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Tallahassee, FLPermit No. 407

SPRING 2000

GPS Technologies – Equipment and Costs

2 SPRING 2000

Sonar Ad 4/c P/USeapro

WILDLAND WEEDS 3

Wildland WeedsWildland WeedsSPRING 2000, Volume 3, Number 2

Wildland Weeds (ISSN 1524-9786) is a quarterly publication of the FloridaExotic Pest Plant Council (EPPC)

Wildland Weeds is published to provide a focus for the issues and con-cerns regarding exotic pest plant biology, distribution and control. To be-come a member of the Florida EPPC and receive the Council newsletterand Wildland Weeds Magazine, contact the Treasurer.

About the cover:

GPS in Action.Lourdes Rojas uses aGPS unit to trackenvironmentalfeatures along thewest coast of Florida.Photo by Pat Lynch,SFWMD.

FLORIDA EXOTIC PEST PLANT COUNCIL

The Florida Exotic Pest Plant Council has not tested any of the products advertised or re-ferred to in this publication, nor has it verified any of the statements made in any of theadvertisements or articles. The Council does not warrant, expressly or implied, the fitnessof any product, advertised or the suitability of any advice or statements contained herein.

Direct editorial inquiriesto Amy Ferriter, EditorWildland Weeds Magazine:3301 Gun Club Rd.West Palm Beach, FL 33406aferrite@sfwmd.gov

Editorial BoardMike BodleJim CudaRoger HammerKen LangelandSteve ManningDan Thayer

For advertisinginformation contact:Outdoor Tech, Inc.6791 Proctor Rd.Tallahassee, FL 32308Phone 850 668-2353Fax 850 668-2664Debra Tarver

Officers

Tony Pernas, ChairmanP.O. Box 279Homestead, Florida 33030(305) 242-7846tony_pernas@nps.gov

Ken LangelandChair Elect7922 NW 71st StreetGainesville, FL 32606(352) 392-9614kal@gnv.ifas.ufl.edu

Jackie Smith, Secretary3111-B13 Fortune WayWellington, FL 33414(561) 791-4720Smithj1@mail.state.fl.us

Dan Thayer, TreasurerPO Box 24680West Palm Beach, FL 33416(561) 682-6129dthayer@sfwmd.gov

Amy Ferriter, EditorP.O. Box 24680West Palm Bch, FL 33416-4680(561) 682-6097aferrite@sfwmd.gov

Directors

Mike BodleP.O. Box 24680West Palm Bch, FL 33416(561) 682-6132 mbodle@sfwmd.gov

Keith Bradley22601 SW 152nd AveMiami, Florida 33170(305) 247-6547 bradley2@gate.net

Hillary CherryP.O. Box 118526Gainesville, FL 32609(352) 336-2623hcherry@ufl.edu

Dan Clark800 Dunlop Rd.Sanibel, Fl 33957(941) 472-3700dclark@peganet.com

Ed FreemanP.O. Box 8Sarasota, Fl 34230(941) 378-6142efreema@co.sarasota.fl.us

Doria GordonP.O. Box 118526Gainesville, FL 32611(352) 392-5949dgordon@botany.ufl.edu

Francois LarocheP.O. Box 24680West Palm Bch., FL 33461(561) 682-6193flaroche@sfwmd.gov

Brian Nelson2379 Broad StreetBrooksville, Fl 34609(352) 796-7211brian.nelson@SWFNMD.state.fl.us

Committee Chairs

By-LawsFrancois LarocheP.O. Box 24680West Palm Bch., FL 33461(561) 682-6193flaroche@sfwmd.gov

EditorialAmy FerriterP.O. Box 24680West Palm Bch., FL 33416(561) 682-6097aferrite@sfwmd.gov

Legislativevacant

MembershipBrian Nelson2379 S. Broad St.Brooksville, FL 34009(352) 796-7211

MerchandiseJackie Smith3111-B13 Fortune WayWellington, FL 33414(561) 791-4720791-4722Smithj1@mail.state.fl.us

Plant ListDan Austin/Kathy BurksFlorida Atlantic UniveristyDepartment of BiologicalSciencesBoca Raton, FL 33431(561) 297-3327daustin@fau.edukathy.burks@dep.state.fl.us

PublicationsKen Langeland7922 NW 71st StreetGainesville, FL 32606(352) 392-9614kal@gnv.ifas.ufl.edu

ProgramKen Langeland7922 NW 71st StreetGainesville, FL 32606(352) 392-9614kal@gnv.ifas.ufl.edu

SymposiumTony PernasP.O. Box 279Homestead, Florida 33030(305) 242-7846tony_pernas@nps.gov

ResearchJohn Volin2912 College Ave.Davie, FL 33314(954) 236-1115jvolin@fau.edu

EducationJim DuquesnelP.O. Box 487Key Largo, FL 33037(305) 451-1202jpcrsp@reefnet.com

VendorsPhil Waller6651 Englelake Dr.Lakeland, FL 33813(941) 619-6255phil_waller@py.cyanamid.com

Task Forces

Brazilian PepperDean Barber5882 South Semoran Blvd.Orlando, FL 32822(407) 275-4004barber1@mail.state.fl.us

LygodiumAmy Ferriter andTom Fucigna3301 Gun Club Rd.West Palm Bch., FL 33416(561) 682-6097aferrite@sfwmd.gov

CarrotwoodEd FreemanP.O. Box 8Sarasota, FL 34230(941) 378-6142Fax 378-6136efreema@co.sarasota.fl.us

VinesMike BodleP.O. Box 24680West Palm Bch, FL 33416(561) 682-6132mbodle@sfwmd.gov

Exotic GrassesJoe Maguire22200 Sw 137th AvenueGoulds, FL 33170(305) 257-0933flameabl@shadow.net

Skunk VineSheryl Bowman andBrian Nelson10940 McMullen Rd.Riverview, FL 33569(813) 672-7876resmgmt@scfn.thpl.lib.fl.us

Chinese TallowGreg Jubinsky3915 Commonwealth Blvd.MS710Tallahassee, FL 32399(850) 487-2600greg_jubinsky@dep.state.fl.us

