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Management of Melaleuca by Professional Land Managers in South Florida1
Katherine Carter-Finn, Alan W. Hodges, Donna J. Lee, and Michael T. Olexa2The Melaleuca Management Survey
Although the invasive plant Melaleuca has been in Florida for over 100 years, very little information exists on the extent of its coverage, area treated, control methods used, treatment costs, and the negative economic and environmental effects caused. To help remedy this lack of information, a survey of professional land managers in south Florida was undertaken in 2003. This research was undertaken as part of the Areawide Management Evaluation of Melaleuca (TAME Melaleuca), in collaboration with the USDA-Agricultural Research Service and the South Florida Water Management District. Surveys were conducted for both residents and professional land managers (see companion report on results for professional managers, FE672 ).Written questionnaires were developed for the survey in consultation with cooperating agencies. The questionnaires and informed consent protocol for the survey were reviewed and approved by the University of Florida Institutional Review Board. Following Dillman's (1978) Total Design Method, each survey had an arrangement of colored photographs on the front cover, an introductory statement explaining the purpose of the study, and general instructions for completing and returning the questionnaire in an enclosed postage-paid envelope. The survey was a total of nine pages long.
The study area for the survey included the ten (10) southernmost counties in Florida: Broward, Charlotte, Collier, Glades, Hendry, Lee, Martin, Miami-Dade, Monroe, and Palm Beach ( Figure 1 ). This area contains over 2.5 million households (BEBR, 2004). Both agricultural owners/operators and managers of public parks/preserves were targeted for the survey. Agricultural landowners were selected from a list compiled from county property appraisers by the Florida Department of Revenue in Tallahassee. A random sample of 2,000 of these landowners was selected for the survey. This number represented 17 percent of the total population of about 11,500 landowners. For public lands, a list of 285 managers was obtained from the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) representing managers of parks and preserves for local, state, and federal government agencies, and managers of rights-of-way for public utilities. Surveys were mailed to all managers on this list. A total of 435 responses were received (Table 1 ). Thirty-two percent of park mangers and 22 percent of agricultural mangers responded to the survey. Results of the survey are described herein.
Figure 1. Map of Melaleuca distribution in south Florida (http:www.invasive.org). Land Area and Land Use
Land area owned and leased by professional owners/managers responding to the survey is summarized in Table 2 . A total of 5.4 million acres were reported, which consisted of about 5.1 million acres controlled by park managers and 317,000 acres controlled by agricultural managers. The vast majority (98%) of land managed by park/preserve managers was publicly owned, although 86,372 acres were privately owned. In contrast, most of the land managed for agricultural purposes was privately owned. Publicly-owned landholdings managed as parks/preserves averaged 74,488 acres per manager and ranged in size from 4 acres to 1,400,000 acres. Privately-owned agricultural landholding averaged 775 acres per manager and ranged from less than 1 acre to 140,000 acres. A relatively small amount of land was being privately leased by both park and agricultural managers. When these numbers are expanded to represent the full population of agricultural managers in the 10-county study area of south Florida, an estimated 1.74 million acres would fall under private ownership, 73,893 acres would be privately leased, and 8,884 acres would be classified publicly owned.In terms of specific land uses, 6.94 million acres were reported as managed by park/preserve managers, while 319,771 acres were reported as managed by agricultural managers, giving a total of 7.26 million acres (Table 3). The largest type of land-use by area as reported by park/preserve managers was for parks/preserves, comprising a total of 4.80 million acres. Miscellaneous other uses, totaling 356,262 acres, included target ranges, recreational areas, and office buildings. Some park/preserve managers indicated that some of their land was used for pasture/range land, crop production, fruit/citrus groves, and nurseries, but none indicated that their land was being used as forest for commercial timber production.
