Transcript SilvoPasture with Hybrid Poplars and Sheep

SilvoPasture with Hybrid
Poplar and Sheep
GreenWood Resources
Columbia Tree Farm
Clatskanie, Oregon
GreenWood Resources, Inc.
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Natural resource management company
established in 1996, based in Portland, Oregon
GreenWood Resources, Inc.
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Currently manage nearly 15,000 acres of
hybrid poplar plantations
6,000 acres west of the
Cascade Mountains
8,700 acres east of the
Cascade Mountains
GreenWood Resources, Inc.
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World-wide development and management of
poplar plantations
Development of elite hybrid poplar and
cottonwood genotypes
France
N. America
China
Japan
New Zealand
Chile
What is Hybrid Poplar?
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Crosses between
Populus species
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Black cottonwood
(P. trichocarpa)
Eastern cottonwood
(P. deltoides)
Japanese poplar
(P. maximowiczii)
European black
poplar (P. nigra)
Creating Hybrid Poplars
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Traditional hybridization through controlled
pollination, propagation and testing of progeny
Uses of Hybrid Poplar
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Wood products including veneer & lumber
Photo courtesy of British Columbia Ministry of Forestry and Lands
Uses of Hybrid Poplar
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Pulping fibers for the paper industry
Uses of Hybrid Poplar
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Feedstock for energy industry; co-firing with coal
and liquid fuels
Uses of Hybrid Poplar
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Land application of municipal effluent
Phytoremediation of industrial sites and waste
water treatment
Uses of Hybrid Poplar
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Carbon sequestration
The Columbia Tree Farm (CTF)
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Established in 1982
The Columbia Tree Farm (CTF)
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50% owned land, 50% leased
The Columbia Tree Farm (CTF)
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Initially created to support area pulp and
paper mills
The Columbia Tree Farm (CTF)
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Operate as agriculture, employing many
conventional farm practices and equipment
Characteristics of the CTF
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Soils are loams to silty loams with high organic
matter, low clay content
Excellent soil nutrient capacity
Moderate temperatures throughout the year
Rainfall up to 45” annually, primarily in the late
fall, winter and spring
Plantations were initially planted with 600 to
900 trees-per-acre for rotations of 6 to 8 years
CTF Management Strategy
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Became independent of paper company in
December, 2000
Free to pursue highest value markets for wood
products
Transition to:
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Longer rotations, 12 to 15 years
Wider spacing, density of 300 trees per acre
Pruning in sequential lifts to produce clear lumber
Larger piece sizes to maximize board-foot yields
Challenges at the CTF
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Longer period of weed
control
– Four versus two years
– Mechanical and chemical
control
– Increased cultivation
expense
Increased potential for
damage from voles where
vegetation creates good
habitat
Purpose of SilvoPasture Trial
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Explore the range of plantation ages and stock
types where sheep grazing could take place
without injurious effects
Demonstrate benefits to plantation
management and sheep ranching
To see if sheep grazing can be an effective
means of weed control in wider spaced
plantations
Test Sites
4 year old
trees, from
14” cuttings
Test Sites
2 year old
trees, from
5’ to 6’ tall
whips
Test Sites
1 year old
trees, from
large 6’ to
7’ tall whips
Test Sites
Thirty-six-tree plots were established inside and
outside of each grazing plot for evaluation and
comparison of tree growth and performance
Fenced grazing plot
Grazed
Control
Preparation of Test Plots
Sowed cover crop
in April, 2004
Disked between
the tree rows
– Forage oats at
50 lbs per acre
– Forage rape at
10 lbs per acre
– 50 lbs N fertilizer
per acre
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Preparation of Test Plots
Oats established
well, rape did not
establish
Preparation of Test Plots
Electric fence
and water
supplies
installed in
late July,
2004
Introduction of Sheep
Sheep were placed on August 2nd, 2004
Introduction of Sheep
Sheep were 4 to 4½ month old lambs, and weighed 60 to
65 pounds
Introduction of Sheep
The number of sheep per plot ranged from 7 to 20 head,
based on quality and quantity of forage
Introduction of Sheep
Targeted one month of grazing within each plot
Introduction of Sheep
Mid-month adjustment in number of head per plot, based
on how rapidly the forage was being consumed and
trampled
Results from Sheep Grazing
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Lambs gained 6 to 7 pounds during 29 days grazing on
the test plots
Slightly below average weight gain compared to lambs
grazing pasture with no supplemental feed
Failure of rape reduced the
quality of forage; additional
weight gains may have been
seen had it established
Evaluation of the lambs
during and at the end of the
grazing period showed them
to be vigorous and healthy
Results in Age 4 Trees
Tree Treatment
2004
2004
Damage
Age
Diameter
Height
(years)
Increment Increment
(inches)
(feet)
4
Grazed
1.2
11.2
Minor leaf
browsing
4
Control
1.1
11.0
No
damage
Results in Age 4 Trees
Results in Age 2 Trees
Tree Treatment
2004
2004
Damage
Age
Diameter
Height
(years)
Increment Increment
(inches)
(feet)
2
Grazed
0.8
7.7
Minor leaf
browsing
2
Control
0.7
7.5
No
damage
Results in Age 1 Trees
Tree Treatment
2004
Damage
Age
Height
(years)
Increment
(feet)
1
Grazed
0.6
17% showed stem
and/or terminal
damage
1
Control
0.6
No
damage
Conclusions
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Minor positive growth impacts with no damage were
seen in the 2 and 4 year old grazing plots
Trees age 2 and older can can be grazed successfully
Trees that are 1 year old, even if established from
whips, suffer unacceptable levels of browse damage
Sheep remained healthy and vigorous, but weight
gains were not exceptional
Observations
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Careful management of livestock density is critical
Current grazing lease rates in the lower Columbia
River area do not justify the expense of sowing a cover
crop for forage
Grazing only native vegetation could prove more cost
effective and might substitute for one or more
mechanical cultivations
As a result of this trial, approximately 500 sheep were
wintered in several fields of the CTF, with favorable
results reported by two different ranchers
Acknowledgements
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This study was funded by a grant from Western
Sustainable Agriculture Research and Education
(WSARE), under project number FW04-109
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We wish to acknowledge the contributions of:
– McClellan “Mac” Stewart, Magruder Farms,
Clatskanie, Oregon, for technical assistance in
selecting cover crops and managing livestock
– GMO Forestry Fund 3, Boston, Massachusetts, for
their in-kind contribution of the land and tree
plantations on which the study was conducted