57
Factors Influencing Birch Sap Production in Alaskan Birch (Betula neoalaskana Sarg.) Kimberley Anne C. Maher UAF SNRAS

06 Factor Influence Birch Sap

Embed Size (px)

Citation preview

Page 1: 06 Factor Influence Birch Sap

Factors Influencing Birch Sap Production

in Alaskan Birch (Betula neoalaskana

Sarg.)

Kimberley Anne C. Maher

UAF SNRAS

Page 2: 06 Factor Influence Birch Sap

Everything you want to know

Korolyak, I.S. and R.I. Tomchuk. 1971. [Intensifyting sap extraction from birch trees]. Lesnoe Khozyaistvo. 5:34-36.

Mednikov, F.A. 1977. [Conference on the tapping of broadleaved species and processing the sap.]. Lesnoi Zhurnal. 6:162-3.

Page 3: 06 Factor Influence Birch Sap

Outline•Birch as a non-timber forest resource•Sap use in Alaska and elsewhere•Previous research

- Factors influencing sap production- Consequences to the tree from tapping

•Research conducted in Alaska•Future directions for research in Alaska

Page 4: 06 Factor Influence Birch Sap

Betula neoalaskana Sargent

•Formerly referred to as B. resinifera Regel•A Beringian species—most closely related to Asian species•Diploid

Page 5: 06 Factor Influence Birch Sap

Distribution of

Source: Flora of North America 1993+

B. papyrifera MarshallB. neoalaskana

Page 6: 06 Factor Influence Birch Sap

Non-timber Forest Products“all forest products except timber”

• Resins • Oils• Leaves • Bark

• Plants other than trees• Fungi• Animals or animal products

Page 7: 06 Factor Influence Birch Sap

Birch as a NTFP

Page 8: 06 Factor Influence Birch Sap

Birch Sap

• Harvested in spring• Similar to maple sap• Consumed as a tonic or processed

into syrup

Page 9: 06 Factor Influence Birch Sap

Birch sap harvest in Alaska• Main commercial use is to process into

birch syrup• 1992 Producers formed the Alaska Birch

Syrupmakers’ Association (ABSA)

Page 10: 06 Factor Influence Birch Sap

ABSA• “Coopertition” amongst member birch syrup

producers • Created a “Best Practices”

guide for tapping and syrup production

• Information and sales booth at Palmer State Fair

• Would like to develop syrup grading standards

Page 11: 06 Factor Influence Birch Sap

ABSA Best Practices for producing high quality birch syrup

• Tree tapping• Sap collection• Sap storage• Syrup production– reverse

osmosis• Syrup production– evaporator• Syrup finishing

Page 12: 06 Factor Influence Birch Sap

Growth of the Alaska Birch Syrup Industry

0123

4567

1989 1992 1995 1998 2001

year of syrup production

num

ber o

f com

pani

es

invo

lved

in s

yrup

po

rduc

tion

ABFC 2005

Page 13: 06 Factor Influence Birch Sap

Alaska syrup production

Year Number of companies producing

Estimated gallons of

syrup produced

2001 6 1400

2005 4 1500

ABFC 2005; Maher et al. 2005

Page 14: 06 Factor Influence Birch Sap

Birch sap utilization elsewhere

Three birch syrup producers in Canada (2 in British Columbia; 1 in Yukon)

Birch sap harvested, sold, and drank as health tonic in many Northern countries

Page 15: 06 Factor Influence Birch Sap

Birch sap tonic

Adapted from Terazawa 1995

Japan Korea China Finland Russia

Hypertension X X XUrinary problems X X X XGout X X X XDecreased work capacity X X X XGastritis X X X XKidney problem X X XScurvey X X X

Traditional medicine used in Northern countries

Page 16: 06 Factor Influence Birch Sap

Terazawa 1995

Page 17: 06 Factor Influence Birch Sap

Birch sap beverages

“Birch sap with sugar” contains11.5 % sugar and 0.4 % citric acid (Tomchuk et al. 1973)

“Forest drink” contains concentrated birch sap with cranberry juice (Telishevskyj 1970)