The most commonly reported land use by agricultural land managers was pasture/rangeland, with 38 percent of respondents reporting a total of 143,243 acres (Table 3 ). Miscellaneous other uses, totaling 18,272 acres, reported by agricultural managers included residences, ponds, horse farms, and barns. When these numbers are expanded to represent the population of agricultural managers in south Florida, it is estimated that a total of 1.83 million acres were being managed. This would include 823,647 acres for pasture/rangeland; 669,231 acres for crop land; 197,081 acres for fruit/citrus groves; 26,145 acres for rights-of-way; and 105,064 acres for miscellaneous other uses.
Factors Affecting Land Management
Survey respondents were asked to rate various factors that influenced their land management decisions as significant, moderate, or none. These factors included agency funding; adverse weather conditions; availability of agricultural land; encroachment of urban land uses; foreign or other state competition; cost of inputs or supplies; prices for crops, fruit, or livestock; invasive plants; predators; insect pests; and the ability to conduct prescribed burns.For park/preserve managers, it was not surprising that agency funding was the most influential factor in land management decisions, being rated as significant by 77 percent and moderate by 19 percent of the respondents. Invasive plants were rated as a significant factor by 73 percent of park managers, while 25 percent rated them as a moderate influence. The ability to conduct prescribed burns was rated as significant by 39 percent of park managers and as moderate by 23 percent. Input costs were considered significant by 36 percent and moderate by 53 percent of park/preserve mangers. Urban encroachment was rated as a significant or moderate influence by 28 percent and 40 percent of these respondents, respectively. Adverse weather was viewed as a moderate influence (71%), although this may be considered more important after the 2004 hurricane season. Only 8 percent indicated that predators or insect pests were a significant factor in their management, while 42 percent rated them as moderate and 50 percent considered them of no significance.
For agricultural managers, the factors influencing their land management decisions were rated lower overall. The price for crops, fruit, and livestock was the most important factor, with 29 percent indicating it was significant and 33 percent as moderate. The cost for inputs or supplies was rated as a significant factor by 24 percent of agricultural managers and as moderate by 41 percent. Adverse weather conditions were a significant factor for 23 percent, urban encroachment was rated as significant by 23 percent, and availability of agricultural land was significant for 20 percent. Some 19 percent of agricultural managers rated predators and insect pests as a significant factor, with 46 percent rating them as moderate. Invasive plants were rated as significant by 16 percent and as a moderate influence by 43 percent. Foreign or other state competition was generally not viewed as important, which is somewhat surprising, given the significance of commodity prices.
Area of Invasive Plants Occupied And Treated
The importance of Melaleuca as an invasive plant was assessed in relation to other invasive plants, based on the area currently occupied or infested in 2003, and the area treated during the period between 1990 and 2003 (Table 4 ). The area occupied was intended to represent the areas of contiguous stands, not small isolated patches or individual outlying trees. The ratio of the area treated since 1990 to the area currently occupied was also taken as a gauge of the intensity of treatment by land managers.For park/preserve managers, Melaleuca was the invasive plant reported to occupy the largest area (619,317 acres) in 2003. Melaleuca also had the largest area treated between 1990 and 2003 (402,088 acres), which represents 65 percent of the area currently occupied. Brazilian Pepper was the second most common invasive plant, occupying 425,805 acres in 2003, with 75,215 acres treated between 1990 and 2003. This represented 18 percent of the area occupied in 2003. Among other species, Old World Climbing fern (Lygodium) occupied 113,884 acres, and 49,213 acres were treated (43% of area occupied). Australian Pine (Casuarina) occupied 111,782 acres, with 16,598 acres treated (15%); Cogon grass (Imperata) occupied 20,147 acres, with 6,527 acres treated (32%); Tropical Soda Apple (Solanum) occupied 15,418 acres, with 3,475 acres treated (23%); and miscellaneous other plants occupied 11,433 acres, with 7,094 acres treated (62%). Some of the other plants frequently listed were Air Potato (Dioscorea bulbifera), Downy Rose Myrtle (Rhodomytrus tomentosa), Latherleaf (Colubrina asiatica), Carrot Wood (Cupaniopsis anacardioicles), and Cattail (Typha).
