Symposium on wild forest mushrooms and other NTFPs: Innovations and perspectives
27-28 August 2014
La Pocatière (QC), Canada
Predicting the yields of commercially
important mushrooms in Finland
Veera Tahvanainen, Mikko Kurttila, Jari Miina & Kauko Salo
Contents
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Mushrooms as NWFPs in Finland
Sample plots for mushroom yields
Yields of commercially important mushrooms
Expert and empirical models for Boletus edulis yields
A challenge of predicting the yields of Boletus edulis
Conclusions
More information (in Finnish): Miina, J., Kurttila, M. & Salo, K. 2013.
Kauppasienisadot itäsuomalaisissa kuusikoissa – koealaverkosto ja tuloksia vuosilta
2010–2012 http://www.metla.fi/julkaisut/workingpapers/2013/mwp266.htm
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Mushrooms in Finland - underutilized forest
resource
The forest mushrooms:
• Forest cover: 76 % of the land area,
some 23 million hectares
• Grows naturally (not cultivated)
• About 200 edible species
• 31 species listed as commercial
mushrooms -> 10 species commonly
marketed
• Less than 1 % of biological yield
collected
• NWFPs not considered in forest
management decisions
Picture: Satu Sivonen
Markets for NWFPs
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Everyman's rights allow the picking of NWFPs
Selling of NWFPs taxfree for the pickers
Low value-added: exported and sold fresh or frozen
In Finland, the value of commercial NWFPs picking (berries and mushrooms) is
about 1% of the value of wood from forests
• 6 million kg of mushrooms picked by Finnish households in year 2011 (12 % for
sale)
Amounts (1000 kg a-1) of mushrooms bought by organised trade and industry
1997-2013
1400
1200
1000
800
Boletes
600
Milk caps
400
200
0
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
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Sample plot network in Eastern Finland
40
35
Stand basal area, m2ha-1
• 52 mushroom sample plots
(20 x 20 m)
• Mainly in middle-aged,
planted spruce stands
• Stand and ground cover
characteristics were
measured from the sample
plots
• Commercial mushroom
yields inventoried during 4
seasons
30
25
20
15
10
No thinnings
Thinned before
establishment
Thinned after establishment
5
0
0
10
20
30 40 50 60
Stand age, years
70
80
90
5
Yields (kg/ha/a) of commercial mushrooms
Mushroom species
Mean
Std dev.
Min.
Max.
Boletus edulis
6.1
7.4
0.0
30.0
Suillus variegatus
0.1
0.3
0.0
1.8
Leccinum versipelle
2.5
5.6
0.0
24.2
Boletus pinophilus
0.0
0.0
0.0
0.0
Leccinum vulpinum
0.1
0.4
0.0
2.8
Lactarius trivialis
8.2
10.2
0.0
55.3
Lactarius rufus
8.7
23.9
0.0
170.3
Lactarius torminosus
0.4
1.1
0.0
4.2
Russula paludosa
2.3
6.6
0.0
35.3
Russula decolorans
0.1
0.1
0.0
0.7
Russula claroflava
0.2
0.6
0.0
3.8
Russula vinosa
1.1
2.2
0.0
14.3
Rozites caperatus
0.2
0.4
0.0
2.3
Cantharellus cibarius
0.4
1.6
0.0
10.4
Albatrellus ovinus
0.0
0.2
0.0
1.7
Craterellus cornucopioides
0.0
0.0
0.0
0.0
Hygrophorus camarophyllus
0.0
0.0
0.0
0.0
Cantharellus tubaeformis
0.1
0.8
0.0
5.6
Hydnum repandum
0.0
0.3
0.0
2.1
30.6
27.6
4.0
178.7
All edible mushrooms
Yields of Milk
caps and
Boletes are the
highest!
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Value (€/ha/a) of commercial mushrooms
Mushroom
species
Boletus edulis
Other boletes
Lactarius trivialis
Other milkcaps
Russulas
Other edible
mushrooms
All edible
mushrooms
Mean
Std dev.
Min.
Max.
22.2
26.7
0.0
108.8
3.5
7.5
0.0
32.5
16.3
20.2
0.0
109.6
11.9
31.1
0.0
221.3
4.8
9.1
0.0
47.0
2.7
8.7
0.0
54.5
61.4
48.3
10.4
235.7
Boletus edulis
1/3 of total
value!
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Mean annual yield and income from the sale of
mushrooms by stand age classes
Yields are
decreasing
with age
Highest
yields in
young spruce
forests
(20-40 years)
High annual
variation
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Empirical and expert model for Boletus edulis
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25 sample plots photographed for expert modelling
25 forest and mushroom experts evaluating the goodness of the stands for Boletus
edulis production using pairwise comparison method (Saaty 1980)
Empirical Boletus edulis yields and priorities calculated from expert evaluations for
Boletus edulis yields were regressed with the stand and site characteristics using
regression method
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The effect of stand basal area on the development of
Boletus edulis yields: empirical and expert model
Number of Boletus/sample
plot
3,500
Priority
0,044
3,450
0,042
3,400
0,040
3,350
3,300
0,038
3,250
0,036
3,200
3,150
0,034
3,100
0,032
3,050
0,030
3,000
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9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
Stand basal area, m2ha-1
expert opinion on yields
empirical yields
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A challenge of predicting the yields of Boletus edulis
Challenges
• High annual variation in mushroom yields
• Many unknown and yet unmeasured factors affecting the yields: biotic
and abiotic
• Complex and inadequately known ecology of the mushroom species
(Boletus edulis)
Empirical modelling
– Environmental factors such as precipitation and temperature should
be included in the analyses
– Long time series of mushroom yields is essential
Expert modelling
– Some problems of empirical modelling could be avoided
– Sample plots should be more representative to distinquish the
differencies between the sites
– Competent experts and method of comparing sites
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Conclusions
• Spruce stands produce high amounts of commercial mushrooms
– Between-year variation in the yields is a problem for commercial
utilization
– The effect of forest management still unknown -> Long-term
monitoring of experimental plots is needed
• Including mushroom yields in forest management planning systems
would promote the joint production of timber and mushrooms
– The yields of commercially important mushrooms do not seem to
be in a highly competitive relationship with timber production
-> small changes in management of the most productive spruce
stands for the benefit of mushroom yields could be done without
causing dramatic changes in timber production
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Thank you
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