Page 18: 06 Factor Influence Birch Sap

Harvesting birch sap increases the value of a stand

• Tapping birch for 5-10 years before harvesting the trees can increase profit several times over the price of wood alone (Tomchuk et al. 1973)

• Profit from natural (fresh?) sap is 2 to 3 times that of the wood while the profit from preserved sap is 7 times that of the wood (Telisevskij 1970)

Page 19: 06 Factor Influence Birch Sap

Factors affecting sap yields

• Sap yields were virtually independent of tree age but were directly proportional to tree diameter (Davidov 1979)

Page 20: 06 Factor Influence Birch Sap

R2 = 0.9817

R2 = 0.9708

0

20

40

60

80

100

120

140

160

180

200

0 20 40 60 80

tree diameter (cm)

avera

ge p

rod

ucti

vit

y (

lite

rs)

B. platyphylla

B. costata

Tagiltsev et al 2005

Average sap productivity of birch species in Russian Far East

Page 21: 06 Factor Influence Birch Sap

Factors affecting sap yields

• Sap yields were virtually independent of tree age but were directly proportional to tree diameter (Davidov 1979)

• Air temperature and crown diameter were the most important factors affecting yield (Fesyuk 1980)

Page 22: 06 Factor Influence Birch Sap

Sap flow and temperatures

• At the beginning of the sap season, sap flow increases with increasing air temperatures

• At the end of the sap season, sap flow decreaseswith increasing air temperatures

• Sap flow has a closer correlation to soil temperature (15 cm depth) and bole temperature (sapwood portion)

(Ryabchuk 1974)

Page 23: 06 Factor Influence Birch Sap

Site conditions effects• Poorly drained bog sites produce more sap

than dry sites or higher elevation sites

• Sap from drier sites have higher sugar concentrations

(Telisevskij 1970)

Page 24: 06 Factor Influence Birch Sap

Effects of tapping on health of the tree• Tapped trees grow as well as trees that are not

tapped (Lahteenkorva 2005)

• Tapping causes a slight reduction in the current diameter increment compared to untapped trees Exception-- on two plots the diameter increment of the tapped trees were greater than that of the controls (Osipenko and Ryabchuk 1973)

• Tapping for 3 years does not alter the sugar content of the sap (Ryabchuk 1977)

• Tapping for 3-7 years did not have a significant effect in the phenology of the tree (Ryabchuk 1979)

Page 25: 06 Factor Influence Birch Sap

Ukrainian tree tapping guide

(Telisevskij 1970)

tree diameter (cm) # of taps

20-24 1

25-28 2

> 28 3

Page 26: 06 Factor Influence Birch Sap

Affects of multiple taps on sap sugar content

Sugar content tends to decrease with increasing tapping load (Ryabchuk 1977)

Page 27: 06 Factor Influence Birch Sap

Effects of a tap hole on wood discoloration• Wood changes color in the zone above and below the

tapping holes (Ryabchuk 1975)

• 1 meter of longitudinal discoloration (Dujesieken et al. 1989)

• Greatest color change is along the grain; much less in the radial direction, and minimal in the tangential direction holes (Ryabchuk 1975)

• Optical properties (wavelength, purity and brightness) of the discolored wood showed that the brightness of discolored wood was 15.1-20.2% lower than wood from untapped trees (Ryabchuk 1975)

• After the initial discoloration, the color characteristics of the wood did not change significantly (Ryabchuk 1975)

Page 28: 06 Factor Influence Birch Sap

Harvesting sap from stumps• Trees felled with an angle of 160-165 degrees

between the planes of the undercut and the main cut (Gavrilyuk et al. 1980; Osipenko and Ryabchuk 1975)

• Mean sugar content of stump sap and tree sap is almost identical (Ryabchuk 1977)

• Grooves can be cut on the stump surface to guide the sap flow (Gavrilyuk et al. 1980)

• Sap yield was greatest when the felling was done in mid March (Osipenko and Ryabchuk 1975)

Page 29: 06 Factor Influence Birch Sap

Sap research in Alaska• Examined sap harvest at different locales

• Compared sap production temporally

• Identified characteristics that indicate productive stands to tap

Page 30: 06 Factor Influence Birch Sap

Research design

•Three transects•Three sites per transect•Ten trees per site (n=90)•Two full seasons (’02 & ’03)•One preliminary season (one transect ’01)