For agricultural managers, 94 managers reported a total area of 2,134 acres occupied by Melaleuca in 2003, and 57 managers reported treating a total of 1,460 acres between 1990 and 2003 (Table 4 ). This represented 68 percent of the total area occupied. This suggests that agricultural managers have treated Melaleuca at similar rates as park managers; however, other indicators in this survey and research by other scientists imply that park managers have acted much more aggressively. Tropical Soda Apple (Solanum) was reported by agricultural managers to occur on 10,393 acres in 2003, and 7,855 acres (76%) were treated. Brazilian Pepper (Schinus) occupied 7,096 acres and 2,768 acres (39%) were treated. Miscellaneous other invasive plants, including air potato, dog fennel, and smut grass, occupied 2,561 acres, and 2,094 acres (82%) of those plants were treated. When these numbers are expanded to represent the total population of agricultural managers, Melaleuca is estimated to cover 12,271 acres of agricultural land in south Florida during 2003, and 8,395 acres were treated between 1990 and 2003. The area infested by other invasive plants on agricultural lands is estimated at 139,058 acres, including 59,760 acres for Tropical Soda Apple and 40,802 acres for Brazilian Pepper (Schinus).
Methods Used for Treating Melaleuca
Managers were asked indicate if they had used a specific method for controlling Melaleuca, and then to indicate the area they treated with that method in 2003 and cumulatively from 1990 to 2003 (Table 5) . Respondents were given a choice of several options:
Since respondents were given the opportunity of indicating more than one control method, a count was taken to see how many managers chose at least one control choice, and this number was used to compute the percentage of managers responding in the affirmative for using a particular control method.
- Mechanical removal (felling, mowing, tilling, grubbing, disking, etc.).
- Foliar or soil applied herbicides.
- Basal frill followed by herbicide treatment (hack-and-squirt).
- Girdling followed by herbicide treatment (a ring of bark is removed from the base of the tree and then treated with an herbicide).
- Felling followed by herbicide treatment on the cut stump (stump treatment).
- Biological control with beneficial insects (natural enemies of the tree are released which may cause stress in established trees and death of younger saplings).
- Biological controls combined with one or more other methods.
Among park/preserve managers, 82 percent indicated that they had employed a stump treatment; 59 percent used hack-and-squirt; 51 percent used mechanical control methods; 28 percent employed biological control; 21 percent used biological control combined with one or more other form(s) of control; and 7 percent reported using some other method of control, such as fire. Many agricultural managers did not have Melaleuca on their property and, if they did, a substantial percentage chose not treat it. So, it was not surprising that 71 percent of agricultural managers had not used any particular control measures for Melaleuca. Among agricultural managers who did use controls, 33 percent indicated they had employed mechanical methods for control, 10 percent used foliar or soil applied herbicides, 8 percent reported using stump treatment, and 4 percent used hack-and-squirt (Table 5 ).
The area of Melaleuca treated using various control methods in 2003 and cumulatively from 1990 to 2003 is summarized in Table 6 . For park/preserve managers, the total area treated in 2003 was 84,740 acres, and the area treated since 1990 was 419,741 acres. The stump treatment (felling + herbicide) was used over the largest area (303,933 acres) since 1990, followed by hack-and-squirt (52,476 acres), foliar or soil applied herbicides (36,622 acres), mechanical methods (16,625 acres), and biological control (12,642 acres). Biological controls combined with one or more other method(s) were used on 80,575 acres, and together with the area treated strictly by biological control represented 93,217 acres. For areas treated in 2003, the most important method used was stump treatment (46,958 acres), followed by foliar/soil herbicides (15,987 acres) and hack-and-squirt (11,494 acres). In comparing the area treated in 2003 with the average annual rates since 1990, it is apparent that the use of all treatment methods accelerated in 2003 for parks/preserves.