MelaleucaFrancois LarocheP.O. Box 24680West Palm Bch., FL 33461(561) 682-6193flaroche@sfwmd.gov

Visit these websites:

Florida EPPC’s: www.fleppc.orgTennessee EPPC’s: www.webriver.com/tn-eppc

California EPPC’s : www.caleppc.org

Table of Contents4 Editor’s Note

4 Exotic Weeds that Threaten the Caribbean: ABrief Overview and Early Alarm Call.by Richard Moyroud

10 GPS and Surveying of WeedPopulations: Equipment andCostsby Pat Akers

15 NAEPPC Meets at Natural AreasAssociation Conferenceby Brian Bowen

16 SE-EPPC President’s Messageby Dan Brown

17 Internodes

4 SPRING 2000

editor’s note

By Richard Moyroud

South Florida has a recent historywhich is highlighted by the introduc-tion of plant species from distant partsof the world. Some of these plant im-portations have proven to be extremelyharmful to the natural environmentand human infrastructure, thus insti-gating work leading to a better descrip-tion of the problem and control

measures. Concerned individuals inFlorida were the first in the UnitedStates to organize a council to identifythe most serious pest plants and com-pare notes on control methods, if any.The Florida Exotic Pest Plant Councilwas established in 1984, and one of theearly documents created was a check-list of the pest plants recognized at thattime. Today, the list includes more than120 species in two categories, based on

Exotic Weeds

ThreatenCaribbean:

A BRIEFOVERVIEWAND EARLYALARM CALL.

oral and written field reports compiledfrom a wide spectrum of observers(FLEPPC 1996, 1999). Category 1 plantsare considered the most serious, sincethese are defined as “Species that areinvading and disrupting native plantcommunities in Florida.” Category 2species have “shown a potential to dis-rupt native plant communities.”

An equally important issue is theeffort to prevent the introduction of

Colubrina asiatica in Dangriga, Belize

THAT

THE

Ten years ago, Global Positioning System (GPS) technol-ogy was just becoming available to the public – emergingfrom a shroud of covert military operations. What once keptPentagon generals huddled in secrecy today tracks Cadillacswith flat tires and sailors aiming for Bimini. Paramedicscan find you in an emergency and trucking companies knowwhich drivers are lingering too long at roadside greasyspoons. Some applications are more notable than others,but the bottom line - it’s hard to imagine what we did beforeGPS.

This technology is extremely important in the exotic plant

management field. Natural areas, by definition, should notbe navigable using a roadmap. GPS lets land managers navi-gate remote properties, inventory plant populations andtrack management efforts. Pat Akers offers a primer on howGlobal Positioning works and some tips on choosing theright equipment in his article, “GPS and Surveying of WeedPopulations: Equipment and Costs” on page 10.

Also in this issue, Richard Moyroud sounds the first alarmfor several plants now invading Caribbean locales (see ar-ticle below). Richard is well acquainted with these inva-sive exotic plants in the United States, and hopes that neigh-boring countries will stop these invaders before they expandand seriously threaten the ecological health of the Carib-bean basin. –Amy Ferriter

WILDLAND WEEDS 5

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any new pest plants. Many research-ers agree that one of the best predic-tors of invasiveness is invasivebehavior documented elsewhere. Car-ibbean Islands and the Central Ameri-can coastline share a large number ofnative and exotic plant species withFlorida. Many of the pest plants inFlorida are just beginning to appear inthe Caribbean, and may become pestsat least as serious as they are in Florida.There are enough signs to warrantthorough research and perhaps earlycontrol efforts.

Surveys by the author throughoutthe Caribbean region - sometimes inthe company of expert botanists, orarmed with the most recent floras ofthe region - suggests that the disrup-tion of native plant communities is inthe earliest stages of development. Cli-matic or edaphic conditions, competi-tion with other species, and existingherbivores may slow or arrest the ex-plosive growth of some pest plant spe-cies, but it would be wise to eradicatethe relatively small nuclei of the worstpest plants as soon as possible.

Bermuda has recently discoveredthe harmful effects of introduced ex-

otics, and has successfully used theFlorida EPPC list to evaluate specieswhich are beginning to show pest plantbehavior. This program of early recog-nition and prompt response is a modelfor other islands (Francis 1999).

In the Bahamas, there are coastaland forest plant communities similarto those in South Florida, completewith many of the same invasive spe-cies. Of the pest plant species listed forFlorida, 29 of the 65 in category 1, and26 of the 58 in category 2 occur in theCorrells’ Flora of the Bahamas Archi-pelago, some with a warning of the in-cipient harm, based on the authors’observations of the species in Florida(Correll and Correll 1982). In additionto disruption of native plant commu-nities, pest plants have been observedin habitats critical to endangeredfauna. In the Bahamas, critically en-dangered rock iguanas (Cyclura spp.)are now restricted to small, rocky cayswhere they subsist on native plants,but need loose sand in which to dignests for their eggs. Australian pine(Casuarina sp.) has been observed withextensive, impenetrable root systemsin the only sandy spot on one such cay,

thus interfering with Cyclura reproduc-tion (International Iguana Society FieldExpedition, March 1992). Brazilianpepper (Schinus terebinthifolius) hasbeen seen on other remote islands, andcould also interfere with nesting sites.Near the airport on San Salvador Is-land, one small population of fruitingS. terebinthifolius was observed in Juneof 1994; it may still be possible to eradi-cate this species from this and otherislands before the populations expandto unmanageable dimensions.

In the drier islands (Turks andCaicos group, St. Croix, etc.), or on drysides of larger islands, giant milkweed(Calotropis procera) and rubber vine(Cryptostegia grandiflora ) are well es-tablished and spreading (Nellis 1997.)These highly poisonous plants addanother dimension to the issue, as live-stock or humans (including tourists)could be harmed by these unwantedplants.

In the Greater Antilles (Cuba, Ja-maica, Hispaniola, and Puerto Rico),approximately half of both Category 1and Category 2 of Florida’s pest plantsshow up in recently published floras(Adams 1972, Liogier and Martorell

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WILDLAND WEEDS 7

1982, Borhidi 1991.) Ironically, there are a few species con-sidered native to the West Indies which appear on the EPPClists, but this does not alter the argument against the otherspecies. Similarly, some species native to Central America,such as Mimosa pigra and Leucaena leucocephala, have behavedas pest plants when introduced into the Caribbean islands.