Page 31: 06 Factor Influence Birch Sap

Sites Transects

Position on slope Ballaine Ester Murphy Dome

top Zachel Calypso Spinach Creek

mid Wood Via Frenchman

Bottom Pearl Creek Garner Moose Mountain

Research designTransects

Position on slope

Ballaine Ester Murphy Dome

top Zachel Calypso Spinach Creek

mid Wood Via Frenchman

bottom Pearl Creek Garner Moose Mountain

Z C SCW V FPC G MM

Page 32: 06 Factor Influence Birch Sap

Results: Vegetation•Closed Paper Birch Forest (AK Vegetation Classification, Viereck 1992)

•Common species include white spruce, apsen, balsam poplar, lingonberry, Labrador tea, prickly rose, twin flower, willow, alder, and lichens

Page 33: 06 Factor Influence Birch Sap

Daily maximum air temperatures for ’01, ’02, & ’03

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

25.0

29-Mar 3-Apr 8-Apr 13-Apr 18-Apr 23-Apr 28-Apr 3-May

date

degr

ees

C

2001

2002

2003

95-year meandaily maximumtemperature

Page 34: 06 Factor Influence Birch Sap

April Precipitation

year precip. (cm)2001 0.412002 7.772003 0.13

95 yr average 0.75 (s.d. 1.10)

Page 35: 06 Factor Influence Birch Sap

Results: Sap harvestYear Begin of flow End of sap collection Number of days

2001 April 19th May 8th 19

2002 April 30th May 17th 18

Year Begin of harvest

End of sap harvest

Number of days

2001 April 19th May 8th 19

2002 April 30th May 17th 18

2003 April 19th May 5th 16

Page 36: 06 Factor Influence Birch Sap

Sap harvest per site in ’02 & ’03

0

10

20

30

40

50

60

70

80

90

14-Apr 19-Apr 24-Apr 29-Apr 4-May 9-May 14-May 19-May

L s

ap

Z 2003

W 2003

PC 2003

C 2003

V 2003

G 2003

SC 2003

F 2003

MM 2003

Z 2002

W 2002

PC 2002

C 2002

V 2002

G 2002

SC 2002

Page 37: 06 Factor Influence Birch Sap

2001 Daily maximum air temperatures & sap harvest

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

29-Mar 8-Apr 18-Apr 28-Apr 8-May 18-May 28-May

date

degr

ees

C

-10

0

10

20

30

40

50

60

70

L sa

p

daily max temp

Zachel

Wood

Pearl Creek

Page 38: 06 Factor Influence Birch Sap

Results: Mean sap harvest per tree by site in 2002 & 2003

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Z W PC C V G SC F MM all

site

L sa

p 02 sap

03 sap

Z C SCW V FPC G MM

Page 39: 06 Factor Influence Birch Sap

Results: Average sugar concentration by site in ’02 & ’03

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Z W PC C V G SC F MM

degr

ees

BR

IX

2002

2003

Z C SCW V FPC G MM

Page 40: 06 Factor Influence Birch Sap

Daily Maximum air temperatures for ’76 & ’77

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

25.0

30.0

29-Mar 8-Apr 18-Apr 28-Apr 8-May 18-May 28-May

date

degr

ees

C

1976

1977

95-year meandailytemperature

Page 41: 06 Factor Influence Birch Sap

Distribution of total sap harvest per tree in 2002 & 2003

0

5

10

15

20

25

30

35

40

0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90-99

Sap production per tree (L)

per c

ent o

f tre

es

2002

2003

Page 42: 06 Factor Influence Birch Sap

2002 Mean liters of sap harvested per tree from each site

Sites Transects

Position on slope

Ballaine Ester Murphy Dome

top 23.7 (Z)s.d 9.6

30.7 (C)s.d. 11.9

39.3 (SC)s.d. 13.2

mid 32.3 (W)s.d. 11.7

30.0 (V)s.d. 14.1

31.0 (F)s.d. 13.2

bottom 46.9 (PC)s.d. 16.2

42.3 (G)s.d. 20.9

31.3 (MM)s.d. 13.3

Transects

Position on slope

Ballaine Ester Murphy Dome

top23.7 (Z)