For agricultural managers, the overall area of Melaleuca treated by any particular method since 1990 was significantly less than the area treated by park/preserve managers. Agricultural managers treated about 2,707 acres in total, including 1,957 acres by mechanical methods, 274 acres with stump treatments, and 355 acres using foliar/soil-applied herbicides. The smaller area treated from 1990 to 2003 in some cases was apparently due to reporting errors.
Managers were also asked to indicate whether they planned to use or continue using various control methods. Among park/preserve managers who answered this question, the largest share intended to use stump treatment (85%), followed by hack-and-squirt (72%), mechanical control (50%), biological control (45%), and biological control combined with other methods (40%). For agricultural land managers, the majority intended to use mechanical methods (70%), with much fewer intending to use foliar/soil applied herbicides (29%), stump treatment (27%), or hack-and-squirt (16%). Very few agricultural managers expressed interest in biological control.
Managers were asked whether they were interested in receiving additional information about any of the specific Melaleuca control methods. Most park/preserve managers were interested in learning more about biological control (74%). A majority was also interested in foliar/soil applied herbicides and stump treatment (65%), hack-and-squirt (58%), and mechanical methods (52%). Among agricultural managers who responded to this question, around 50 percent wished to learn more about biological control, stump treatment, soil/foliar herbicides, and hack-and-squirt. The low interest in learning more about mechanical control (this group expects to continue using this method extensively) suggests that this method is well understood.
Barriers to Controlling Melaleuca
Land managers were asked to choose from a list of factors that may have limited their ability to control Melaleuca (Table 7 ). Among park/preserve managers, the biggest barriers identified were inaccessibility to infestations (22%), expense (18%), excessive size of infestations (15%), lack of cost-sharing programs (13%), and lack of time (12%). However, a significant proportion of these respondents (32%) indicated that they encountered other types of barriers not specifically identified in the question, such as infestations are too small, lack of needed equipment or knowledge to use controls, fear of harming other beneficial plants, fear/dislike for using chemicals, and environmental regulations. Although they were listed in the question, some respondents wrote in that lack of money and lack of time were barriers to implementing controls. Only 13 percent of park/preserve managers said that Melaleuca was not a problem for them.Agricultural land managers responded quite differently to the barriers to control question. Seventy-four percent indicated that they did not have Melaleuca on their property, and 31 percent reported that Melaleuca was not a problem for them even it they did have it. Some 5 percent indicated a barrier other than those listed in the survey. It is interesting to note that one respondent stated that Melaleuca trees provide shade in pastures, which suggests that there may be some benefits of Melaleuca for agricultural use.
Sources and Usefulness of Information for Melaleuca Control
Park and agricultural land managers were asked to classify various sources for Melaleuca information as useful, somewhat useful, or not useful (Table 8 ). These classifications were scored on a scale of 2, 1, or 0, respectively, in order to compute a weighted average rating in Table 8 . For park/preserve managers, 88 percent rated information from state and federal agencies as a useful source, 10 percent rated it as somewhat useful, and 2 percent indicated it was not useful, representing an overall average score of 1.9. Other information sources with high average usefulness ratings were UF/IFAS Extension (1.9), manager observations (1.8), land manager advice (1.8), weed professionals (1.8), professional organizations (1.7), internet websites (1.7), pamphlets/bulletins (1.6), and the TAME project (1.6).In terms of usefulness of information for agricultural managers, the top rated sources were UF/IFAS Extension (1.4), manager observations (1.1), state/federal agencies (1.1), weed professionals (1.1), land manager advice (1.1), and internet websites (1.1). None of the agricultural managers indicated they considered area demonstration plots, computer software/decision aids, or email/direct notifications as being useful sources of information.
