Table 3 Average sensitivity scores of explanatory variables relative to the observed percentage of sanitary felling due to Ips typographus infestation (relative to total spruce volume in a stand) during 1998–2004

Explanatory variables

Source

1998

1999

2000

2001

2002

2003

2004

Mean age of spruce

Forest management plans

2.102

1.228

1.203

1.198

1.189

1.123

1.910

Spruce proportion

1.952

1.895

1.918

1.165

2.001

2.101

1.107

No. of vertical layers

1.187

1.067

0.999

1.110

1.000

1.150

1.201

Mean stands density

1.036

1.150

0.999

1.110

1.164

1.205

1.110

Mean stand DBH

1.052

1.010

0.997

1.033

1.110

1.100

1.091

Spruce volume

1.179

1.455

1.033

1.110

1.179

1.411

1.050

Proportion of broadleaved

1.178

1.219

1.034

1.218

1.174

1.530

1.019

Elevation

Digital elevation model

1.163

1.000

1.000

1.003

1.188

1.010

1.114

Terrain slope

0.999

1.160

1.039

1.067

1.150

1.001

1.110

Terrain aspect

1.051

1.109

1.102

1.053

1.010

1.080

1.000

Potential solar irradiation

1.111

1.000

1.169

1.000

1.003

1.032

1.110

Stand radiation regime

Forest typology maps

1.003

1.000

1.051

1.129

1.174

1.211

0.999

Stand water regime

1.155

1.036

0.988

1.133

1.010

1.110

0.996