s.d 9.630.7 (C)s.d. 11.9

39.3 (SC)s.d. 13.2

mid32.3 (W)

s.d. 11.730.0 (V)s.d. 14.1

31.0 (F)s.d. 13.2

bottom46.9 (PC)

s.d. 16.242.3 (G)s.d. 20.9

31.3 (MM)s.d. 13.3

Page 43: 06 Factor Influence Birch Sap

ANOVA results: 2002• No significant between transects (F= 0.07)• Significance between location on the slope (F= 5.00) • Significant difference considering transect and position on

the slope (F= 3.33) • Bottom significantly different than mid (p= 0.02) and top

sites (p= 0.03)• Mid and top sites not significantly different (p= 1.00)

Page 44: 06 Factor Influence Birch Sap

2003 Mean liters of sap harvested per tree from each site

Sites Transects

Position on slope

Ballaine Ester Murphy Dome

top 11.4 (Z)s.d. 6.5

30.1 (C)s.d. 22.3

23.6 (SC)s.d. 10.9

mid 10.3 (W)s.d. 8.8

21.1 (V)s.d. 13.1

8.4 (F)s.d. 6.0

bottom 51.6 (PC)s.d. 22.6

35.1 (G)s.d. 27.7

8.1 (MM)s.d. 6.9

Transects

Position on slope

Ballaine Ester Murphy Dome

top11.4 (Z)

s.d. 6.530.1 (C)s.d. 22.3

23.6 (SC)s.d. 10.9

mid10.3 (W)

s.d. 8.821.1 (V)s.d. 13.1

8.4 (F)s.d. 6.0

bottom51.6 (PC)

s.d. 22.635.1 (G)s.d. 27.7

8.1 (MM)s.d. 6.9

Page 45: 06 Factor Influence Birch Sap

ANOVA results: 2003

Data violates assumption of normal distribution

Page 46: 06 Factor Influence Birch Sap

VegetationZ W PC C V G SC F MM

Tree species Cover Cover Cover Cover Cover Cover Cover Cover CoverPICGLA 1a 1a 1a 1b 1a 1a 2aPOPTRE 1a 1a p 1aPOPBAL 1a 1aBETNEO 5 5 5 5 5 5 5 5 5

Shrub species Cover Cover Cover Cover Cover Cover Cover Cover CoverVACVIT + r pLEDGRO pROSACI 2a 4 3 1b 1b 2a 1b 4 2aLINBOR + + r r + + 1a 1aSAL spp + 1a 2a 1a 2b 1a +ALN CRI 1a 1a 1a

Forb species Cover Cover Cover Cover Cover Cover Cover Cover CoverPYROLA SP. + r r rVIBEDU 3 2b + 2a 3 1a 1a 2b 2aEPIANG p + 1b 2b 2b 1a 1a 1a +

Page 47: 06 Factor Influence Birch Sap

VegetationMM F W Z SC V G C PC

Tree species Cover Cover Cover Cover Cover Cover Cover Cover CoverPICGLA 2a 1a 1a 1a 1b 1a 1aPOPTRE 1a 1a 1a pPOPBAL 1a 1aBETNEO 5 5 5 5 5 5 5 5 5

Shrub species Cover Cover Cover Cover Cover Cover Cover Cover CoverVACVIT p r +LEDGRO pROSACI 2a 4 4 2a 1b 1b 2a 1b 3LINBOR 1a 1a + + + r + rSAL spp + 1a + 1a 1a 2b 2aALN CRI 1a 1a 1a

Forb species Cover Cover Cover Cover Cover Cover Cover Cover CoverPYROLA SP. r r + rVIBEDU 2a 2b 2b 3 1a 3 1a 2a +EPIANG + 1a + p 1a 2b 1a 2b 1b

Page 48: 06 Factor Influence Birch Sap

Low Performing stands Consistent Performing stands

Sites Moose Mtn, Frenchman, Wood, Zachel Via, Garner, Calypso, Pearl Creek

Criteria <115 L sap per site in ‘03; statistically significant less sap harvested in '03 compared with ‘02