In islands with significant agricultural production, thefocus has been on unintentionally introduced crop weeds,but some pest plants are known to originate from ornamen-tal introductions. Cuba has had a long standing problemwith Dichrostachys cinerea, a small thorny shrub introducedfrom Madagascar for its attractive flowers (Borhidi 1991).This species (called “aroma” in Cuba) infests many areas,displacing native plant communities and interfering withaccess to coastal sites. D. cinerea is also established in Florida,and has been found germinating in coastal strand of thelower Keys after the disturbance caused by HurricaneGeorges in 1998 (Robert W. Ehrig, personal communication.)It is possible that the seeds for this most recent invasionwere brought to Florida by the hurricane. The establishmentof pest plants in the Caribbean has obvious implications forFlorida, since the unrestricted movement of propagules bywind, water, and human transport is well known.

In Jamaica and Puerto Rico, the damage caused by pestplants may be more subtle. The exotic Selaginella willdenoviihas invaded the understory of some forests (Proctor 1985).This species has long clambering stems and is displacing avariety of native species. Erythrina poeppigiana was intro-duced from Peru as a fast-growing shade tree, but is nowspreading throughout many forests, perhaps replacing the

native Erythrina species. Rose apple (Syzygium jambos) is nowa common component of the understory throughout theCaribbean, but probably passes unnoticed, thus allowingthe species to become firmly established. Finally, rivers suchas the Rio Cobre in Jamaica are choked with Hydrillaverticillata, but no attention is given to the problem (GeorgeR. Proctor, personal communication).

In the Lesser Antilles, there are many pest plants nowidentified as “weeds,” again with an emphasis on crop pests(Fournet and Hammerton 1991). Some of these are well-known pests in Florida, but in stark contrast to the experi-ence in Florida, Australian Melaleuca quinquenervia is knownin the French Antilles as a pleasant ornamental which doesnot yet show invasive behavior. Still, approximately half ofthe Category 1 and half of Category 2 plants from the FloridaEPPC list are included in the Flora of the Lesser Antilles(Howard 1979).

The nation of Belize is located on the Caribbean Coast ofCentral America, and is bordered to the north by Mexicoand to the south and west by Guatemala. Formerly knownas British Honduras, it has had a long history of British for-estry activity, including the introduction of exotic species.Few exotics were noted in vegetation checklists publishedtwenty years ago (Spellman et al.1975, Dwyer and Spellman1981.) Today we can see Casuarina spp., Gmelina arboreaRoxb., and teak (Tectona grandis), all introduced as potentialforest resources, but all of seemingly limited expansion atthis time. Most recently, two species have come to lightwhich could represent the earliest phase of pest plant inva-sion. Latherleaf (Colubrina asiatica ) an aggressive sprawl-ing shrub, is now recognized as a severe problem in thesouthern coastal areas of Florida. One isolated populationhas recently been seen in a mangrove fringe in South Cen-tral Belize, where it has the potential to invade large areas,both natural and farmed (shrimp farms are currently themost important activities in this area). It may not be pos-sible to establish how and when the first plants arrived, butthe current population is small enough to be easily eradi-cated. Australian cajeput or paperbark trees ( Melaleuca spp.)are evident in several regions of the country, and were cer-tainly introduced as part of the early forestry activity.Records may exist with details of species used, origins, andplanting sites. Until recently, the mature trees seemed to beconfined to planted groves, and reproduction was not evi-dent. One small population of old trees (tentatively identi-fied as Melaleuca leucadendron) on a coastal sand berm maybe approaching the century mark, and despite the presenceof capsules with seeds, no seedlings were found anywherein the vicinity. Unfortunately, another population near theinternational airport has been observed to be reproducingrapidly, with many size class individuals spreading from acore population. Given the extensive seasonal savanna ar-eas adjacent to this site, and knowing the behavior of a re-lated species in Florida (M. quinquenervia), we may be seeingthe early phase of an invasion, which could easily be ar-rested before the cost becomes prohibitive, and before irre-versible ecological damage is done.

This brief overview of exotic plants in the Caribbean of-fers a glimpse of a new, underestimated ecological prob-

8 SPRING 2000

lem. In many cases, the results of eco-logical abuse or alteration are quicklymade visible. In the world of plants,the changes are often slow and subtle,and may escape detection until thedamage is extreme. For the people wholive in the islands or mainland, therewill always be questions of resourceuse and protection. In addition, socialpriorities may delay any response tothe pest plant issue. Given our experi-ence in Florida, it seems that the inves-tigation of pest plants in the Caribbeanis an ideal subject for educators, re-searchers, agencies, and others whohave an interest in the health of theecosystems and people of our nearestneighboring lands.

Richard Moyroud is a well-traveledplant aficionado and the owner of Meso-zoic Landscapes, Inc., 202 Grove Way,Delray Beach, FL 33444. (561) 967-2630Fax: (561) 276-8102, e-mail: RNVX54A@prodigy.com

References:Adams, C.D. 1972. Flowering Plants of

Jamaica. University of the West Indies,Mona.

Borhidi, A. 1991. Phytogeography andVegetation Ecology of Cuba.Akadémiai Kiadó, Budapest.

Correll, D.S., and H.B.Correll. 1982. Floraof the Bahama Archipelago. J. Cramer,Vaduz.

Dwyer J.D. and D.L. Spellman. 1981. Alist of the Dicotyledonae of Belize.Rhodora 83:161-236.

FLEPPC. 1996. Florida Exotic Plant Coun-cil occurrence database. Data availablevia Web site: http://www.fleppc.org/.

FLEPPC. 1999. Florida Exotic Pest PlantCouncil’s 1999 List of Florida’s MostInvasive Species. Data available viaWeb site: http://www.fleppc.org/.

Fournet, J. and J.L. Hammerton. 1991.Weeds of the Lesser Antilles/Mauvaises Herbes des Petites Antilles.Institut National de la RechercheAgronomique, Paris.

Francis, Keanya, 1999. Exotic Weeds that

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Threaten the Caribbean. In: Mitigatingthe effects of Exotic Pests on Trade andAgriculture in the Caribbean. Univer-sity of Florida, Gainesville.

