Presented at the South Florida Native Plant Seminar
Presented at the South Florida Native Plant Seminar
October 18-19, 2023
October 18-19, 2023
Naples Botanical Garden
Naples Botanical Garden
Thank you to our sponsors
BEACH DUNE HABITAT MANAGEMENT AND SEAGRAPE PRUNING
How a continuing obsession with one species harms the ecosystem as a whole.
Robert H. Barron, Coastal Management and Consulting, Coastal Growers Inc.
Continuing Education Credit Course presented for Landscape Architects and Natural Resource Managers, , FLORIDA ASSN. OF NATIVE NURSERIES
This presentation is a condensation of materials delivered to a number of objective hearings and committees reviewing the issue of pruning seagrape, Coccoloba uvifera, in context of management of beach dune systems, in southeast Florida. Basic tenets include:
• Seagrape was not a dominant plant in the natural historic condition.
• Seagrape is a fast growing and brittle wood which fares poorly in a storm, and in tree form breaks apart and uproots.
• Seagrape, if not controlled is highly invasive; overshadowing and killing other components of the dune system.
• Seagrape can be heavily pruned, in a comprehensive program of dune habitat management, with overall reduction in turtle nesting habitat light pollution.
Basic tenets: • Seagrape was not dominant • in the natural historic condition.
First description of Florida dune, by Jonathon Dickinson 1696..”no trees, but only sand hills covered with shrubby palmetto”
Floristic inventories by Craig, 1974, 132 sites, seagrape dominant on 9%. and Richardson, 1977, “all parts of the strand habitat, the dominant species is Serenoa”.
Ocean to river was palmetto dominated strand in natural condition. Historical photos and literature yield character of the wild dune.
Palmetto Park and A1A location, Boca Raton ca 1925. Ocean to river was palmetto scrub. No tree form seagrape.
1876 US LIFESAVING SERVICE
HOUSE OF REFUGE, DELRAY BEACH
PALMETTO SCRUB.. NO TREES
EARLY DELRAY BEACH COASTAL HOMESITE..no trees.
DELRAY BEACH CLUB SITE
CA 1950
NO TREES except Australian pines
Scrub species and palmetto
SEAGATE DELRAY. 1951 early development in natural system..
From FLORIDA DUNES AND SCRUB, Florida Geological Survey, 1942
Compare to
CANAVERAL NATIONAL SEASHORE, 2017
20 plus miles of coastal strand in natural condition
SPESSARD HOLLAND BEACH, BREVARD COUNTY, 2014
EXISTING COASTAL STRAND IN NATURAL CONDITION
is the model for our dune management program.
Seagrape was historically controlled to shrub height by occasional freezing temps. NOAA historical records demonstrate much more frequent freezing episodes throughout South Florida, but less and less as urban heat sink increased with development. A three day hard freeze destroyed agriculture in Delray in the 1920’s.
1991 freeze at Atlantic dunes
Seagrape, cocoplum frozen to grade
1991 freeze incident, Boca Raton Park.
Explains historic regional domination of palmetto in strand. Even today, seagrape not common above Daytona.
. Basic tenets:
Seagrape is a fast growing, shallow rooted and a brittle wood which fares poorly in a storm. Tree forms uproot and break apart, delivering damaging missiles to the wind.
“The Worst Tree”, as described by U. of F. study.. Hurricane Andrew Damage to the Urban Forest, A Preliminary Evaluation”
“The Worst Tree”
University of Florida Study
HURRICANE ANDREW DAMAGE TO THE URBAN FOREST: A PRELIMINARY EVALUATION Duryea et al
Crandon Park, 2 weeks after H. Andrew
Excavation of oceanfront development site reveals comparative depth of Coccoloba (dark color) vs Serenoa (light) roots. Half of seagrape rootmass is in top 8 inches of soil, from Eisenstadt, UF Citrus Lab study “Seagrape Root Distribution Following Hedging’
Seagrape tree toppled by tropical storm force winds
Ilustrates shallow root system.
Seagrapes planted in 1980 did not begin to thrive until after sea oats foredune was installed six years later..then grew to 25 ft. in the next 16 years.
6 year old seagrape clusters, installed at Delray Beach at 10 X 15 feet
Section17Seagrapeexpansion since1985
Redlineis approximatefootprintofseagrapeclusters as installedtotrapsandataccess points 1982;about300 sqft.