Costs for Melaleuca Control
Managers were asked to indicate the costs incurred during 2003 for the control of Melaleuca. The total annual cost for controlling Melaleuca for surveyed park/preserve managers was $10,866,113 (Table 9 ). This included $8,066,544 for contract services; $837,000 for labor costs; $796,000 for herbicides; $308,000 for equipment; $330,000 for indirect costs; and $528,000 for other miscellaneous costs.Surveyed agricultural managers reported spending $204,790 in 2003 to control Melaleuca, with $129,900 for contract services; $28,975 for labor; $21,610 for herbicides; $17,855 for equipment; $5,950 for indirect costs; and $500 for other costs. If these numbers are expanded to represent all agricultural managers in south Florida, a total of $1,177,543 is estimated to have been spent by these managers on controlling Melaleuca in 2003.
Managers were also asked to indicate expenses for any special equipment or heavy machinery purchased since 1990 specifically to control Melaleuca. It is important to note that these expenses may be partly captured in the previous section under annual costs for equipment expenditures. Park/preserve managers surveyed reported spending an approximate total of $1.44 million for special equipment, with a maximum expenditure of approximately $1.20 million. Agricultural managers reported spending $244,000 on special equipment, which would represent an approximate total of $1.40 million when expanded to represent the population in the region.
Managers were asked how costs for controlling Melaleuca on their land had changed over the past five years: whether the costs had increased, decreased, or remained the same. If there had been a change, they were asked to indicate the percentage change. Among park/preserve managers, 21 percent indicated that costs had increased, 26 percent indicated that costs had decreased, and 32 percent indicated no change in costs. For those indicating a change in costs, the average estimated increase was 253 percent and the average estimated decrease was 117 percent. Among agricultural managers, 11 percent indicated that costs had increased, 9 percent indicated that costs had decreased, and 41 percent indicated that costs had stayed about the same. For those indicating a change in costs, the average increase was 81 percent and the average decrease was 87 percent.
These results suggest that costs for Melaleuca control may be increasing more for park/preserve managers than for agricultural land managers. A plausible explanation could be the fact that most park/preserve managers are managing sensitive ecosystems and are mandated to control invasive plants such as Melaleuca to keep their management area in a more naturally pristine state. Many agricultural managers do not seem to think Melaleuca is much of a problem so they are probably less interested in removing it, along with the fact that some managers find it sometimes provides benefits for their operations.
Impacts of Melaleuca
Information was sought from managers regarding any negative impacts Melaleuca had on their land and management over the past five years. The first part of the question provided the respondents with a list of options as well as giving them the opportunity to specify any other adverse impacts. The second part of the question sought to quantify the impact in terms of the percentage change in function. Among park/preserve managers, 88 percent of those who indicated any impact reported that Melaleuca had impaired the ecological function of their management area, while 35 percent indicated a reduction in the recreational use or value of their land (Table 10 ). A small number of park/preserve managers reported other impacts such as increased fire danger, restriction of necessary clearances, and smoke management issues with prescribed burns. Among agricultural land managers who answered this question, 59 percent indicated that Melaleuca had reduced their land's agricultural productivity, 39 percent said it impaired the ecological function of their land and diminished its recreational use, and 20 percent said that their land market values were reduced. Some of the other negative impacts listed included allergies caused by pollen and various maintenance problems such as damage by falling trees to fences.As a follow-up, managers were asked to estimate the percentage change in value or utility due to Melaleuca infestations. Averages were derived from the responses (Table 11 ). Park/preserve managers estimated that the loss of ecological function and recreational use averaged 23 percent, while agricultural managers estimated that Melaleuca had caused an average loss of 25 percent in recreational use and 24 percent in agricultural productivity.