Howard, R. A. 1979. Flora of the LesserAntilles. Harvard University Press, Ja-maica Plain.

Liogier, H.A. and L.F. Martorell. 1982.Flora of Puerto Rico and Adjacent Is-lands: a systematic synopsis. Editorialde la Universidad de Puerto Rico, RioPiedras.

Nellis, David.W. 1997. Poisonous Plantsand Animals of Florida and the Car-ibbean. Pineapple Press, Sarasota.

Proctor, G.R. 1985. Ferns of Jamaica.British Museum. London.

Spellman, D.L., J.D. Dwyer, and G.Davidse. 1975. A list of theMonocotyledonae of Belize includinga historical introduction to plant col-lecting in Belize. Rhodora 77:105-140.

Melaleucaleucadendron inAll Pines, Belize

Melaleuca leucadendron near the Belize National Airport, Belize

WILDLAND WEEDS 9

Sepro full page 4/c

“Nautique”

10 SPRING 2000

GPS and Surveying ofWeed Populations

Equipment and CostsBy: Pat Akers, Integrated Pest Control Branch,

California Dept. of Food and Agriculture

Nowadays most people are prob-ably aware of the existence of the Glo-bal Positioning System, better knownas GPS. Many know that it’s useful forsurveying, agriculture, mining, geol-ogy, navigating and locating objects onthe earth. In fact, GPS has found manyimportant uses in natural resourcemanagement, including the mappingof weed populations. This article de-scribes the selection of GPS equipmentfor the mapping and management ofweeds.

A Primer on How it WorksGPS has three major components.

The first component is the GPS unit,which gives us access to the system.A GPS unit is a specialized radio re-ceiver combined with electronics for

calculations. Some GPS units will stopcollecting data under such conditions,and all you can do is wait 20-40 min-utes until the satellites move into abetter arrangement.

Choosing a GPS Unit:Juggling Needs

The selection of a GPS unit willstrongly depend on the needs of theuser. Examples of common user needsare:

1) Accuracy for navigation.

2) Accuracy for detailed mapping(with 2-3 meter accuracy being ad-equate).

3) Accuracy without having to remainon a single location for more than 1second.

4) The GPS data must be easily trans-ferred to a mapping program (Geo-graphic Information System or GIS).

5) The ability to record specific descrip-tive information along with the po-sitional data.

6) The unit should be as convenient touse as possible.

7) Costs should be kept as low as pos-sible. Meeting different require-ments affects the cost of the GPS so-lution.

Low-end Systems - The absolutelylowest cost option is one of the manysportsman GPS models on the market.Many of these units are highly sophis-ticated, very portable, offer a numberof convenient bells and whistles, andcost less than $300, sometimes as littleas $200. For example, both Garmin andEagle manufacture 12-parallel-channelGPS units which have received good

filtering andcalculations.The secondmajor compo-

nent is a set of24 specialized

satellites that theGPS receiver uses for calculating its po-sition. The third component is a set ofground stations for tracking the satel-lites. Each satellite broadcasts severaldifferent sets of information, of whichthree are most important to our discus-sion: 1) a time signal, 2) informationon the satellites’ positions, and 3) aunique binary sequence code (C/A).By receiving the satellite signals, theGPS receiver can triangulate its posi-tion by calculating its distance fromeach satellite. For an expanded descrip-tion of different sets of information seewww.cdfa.ca.gov/gps.

Effects of the System on theField User

The characteristics of the systemhave at least four major effects on itsuse in the field: 1) Ninety-five percentof the time, the system (itself) will es-timate a position within about 22meters of the true position. The De-partment of Defense adds an addi-tional error signal to the system,degrading its accuracy to about 100meters. This makes the accuracy of anexpensive GPS about the same as alow-end model. 2)The receiver has tobe able to lock onto at least four satel-lites in order to determine a positionin three dimensions. 3) Trees, hills orbuildings can obscure the satellite sig-nals. 4) At times, the satellites will beclustered in one small part of the sky.Such an arrangement can seriouslydegrade the accuracy of the position

Scott Park uses a GPS unit to measure aLygodium infestation in the Big CypressSeminole Indian Reservation in Florida.Photo by John Volin.

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reviews from users. These systems arelimited to 100 meter accuracy unlessdifferentially corrected. Althoughmany of these units describe them-selves as “DGPS ready,” an antennaand receiver for the correction datamust be added separately. They alsohave limited capabilities to store GPSposition information, especially de-scriptive data.

The next important improvement isthe addition of differential correctioncapability. There are a lot of options,with lots of trade-offs. However, theissue is further complicated becauseTrimble’s “mapping-quality” GPSunits all provide essentially a completemapping package, including the abil-ity to differentially correct data usingPPDGPS. Since there is almost a quali-tative divide between them and otherGPS systems, I will treat Trimble prod-ucts separately.

Trimble vs. Everybody Else: “MappingGrade” GPS systems - Trimble map-ping products are expensive, but theyprovide mapping data with 0.5-3 meteraccuracy, using a standard computer

and Internet connection. Their systemincludes software (Pathfinder Office)that runs on the PC computer and pro-vides a powerful and easy PPDGPSfacility. The package provides reason-ably flexible data entry capabilities, theability to record information on line-type or area-type objects (instead ofjust points), and flexible integrationwith GIS systems.

Trimble has essentially two linesthat depend on PPDGPS. 1) Trimble’sGeoExplorer is a hand-held GPS thatcosts about $3500 with the batterypack. It provides 1-3 meter accuracy,differentially corrected. It has a fairlyflexible data entry capability and it’scontrolled through a series of menus,but it has only 8 buttons on the key-pad. Text data is entered by scrollingthrough the entire alphanumeric char-acter set, which can be quite tedious.Fortunately, the data entry screens al-low the creation of menus, which canoften minimize the need to enter text.2) Trimble’s Pathfinder Pro XL has theGPS receiver mounted in a backpack,attached to a handheld datalogger, andits 8- or 12-channel GPS engine pro-

vides accuracy to less than a meter.Trimble no longer manufactures it, butit can often be found used. The up-dated versions of the ProXL are theProXR and ProXRS, which integrateRTDGPS capability and provide accu-racy down to 0.5 meters. They cost$9,000 to $12,000. The “ProX” linedataloggers provides better informa-tion about the GPS status than theGeoExplorer and they have full alpha-numeric keypads. For further discussionsee www.cdfa.ca.gov/gps.

