1
ECONOMIC IMPACT OF
COGONGRASS ON PRIVATE, NONINDUSTRIAL FOREST OWNERS IN
FLORIDA
Nandkumar Divate
Agribusiness
Dr. Michael Thomas
Dr. Moses Kairo
Dr. David Harding
Dr. Kome Onokpise
Introduction
2

Native to southeast Asia

Infests nearly 500 million acres worldwide


Found on every continent
 Except Antarctica
 Tropical and subtropical areas, limited spread to northern
temperate regions
Considered to be one of the worst weeds
Introduction to U.S.
3


First appearance

Grand Bay, Alabama

Escape from crate packing in 1912
Intentional introduction



Mississippi as a possible forage in 1921
Florida introduction 1930s and 1940s
However, little economic (forage) benefit
Worldwide Distribution
4
The general distribution of Imperata cylindrica throughout the world, depicted by
areas of white. (Based on information from
Holm et al., 1997.)
Cogongrass infestation in the southeastern
United States
5
Points of introduction
Statement of Problem
6
Objectives
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




Develop an instrument to survey owners of private, nonindustrial forestland in Florida and conduct a statewide sample
of private, non-industrial forest owners in Florida.
Use the sample results to document the direct impact of
cogongrass on;
- lost forest inventory and reduced forest regeneration
and productivity,
- and the direct economic impact of control efforts.
Apply these estimates of direct economic impact to an
input/output economic model and extrapolate the indirect and
induced effects of these losses to the economy at large.
Methodology
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


A mail survey was designed and sent to 2800 forest owners
It asked forest owners about their knowledge of the spread,
impact, and control techniques of cogongrass.
The instrument has four sections.
Survey Instrument
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Methodology
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

Economic impact of cogongrass will be estimated with
input/output (IO)
IO analysis tracks direct, indirect and induced economic
effects from




lost forest productivity and
expenditures use to control cogongrass.
Results are reported regional and statewide
Extrapolate the indirect and induced effects to the economy
at large.
Data
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
-
-
Source for List of Private
non industrial forest
owners
Institute of Food and
Agricultural Sciences,
School of forest research
and Conservation,
University of Florida
2832 woodland owners in
Florida.
Targeted Survey Population
Survey Results
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Category
Total Mailed
Undelivered questionnaires
Survey
2,832
350
Adjusted sample size
2,482
Returned questionnaires
1,130
Response rate
45.52%
Source: Survey questionnaire
Reason For Owning Woodland
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Reason for Owning Woodland
Production of firewood or bio-fuel (energy)
Cultivation/collection of non timber forest products
Recreation other than hunting & fishing
Part of home or vacation home
Hunting or fishing
Privacy
2.09
2.1
Key
Importance on the scale of
1to 5.
1- least important
3.28
3.42
3.51
3.79
Part of farm or ranch
3.8
Production of saw logs, pulpwood or other products
3.8
Financial investment
3.85
Inherit
3.9
Protect biological diversity
Beauty or scenery
4.19
4.29
Source: Survey questionnaire
Cost share Program Participation
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Responses %
•57% respondents cost-share program.
•52 % Used in last five years.
20
18
16
14
12
10
8
6
4
2
0
19.05
Cost share Program Participation
16.39
14.34
12.7
8.81
8.4
7.99
6.96
2.66
2.45
0.2
Source: Survey questionnaire
Relative importance of common
weeds found in Woodlands
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Common Weeds
Mean
Std. Error
% Don’t Know
Cogongrass
1.86
.052
37.33
Japanese climbing fern
1.76
.053
55.88
Japanese privet
1.72
.058
73.05
Chinese tallow (Popcorn Tree)
1.71
.047
39.27
Blackberry
1.59
.033
17.53
Muscadine grape
1.54
.036
21.85
Tropical soda apple
1.52
.046
52.91
Mimosa
1.50
.037
29.81
Air potato vine
1.39
.038
54.98
Kudzu
1.37
.036
21.51
Japanese honeysuckle
1.33
.033
58.74
Morning glory vine
1.31
.028
34.64
Coral ardisia
1.14
.030
97.95
Mean on the index of 1 to 5
Source of information about
Cogongrass
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• 51% respondents are familiar with cogongrass.
Source of Information about Cogongrass
30
27.52
Responces %
25
20
15
10
5
10.55
9.54
8.9
6.24
3.39
3.3
2.2
1.01
0.92
0
Source: Survey questionnaire
Cogongrass
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Awareness about presence of cogongrass
(approx. 4.5 years)
Presence of Cogongrass (30% & 33% don’t know)
Have problem with cogongrass (25 % )
Woodland Covered with cogongrass (5 % )
Negative effect of cogongrass On Tree Growth.
(40% believe )
believe Cogongrass, Cause wildfire (54% )
Cogongrass control
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• 78% Tried to control
• Average cost of control $81.56 per acre.
• Major chemical – Roundup (83%).
Mechanical
9%
Other
2%
Burning
8%
Control Methods
Chemical
81%
Source: Survey questionnaire
Demographic responses
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Plans for woodland (minimum activity, Harvest and Bequest)
Years owning forest property in Florida (Average 22 years)
Inherit woodland or forest (33%)
Importance of woodland income in household (1.9)
Household income earned from woodland (11%)
Approx household annual income (Avg $104630.6 )
Private non-industrial forest owners
area distribution in Florida.
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Private non-industrial forest land in Florida by region
Southern
11%
Central
16%
North Eastern
40%
North Western
33%
Source: Florida division of forestry’s, forest inventory and analysis factsheet (2007).
Cost of control model
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Regional cost of control (RCi) can be calculated as follows
RCi = ƒ (Ii, Ai, Pi, Ci)
(1)
Where:
Ii = Cogongrass infestation rate for region i.
Ai = number of acres of woodland owned by private nonindustrial individuals in the
region i.
Pi = proportion of woodland owners trying to control
cogongrass in region i.
Ci = average cogongrass control cost for region i.
(For region i, i = northeastern, northwestern, central &
south)