Yellowis footprintattimeof2001FDEPpruningpermit; about4,500sq.ft.
Whitelineis seagrapefootprintat2015FDEPexotic removalpermit;about10,500sq.ft.
35Xincreasesinceplanting,2.3Xincreasesincepruning began.7%/year,expansionsincepruningbegan.
20 years after planting..
Comprehensive Dune Management Plan was written in 1997, to include exotic removal, pruning, replanting.
phototropic habit of coccoloba leaves large areas under canopy unrooted and vulnerable
Deliquescent growth form spreads to light and overshadows everything below. This is a single individual with branches that rooted into ground at touchpoints and started new trunks.
Yucca aloifolia under seagrape canopy in Juno.
Struggling and will fail with reduced light.
DEAD SAW PALMETTOS. Remember that this was the dominant species in the natural state.
Shading by seagrape has killed most of the native strand species which occupied this park only 20 years ago. Rare and listed plant species are lost. This was a choice!
Overshadowing has cost most of the biodiversity. The rich natural character is all but lost..
What remains is a near sterile monoculture.
only seagrape
WHY IS SEAGRAPE SO COMMON ON THE DUNE?
Cheapest and fastest growing nursery plant with the word “sea” in common name
First shrub species designed in to new Beachfront landscape plans.
Can be cut almost to grade at any time of year with zero mortality
This dune area was illegally cut to ground level in June of 2019, and has recovered to three feet.
What is the scientific rationale for these pruning height treatments?
Why 3 feet?
Why 10 feet?
Why any of this?
Why 15 feet?
Just above bollard height is adequate to shield marine turtle nesting zone from road light
So..What is a reasonable and prudent alternative?
MANAGE FOR THE WHOLE ECOSYSTEM
RATHER THAN JUST
ONE SPECIES OF TREE
ECOSYSTEM MANAGEMENT
OBJECTIVE:
Restore the complete natural plant complex and full habitat function.
Objective FDEP evaluation yields permits to do this.
Work in progress.. exotics removed..
But wait !
Uninformed public ALWAYS freaks out, like early controlled burns. County ERM complains to FDEP and work is halted.
However, the science holds up, and
after much turmoil and thorough review, FDEP reaffirms, approves, and funds the comprehensive habitat managent program.
March 2017, most recent FDEP permitted coppicing, exotic removal, species enhancements, to guidelines of international Society for Ecological Restoration.
Comprehensive Habitat Restoration
A 35 year project
More than 110 species, including threatened and endangered State and Federal species, several rescued from at risk locations, including County Parks.
from International Standards for the Practice of Ecological Restoration
Society for Ecological Restoration acknowledges Delray Beach dune project based on these principles as example of 4/5 star recovery.
SO..What about permits to prune or modify the dune?
STATE FDEP Coastal Construction
Control Line review will determine what permit level is required. either:
Exempt ( risky but no cost),
Field Permit (simple, low cost, quick), or
Admin Permit (complex, costly, slow). And there are a few conflicting local or county processes as well.
FDEP Field Permit is best option.
SPECIALPERMITCONDITIONS Thepermi isvaldonlyafteralapplcable ederal sate andlocalpermtsareobtainedanddoesnotauthorzeconravenion of oca setbackrequrementsorzoningorbuildingcodes Thspermi andpubicnotceshal beposedonthesieimmedaeyuponissuanceandshal emanposted alongwih ocalapprovaluntlthecompleionofanyactviyauthorzedbythspermi Otherspeca condtonsofthispermi ncude:
Standardfieldpermitconditionsprevail. Noadditionsand/ormodificationsw/opriorDEPapproval. Anyworkoccurringseawardofthedunecrestand/orwithinmarineturtlenestinghabitatmustbecoordinatedthroughandwithFWC MarineTurtlePermitHolder,daily.
Useofheavyequipmentisnotauthorizedonduneand/orbeach. Allnewplantingsmustachieveandmaintainasurvivabilityrateofatleast85%.,otherwiseadditionalplantingswillbecome necessary.
