Selecting Coastal Plain Species for Wind Resistance

Mary L. Duryea and Eliana Kampf


 

Figure 0. 
Figure 0. 

 

Wind damage to urban trees increases with storm intensity, but not all tree species withstand high winds to the same degree, making some trees better choices than others for including in coastal landscapes. A team of scientists at the University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) studied 10 hurricanes to determine their effect on the urban forest. One of the major goals of this study was to assemble lists of relative wind resistance for different urban tree species to help communities better prepare for future hurricane seasons by selecting proper species. (Chapter 9 reports on tropical and subtropical tree species). This fact sheet presents the research and methodology that lead to these lists of relative wind resistance. It also discusses in detail the results and additional recommendations for selecting and establishing trees for a healthier and more wind-resistant urban forest.

 

The Study

In 2004, four hurricanes struck Florida with maximum sustained winds ranging from 169 to 233 km/h (105 to 145 mph). In 2005, Hurricane Dennis struck the Florida panhandle at 193 km/h (120 mph). The impacts of these five hurricanes were widespread. They affected urban areas, agricultural croplands, and Florida's natural ecosystems (Duryea et al. 2007). Since 1992 when Hurricane Andrew struck south Florida, we have been studying the impacts of hurricanes on the urban forest (Duryea et al. 1996). We continued with measurements of hurricane wind damage to urban neighborhoods again in 1995 when two hurricanes struck the Pensacola area (Duryea 1997) and then again in 1998 when Hurricane Georges crossed over the entire island of Puerto Rico. These nine hurricanes with their varied wind speeds gave us the opportunity to study over eighty tree species and their comparable responses to hurricanes. This study reports on the relative wind resistance of southeastern coastal plain species in urban forests (including plant hardiness zones 8 and 9).

Methods

Urban Tree Damage Measurements

Urban tree damage was measured within three to six days following each hurricane that struck the Florida panhandle: Erin, Opal, Ivan, and Dennis (Figure 1). We also report the hurricane response of coastal plain species such as live oak (Quercus virginiana) and sabal palm (Sabal palmetto) that occur throughout Florida and were impacted by Hurricanes Andrew, Charley, Frances, and Jeanne. Hurricane Andrew results were collected in a survey of 128 homeowners in Dade County, Florida who reported the impacts of the hurricane on trees in their yards (Duryea et al. 1996). The methodology for the other eight hurricanes was the same and was as follows. Neighborhoods at the point of landfall of the hurricane were randomly chosen on the strong side of the storm. For each neighborhood, all trees in front yards were observed along street transects. (If invited, we also measured trees in backyards.) Overall we sampled 100 neighborhoods and 18,200 trees. Each tree's diameter at breast height (for dicots and conifers) or height (for palms) was measured (estimated for height), and then it was determined if the tree was standing, leaning or had fallen. Leaning trees were those that were leaning as a result of the storm at less than a 45 degree angle. Fallen trees were either broken at the main stem or lying on the ground. All fallen trees were assessed as either broken or uprooted. Percent survival was calculated for each species using trees that were standing after the hurricane (Trees were considered not surviving if they had fallen or if they were leaning at less than a 45 degree angle.)

Crowns of all standing trees were first assessed for percent branch loss and then for leaf loss from the hurricane. For palms, only percent leaf loss was assessed. Then for dicots and conifers, if a tree had 50% or greater branch loss from the hurricane, it was declared dead and a new second survival percentage was calculated. This is called the "recalculated survival" throughout this document.

 

Figure 1. Urban trees were measured following hurricanes striking Florida, the Gulf Coast, and Puerto Rico. For each hurricane, the arrow points to the location of landfall. The maximum sustained wind speed (mph) and year are included.
Figure 1.  Urban trees were measured following hurricanes striking Florida, the Gulf Coast, and Puerto Rico. For each hurricane, the arrow points to the location of landfall. The maximum sustained wind speed (mph) and year are included.

 

 

Figure 1b. 
Figure 1b. 

 

 

The Survey

After four hurricanes struck Florida in 2004, we concluded that urban forest professionals in the state were a resource of knowledge about wind resistance. In June 2005, we sent out 240 surveys to arborists, urban foresters, and forest scientists who were members of the International Society of Arboriculture (Florida chapter) or the Florida Urban Forestry Council or who were faculty at the University of Florida. We asked them to rank the wind resistance (high, medium, or low) of those urban tree species they observed after hurricanes. Eighty-five (85) surveys (35%) were returned. We report these numbers and percentages in this publication and then use these ratings along with our measurements and analyses and the scientific literature to formulate wind resistance lists for tree species in urban areas.

