Silva Fennica

Fig. 1. The nine planting sites of the study located in western Finland, five of them too close to be distinguished on the map. The coordinates of the study area are 60°41’52”N–61°59’38”N and 21°36’24”E–23°48’49”E. The map was created using ArcGIS Pro (version 3.1.0) software.

Table 1. Information on the planting sites of the study (1–9). The topsoil stoniness class (soil stoniness) of the site was visually determined as being either stoneless, normal, or stony.
Site	Area (ha)	Soil class¹	Site class²	Soil stoniness	Slash harvested (yes/no)	Stumps harvested (yes/no)	Seedlings planted (pcs)	Planting density (pcs ha^–1)
1	3.7	P	VT	Stoneless	No	No	6736	1821
2	1.6	M	MT	Stony	No	No	2626	1641
3	5.6	M	MT	Normal	Yes	No	10 444	1865
4	7.9	M	MT	Normal	Yes	No	14 495	1835
5	3.5	M	MT	Normal	Yes	No	5743	1641
6	4.6	M	MT	Normal	Yes	No	7882	1713
7	7.2	M	MT	Normal	Yes	No	12 269	1704
8	3.0	M	OMT	Normal	Yes	Yes	5406	1802
9	3.5	M	MT	Normal	Yes	No	6302	1801
Total	40.6						71 903
Average	4.5							1771
¹Soil class: P = peatland, M = mineral soil. ²Site class according to Cajander (1926): VT = Vaccinium vitis-idaea type (sub-xeric heath forests), MT = Vaccinium myrtillus type (mesic heath forests), OMT = Oxalis–Myrtillus type (herb-rich heath forests).

Table 2. Productivity levels of mounding and MECP (ha G₁₅-h^–1, including short [<15 min] delays) and the machine utilization rates used in the cost analysis of the study. The life spans of the base machines and devices are also given, as well as the total annual work time, operating working hours, and silvicultural use.
Variable	Base machine
	Excavator (17 t)	Forwarder (18 t)	Excavator (17 t)
	Device
	Mounding bucket	Mounder	Planting device
	Mounding bucket	Bracke M24.a	Risutec PM-160
Productivity (ha G₁₅-h^–1)	0.167^ab	0.900^b	0.119^c
Machine utilization rate (%)	85^d	85^d	80
Life span (h)
Base machine	12 000^d	12 000^d	12 000^d
Device	7500^d	7500^d	7500^d
Worktime (h yr^–1)
Total	2220	2220	2136
Silvicultural	1332	1332	1080
Operating hours (G₁₅-hyr^–1)
Total	1887	1887	1709
Silvicultural	1132	1132	864
Silvicultural use (ha yr^–1)	189	1019	103
^a Saksa et al. (2002). ^b Saarinen (2006). ^cThe productivity of the MECP was based on the results of this study. ^d Same value as used in the studies by Strandström et al. (2011) and Hallongren et al. (2014).

Table 3. Fixed and variable costs and other main parameters of the cost analysis of the study.
Variable	Base machine
	Excavator (17 t)	Forwarder (18 t)	Excavator (17 t)
	Device
	Mounding bucket	Mounder	Planting device
	Mounding bucket	Bracke M24.a	Risutec PM-160
Purchase price (€)
Base machine	179 000	350 000	179 000
Device	5000	130 000	60 000
Annual depreciation (%)
Base machine	15	15	15
Device	40	40	40
Interest rate (%)	5	5	5
Storage costs (€ yr^–1)	1058	1410	1058
Insurance costs (€ yr^–1)	900	1800	900
Administration costs (€ yr^–1)	8000	8000	8000
Maintenance supplies (€ yr^–1)	747	747	1121
Maintenance costs (€ yr^–1)	5520	14 400	7170
Labor costs
Hourly wages (€ h^–1)	16.18	16.18	16.18
Indirect wage cost (%)	55	55	55
Kilometer allowance (€ km^–1)	0.57	0.57	0.67
Fuel and lubrication costs
Fuel consumption (l h^–1)	9	17	9
Fuel price (€ l^–1)	1.25	1.25	1.25
Lubricant consumption (l h^–1)	0.2	0.2	0.2
Lubrication price (€ l^–1)	3.6	3.6	3.6
Relocation costs (€ km^–1)	2.35^a	2.35^a	2.35^a
^aAhtikoski et al. (2024).

Table 4. Average loading time consumption of the seedling cassette by site (1–9) and average of all loading times in the study. The seedling cassette of the Risutec PM-160 was loaded with 160 seedlings at a time.
Loading time	Site number									Average
Loading time	1	2	3	4	5	6	7	8	9	Average
min.s	11.34	9.29	8.30	8.39	10.17	12.38	10.15	10.54	10.57	10.08

Fig. 2. Distribution of the seedling cassette loading times, with 371 loading time observations included in the final data of this study.

Fig. 3. Distribution of the planting times based on the data from this study.

Fig. 4. Operating hour productivity (seedlings G_15-h^–1, including short [<15 min] delays) and standard deviation of operating hour productivity by planting site (1–9) of the study.

Fig. 5. Relative hectare-based costs of each planting chain (EXC + MAP = excavator-based mounding and manual planting; CONT + MAP = continuously advancing mounding and manual planting; MECP = excavator-based mechanized planting). The operating costs of EXC + MAP are given as 100%, with the costs of the other planting chains being proportional to EXC + MAP.

Table 5. Effect of the purchase price of the MECP base machine on the relative hectare-based costs (100 = EXC + MAP) when the price changed by ±15%, ±25%, and ±35% in the sensitivity analysis of the study. For each price category of the base machine, the minimum productivity required for MECP to be a competitive option for planting is given.
Price change	Purchase price	Relative cost	Requested productivity
(%)	(€)	Relative cost	(ha G₁₅-h⁻¹)	(seedlings G₁₅-h⁻¹)
–35	116 350	88	0.105	189
–25	134 250	90	0.107	193
–15	152 150	92	0.109	196
0	179 000	95	0.112	202
15	205 850	98	0.117	211
25	223 750	100	0.119	214
35	241 650	102	0.121	218