated by Carpinus betulus Parrotia persica (natural forest), mono-species Quercus castaneifolia stand (plantation), land including Citrus sinensis tangerina trees (garden), Brachypodium pinnatum Carex sylvatica (rangeland) rice cultivation (agriculture), following 32 years changes, located northern Iran. results showed that MBN, MBP, PON, DON significantly higher under site, while plantation enhanced BR, DOC, MBC/Corg, POC/PON, DOC/DON. planting preservation increased amounts SIR, MBC, POC, BR/MBC, BR/SIR comparison studied covers. Although decreased MBC/MBN MBC/MBP indicators, maximum values geometric mean (GME) urease/Corg, phosphatase/Corg, arylsulfatase/Corg, invertase/Corg, urease/MBC, phosphatase/MBC, arylsulfatase/MBC stand. There no significant differences (p > 0.05) MBN/MBP ratio, Shannon's diversity index (H′) invertase/MBC among ecosystems anthropogenic sites. Based on PCA, followed tree presented good conditions fertility activities. While these characters mostly suppressed non-forest As conclusion, ecological stoichiometry indicators reveals clearly more responses than absolute which can be used measure long-term variations topsoil.