Results

Tree Survival and Branch Loss

Tree species in the Southeastern Coastal Plain respond differently to hurricanes. Response of species to Hurricane Ivan in 2004 illustrates differences at 209 km/h (130 mph) wind speeds (Figure 2). Tree species demonstrating the highest survival in these winds were sand live oak (Quercus geminata), American holly (Ilex opaca), southern magnolia (Magnolia grandiflora), live oak, wax myrtle (Myrica cerifera), sweetgum (Liquidambar styraciflua), crape myrtle (Lagerstroemia indica), dogwood (Cornus florida), and sabal palm. Dogwood, live oak, sabal palm, sand live oak, and southern magnolia were also the best survivors in Hurricanes Erin and Opal in 1995 (Duryea 1997).

A more detailed look at live oak and sabal palm demonstrates their repeated resilience to hurricane-force winds (Table 1). However, it can also be seen that in south Florida when the winds reached 233 and 265 km/h (145 and 165 mph) in Hurricanes Charley and Andrew, survival of live oak decreased to 78%.

 

Figure 2. Survival (percentage of trees still standing) of species in Hurricane Ivan, which struck at 209 km/h (130 mph). The LSD (Least Significant Difference) is at the 0.05 level.
Figure 2.  Survival (percentage of trees still standing) of species in Hurricane Ivan, which struck at 209 km/h (130 mph). The LSD (Least Significant Difference) is at the 0.05 level.

 

In a statistical comparison of sand live oak, live oak, and laurel oak, laurel oak had poorer overall survival than both live oak and sand live oak in four panhandle Florida hurricanes (p<0.001) (Figure 3). In several publications, live oak, sabal palm, baldcypress (Taxodium distichum) and pondcypress (Taxodium ascendens) have been ranked at the top of lists for hurricane-related wind resistance (Touliatos and Roth 1971; Swain 1979; Barry et al. 1993).

Branch loss in hurricanes may also be an important measure of trees' resilience (Figure 4). In Hurricane Ivan, southern red cedar (Juniperus virginiana var. silicicola), sycamore (Platanus occidentalis), southern red oak (Quercus falcata), and laurel oak lost on average over 25% of their branches. Sweetgum, silver maple (Acer saccharinum), sycamore, and southern red cedar were species losing the most branches in Hurricanes Erin and Opal (Duryea 1997). Species with 10% or less branch loss were crape myrtle, loblolly pine (Pinus taeda), American holly, and tulip poplar (Liriodendron tulipifera).

When we looked at tree diameter and branch loss, we found that large trees (100-200 cm, 39-79 in diameter) lost the most branches (30%), followed by medium sized trees (50-99 cm, 20-39 in) with 25% loss, smaller trees (20-49 cm, 8-19 in) with 20% loss, and finally the smallest trees (< 20 cm, 8 in), which lost 12% of their branches (p<0.0001). Glizenstein and Harcombe (1988) also found that damage was positively correlated with average stem size in a forest stand. In their review, Everham and Brokaw (1996) summarize that most researchers have found a positive correlation between stem size and wind damage. Webb (1989) found that larger trees were more likely to be damaged directly by the wind compared to smaller trees, which were more likely to be indirectly damaged by other falling trees.

Since trees with large amounts of branch loss from a hurricane may not be considered as healthy urban trees, we re-analyzed survival, taking into account branches lost. As mentioned before, standing trees that had 50% or greater branch loss were called dead and a "new" survival was calculated (named "recalculated survival" henceforth) (Figure 5).

 

Figure 3. In a statistical comparison of sand live oak, live oak, and laurel oak survival in four Florida panhandle hurricanes, laurel oak survival was significantly less than the other two oaks (p<0.001). There was no difference between sand live oak and live oak survival.
Figure 3.  In a statistical comparison of sand live oak, live oak, and laurel oak survival in four Florida panhandle hurricanes, laurel oak survival was significantly less than the other two oaks (p<0.001). There was no difference between sand live oak and live oak survival.

 

 

Figure 4. Average branch loss (%) for each tree species in Hurricane Ivan, which struck land at 209 km/h (130 mph). The LSD (Least Significant Difference) is at the 0.05 level.
Figure 4.  Average branch loss (%) for each tree species in Hurricane Ivan, which struck land at 209 km/h (130 mph). The LSD (Least Significant Difference) is at the 0.05 level.

 

 

Figure 5. A recalculation of survival (%) after declaring trees with ³ 50% branch loss dead after Hurricane Ivan. The LSD (Least Significant Difference) is at the 0.05 level.
Figure 5.  A recalculation of survival (%) after declaring trees with ³ 50% branch loss dead after Hurricane Ivan. The LSD (Least Significant Difference) is at the 0.05 level.