>200 L sap per site in ‘03; not statistically significant less sap harvested in '03 compared with ‘02

Species present only in this group

Populus tremuloides Michx.(TremblingAspen)

Populus balsamifera L. (Balsam Poplar)Pyrola ssp. (Wintergreen) Gallium boreale L. (Northern Bedstraw)

None

Species present in high abundance in this group

Actaea rubra (Ait.) Willd. (Baneberry)Linnaea borealis L. (Twin Flower)Rosa acicularis Lindl. (Prickly Rose)

Salix ssp. (Willow species)Epilobium angustifolium L. (Common Fireweed)Cornus canadensis L. (Dwarf Dogwood)

Species common to both groups

Picea glauca (Moench) Voss (White Spruce)Equisetum pratense L. (Meadow Horsetail)

Hedysarum alpinum L. (Northern Hedysarum)Mertensia paniculata (Ait.) G. Don (Tall Bluebells)

Calamagrostis canadensis (Michx.) Beauv. (Reed Grass)Mosses and Lichens

Page 49: 06 Factor Influence Birch Sap

Ordinal ranking of tree sap production

• Examining for intrinsic factors affecting sap production

• Trees assigned into percentile groups for each year: Top 20%, Top 50%, Bottom 20%, and Bottom 50%

Page 50: 06 Factor Influence Birch Sap

2002 Ranking # of trees that stayed in the same category

# of trees that ranked in Top 20% in 2003

# of trees that ranked in Top 50% in 2003

Top 20% 10/18 10/18 14/18

Top 50% 33/45 14/45 33/45

Bottom 20% 8/18 0/18 1/18

Bottom 50% 33/45 4/45 12/45

Comparison of sap production rank orders between ’02 & ’03

2002 Ranking # of trees that stayed in the same category in 2003

# of trees that ranked in Top 20% in 2003

# of trees that ranked in Top 50% in 2003

Top 20% 10/18 10/18 14/18

Top 50% 33/45 14/45 33/45

Bottom 20% 8/18 0/18 1/18

Bottom 50% 33/45 4/45 12/45

Page 51: 06 Factor Influence Birch Sap

Regression of sap production by tree diameter

0

10

20

30

40

50

60

14 16 18 20 22 24

DBH cm

L sa

p

0

10

20

30

40

50

60

14 16 18 20 22 24

DBH cm

L sa

p

2002R2 = 0.288

slope = 1.79 p = 0.13

2003R2 = .516

slope = 4.61 p = 0.028

Page 52: 06 Factor Influence Birch Sap

Ordinal ranking of tree diameter and sap production

• Examining relationship between tree diameter and sap production

• Trees assigned into percentile groups by dbhand by sap production for each year: Top 20%, Top 50%, Bottom 20%, and Bottom 50%

Page 53: 06 Factor Influence Birch Sap

Comparison of tree diameter rank order and sap production

2002 Ranking # of trees that stayed in the same category

# of trees that ranked in Top 20% in 2003

# of trees that ranked in Top 50% in 2003

Top 20% 10/18 10/18 14/18

Top 50% 33/45 14/45 33/45

Bottom 20% 8/18 0/18 1/18

Bottom 50% 33/45 4/45 12/45

Dbhranking

Sap Production Top 20% in 2002 & 2003

Sap Production Top 20% at least one year

Sap Production Bottom 20% in 2002 & 2003

Sap Production Bottom 20% at least one year

Top 20% 6/18 12/18 0/18 0/18

Top 50% 7/45 19/45 1/45 10/45

Bottom 20% 1/18 2/18 5/18 10/18

Bottom 50% 2/45 8/45 7/45 18/45

Page 54: 06 Factor Influence Birch Sap

Conclusions from field experiments• Trees produced more sap in wet, cool spring of

’02 than dry, warm spring of ’03 • In general, large diameter trees produce more

sap than small diameter tree. This finding is especially true in the dry, warm spring

• Sap production differed in some transects by position on hillside, although other factors can strongly affect amount of sap produced