Annual Income or Budget and Comparison of Reported Melaleuca Control Expenses
Park/preserve managers were asked to indicate their agency's budget for land management activities, and agricultural managers were asked about their gross income from agricultural operations for the year 2003, or to indicate the appropriate range of values (Table 12 ). A small percentage (16%) of park/preserve managers reported their actual budgets, which totaled $9,105,400. Among park preserve managers, 30 percent indicated their budget was less than $50,000; 7 percent said it was within the range of $50,000 to $99,999; 11 percent said $100,000 to $249,999; 9 percent said $250,000 to $499,999; 5 percent said $500,000 to $999,999; and 29 percent indicated their annual income/budget was $1,000,000 or more. Among agricultural managers, 10 percent reported actual income totaling $7,829,795. Some 55 percent indicated their income was less than $50,000; 6 percent indicated $50,000 to $99,999; 12 percent indicated $100,000 to $249,999; 2 percent indicated $250,000 to $499,999; 3 percent indicated $500,000 to $999,999; and 6 percent indicated $1,000,000 or more.Reported expenses for the control of Melaleuca were compared to reported income or budget in order to gauge the relative level of effort allocated to this effort. If managers chose to write in their income, that exact figure was used in the comparison. However, if their income/budget was reported for a range of values, then the midpoint for that range was used, and for the highest and lowest ranges (less than $50,000; $1 million or more), $25,000 and $1.5 million were used, respectively. Only managers who reported both expenses and budget/income information could be used for this analysis.
The analysis revealed that a weighted average of 38 percent of park managers' budgets was expended on control measures for Melaleuca. For some managers, reported expenses were as much as three to eight times more than their budget. A few of the respondents indicated that less than 1 percent of their income/budget was used on controlling Melaleuca. These outliers may be due to reporting errors or may simply be due to the fact that some agencies/operations are involved in deficit spending, such as spending more than their budget provides (e.g., unbudgeted emergency expenditures).
For agricultural managers, an average of 4 percent of their income was spent controlling Melaleuca. The majority of these managers fell into the 1 to 5 percent range, and some reported their control expenses were less than 1 percent. However, some indicated that 60 to 100 percent of their income went to controlling Melaleuca.
References
Bureau of Economic and Business Research (BEBR). 2004. Florida Statistical Abstract. Warrington College of Business, University of Florida, Gainesville, FL.Dillman, D.A. 1978. Mail and Telephone Surveys: The Total Design Method. New York, NY: Wiley and Sons.
Acknowlegments
This research was sponsored in part by the USDA-Agricultural Research Service, under The Areawide Management Evaluation of Melaleuca (TAME Melaleuca). Valuable assistance was provided by Cressida Silvers and Paul Pratt (USDA-ARS); Francois Laroche, Amy Ferriter, and Sharon Wallace (South Florida Water Management District); Debbie Gillet (Southwest Florida Water Management District); Chris Wassil and Gary Lewis (Florida Division of Forestry); and Gail Baxley (Florida Department of Environmental Protection). Critical reviews of this paper were provided by Ferdinand Wirth, Sherry Larkin, and Thomas Stevens of UF/IFAS.
Tables
Table 1. Population size and response rates for Melaleuca management survey.
Park Managers
Agricultural Managers
Population Size 285
11,500
Sample Size 285
2,000
Number of Responses 90
445
Response Rate (%) 32%
22%
Table 2. Land area managed by surveyed professional land managers.
Classification Respondents
Sum
Mean
Minimum
Maximum
(Number)
(Acres)
(Acres)
(Acres)
(Acres)
Park/Preserve Managers
80
5,084,967
Privately Owned 10
86,372
8,637
7.0
70,000
Publicly Owned 67
4,990,670
74,488
4.0
1,400,000
Privately Leased 3
7,925
2,642
105.0
7,500
Agricultural Managers 431
316,528
Privately Owned 390
302,132
775
0.3
140,000
Publicly Owned 3
1,545
515
5.0
1,380
Privately Leased 38
12,851
338
1.0
2,700
Overall Total 511
5,401,495
10,570
Table 3. Land use types and areas managed by professional land managers.