Regions with acres Bounds
Input for IMPLAN analysis
Infestation rate (%)
Proportion that
Cost of
/acre ($)
control Regional cost of
control ($)
control (%)
Northeastern
22
(1,949,000)
Northwestern
(1,608,220)
Central
(7,79,740)
Southern
(536,070)
State
(4,873,030)
Average
3.89
74
127.62
7,159,982
Lower
2.89
73.88
43.39
1,808,224
Upper
4.88
74.11
211.85
14,951,489
Average
5.11
78
115.24
7,386,934
Lower
3.6846
77.932
75.3
3,477,890
Upper
6.5354
78.068
155.17
12,731,888
7.022
86
133.64
6,292,824
Lower
3.4304
85.87
10.2
234,280
Upper
10.613
86.13
257,08
18,323,596
4.33
1
76.25
17,699
Lower
0.664
1
0
0
Upper
7.996
1
119.11
51,055
Average
5.009
78
81.56
15,501,506
Lower
3.9946
77.946
63.54
9,641,540
Upper
6.0234
78.054
99.57
22,813,790
Average
Average
IMPLAN analysis
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• State wide average Impact $14,933,490.
Average Economic Impact of Cogongrass
7,000,000
6,000,000
Impact $
5,000,000
4,000,000
6,744,703
6,921,156
5,951,266
3,000,000
2,000,000
1,000,000
16,701
0
Northeastern
Northwestern
Central
Southern
Region
Source: IMPLAN analysis results
Detailed IMPLAN analysis
Regions
Output
Direct ($)
Indirect ($)
Induced ($)
Total output ($)
Northeastern
Average
6,693,955
29,917
20,831
6,744,703
Lower
1,690,531
7,555
5,261
1,703,347
Upper
13,978,331
62,473
43,500
14,084,304
Average
6,906,136
9,179
5,841
6,921,156
Lower
3,251,522
4,321
2,750
3,258,593
Upper
11,903,199
15,820
10,067
11,929,086
5,883,239
42,709
25,318
5,951,266
Lower
219,031
1,590
943
221,561
Upper
17,130,956
124,361
73,722
17,329,039
16,547
98
57
16,701
Lower
0
0
0
0
Upper
47,732
282
163
48,177
14,492,548
272,401
168,542
14,933,490
Lower
9,013,994
169,426
104,829
9,288,249
Upper
21,328,892
400,896
248,045
21,977,834
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Northwestern
Central
Southern
State
Average
Average
Average
Source: IMPLAN analysis results
CONCLUSION
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


Cogongrass was ranked by Private Non-industrial
Forest Owners as the most common forest weed
across the state of Florida.
Private Non-industrial Forest Owners are more
willing to control Cogongrass using Chemical control
rather than Mechanical control.
With Cogongrass’s continued spread, it will likely
generate more economic losses to the woodland
industry.
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Thank you