Page 55: 06 Factor Influence Birch Sap

Recommendations to sap harvesters• Choose stands with willow, firewood, and dwarf

dogwood (especially in dry, warm springs)• Since sap carbohydrate content is fairly

consistent between trees and years, choose trees based on the amount of sap produced

• Choose trees with large diameters or that have produced well in previous years

Page 56: 06 Factor Influence Birch Sap

Future directions for research in Alaska

•Does tapping increase the incidence of pathogens; if so, how can this be minimized

•What is the best way to utilize the sap resource–syrup products, sap beverages

•How can management improve sap yields and/or sugar content

•What does the industry need in order to thrive

Page 57: 06 Factor Influence Birch Sap

ReferencesAlaska Boreal Forest Council. 2005. Review of the 2001 Birch Sap Harvest in Alaska. 4 p.Davidov, G.M. 1979. [Calculating the yield of birch sap by the mensurational characteristics of the stands.]. Lesnoi

Zhurnal. 1 :116-7. Dujesieken, D., S. Ebenritter, and W. Liese. 1989. [Wound reactions in wood tissue in birch, beech, and Tilia

cordata.]. Holzals Roh- und Werkstoff. 47:495-500. Fesyuk, A.V.and V.V. Grimashevich. 1980. [Effects of different factors on the sap yield of Betula pendula.].

Lesovodstvo, Lesnye Kul'tury i Pochvovedenie. 9:89-94. Flora of North America. 1993+. Editorial Committee, editors. Flora of North America North of Mexico. 7+ vols. New

York and Oxford. Available: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=103887Gavrilyuk, V.M., Yu.O Osipenko, and V.P. Ryabchuk. 1980. [Harvesting sap from stumps.]. Lesnoe Khozyaistvo.

5:62-64. Lahteenkorva, J. 2005. Practical experience of birch sap collection, producing and marketing in Finland. In: Tree Sap

III Proceedings of the 3rd International Symposium on Sap Utilization (ISSU). Bifuka, Hokkaido, Japan, April 15-17 p.7-9.

Osipenko, Yu.F. and V.P. Ryabchuk. 1973. [Effects of tapping [for sap] on the diameter increment of Betulaverrucosa.]. Lesnoe Khozyaistvo. 9:27-9.

Osipenko, Yu.F. and V.P. Ryabchuk. 1975. [Obtaining Birch sap from stumps.]. Lesnoe Khozyaistvo. 4:14-5 .Ryabchuk, V.P. 1974. [Sap exudation of Birch and temperature conditions]. Lesnoe Khyzyaistvo. 5:25-7. Ryabchuk, V.P. 1975. [Effects of tapping Birch on the colour of the wood.]. Lesnoi Zhurnal. 4:146-8. Ryabchuk, V.P. 1977. [The sap of Betula pendula.]. Lesnoe Khozyaistvo. 4:80-2. Ryabchuk, V.P. 1979. [Effects of tapping on the phenological condition of broadleaved species.]. Lesnoi Zhurnal.

1:15-7. Tagiltsev, Y.G., V.A. Tsupko, V.I. Tolstyh, A.G. Izmodenov, E.V. Lysun, R.D. Kolesnikova, and V.S. Ostronkov.

2005. Sap of Far Eastern birch species. In: Tree Sap III Proceedings of the 3rd International Symposium on Sap Utilization (ISSU). Bifuka, Hokkaido, Japan, April 15-17 p.37-42.

Telisevskij, D. 1970. [Collection and use of Birch sap.]. Lesn. Hoz. 80-2. Terazawa, M. 1995. Shirakamba Birch, Splendid Forest Biomass--Potential of Living Tree Tissues. In: Tree Sap

Proceedings of the 1st International Symposium on Sap Utilization (ISSU), Bifuka, Hokkaido, Japan, April 10-12. p. 7-12 .

Tomchuk, R.I. I.S. Korolyak, N.F. Fedchuk, and Ya.G. Kiba. 1973. [Use of Birch sap in the food industry.]. LesnoeKhozyaistvo. 5:16-18.

Viereck L.A. 1992. The Alaska Vegetation Classification. USDA Forest Service General Technical Report. PNW-GTR-286 278 p