Land Use Type Park Managers
Agricultural Managers
All Managers
Number
Sum
Mean
Number
Sum
Mean
Sum
(Acres)
(Acres)
(Acres)
(Acres)
(Acres)
Park/Preserve 65
4,802,389
73,883
8
30
4
4,802,419
Right-of-Way 16
871,483
54,468
36
4,547
126
876,030
Lakeshore 6
508,272
84,712
7
19
3
508,291
Mitigation/Wetland 14
373,017
26,644
9
251
28
373,268
Pasture/Range 4
25,210
6,503
168
143,243
853
168,453
Crop 2
900
450
50
116,388
2,328
117,288
Fruit/Citrus 3
1,908
636
98
34,275
350
36,183
Nursery 5
19
4
103
1,395
14
1,414
Forest 0
10
1,351
135
1,351
Other Use(s)
16
356,262
22,266
83
18,272
220
374,534
Total of All Uses
6,939,460
319,771
7,259,231
Table 4. Land area infested with and treated for invasive species by professional managers.
Species Park/Preserve Managers
Agricultural Managers
Area Currently Occupied
Area Treated Since 1990
Area Currently Occupied
Area Treated Since 1990
#
Acres
#
Acres
#
Acres
#
Acres
Paper Bark or Punk Tree (Melaleuca)
59
619,317
54
402,088
94
2,134
57
1,460
Australian Pine (Casuarina)
55
111,782
50
16,598
29
34
15
5
Brazilian Pepper (Schinus)
68
425,805
65
75,215
146
7,096
104
2,768
Cogon Grass (Imperata)
33
20,147
31
6,527
14
320
9
73
Old World Climbing fern (Lygodium)
45
113,884
40
49,213
23
178
16
24
Torpedo Grass (Panicum)
33
25,060
31
11,008
40
1,468
31
888
Tropical Soda Apple (Solanum)
32
15,418
25
3,475
37
10,393
32
7,855
Other Plants
37
11,433
36
7,094
33
2,561
18
2,094
Total
362
1,342,846
332
571,218
416
24,184
282
15,167
Table 5. Methods used for treatment of Melaleuca by professional land managers.
Method Used Park Managers
Agricultural Managers
Number
Percent
Number
Percent
Mechanical 31
51
70
33
Foliar/Soil Herbicides 22
36
20
10
Hack-and-Squirt 36
59
8
4
Felling and Herbicides (stump treatment) 50
82
16
8
Biological Control 17
28
3
1
Biological Control + Other Method 13
21
0
0
Other Methods 3
7
4
2
No Controls 13
21
149
71
Table 6. Number of professional managers using various control methods and area of Melaleuca treated, 2003 and 1990-2003.
Method Used Park Managers
Agricultural Managers
Total Area Treated 1990-2003
Area Treated 2003
Area Treated 1990-2003
Area Treated 2003
Area Treated 1990-2003
#
Acres
#
Acres
#
Acres
#
Acres
Acres
Mechanical 20
4,592
22
14,669
43
1,367
37
1,957
16,625
Foliar/Soil Herbicide 15
15,802
15
36,267
15
185
8
355
36,622
Hack-and-Squirt 23
11,454
28
52,437
7
40
5
39
52,476
Felling + Herbicide 37
46,562
37
303,659
14
396
10
274
303,933
Biological Control 7
6,310
10
12,600
2
3
2
42
12,642
Biological + Other 4
4,242
6
80,575
0
0
0
0
80,575
Other Control 3
20
3
110
0
0
1
40
150
Total* 109
84,740
121
419,742
81
1,991
63
2,707
442,449
* Total area excludes biological plus other control methods to avoid double counting. Table 7. Barriers to controlling Melaleuca by professional managers.
Barriers Park Mangers
Agricultural Managers
Number
Percent*
Number
Percent*
No Melaleuca on property
17
28
227
74
Not a problem 8
13
96
31
Don't care 0
0
13
4
Infestations too small 5
8
28
9
Infestations too large 9
15
8
3
Controls won't work 0
0
3
1
Don't know how to use controls 7
12
3
1
No time to use controls 3
5
8
3
Afraid of harm 3
5
5
2
Afraid/Dislike 3
5
5
2
Infestation inaccessible 13
22
6
2
Lack equipment 5
8
16
5
Environmental regulations 2
3
4
1
No cost sharing 8
13
12
4
Controls too expensive 11
18
19
6
Other reason 19
32
14
5
* Percent of respondents answering each question. Table 8. Usefulness of information received by professional land managers.