 

 

Some species with heavy branch loss had significantly lower recalculated survival. Southern red cedar survival was decreased from 61% to 46% due to heavy branch loss. Sycamore survival was reduced from 73% to 52%. Even live oak trees had significant branch loss, and their survival was decreased from 91% to 81%. When we statistically compared the recalculated survival of oak species after Hurricane Ivan, the ranking from greatest to lowest survival was sand live oak (98% survival), live oak (81%), laurel oak (66%), water oak (Quercus nigra) (65%), and Southern red oak (50%) (p=0.0001). A study in South Carolina coastal plain forests after Hurricane Hugo also found that live oak was less damaged than laurel and water oaks (Gresham et al. 1991).

Survival of pine species showed significant differences with greatest survival for slash pine (Pinus elliottii var. elliottii) (71%), then loblolly (64%), longleaf (Pinus palustris) (57%), sand pine (Pinus clausa) (43%), and spruce pine (Pinus glabra) (38%) (p=0.0014). Three months after Hurricane Ivan, we re-measured pines and found that 2% to 3% of the slash and longleaf standing trees had died and 56% of the standing sand pine had died. In the southeastern coastal plain forest, longleaf pine was less damaged than loblolly during Hurricane Hugo (12% versus 73% damaged) (Gresham et al. 1991), but a tornado in Texas resulted in equal and intense damage to loblolly, longleaf, and shortleaf (Pinus echinata) pines (Glitzenstein and Harcombe 1988). Two conifer species that have shown repeatedly poor performance in our studies during hurricanes are sand pine and southern red cedar (Duryea 1997) (Table 1).

Defoliation

There were distinct species differences in defoliation during Hurricane Ivan. Species like sand live oak, crape myrtle, and dogwood lost an average of 94%, 88%, and 86% of their leaves compared to southern red cedar, wax myrtle, slash pine, longleaf pine, and loblolly pine, which lost 32%, 31%, 29%, 19%, and 11% of their leaves, respectively (lsd=17%) (Figure 6).

Leaf loss had a positive relationship (p<0.0001) with both survival and recalculated survival (trees with = 50% branch loss excluded), which is to say that losing leaves during the hurricane meant higher survival. Francis and Gillespie (1993), reporting on urban trees in Puerto Rico after Hurricane Hugo in 1989, also found that crown damage appeared to be avoided if the crown surface area was reduced quickly with leaf and twig loss during the hurricane. There are some exceptions to defoliation being a strategy for survival; southern magnolia, American holly, and sabal palm are all excellent survivors, but they only lost 43%, 34%, and 27% of their leaves.

Native and Exotic Species

In the coastal plain area, exotic tree species made up 8% of the trees in the urban forest. The major exotic species were crape myrtle, Chinese tallow (Sapium sebiferum)—a prohibited invasive species, camphor tree (Cinnamomum camphora)—an invasive species, Bradford pear (Pyrus calleryana), and palms such as pindo palm (Butia capitata) and Washington fan palm (Washingtonia robusta). As a group, native trees survived the same as exotic trees (73% versus 77%, not significantly different [n.s.]) and lost the same amount of branches (20% versus 15%, n.s.) and leaves (58% versus 60%, n.s.). In contrast, after Hurricane Andrew struck south Florida, native trees survived winds better than non-native trees (Duryea et al. 1996). Other studies have shown trends toward increased wind damage of exotic species in rural plantation forests (King 1945; Everham and Brokaw 1996)

The Survey

Arborists' and urban foresters' ratings of wind resistance for coastal plain species show a strong agreement with our measurements over several hurricanes. Small trees that were awarded high wind-resistance ratings were fringe tree (Chionanthus virginicus), dogwood, persimmon (Diospyros virginiana), myrtle oak (Quercus myrtifolia), sparkleberry (Vaccinium arboretum), and the hollies (Ilex spp.) (Table 2).

 

Figure 6. By readily losing its leaves right after a hurricane, sand live oak is one of the species that survives hurricanes well.
Figure 6.  By readily losing its leaves right after a hurricane, sand live oak is one of the species that survives hurricanes well.

 

While live oak and sand live oak were rated as high, other oaks such as southern red oak and swamp chestnut oak (Quercus michauxii) were rated as medium, and in agreement with our results, laurel and water oaks were rated as having low wind resistance. Although we have consistently seen low survival or heavy branch damage in southern red cedar, the ratings were even for each of the wind-resistance categories in the survey results. However, 91% of the respondents rated baldcypress and pondcypress with high wind resistance (Figure 7). Both cypresses were stated to have the best wind resistance along with live oak and sabal palm after Hurricanes Camille and Frederick struck the Gulf Coast in 1969 and 1979 (Swain 1979).

In the survey, sand pine received a low rating, which is consistent with our results (Figure 8), while the other pines were mostly rated as medium, again consistent with our results. In their summarizing list of wind resistance for forest species, Everham and Brokaw (1996) cite ten studies where loblolly, slash, and longleaf pines are ranked with low to intermediate wind resistance.

