W. Neil Gillies Frank Rodgers Cacapon Institute High View, WV A LOW COST DEER EXCLUSION APPROACH FOR FORESTED RIPARIAN BUFFER PLANTINGS.

W. Neil GilliesW. Neil Gillies

Frank RodgersFrank Rodgers

Cacapon InstituteCacapon Institute

High View, WV High View, WV

A LOW COST DEER EXCLUSION APPROACH FOR FORESTED RIPARIAN BUFFER PLANTINGS

It is not the number of trees planted but the number of trees we grow that will restore

our forests and protect our waters.

The Lab and other partners on the Hampshire County Riparian Buffers Task Force developed this riparian buffer demonstration project in 1995.

They did a good job with the planting, and no trees survived – despite repeated attempts.

In 2005 we helped replant the Yellow Spring site, this time using tree tubes.

This was one of the first two WV Potomac Tributary Strategy Implementation Team demonstration projects, and

was funded by the Chesapeake Bay Program.

Trees were planted in 2’ and 4’ tubes by a WV CREP contractor.

Species Planted

Yellow Spring

White Ash 15

Shagbark Hickory

15

Sugar Maple 15

Northern Red Oak

15

White Oak 15

Yellow Poplar 20

Black Walnut 15

Crabapple 35

Buttonbush 35

Washington Hawthorne

35

Hazelnut 35

Flowering Dogwood

35

Chinese Chestnut

35

Total Count 320

13 species were planted. We even put up a new sign.

Now that the trees were in tubes, how did the

plantings fare?

Yellow Spring - Browse

0%

25%

50%

75%

100%

July2005

June2006

Sept2006

Not Browsed Browsed

Deer browsing was a huge problem!

After two years, only a few scraggly Hawthornes and crabapples were growing much past the top of the tubes, every plant that could be browsed was, and survival was dropping fast.

Yellow Spring - Survival

0%

25%

50%

75%

100%

July2005

June2006

Sept2006

Leaf No Leaf

How can you have successful riparian plantings in areas with abundant deer at a reasonable cost?

I started a backyard experiment in 2006 testing the use of parallel electric wires run through a riparian zone in a very high deer area. Initial results were very promising. Trees planted without tubes were not browsed. Natural recruitment was observed.

No unprotected trees outside the fenced area that are < 7’ high survive on this 54 acre property.

Based on the early success of this backyard experiment, WVDEP provided us with a small grant to do pilot trials on two study sites.

The first site was the Yellow Spring riparian site, set up in May 2007. It had two experimental blocks with three wire perimeters, two control blocks with a single electric wire running along one side, and one control block with no electric wires. All blocks were 60’ x 100’. Power was from a solar charger.

All of the trees at this site (that had grown to the top of their tube) had been browsed repeatedly over the previous two years. Many were quite weak.

We replaced a number of the dead trees in each study block with chestnut oak, ash, silky dogwoods and persimmons in May 2007 . . . in 1’ tubes for rodent protection.

Yellow Spring Site

0%

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60%

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100%

Contro

l no w

ire Ju

ne 07

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l no w

ire Ju

ly 07

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l no w

ire A

ug 0

7

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l no w

ire S

ept 0

7

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l no w

ire M

ay 0

8

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l no w

ire Ju

ne 08

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l w/ w

ire J

une 0

7

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l w/ w

ire J

uly 07

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ire A

ug 07

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ire S

ept 0

7

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ay 08

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une 0

8

Exper

imen

tal J

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07

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Pe

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of

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No-Damage Uncertain Browse Damage

Yellow Spring Results

Browse damage in Experimental plots in August 2007 was probably due to heavy weed growth that reduced voltage on the electric fence to less than 2500V.

May 2007

June 6, 2008

May 2007

June 6, 2008

HazelnutSilky Dogwood

Experimental

Hawthorne

June 6, 2008

May 2007

June 6, 2008

May 2007

Sugar Maple

Experimental

June 6, 2008

May 2007

Hazelnut

June 6, 2008

May 2007

Hawthorne

Control

Yellow Spring Results

Median Height above Tube ResultsExcluding Hawthorne

0

0.5

1

1.5

2

2.5

NCB SCB NCBNW SEB NEB

Site

Hei

gh

t ab

ove

Tu

be

Jun-07 Jul-07 Aug-07 Sep-07 May-08 Jun-08

Experimental SitesControl Sites

Median height of highest intact leaf above tube.

Yellow Spring Results

Sample Size Leaves above TubeExcluding Hawthorne

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35

NCB SCB NCBNW NEB SEB

Site

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er a

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Jun-07 Jul-07 Aug-07 Sep-07 May-08 Jun-08

Experimental SitesControl Sites

Sample size of plants with intact leaves above tube.

Site 2 is a USDA-CREP (Conservation Reserve and Enhancement Program) site near Baker, WV.  Forest condition in the area and the landowner indicated a deer problem exists.  This area was planted and a high tensile, electric cattle fence installed in the spring of 2007 under CREP.  The two control and two experimental test blocks are 100 feet long and ~35 feet wide, the standard buffer width in WV.  There are two perimeter wires spaced four feet apart.  Fence was initially powered via a tap from the high tensile fencing.

There were problems at Site 2:

•Early browsing in experimental plots led to discovery that CREP fence powering the site had insufficient voltage (<2500V)

•Installed solar fence charger for test blocks in July 2007, but still had some browsing in early August 2007. Discovered a short in fence that reduced voltage to ~2200V. Sigh.

