Urban Forest Hurricane Recovery Program

Urban Forest Urban Forest Hurricane Recovery Hurricane Recovery

ProgramProgramhttp://treesandhurricanes.ifas.ufl.edu

Selecting Wind Resistant

Trees:Coastal Plain

SpeciesMary DuryeaEliana Kampf

• Study• Methodology• Results• Lists of wind resistance• Recommendations for a healthy urban forest

Andrew165 mph1992

Georges

110 mph1998

Katrina125 mph2005Rita

120 mph2005

Ivan130 mph2004

Opal125 mph

1995

Erin85 mph

1995

Dennis120 mph

2005Charley145 mph

2004Puerto Rico

Louisiana

Mississippi

Alabama

Florida

Georgia

Hurricanes Measured in StudyFunding: FL DOT and DOF, USDA Forest Service

Jeanne120 mph

2004

• SE Coastal Plain

• Subtropical & Tropical

• Urban neighborhoods randomly chosen at point of landfall

• All trees along streets were measured• Standing, leaning or fallen• Measured dbh, height for palms• Defoliation, branch damage

Methodology

• Surveyed 240 arborists, urban foresters, forest scientists• Asked them to rank 160 tree species for wind resistance

Wind and Trees Survey

sand

live o

akSu

rviv

al (%

)

Tree Species

loblolly pine

american

SE magnolia

live o

ak

wax m

yrtle

sweet

gum

crape m

yrtle

dogwood

sabal palm

laurel oak

pecanred

maple

chinese

tallo

w*

sycamore

slash pine

water o

ak

Bradford pear

black ch

erry

SE red ce

dar

SE red oak

longlea

f pine

Carolin

a

sand pine

spruce

pine

tulip

poplar

0

10

20

30

40

50

60

70

80

90

100

laurelch

erry

holly

* prohibited species in Florida

LSD = 35%

ResultsHurricane Ivan

(130 mph)

Aver

age

Bran

ch L

oss (

%) spru

ce

pine

sycamore

SE red oak

laurel oak

SE red ce

dar

sweet

gum

chinese

tallo

w*

live o

ak

pecanwate

r oak

red m

aple

black ch

erry

SE magnolia

slash pine

longlea

f pine

sand live o

ak

Bradford pear

wax m

yrtle

dogwood

crape m

yrtle

loblolly

pine

American holly

sand pine

tulippoplar

0

5

10

15

20

25

30

35

C. laurel

cherr

y

* prohibited species in Florida

Hurricane Ivan (130 mph)

Tree species

LSD = 11%

Results

Bran

ch L

oss

( %)

0

5

10

15

20

25

30

35

Tree Diameter

P<0.0001

39-79 in.20-39 in.8-19 in.< 8 in.

Large trees do more poorly than

small trees

Surv

ival

(Rec

alcu

late

d) (

%)

* prohibited species in Florida

Tree Species

American

holly

wax m

yrtle

SE magnolia

crape m

yrtle

live o

ak

dogwood

sabal palm

slash pine

pecan

red m

aple

Bradford pear

laurel oak

water o

ak

loblolly

pine

black ch

erry

longleaf p

ine

chinese

tallo

w*

sycamore

SE red oak

SE red ce

dar

sand pine

C. laurel

cherr

y

spruce

pine

tulippoplar

0

10

20

30

40

50

60

70

80

90

100Hurricane Ivan

(130 mph)

sand live o

ak

sweet

gum

LSD = 25%

Results

Laurel Oak

• Rapid growing, short lived (mature at 50 yr)

• Light wood (0.56 g/cm3)• Damaging when it falls

Survival of Oaks in North FL

Sand live oak Live oak Laurel

Surv

ival

(%)

Erin (85 mph)

Dennis (120 mph)

Opal (125 mph)

Ivan (130 mph)

20

40

60

80

100

0

P<0.001

Hurricane

Sabal Palm

85 120 125 130 145Surv

ival

(%

)

Wind Speed (mph)

020406080

100

165

92%

93%

Erin Jeanne Opal

IvanCharley Andrew

Southern Magnolia

• 96%, 97%, 92% standing after Erin, Opal, Ivan

• Excellent survival rate even though it lost about 43% of its leaves

Southern Red Cedar

0

20

40

60

80

100

Surv

ival

(%

)

Wind Speed (mph)85 12

0125

130

Erin Dennis

Opal Ivan

Wind Speed

0

20

40

60

80

100

0

20

40

60

80

100

85 120 125 130 14585 120 125 130 145

Erin

Jeanne

OpalIvan

Erin Opal

CharleyIvan

Slash PineErin

JeanneOpal

CharleyIvan

Longleaf Pine

Sand Pine Loblolly PineOpal

Ivan

Surv

ival

afte

r Hur

rican

es (%

)

Andrew

165 165

Pines

Pines

• Dangerous to have large trees close to buildings• Medium to Poor wind resistance:

• Longleaf & Slash > Loblolly > Sand & Spruce pine• Continue to die after hurricanes:

• Ivan (130 mph): Lost an additional 2-3%• Charley (145 mph): Lost an additional 50%

Live Oak

Defoliates early –Leaf loss was positively correlated with survival(p<0.0001)

