Scale-Location Dependence Relationship between Soil Organic Matter and Environmental Factors by Anisotropy Analysis and Multiple Wavelet Coherence

Soil organic matter (SOM) and environmental factors have been shown to a scale-location dependence relationship. However, few studies considered the anisotropy, relationship may not be fully characterized. In this study, transects with dominant directions of SOM variability in dryland farming regions Songliao Plain, China were extracted by anisotropy analysis. The specific multivariate relationships between along two examined using multiple wavelet coherence. Results indicated that scale location-specific variations direction-specific. major direction most significant was 56° east north, while minor perpendicular direction. strongest single factor for explaining differed directions, sand (average coherence (AWC) = 0.57, percentage area (PASC) 40.32% at all scales) bulk density (BD) (AWC 0.66, PASC 50.16% scales). combination mean annual temperature (MAT) BD best explain 0.78, 46.23% A two-factor is adequate direction, whereas sufficient explanation More did evidently increase or even decrease domains where significantly explained. This work has important implications developing future sampling strategies preparing detailed digital soil maps.