Impacts of winter feeding of reindeer on vegetation and soil in the sub-Arctic: insights from a feeding experiment

Figures & data

Fig. 1  Location of the reindeer winter feeding experiment in the Hammastunturi herding cooperative (circle) and of the weather station in Saariselkä (star). In the upper map, the reindeer herding area in Finland is indicated in black.

Table 1 The results of the analysis of grass silage produced in summer 2008 and 2009 and pellets used in the reindeer feeding experiment. The analysis was carried out by Viljavuuspalvelu Ltd. (Mikkeli, Finland).

Parameter	Grass silage 2008	Grass silage 2009	Tähti-Poro Artic pellets	Tähti-Poro 2 Balans pellets
Dry weight (%)	20.4	24.8	87.0	87.2
Crude protein (%)^a	14.5	16.2	11.4	11.5
Raw fibre (%)	31.2	25.7	11.3	10.8
Ca (p/kg)^a	5.5	4.6	13	12
P g/kg^a	3.1	2.8	4.0	4.4
Mg g/kg^a	2.7	3.0	3.9	3.8
K g/kg^a	18	29	8.8	8.6
Na g/kg	0.21	0.21	1.8	2.6
Cu mg/kg^a	8.1	5.3	21	19
Mn mg/kg			76	86
Zn mg/kg^a	33	34	110	120
Fe mg/kg	88	63	170	190
Total content of bacteria cfu/g	530 000		2100	<1000
Ca/P	1.8	1.7	0.2	0.2
Yeast content cfu/g	77000		<100	<100
pH		3.9
Sugar %		8.4

^aAnalysis in accordance with Finnish Accreditation Service standard ISO/IEC 17025.

Fig. 2  The mean (with standard error) coverage (%) of (a) faeces and (b) uneaten grass silage+hay in the feeding experiment after the first winter (2009) and the second (2010), n=10 plots per feeding practice.

Fig. 3  The mean (with standard error) coverage (%) of (a) Empetrum nigrum, (b) Calluna vulgaris, (c) Vaccinium myrtillus, (d) Vaccinium vitis-idaea and (e) Deschampsia flexuosa in the field layer, and (f) all mosses and hepatics, (g) Pleurozium schreberi, (h) Dicranum sp. and (i) all lichens in the ground layer of a sub-xeric heath forest before the feeding experiment was started (2008), after the first winter (2009) and the second (2010). The figures for 2008 are starting means, and those for 2009 and 2010 covariate-adjusted means (2008 values as a covariate) for feeding practices. The different letters denote differences between the feeding practices at significance level P=0.05, n=10 plots per feeding practice.

Table 2 F-tests of the effects of feeding practice (10 plots per feeding practice) and the year 2008 (data measured before the experiment was established) on the species coverage in the ground and field layer of the sub-xeric heath type forest after two winters of experimental feeding of reindeer in 2010.

	Feeding practice		2008 (covariate)
	F	Significance	F	Significance
Field layer
Empetrum nigrum	5.26	0.002	199.90	<0.0001
Calluna vulgaris	5.63	0.001	1510.28	<0.0001
Vaccinium myrtillus	1.20	0.323	108.96	<0.0001
V. vitis-idaea	2.36	0.068	4.63	0.037
Deschampsia flexuosa	8.70	<0.0001	142.24	<0.0001
Ground layer
Mosses and hepatics	9.03	<0.0001	20.57	<0.0001
Pleurozium schreberi	3.45	0.016	211.84	<0.0001
Dicranum sp.	5.44	0.001	123.15	<0.0001
Lichens	3.75	0.010	39.02	<0.0001

Fig. 4  Mean (with standard error) N concentration (%) in leaves of (a) Empetrum nigrum and (b) Vaccinium vitis-idaea, and (c) C/N of soil on the plots in the sub-xeric heath forest before the feeding experiment was started (2008), after the first winter (2009) and after the second (2010). The figures for 2008 are starting means, and those for 2009 and 2010 covariate-adjusted means (2008 values as a covariate) for feeding practices. The different letters denote differences between the feeding practices at significance level P=0.05, n=10 plots per feeding practice.

Table 3 F-tests of the effects of feeding practice (10 plots per feeding practice) and year 2008 (data measured before the experiment was established) on N concentration (%) and C/N in E. nigrum, V. myrtillus and soil, and soil pH after two winters of experimental feeding of reindeer in 2010, as well as the multiple comparisons (Tukey–Kramer method) of the covariate-adjusted feeding practice means.

	Feeding practice		2008 (covariate)		Covariate-adjusted feeding practice means (standard error) 2010
	F	Significance	F	Significance	Control (fenced)	Control	Grass silage+hay, not cleared	Grass silage+hay, cleared	Pellets
E. nigrum
N	9.94	<0.0001	0.29	0.591	1.26 (0.03)^a	1.31 (0.03)^a	1.47 (0.03)^b	1.44 (0.03)^b	1.36 (0.03)^ab
C/N	10.84	<0.0001	0.45	0.506	43.99 (0.85)^a	42.42 (0.85)^a	37.28 (0.84)^bc	38.4 (0.84)^b	40.76 (0.84)^ab
V. myrtillus
N	6.14	0.0005	4.96	0.031	1.46 (0.05)^a	1.49 (0.04)^a	1.68 (0.04)^b	1.57 (0.04)^ab	1.70 (0.04)b
C/N	6.90	0.0002	7.80	0.008	36.16 (0.95)^a	35.00 (0.83)^a	31.34 (0.83)^b	33.40 (0.87)^ab	30.79 (0.84)^b
Soil
N	0.38	0.818	0.94	0.339	0.068 (0.01)	0.064 (0.01)	0.075 (0.01)	0.066 (0.01)	0.069 (0.01)
C/N	2.69	0.044	0.07	0.793	23.87 (1.50)^a	19.34 (1.50)^ab	21.90 (1.50)^ab	17.40 (1.54)^b	19.68 (1.60)^ab
Ph	1.03	0.403	3.18	0.082	4.61 (0.10)	4.75 (0.10)	4.66 (0.10)	4.87 (0.10)	4.68 (0.10)

^a,b,cDifferences between the feeding practices at significance level P= 0.05.