•Fixed short, voltage >5000, browsing problem eliminated in September 2007.

•Vegetation got ahead of us in June 2008, fence voltage down below 3000V.

•All of the above issues led to “training to the fence” inconsistency.

•Despite the problems, how did the plants fare?

Baker CREP Site

0%

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100%

Contro

l June

07

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l July

07

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l Aug 0

7

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l Sep

t 07

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08

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l June

08

Exper

iment

al J

une 07

Exper

iment

al J

uly 0

7

Exper

iment

al A

ug 07

Exper

iment

al S

ept 0

7

Exper

iment

al M

ay 08

Exper

iment

al J

une 08

Pe

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of

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No-Damage UncertainBrowse Damage Below Tube Top

CREP Site Results

May 2007 June 26, 2008

Inside exclosure

Outside exclosure

Experimental Block East Experimental Block West

Control Block EastControl Block West

Bears Hell Results

Median Height Above Tube

0

0.5

1

1.5

2

ECB WCB EEB WEB

Site

Hei

gh

t A

bo

ve T

ub

e (f

t)

7/20/2007 8/11/2007 9/19/2007 5/26/2008 6/23/2008

Median height of highest intact leaf above tube.

Experimental SitesControl Sites

Bears Hell Results

Sample size of plants with intact leaves above tube.

Sample Size Leaves Above Tube

0

10

20

30

40

50

ECB WCB EEB WEB

Site

No

. w

ith

Lea

ves

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ove

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7/20/2007 8/11/2007 9/19/2007 5/26/2008 6/23/2008

Experimental SitesControl Sites

Estimated Material Costs per Acre

Area Fence Tubes and stakes

One acre $ 668 $ 758

Two acres $ 1,045 $ 1,516

Three acres $ 1,423 $ 2,274

Four acres $ 1,800 $ 3,032

Notes:

1. assume weed mats used for each setting

2. Retail prices for materials

3. Tree tube stakes are estimated, probably cost more.

4. Assume 2-wire perimeter fence installed with temporary fence materials.

How is my “backyard” experiment doing?

•A significant amount of natural recruitment has taken place, including: black walnut, witch hazel, hornbeam, hophornbeam, linden, red maple, oak spps, hickory, dogwood, cherry, ash, box elder, tulip poplar, locust.

•There have been only two plants slightly browsed in two years.

•Every tree outside the fence exclosures is heavily browsed.

•Three non-tubed plants were lost overwinter to vole damage.

•Lack of browse = potential for proper forest structure below 6 ft.

Here is a summary of what we observed between June 2007 and June 2008:

• If the fence is properly installed, energized, and clear of heavy weed growth, protection within fenced areas can be ~100%. •In the first few weeks after installation, check the fence for damage as the deer get very upset when they first get in it.  The inner wire is more likely to be broken than the outer wire. •There does not appear to be much of an edge effect (if any) where trees near the fenced area are protected.  •Failure to maintain the fence reasonably clear of heavy weed growth results in lowered voltage on the fence and, over time, dramatically reduced success.  •Just as the literature says, voltages in the 2000-2500 voltage range are not terribly effective against deer.  •The fencing sadly doesn’t protect against drought, insects, or rodents.  

“We are going ahead with the planting this weekend and  installing  two fenced areas according to your specifications on  "site 1" of your  study for the walnut planting here at the farm.  One of the plots is  about 360ft x 30ft and another is about 250ft by 180ft. . . . The trees that will be within the perimeter of the fence are going  to have to fare without tree tubes.” (Fall 2007)

June 2008: “Our trees are . . . doing very well. We have two plantings. The  one on a hillside has been easy to access and is mown regularly. The  other planting was underwater for some time this spring and the grass  got away from us while we could not get to it with the little mower.  I am not sure how those trees are doing at the moment.

The maintenance has been the major downside, we have had to mow  with a garden mower and the tractor took out the outside strand at  one point this spring. Fortunately, repair is easy. Other than  maintenance, we are very pleased with the very high survival rate and  healthy growth of the trees.

Louise McDonaldThe Bower Farm

A local landowner used our fence design on their planting project.

We have a National Fish and Wildlife Foundation grant to expand this project to

other riparian sites, and also to upland forest settings, in the Chesapeake Bay watershed.

We are looking for cooperators to help select suitable sites and participate in the project by

by performing routine maintenance.

Please let me know if you are interested.

When white tail deer are too abundant, both the understory and the forest floor layers become degraded, sometimes severely. 

The understory becomes thin, with few or no new seedlings given a chance to grow, and few leaves left below the deer browse height. The accumulation of fallen leaves that forms much of the litter layer

on the forest floor can largely disappear.  

The role that a thick bed of decaying leaves and good forest soil structure play in slowing runoff, storing moisture, and cycling

nutrients may be diminished as a result.  If true, this would lead to drier hillsides, more erosive runoff, less infiltration (less

groundwater recharge), and flashier streams that dry up easily.  

Thanks to the National Fish and Wildlife Foundation grant, CI is starting a long-term study to determine if exclusion of deer from

sections of forest leads, over time, to an increase in leaf litter retention, restoration of a healthy forest soil structure, and an

increase in retained moisture. 

Any questions?

It is not the number of trees planted but the number of trees we grow that will restore our forests and protect our waters.

Cacapon Institute at www.cacaponinstitute.org