Spacial pattern and sampling techniques of Geranium carolinianum Linn.in the rape field
Investigation on 36 kinds of rape field has been conducted.Five aggregation indices test show that the dominant spacial pattern of Geranium carolinianum Linn.is aggregated distribution,and random distribution exists in the low density fields.Regression analysis indicates that this two kinds of distribution pattern depend on the plant density,and suggesting the suitable sampling techniques are "five points"and "Z"shape sampling.The theoretical sampling number is also presented under different densities.