Strong wood – 0.8 g/cm3

Species with higher wood density survived better

and lost less branches (p<0.0001)

Strong roots

Native vs. Exotic Trees Su

rviv

al

(%)

Hurricane

********NS

Native speciesExotic species

020406080

100

Jeanne Ivan Charley

• 85 surveys (35%) were returned• Combining:

• our study results• survey• scientific literature

Lists of Wind Resistance

Wind and Trees Survey – Results

Scientific Name Common Name

Wind ResistanceHigh Medium Low

# % # % # % Total #

Liquidambar styraciflua

sweetgum 18 43 21 50 3 7 42

Magnolia grandiflora SE magnolia 44 83 8 15 1 2 53Pinus clausa sand pine 3 7 7 17 32 76 42Pinus palustris longleaf pine 23 59 11 28 5 13 39Pinus elliottii slash pine 16 26 35 57 10 16 61Quercus laurifolia laurel oak 3 4 26 39 38 57 67Quercus virginiana live oak 63 89 8 11  0 0 71Sabal palmetto sabal palm 71 99 1 1 0 0 72Phoenix canariensis Canary Island

date palm 49 89 4 7 2 4 55

Taxodium distichum bald cypress 59 91 6 9  0 0 65Taxodium ascendens pond cypress 40 91 4 9 0  0 44

Highest Wind ResistanceDicotsCarya floridana, FL scrub hickoryCornus florida, dogwoodIlex cassine, dahoon hollyIlex glabra, inkberryIlex opaca, American hollyIlex vomitoria, yaupon hollyLagerstroemia indica, crape myrtleMagnolia grandiflora, southern

magnoliaQuercus geminata, sand live oakQuercus laevis, turkey oakQuercus myrtifolia, myrtle oakQuercus virginiana, live oakPodocarpus spp, podocarpusVaccinium arboreum, sparkleberryConifersTaxodium distichum, baldcypressTaxodium ascendens, pondcypressPalmsButia capitata, pindo or jellyPhoenix canariensis, Canary Island datePhoenix dactylifera, dateSabal palmetto, cabbage, sabal

Medium-High Wind ResistanceDicotsAcer saccharum subsp. floridanum, FL sugar

mapleAcer palmatum, Japanese mapleBetula nigra, river birchCarpinus caroliniana, ironwoodCarya glabra, pignut hickoryCarya tomentosa, mockernut hickory Cercis canadensis, red budChionanthus virginicus, fringe treeDiospyros virginiana, common persimmonFraxinus americana, white ashLiquidambar styraciflua, sweetgumMagnolia virginiana, sweetbay magnoliaMagnolia xsoulangiana, saucer magnoliaNyssa aquatica, water tupeloNyssa sylvatica, black tupeloOstrya virginiana, American hophornbeanPrunus angustifolia, chickasaw plumQuercus michauxii, swamp chestnutQuercus shumardii, Shumard oakQuercus stellata, post oakUlmus alata, winged elmPalmsWashingtonia robusta, Washington fan

Medium-Low Wind Resistance

DicotsAcer negundo, boxelderAcer rubrum, red mapleAcer saccharinum, silver mapleCeltis laevigata, sugarberryCeltis occidentalis, hackberryCinnamomum camphora, camphor *Eriobotrya japonica, loquat **Eucalyptus cinera, silverdollar eucalyptusFraxinus pennsylvanica, green ashMorus rubra, red mulberryMyrica cerifera, wax myrtlePersea borbonia, redbayPlatanus occidentalis, sycamorePrunus serotina, black cherryQuercus alba, white oakQuercus phellos, willow oakSalix xsepulcralis, weeping willowUlmus americana, American elmConifersPinus elliottii, slash pinePinus palustris, longleaf pinePinus taeda, loblolly pine

Lowest Wind ResistanceDicotsCarya illinoensis, pecanLiriodendron tulipifera, tulip poplarPrunus caroliniana, Carolina

laurelcherryPyrus calleryana, Bradford pearQuercus falcata, southern red oakQuercus laurifolia, laurel oakQuercus nigra, water oak Sapium sebiferum, Chinese tallow ***Ulmus parvifolia, Chinese elmConifersJuniperus silicicola, southern red cedarxCupressocyparis leylandii, Leyland

cypressPinus clausa, sand pinePinus glabra, spruce pine

* Invasive, not recommended by University of Florida/IFAS** Caution: manage to prevent escape*** Prohibited in Florida (Fox et al. 2005)

Recommendations for a healthy urban forest

• Consider soil depth, water depth and compaction

When Establishing New Trees:

• Plant a mixture of species, ages and layers

• Plant trees from the highest and medium-high WR lists

• Give trees adequate rooting space: • small trees - at least 3 x 3 m• large trees - at least 10 x 10 m

• Plant trees in groups as opposed to individually

• Establish a structural pruning program early on

• Plant high quality trees

with good structure

• Give trees adequate aerial space when mature

• Consult with a certified arborist or urban forester

When Managing Older Trees:

• Remove hazard trees • Consider removing trees on the lowest WR list

• Know the life span of your tree

• Prune trees regularly• Be aware of root damage during construction

• Have tree health evaluated

Recommendations for a healthy urban forest