And for Everybody Else: Real TimeDifferential GPS (RTDGPS) - RTDGPShas one big advantage over Post-Pro-cessed Differential GPS (PPDGPS): thecorrected, high-accuracy results areavailable immediately in the field. Thismakes RTDGPS extremely useful fornavigation, as its accuracy is 1-20meters, depending on the quality of thereceiver and the reference data. Themajor disadvantage of RTDGPS rela-tive to PPDGPS is that the accurate re-sults depend on remaining in contactwith the reference station. Any loca-tions recorded while out of contact will

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have only 100 meter accuracy, andthere will be no way to improve thataccuracy, either in the field or the of-fice (unless you also have PPDGPS ca-pability, or want to stay on one locationfor an extended period of time so youcan average the results). PPDGPS doesnot depend on remaining in contactwith a reference station. RTDGPS isalso somewhat less accurate thanPPDGPS, but the difference is gener-ally negligible for all but the most de-manding applications. In the past,RTDGPS had other disadvantages hav-ing to do with the complexity and ex-pense of implementing RTDGPSrelative to PPDGPS, especially forimplementing the most dependablesolutions. However, as with mostemerging technologies, costs continueto drop and performance improves. Inthe last year or so RTDGPS solutionshave begun to appear that approachthe cost-effectiveness and dependabil-ity of Trimble units.

The major variable in the cost vs.dependability equation of RTDGPS isthe choice of the source for the differ-ential correction data. For most of us,there are three major sources for cor-rection data: 1) commercial broadcastson FM wavelengths, using transmis-sion facilities of normal commercial

radio, 2) commercial broadcasts fromgeosynchronous satellites, and 3) gov-ernment broadcasts from specializedCoast Guard DGPS transmitters called“Beacons.” As you might expect, thereare trade-offs between cost, conve-nience, and capability for these differ-ent options. For a more completediscussion of sources for data correction seewww.cdfa.ca.gov/gps

Mix and Match - There are two othertrends that can affect the choice of asystem. First, RTDGPS has such over-powering advantages that manufac-turers are integrating RTDGPSreceivers with GPS receivers in theirhigher-end systems. For example,Trimble’s ProXL has been replaced bythe ProXR, which incorporates a Bea-con receiver, and the ProXRS, whichincorporates both a Beacon and satel-lite receiver. The other trend is to turna computer or other equipment into aGPS system. For instance, TeleTypeproduces a small GPS sensor, withoutany readout whatsoever, that can pluginto the PC port of a laptop computerand turn it into a GPS unit. Includingsoftware to allow viewing of the resultsagainst a background map, it costsabout $850. At CDFA, we are about toevaluate a similar system. It combinesa Racal Navigator 2-meter accuracyDGPS sensor (which is a Trimble 8-channel GPS receiver integrated withRacal’s DGPS correction receiver), ahandheld Windows CE computer, anddatalogging/GPS/mapping softwareto create a complete dataloggingRTDGPS system, which should alsoprovide a moving map for navigationpurposes. The sensor costs about$2800, the handheld computer about$600, the software about $700, andvarious costs for cables, battery, andpack bring the total cost to $4500,which includes one year of the satel-lite DGPS subscription service. Thiscompetes in cost with the GeoExplorer,yet provides real-time differential GPSin the field for excellent navigation (es-pecially with the moving map), robustsatellite service, and a very convenientand flexible data entry system.

What’s a Poor Mapper to Do?If you are trying to get into GPS

mapping of weeds, the first step is to

General GPS Web Siteswww.navcen.uscg.mil/dgps –The CoastGuard site for DGPSwww.fs.fed.us/database/gps/ USFS -GPSPage, especially good for access to TrimbleBase Station sitesftp://ftp.trimble.com/pub/cbsfiles/-Trimble’sbase station files from Sunnyvale, CAwww.fs.fed.us/database/gps/eureka.htm -USFSEureka, California GPS base stationwww.cnde.iastate.edu/staff/swormley/gps/dgps.html -Sam Wormley’s DGPSexplanationswww.qualityeng.co.uk/gpstutor -GPS Tutor:fairly detailed treatmentvancouver-webpages.com/pub/peter/index.html -Peter Bennett’s GPS and NMEA Sitewww.geo.swt.edu/reference/Gps.html -GPSLINKSwww.gislinx.com/GPS_Sites/ - Gateway sitefor links to many GPS and GIS issueswww.utexas.edu/depts/grg/gcraft/notes/gps/gps.html –GPS overviewwww.trimble.com/gps/index.htm –TrimbleGPS overview

GPS “General Stores”www.navtechgps.com -Navtech GPS Storewww.cansel.ca –Cansel: sales and rentalsGPS and surveying equipmentwww.geowarehouse.com -Geowarehousewww.nvlt.com/index.html -NVLT GPSReceivers and Satellite CommunicationProducts

Mapping and Surveying GradeGPS Manufacturerswww.trimble.com -Trimble GPS Solutionswww.cmtinc.com-Corvallis Microtech-nology, Incwww.satloc.com/index.stm -Satloc: especiallyfor agricultural applications, but alsomappingwww.ashtech.com -Ashtech, now mergedwith Magellanwww.topcon.com –Topcon, mostly surveying

Consumer-grade GPSManufacturers (includingBeacon RTDGPS receivers)www.eaglegps.com -Eagle Electronicswww.garmin.com -Garmin GPS productswww.magellangps.com -Magellan GPSproducts

Vendors of FM RTDGPSreceivers and serviceswww.accqpoint.com -ACCQPOINT Com-munications Corporationwww.dgps.com -DCI’s DGPS and TMCServices

Vendors of Satellite RTDGPSreceivers and serviceswww.omnistar.com -OmniStarwww.racal-landstar-usa.comwww.racal-landstar.com -Racal LandStar

Post-Processing DGPS Softwarewww.geotronics.se:81/gpssoft.shtml -Geotracer System 2000