Source Park Managers
Agricultural Managers
Useful
Somewhat Useful
Not Useful
Useful
Somewhat Useful
Not Useful
Percent of Respondents
Percent of Respondents
State/federal agencies 88
10
2
41
26
33
Professional organizations 77
19
5
37
20
43
Land manager observations 79
19
2
47
19
34
UF/IFAS Extension 88
10
2
61
16
23
Weed professionals 79
18
3
52
4
44
TAME Melaleuca
63
30
7
13
7
80
Land manager advice 81
15
4
47
20
33
Palmphlets or bulletins 62
33
4
26
41
33
Video cassettes or CDs 43
36
21
14
7
79
Area demonstration plots
53
29
18
0
21
79
Computer software 14
43
43
0
14
86
Website/Internet 79
15
6
40
16
44
E-mail/Direct notification 47
37
15
0
14
86
Other information source 75
25
0
21
21
57
Table 9. Costs of Melaleuca control reported by professional land managers, 2003.
Expense Park Managers
Agricultural Managers
#
Sum
Mean
Max
#
Sum
Mean
Max
($)
($)
($)
($)
($)
($)
Contract services 34
8,066,544
237,251
4,060,000
8
129,900
16,238
100,000
Labor 29
837,470
28,878
400,000
17
28,975
1,704
20,000
Equipment 26
308,428
11,863
225,000
18
17,855
992
5,000
Herbicides 33
796,401
24,133
425,000
19
21,610
1,137
15,000
Indirect 19
329,770
17,356
110,000
5
5,950
1,190
5,000
Other 7
527,500
75,357
500,000
1
500
500
500
Total 10,866,113
204,790
Table 10. Negative impacts of Melaleuca reported by professional land managers.
Impact Park Managers
Agricultural Managers
Number
Percent
Number
Percent
Reduced agricultural productivity 0
0
24
59
Lowered marekt value 0
0
8
20
Impaired ecological function 35
88
16
39
Diminished recreational use 14
35
16
39
Other impacts 4
10
8
20
Table 11. Reduction in utility due to Melaleuca infestation reported by professional land managers.
Impact Park Managers
Agricultural Managers
#
Mean
Min
Max
#
Mean
Min
Max
(%)
(%)
(%)
(%)
(%)
(%)
Reduced agricultural productivity 0
18
24
3
100
Lowered market value 0
6
11
5
20
Impaired ecological function 24
23
1
100
11
22
1
50
Diminished recreational use 8
23
1
100
12
25
5
100
Other impact 1
30
30
30
3
43
5
100
Table 12. Annual income or budget for land management by South Florida professional managaers, 2003.
Income/Budget Range Park Managers
Agricultural Managers
Number
Percent
Number
Percent
Less than $50,000 17
30
105
55
$50,000?$99,000 4
7
12
6
$100,000?$249,999 6
11
22
12
$250,000?$499,999 5
9
3
2
$500,000?$999,999 3
5
5
3
$1,000,000 or more 16
29
12
6
Don't know 5
9
32
17
Approximate Amount Reported Number
Mean
Sum
Max
($)
($)
($)
Park Managers 14
650,386
9,105,400
4,385,000
Agricultural Managers 46
170,213
7,829,795
2,450,000
Footnotes
1. This is EDIS document FE671, a publication of the Food and Resource Economics Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL. Published November 2006. Please visit the EDIS website at http://edis.ifas.ufl.edu.2. Katherine Carter-Finn, graduate student; Alan W. Hodges, Assocate In; Donna J. Lee, Associate Professor; and Michael T. Olexa, Professor; Food and Resource Economics Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.
U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
Copyright Information
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