Semi-variance analysis of A. ordosica populations in the sample plots.

Note: Sill: The semivariance value at which the variogram levels off. Range: The lag distance at which the semivariogram (or semivariogram component) reaches the sill value. Presumably, autocorrelation is essentially zero beyond the range. Nugget: The nugget represents variability at distances smaller than the typical sample spacing, including measurement error. The spherical model actually reaches the specified sill value, at the specified range. The exponential and Gaussian approach the sill asymptotically, with the practical range, the distance at which the semivariance reaches 95% of the sill value.Semi-variance analysis of A. ordosica populations in the sample plots.