No fees, Minimum prep costs
STANDARDPERMITCONDITIONS: Thepermiteeshalcompywih heatachedstandardfedpermi condi ons
APPLICANTINFORMATION:Iherebycert ythatIamether:(1a)theownerof hesubjec popertyor(1b) have heowne’sconsenttosecurethspermi onthe owner’sbehaf;andthat(2)Ishalobainanyapplcablelcensesorpermiswhchmaybe equiredbyfederal sae couny o muncpa awprortocommencemen of heauthorizedwork;(3)Iacknowedgetha heauthorizedwokiswhatIrequesed and(4 Iaccep responsbliyforcompiancewihal permtcondiions
ApplcantsSignaure_ Date TeephoneNo ( )
Applcan sPrintedName_ Address Ifapplcan sanagent
_ /( ) __
Prin ednameofpropertyowner Propertyowner’saddress Propertyowner’s elephoneno
DEPARTMENTFINALACTIONANDFILINGANDACKNOWLEDGMENT:Thsfedpermt sapprovedonbehafoftheDeparmen ofEnvironmenta Protection by heundersignedsafdesignee,andfiedon hsdae pursuant osecion12052,FS wththeundersgneddesignaedDeputyClerk receip ofwhich shereby ack d d / /_
Seeabove 03/20/19
JasonM.Spanier
Staff gn pu y PrintedNameofDesignee/DeputyClerk Da e
EXPIRATIONDATE:
03/20/20
(EmergencypermitsissuedpursuanttoSecion62B-33014,F.AC arevald ornomoethannineydaysandotherfieldpermisarevaldfornomoethan12 months Thestaffdesgneemayspecifyashortertme imi
EMERGENCYPERMIT: NO YES NO Approvedpansaeatached YES
Page2of4 DEPfom73-122(Updated5/05)
Sometimes a nightime lighting survey may be required to demonstrate compliance with FWC marine turtle nesting rules. Applicant must show project does not increase risk to hatchlings.
DSC _0184, Nikon D3400
1 sec, F5.6, ISO 400, EV1, 55mm
26.32.58 N, 80.02.31 W, 285°
South Studio/Main House
Hand drawing includes location, dimensions, existing and proposed conditions. Complies with Field criteria.
What are pruning costs, methods?
Delray Beach, 6,840 feet, three machete cuts/yr, $35K to $40K annually , with staff labor.
Sloans Curve Condo, Palm Beach. First FDEP permit for tree reduction and hedge pruning . 1990
Maintained at 42 inches for 27 years, Four machete cuts/yr, $4,800, 600 feet.
SHI Condo, 600 feet shoreline X 25 feet.
Hand pruned monthly, $6K annual cost
HOW?
Cost of not pruning?
Two seasons with no pruning and 36 inch grows to 6 to 9 feet above grade killing most other beneficial species.
Seven months of neglected pruning
Five feet verticle growth
Two years no pruning
Look for the guy with the mask!
Back to chain saws after two year neglect THE COST for single repair pruning.. nearly $100,000.00
FDEP permitted Hutchinson Island project under way 2020 cuts overshadowing seagrape 12 to 24 inches above grade for maintenance at hip high, and installs 8600 saw palmettos and other strand zone plants (50 + species) on 1 mile of shoreline.
1/3 Million $ Project
Field permit was secured with simple drawing, based on 30 year Delray Beach model.
FPL DUNE HARDENING PROJECT.
Including removal of exotic plant species, pruning native species to restore strand growth habit, and enhancement planting with FDEP approved coastal native species per attached FPL St Lucie Power Plant Dune Hardening Project Description.
Approximately 4650 feet shore parallel from about FDEP monument SCR-085 at the North, to SCR-079 to the South, and from the high water line on the East to the upland base of the dune berm on the West.
Permits are for one year, but subsequent maintenance is exempt.
2013 Juno By The Sea project cut seagrape to shrub height, replanted historically correct species mix, and modified all upland lighting to FWC standards. Rare plants included. Annually maintained exotic free.
So, if not seagrape, then what species?
Blackbead, Pithecellobium keyensis
Florida Privet, Forestiera segregata
White indigoberry, Randia aculeata
The dominant plant in the natural ecosystem was saw palmetto..very deep roots, best for storm resistance
Golden creeper, ( Ernodea litorallis)
Blackbead, (Pithecellobium)
Cocoplum coastal variety, aka “horizontalis Chrysobalanos icaco
Most coastal shrubs are compact leaf, dense and shearable, evolved under salt spray.
Randia aculeata, white indogoberry
Well adapted to high energy salty environments
But can be maintained long term in formal oceanfront Landscapes.
This is an entirely man made dunescape
FANN growers can provide 60+coastal species