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establish your priorities, includingcost. Your budget will determinewhether you can afford differentialcorrection and flexible data entry andmanipulation. Also consider whereyou work. If you work within range ofthe Coast Guard Beacons, this is defi-nitely an option to consider carefully.A simple sportsman model GPS withan added consumer-level Beacon re-ceiver (accurate to 4-12 meters) wouldnot cost much more than $600 total. Foranother $1100-1500 you could add flex-ible data entry, by interfacing a Beacon-based RTDGPS sensor with aconsumer handheld computer andappropriate software. If you work be-yond the range of the Beacons but havea higher budget, Trimble’s GeoExplorerprovides data entry flexibility, goodaccuracy for mapping via PPDGPS,and no continuing subscription costs.If you can afford an additional $800 peryear above the cost of a GeoExplorer,then a handheld computer system in-terfaced with a satellite-based RTDGPSwill give you accurate navigation, veryconvenient data entry, and the freedomof satellite RTDGPS. If you cannot af-ford differential correction, probablygreater overall accuracy can be

achieved with careful marking of 7.5min USGS topographic quads in thefield, rather than GPS. Finally, remem-ber that GPS is an emerging technol-ogy. If you can’t afford what you wantnow, in a year or two it might be avail-able.

Improving the Accuracy of theGPS System: DifferentialCorrection

Most of us would probably wish tolocate a weed to better than 100 meters,or even 20 meters. There are severalways of improving the accuracy of theGPS system, but the one that presentlyoffers the best combination of speed,convenience, cost, and dependabilityis called differential correction, or dif-ferential GPS (DGPS). It is not the mostaccurate, but will provide 0.5 -10 meteraccuracy with one second of data, de-pending on the quality of the GPS re-ceiver. Even the better sportsmanmodels routinely provide 2-5 meteraccuracy using differential correction.One to three meters of accuracy hasproved adequate for our needs atCDFA, and DGPS has so many otheradvantages over more accurate ap-

proaches that we have never imple-mented them.

DGPS works on a simple principle.One unit is stationary, at a known lo-cation, and acts as a reference base sta-tion. The base station unit knows itstrue location, but continues to calcu-late its position according to the infor-mation it receives from the GPSsatellites. The difference between thecalculated position and the true posi-tion provides an accurate estimate ofthe errors in the calculated measure-ment, at the time of the measurement.This estimate of the error can then beapplied to the position calculationsmade at the same time by any GPS unitnearby (called the mobile or roverunit), even if it is moving. For manyapplications, “nearby” can be any-where up to 200 miles.

There are two major methodswhereby differential corrections can beapplied to the measurements made bya mobile unit. 1) Post-Processed DGPS(PPDGPS): The position measure-ments are stored in the mobile GPS andlater downloaded to a computer. Thecorrection measurements from the ref-erence GPS are also downloaded intothe computer, and then specialized

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software applies the corrections to themeasurements made by the mobileunit. 2) Real-Time DGPS (RTDGPS):The correction measurements from thereference GPS are sent to the mobileGPS (almost always by radio), and thecorrections are applied to the positionmeasurements a split second after theyare made. The mobile GPS unit musthave the necessary software and cir-cuitry to apply the corrections to themobile GPS position measurements,but this capability is now common inmodern GPS units, even many sports-man models. Such models use phrasessuch as “DGPS ready” to describethemselves. A separate antenna andreceiver must be added to the GPS unitso it can receive the broadcasts from thereference station. In addition, in manycases access to the reference station sig-nals is sold as a separate service. Inhigh-end professional GPS units, inte-grated receivers for the reference sta-tions are becoming more common.

Pat Akers is a Agricultural Biologistwith the Integrated Pest Control Branch,California Department of Food and Agri-culture, pakers@cdfa.ca.gov

NAEPPC Meets at Natural AreasAssociation Conference

Brian Bowen,SE-EPPC Coordinator

The National Association of the Ex-otic Pest Plant Council met on Octo-ber 13 in conjunction with the 26thAnnual Natural Areas Conference inTucson, AZ. The meeting was well-at-tended with representatives fromCalEPPC, FLEPPC, TN-EPPC, KY-EPPC (forming) and Mid Atlantic-EPPC (MA-EPPC). The PacificNorthwest EPPC was unable to attend.A brief overview was given by BrianBowen regarding the history ofNAEPPC. There was a discussion ofthe MOU signed by FLEPPC,CALEPPC, PACNWEPPC, and TN-EPPC at Asilomar, California in 1995which established NAEPPC. BrianBowen of TN-EPPC, John Randall andNelroy Jackson, both of CALEPPC

who were present a this meeting, alsohelped draft the 1995 MOU. JohnRandall suggested that the MOU beupdated. Nelroy Jackson, who was theoriginal transcriber, agreed to work onupdating it. Brian and John agreed toreview the changes. The MOU willthen be sent to all of the respectiveEPPC boards for approval.

Some noteworthy changes includeupdating the MOU to add the newly-formed Councils. This may also in-clude organizations interested in par-ticipating in the NAEPPC even thoughthey are not an EPPC formally byname, ie., the New York Invasive PlantCouncil. All participating organiza-tions however will be required to sub-scribe to the EPPC mission and itsgoals. The MOU will clearly state thatEPPC’s purpose pertains to naturalarea and wildland weed issues. It was

16 SPRING 2000

also suggested that SE-EPPC have in-dividual state chapter representationto NAEPPC, instead of a single SE-EPPC representative.

Another important topic of discus-sion pertained to completing the EPPCpatent that Florida EPPC began work-ing on last year. A renewed effort willbe made, perhaps enlisting the help ofKY-EPPC, who may have useful legalconnections. NAEPPC will hold thepatent and will have the authority todetermine who can use the name. Thisconcern is based on very non-eppc likegroups forming with very differentpurposes, using the name, and under-mining EPPC’s credibility. Once again,this is very much about keepingEPPC’s original purpose in tact as theonly the non-governmental organiza-tion whose primary focus is naturalarea or wildland weed issues.

