Table 2. Independent variables explaining the occurrence of wetland conversion for four different data sets.

	Data set 1		Data set 2		Data set 3		Data set 4
Selection method:	Back	For	Back	For	Back	For	Back	For
Slope
Temperature	+	+	+	+	+	+	+	+
Precipitation
Market influence	+	+	+	+	+	+	+	+
Population density							+
Built-up area	+	+	+		+	+
Distance to roads
Wetland area	-	-	-	-	-	-	-	-
Cropland area			+	+	+	+
Organic content
Regulatory Quality
ROC	0.908	0.908	0.884	0.880	0.905	0.905	0.908	0.887

The sign of each significant variable is indicated with ‘+’ and ‘-‘. Back = backward selection method and For = forward selection method (Probability for stepwise selection: P_in=0.01, P_out=0.02).