Table 2. Mean heights (cm) of planted Norway spruce (Ns), Scots pine (Sp) and Lodgepole pine (Lp) seedlings following each mechanical site preparation method (MSP) and No MSP, in field experiments and survey studies obtained 3–27 growing seasons after planting. The character ~ indicates values estimated from a diagram and * in ”No MSP” that statistical analysis was reported in that study. Bold values indicate a statistically significant difference from the control (“No MSP”) and values in brackets show differences in percentage relative to “No MSP”. In most experiments, the planted seedlings were protected by an insecticide to reduce pine weevil (Hylobius abietis L.) damage. In the experiments where both protected and unprotected seedlings were planted values are shown for both types.
Tree species Years after planting Latitude
(°N) 		Altitude
(m a.s.l.) 		Temp. sum (d.d. °C) Height (cm) by MSP-method No. of
sites 		Reference
No MSP Patch scarification Disc trenching Mounding Soil inversion Ploughing
Experiments
Ns2 3 60 200 1116 34* 46 (+35) 46 (+35) 1 Brække et al. (1986)
Ns2 3 60 160 1189 ~40 ~48 (+20) 1 Fløistad et al. (2007)
Ns1, 2 3 56–57 150 1384 ~572
~361 		~622 (+9) ~511 (+42) 4 Petersson and Örlander (2003)
Ns2 3 62–63 ~140 1165 46 48 (+4) 46 (±0) 2 Heiskanen et al. (2013)
Ns2 5 56–57 180–250 1329 117 126 (+8) 4 Nilsson and Örlander (1999b)
Ns1 5–6 59–61 80–450 947 ~60 ~64 (+7) 3 Hine (1988)
Ns2 6 60–61 430–620 853 ~58* ~66 (+14) ~72 (+24) 8 Granhus et al. (2003)
Ns2 7 56–57 130–190 1375 146* 166 (+14) 179 (+23) 2 Hjelm, pers. comm. (2017)
Ns2 7 57–58 200 1282 ~1501
~1302 		~1701 (+13) ~1502 (+15) 2
1 		Thorsén et al. (2001)
Ns1 7 62 ~140 1060 68 110 1 Uotila et al. (2010)
Ns1 8 65 480 467 34 51 (+50) 1 Bergan (1990)
Ns2 10 64 275–310 814 ~80* ~145 (+81) ~140 (+75) ~210 (+162) ~165 (+106) 1 Örlander et al. (1998)
Ns1 10 56–57 170–180 1363 ~150 ~270 2 Örlander et al. (2002)
Ns1 12 61 50 1121 ~82* ~117 (+43) 1 Hine (1988)
Ns2 18 64.5 410 683 230 324 (+41) 320 (+39) 8 Johansson et al. (2013a)
Ns2 18 57 215 1287 822 830 (+1) 789 (–4) 2 Johansson et al. (2013a)
Sp2 5 60 150 1172 88* 113 (+28) 1 Johansson et al. (2013b)
Sp2 5 57 200 1312 111* 138 (+24) 1 Johansson et al. (2013b)
Sp1 10 56–57 170–180 1329 ~345 ~395 1 Örlander et al. (2002)
Sp3 18 67 440 507 242* 267 (+10) 303 (+25) 1 Hansson and Karlman (1997)
Sp3 25–27 66–68 180–290 783 591 574 613 8 Mäkitalo et al. (2010)
Lp2 10 64 275–310 814 ~200*   ~265 (+32) ~250 (+25) ~320 (+60) ~280 (+40) 1 Örlander et al. (1998)
Lp1 10 56–57 170–180 1363   ~205       ~370 1 Örlander et al. (2002)
Lp1,2 17 62 370–420 847 320   410 (+28) 430 (+34)   510 (+59) 3 Mattson and Bergsten (2003)
Lp3 18 67 440 507 258* 328 (+27)   360 (+40)     1 Hansson and Karlman (1997)
Surveys
Ns2 3 60–64 20–300 –   53 52 56     1591 Saksa and Kankaanhuhta (2007)
Ns1 4 61–63 90–140 –     33 46     2 Luoranen et al. (2006)
Ns3 4 62 ~140 –   66 64 71     24 Saksa (2011)
Ns3 9 61–63 90–140 –     166 215     22 Saksa et al. (2005)
Ns3 10 62–67 – –     196 196     23 Söderbäck (2012)
Sp3 10 62–67 – –     247 247     31 Söderbäck (2012)
Lp3 10 62–67 – –       286     5 Söderbäck (2012)
1 Seedlings not treated with an insecticide.
2 Seedlings treated with an insecticide.
3 No information given about whether seedlings were treated with an insecticide. Seedlings were probably not treated.