NAEPPC voted to support BrianBowen’s nomination to the NationalInvasive Species Advisory Committee.This Committee will advise the Na-tional Invasive Species Council whosecharge under the President’s ExecutiveOrder is to help shape national policyon invasive exotic species issues. TheInvasive Species Council is required tooversee the completion of a nationalmanagement plan by August 2000.Brian was also nominated to representthe Natural Areas Association, wherehe serves as a board member and chairof the exotic species committee. JilSwearingen agreed to write the sup-port letter for NAEPPC. Other EPPCsupport letters were sent by FLEPPC,TN-EPPC, and SE-EPPC.

As the last order of business, JilSwearingen of MA-EPPC was electedchair person for NAEPPC. Her respon-sibilities entail setting the agenda andorganizing next year’s NAEPPC meet-ing at the Natural Areas Conference inSt. Louis, MO. The NAEPPC meetingadjourned after approximately twoand half hours of productive work (seeminutes on SE-EPPC’s web page formore information, www.se-eppc.org).

-Brain Bowen is the Southeast EPPC Co-ordinator and founding member of TennesseeEPPC and the National Association of ExoticPest Plant Councils. He can be reached via e-mail at: nighttrain0@ home.com.

Dan Brown, SE-EPPC President

A friend told me this short story sev-eral years ago. It is still one of my favor-ites: Two newborn babies are lying inadjacent cribs. They are facing eachother; and they appear to look at eachother and smile. Time passes. Eightyyears later, the same two people meetonce again. They are in adjacent hospi-tal beds, and they both are near death.Their eyes meet; they smile; and one saysto the other: “Well, what did you think?”

Now, you may be thinking: “Brownobviously doesn’t have a president’smessage, because he’s starting out withsome off-the-hospital wall short story.”

Here’s my point: SE-EPPC is new. Alot of changes are going to happenaround us - involving us, and exotic in-vasive plants - over the next few years.During our early years of growth, we(SE-EPPC) can have a lot of impact onwhat those changes are. Take a look atour objectives: We’re basically sayingthat we want to make the public moreknowledgeable about invasive exoticplants. We want them to know how se-riously these plants can spread and takeover areas and even choke-out the na-tive plants. We want them to know how

to control these exotics...and we wantthem to know more about growing na-tive plants.

So, what are some good ways to ac-complish these objectives? If you were(or are) a land owner or land manager,what would you want to know aboutthese exotic pests? Think about it. Talkto other members; talk to the public. Letme, or the other officers, or board mem-bers know what you’re thinking - newpublications, workshops, ways to in-crease membership, newsletter topics,whatever! We can use your ideas to de-velop important, practical activities andproducts relating to our objectives. We’rea new organization. You, the members,have a tremendous amount of knowl-edge and expertise relating to exotic pestplants, and to native plants. Let’s use thatknowledge and expertise to make a posi-tive difference for the Southeastern en-vironment - and beyond.

...and then in the not too distant fu-ture, when someone asks you whatyou think of SE-EPPC; you can say:“................!”

-Dan Brown is the President of the South-east Exotic Pest Plant Council. He can bereached via e-mail at: Mtnrr@ aol.com.

HOSTEDBY THE

NORTH CAROLINA BOTANICAL GARDENThe University of North Carolina at Chapel Hill

To obtain a program and registration form and and for futrher information, call

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www.unc.edu/depts/ncbg

Southeast Exotic Pest Plant CouncilAnnual Symposium

Invasive Exotic Species:Truth and Consequences

March 16, 17, 18, 2000The level of awareness of the negative effects that invasiveexotic plants have on the environment, economy andhuman health is increasing. Concerned individuals mustsustain and expand this educational momentum andstrive to reduce the threats of biological pollution. ThisSymposium is a key forum for bringing togetherindividuals from diverse backgrounds andperspectives to help meet this challenge.

Ampelopsis brevipedunculata, porcelain berry by Sandra Brooks-Mathers 1999

SE-EPPC President’s Message

WILDLAND WEEDS 17

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Maui Invasive SpeciesCommittee Hires ‘SWATTEAM’

The Hawaiian Islands are home ofsome of the world’s most unique bio-logical diversity, yet the 50th state alsohas the highest number of endangeredspecies for the United States. Amongthe many threats to these endemicplants and animals (found nowhereelse on earth!), are invasive speciesbrought from all corners of the globe.An under-funded State Department ofAgriculture has its hands full trying tolimit new serious introductions andlooks forward to developing technolo-gies that will aid them in this hugetask. But in the meantime, how doesHawaii prevent incipient invadersfrom establishing beyond control?

Help is on the way! While tacklingharmful alien species on all of the islandsmay be overwhelming, the islands ofMaui County have organized to set aprecedent for others to follow. Over the

tems similar to Maui’s; it’s anticipated(through a system of scientific criteria)that they will wreak havoc if they’reallowed to become established in MauiCounty. While eradication is a noblegoal for many of these alien threats, thevalue of immediate containment is alsorecognized.

The newly hired MISC field crewwill perform the real ‘on the ground’work to halt the establishment of tar-geted species. Their duties include sur-veying, mapping, control, datatracking, landowner interaction, andpublic outreach and education. Afterrecently taking this crew out on ‘scoutand control’ missions for Miconia(Hawaii’s worst incipient weed), I amhappy to report that the able-bodied‘SWAT Team’ will prove their determi-nation to rid Maui of these unwantedpests. -Pat Bily, The Nature Conser-vancy of Hawaii , pbily@tnc.org.

The “Witch Doctor” isout to pasture

Dr. Robert E. (Bob) Eplee, dubbedthe “Witch Doctor” for his many yearsof service to the witchweed eradicationprogram retired from the USDA on De-cember 31, 1999. Bob is a native ofMcDowell County, NC. He received aB.S. (and he’s good at it) from BereaCollege in Kentucky, a M.S. from theUniversity of Kentucky and Ph.D. fromNorth Carolina State University. Hewas an Extension Agent in Kentuckyfrom 1957-1962, a lead scientist andDirector of the Witchweed/WhitevilleMethods Development Center, USDA,ARS from 1965-1995, and has beenwith USDA, APHIS/PPQ since 1999.

