goats as grazing animals for invasive plant management 2005-2006 bill jacobs, kathy schwager,...
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Goats as Grazing Animals for Invasive Plant Management 2005-2006
Bill Jacobs, Kathy Schwager, Marilyn Jordan: The Nature ConservancyKaren Kazel: Suffolk County Farm
Goats eating Oriental bittersweet.Jordan
SUMMARY: The Nature Conservancy carried out this goat grazing project at the Suffolk County Farm in 2005-2005. Results were presented at the August 24, 2006 meeting of the Long Island Invasive Species Management Area (LIISMA). Goats are great at eating woody plants, and will even eat the bark off of trees. They also eat some herbaceous plants, but first they eat woody species, then they move on to herbaceous plants in order of their gastronomic preference. Mugwort (Artemisia vulgaris) is down near the bottom of the goat menu. Swallow-wort (Cynanchum rossicum and C. louisae) are toxic. Grass cover tends to either increase slightly, or remain unchanged, as long as there are plenty of other plants to eat. Goats eat more intensively "close to home" (i.e. location of water and shelter) than farther away. Thus a long narrow pen like the one we used is not the ideal shape for uniform woody control, though good for seeing effects of browse along an intensity gradient. Browsing doesn't kill woody plants after just one summer of goat exposure, so when goats are removed the woodies (and other plants) grow back. Repeated browsing for a couple of years, or following one year of browse with herbicide in year two, would be required for permanent kill of woody plants (and possibly herbaceous perennials). So goats are good for woody control in grasslands. Not good for forests where abundant deer already fill the goat niche much too well.
Text, data analysis and photograph by Marilyn J. Jordan, Ph.D. Senior Conservation Scientist, The Nature Conservancy on Long Island. Uplands Farm Sanctuary. 250 Lawrence Hill Rd., Cold Spring
Harbor, NY 11724 USA (631) 367-3225 [email protected]
1plot 1 plot 2 plot 3 1 2 1 2
post # 7 10 13 20 21 24 27 37 38
PEN #1 PEN #2 PEN #3 4=UNGRAZED
Goat pen 25 ft x 370 ft
Pen 1 grazed 4/14/06 to 5/21/06
Monitored 1st time: August 15, 2005
Monitored 2nd time: June 29, 2006
Grazed 5 weeks; ungrazed 6 weeks
Pen 2 & 3 grazed 5/21/06
Monitored: June 29, 2006
Grazed 5 weeks
Pen 1 Before & After Grazing
2005 (before)
2006 (after)
Grazed 5 weeks; ungrazed 6 weeks
Effect of Goat Grazing2005 vs. 2006 (pen 1, plots 1-3)
0
10
20
30
40
50
60
70
80
90
100
Celastrusorbiculata
Lonicerajaponica
Prunusserotina
Rosamultiflora
Grasses Artemisiavulgaris
Per
cen
t C
ove
r
Before grazing
After grazing
Goat pen | Sheep pen
Goats prefer woody vegetation whereas sheep prefer herbaceous.
Grazed Pen #2 | Ungrazed Pen #4
June 29, 2006
Grazed and Ungrazed
Grazed and Ungrazed Hedgerow, 2006<2 m height
0
10
20
30
40
50
60
70
80
Celastrusorbiculata
Lonicerajaponica
Prunusserotina
Rosamultiflora
Grasses Artemisiavulgaris
Per
cen
t C
ove
r
Ungrazed <2m
Grazed <2m
Grazed Pen #3 | Ungrazed Pen #4
Bark eaten off trees
Japanese honeysuckle Multiflora rose
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