Many of us know Bob for his long-time involvement in weed science. Heserved as primary liaison with the WeedScience Society of America (WSSA) to-ward passage of the Federal NoxiousWeed Act of 1974. In the 1970s he workedwith the University of Florida and theImperial Valley in California to develophydrilla control methods (hiring theyoung rising star, Randall Stocker to de-velop triploid white amur in CA). In the1980s he worked with state agencies anduniversities to eradicate several FederalNoxious Weeds, including crupina,goatsrhue, wormleaf salsoa, broomrape,

Internodesyears, good relations among variousconservation agencies has led to effec-tive partnerships that identify commongoals for the overall protection of Maui’snatural areas. More recently, these part-nerships have culminated in the forma-tion of the Maui Invasive SpeciesCommittee (MISC).

MISC has interested parties from notonly conservation and local government,but the private and business sector aswell. The committee expanded its focusof simply preventing invasives’ impacton conservation areas, to include threatsto economy, health, and quality of life.Hard work from dedicated individualsresulted in funding from a large pool ofstakeholders, and this formed the oper-ating budget to execute this year’s MISCAction Plan.

This Action Plan prioritizes theworst plant and animal pests that arecurrently at the beginning stages ofbecoming established in Maui County.Research has shown these target spe-cies to have severe impact in ecosys-

18 SPRING 2000

Join the Florida Exotic Pest Plant Council!

Annual Membership Dues Include:Quarterly magazine, Wildland Weeds • Quarterly newsletterLegislative updates regarding exotic plant control issues.

Membership:

INDIVIDUALStudent - $10General - $20Contributing - $50Donor - $51-500

Wildland Weeds subscription - $15/year (does not include other membership benefits)

Name: ______________________________________________________________________________

Address: ____________________________________________________________________________

Telephone:__________________________________e-mail: ________________________________

Membership type: __________________________________________________________________

Mail to: Dan Thayer, 3301 Gun Club Rd., West Palm Bch., FL 33406

INSTITUTIONALGeneral - $100Contributing - $500Donor - $501-$10,000Patron - $10,000 or more

and itchgrass. He was named Weed Sci-ence Fellow by the WSSA in 1993. Mostrecently, many of us have worked withBob or are familiar with his efforts ontropical soda apple, wetland nightshade,and redrice eradication, participation onthe Federal Interagency Committee forthe Management of Noxious and ExoticWeeds, and contributions to the OTAReport on Harmful Non-indigenousSpecies and the Executive Order on In-vasive Species.

For Bob Eplee’s ambition and ac-complishments in solving invasive/noxious weed problems we owe a debtof gratitude. And although he is offi-cially retired I don’t think we’ve heardthe last of him, as he slipped while Iwas talking to him on the telephonethat he was “fixing up an office in theback of the lab.” Keep in touch, Bob.

– Ken Langeland.

IFAS Circular 1204, “Help Pro-tect Florida’s Natural Areas FromNon-Native Invasive Plants” hasbeen updated to reflect speciesthat were added to the DACS Nox-ious Weed List in 1999. Multiplecopies are available free to EPPCmembers from the IFAS Center forAquatic and Invasive Plants. Ifyou would like to obtain copies tohand out at meetings where theycan be used for public educationplease contact us at 352/392-9613/1799 or kpb@gnv.ifas.ufl.edu.

Florida Federation of Garden ClubsBlossoms and Butterflies Conference.Winter Park, FL. March 14-16. ContactCaron Beatty 904/241-1563.

Southeast Exotic Pest Plant CouncilAnnual Meeting. North Carolina Bo-tanical Garden, Chapel Hill. March 16-18. Contact: John Randall jrandall@email.unc.edu.

Association of Southeastern Biolo-gists Annual Meeting. University ofTennessee, Chatanooga. April 5-8.Contact Patricia Dreyer 423/576-8123or see http://am.appstate.edu/top/dept/biology/asb/.

BES/ESA 2000: A Joint Meeting ofthe British Ecological Society and theEcological Society of America. Or-lando, FL. April 9-13. Contact ESA202/833-8773, esahq@esa.org or seehttp://esa.sdsc.edu.

Sixth International Conference onRemote Sensing for Marine andCoastal Environments. Charleston,South Carolina. May 1-3. (A pre-con-ference workshop will address the usesof GPS and geographic informationsystems technologies for natural re-source management.) Contact: NancyWallman, PO Box 134008, Ann Arbor,

Michigan 48113-4008, (734) 994-1200,wallman@erim-int.com, www.erim-i n t . c o m / C O N F / m a r i n e /MARINE.html.

Florida Native Plant Society Annualmeeting, Miami Florida. May 4-7. Con-tact: Keith Bradley 305/644-0452, con-ference@ fnps.org.

Ecosystems Restoration and Cre-ation (formerly Annual Conference onWetlands Creation). HillsboroughCommunity College, Tampa, FL. May11-12. Contact: Frederick J Webb 813/757-2148, webb@mail.hcc.cc.fl.us.

Florida Exotic Pest Plant Council15th Annual Symposium. WestinBeach Resort, Key Largo, FL. May 16-18. Contact: Ken Langeland 352/392-9614, kal@gnv.ifas.ufl.edu.

Third International Weed ScienceCongress. Foz do Iguassu, Parana, Bra-zil. June 6-11. Contact: P. J. Eventos 55/41/372-1177, pj@datasoft.com.br,http://www.sercomtel.com.br/ice/plantas

International Meeting for the Soci-ety of Conservation Biology. Univer-sity of Montana, Missoula. June 9-12.Contact Fred Allendorf 406/243-4184,darwin@selway.umt.edu, http://conbio.rice.edu/scb/announcemts/2000meeting.shtml.

40th Annual and InternationalMeeting, Aquatic Plant ManagementSociety. Handerly Hotel and Resort,San Diego CA. July 16-20. Contact JimSchmidt 800/558-5106, jimschmidt@appliedbiochemists.com.

85th Annual Meeting of the Ecologi-cal Society of America. Snowbird Utah.August 6-10. Contact ESA 202/833-8773, esahq@esa.org or see http://esa.sdsc.edu.

International Conference of the Soci-ety for Ecologial Restoraton. LiverpoolEngland. September 4-9. Contact: SER608/265-8557, ser@macc.wisc.edu,http://www.ser.org.

Mark Your Calendar

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