Sabal palm received a high wind resistance rating from 99% of the survey respondents, in agreement with our ratings and those of Swain (1979). Canary Island date palm (Phoenix canariensis), which is being planted more frequently in north Florida, received a high rating from 89% of the respondents (Figure 9).

Respondents rated sweetgum's wind resistance as medium to high; in a summary table of wind resistance by Everham and Brokaw (1996), seven studies rated sweetgum as having medium to high wind resistance. Our studies have shown that it survives well but is prone to some branch breakage. In a Texas study after a tornado, sweetgum was listed as one of the best survivors, but also the tree with the most branch damage (Gliltzenstein and Harcombe 1988). In a study after Hurricane Kate in 1985, sweetgum had low mortality (2%) in a southern mixed hardwood forest compared to spruce pine with 34% mortality (Batista and Platt 2003). They note that wind-firmness of sweetgum is likely due to its underground connections, short and stout branches, and leaves with slender, long petioles that readily detach from branches in wind. On gravelly ridges, hillsides, and upland piedmont sites, sweetgum has been noted to develop a particularly strong taproot and is very resistant to wind (Kormanik 1990).

Tulip poplar had very poor survival in Hurricane Ivan (24%). Survey respondents rated it as having medium to low wind resistance. Everham and Brokaw (1996) summarize two studies in their table with high levels of wind damage for tulip poplar in high intensity storms.

 

Figure 7. Baldcypress, a species increasingly planted in urban areas, was ranked as a highly wind resistant tree.
Figure 7.  Baldcypress, a species increasingly planted in urban areas, was ranked as a highly wind resistant tree.

 

 

Figure 8. Sand pine had a low survival rate of 43% and was also ranked as a low wind resistance species by respondents during the survey.
Figure 8.  Sand pine had a low survival rate of 43% and was also ranked as a low wind resistance species by respondents during the survey.

 

 

Figure 9. Canary Island date palm, rated as having high wind resistance, is being planted more frequently in north Florida.
Figure 9.  Canary Island date palm, rated as having high wind resistance, is being planted more frequently in north Florida.

 

Recommendations

Taking our survival and branch loss results from hurricanes and incorporating results from the survey and from the scientific literature, we have developed lists of relative wind resistance for tree species in the southeastern coastal plain (Table 3). These lists should be used with caution, with the knowledge that no species and no tree is completely wind proof. In addition, local considerations such as soil, cultural practices, tree age and health, and other urban forest health conditions need to be taken into account. In addition to hurricane wind speed, other conditions accompanying hurricanes such as precipitation and the speed with which the storms move through an area appear to influence tree response.

Literature Cited

Barry, P.J., C. Doggett, R.L. Anderson, and K.M. Swain, Sr. 1993. "How to evaluate and manage storm-damaged forest areas". Management Bulletin R8-MB 63 of the USDA Forest Service, Southern Region. Atlanta, GA. 11 pp.

Batista, W.B. and W.J. Platt. 2003. "Tree population responses to hurricane disturbance: syndromes in a south-eastern USA old-growth forest". Ecology 91:197–212.

Duryea, M.L., G.M. Blakeslee, W.G. Hubbard, and R.A. Vasquez. 1996. "Wind and trees: A survey of homeowners after Hurricane Andrew". J. Arboric. 22(1):44–50.

Duryea, M.L. 1997. "Wind and trees: Surveys of tree damage in the Florida Panhandle after Hurricanes Erin and Opal". Circular 1183. UF/IFAS Extension. Gainesville, FL. 7 pp.

Duryea, M.L., E. Kampf, and R.C. Littell. 2007. "Hurricanes and the Urban Forest: I. Effects on Southeastern U.S. Coastal Plain Tree Species". Arboric. & Urban Forestry 33(2):83–97.

Everham III, E.M. and N.V.L. Brokaw. 1996. "Forest damage and recovery from catastrophic wind". The Botanical Review 62:113–185.

Francis, J.K. and A.J.R. Gillespie. 1993. "Relating gust speed to tree damage in Hurricane Hugo", 1989. J. Arboric. 19:368–372.

Glitzenstein, J.S. and P.A. Harcombe. 1988. Effects of the December 1983 tornado on forest vegetation of the Big Thicket, southeast Texas, USA. For. Ecol. Managem. 25:269–290.

Gresham, C.A., T.M. Williams, and D.J. Lipscomb. 1991. Hurricane Hugo wind damage to Southeastern U.S. coastal forest tree species. Biotropica 23(4) (Part A. Special Issue: Ecosystem, Plant, and Animal Responses to Hurricanes in the Caribbean):420–426.

King, H.C. 1945. Notes on the three cyclones in Mauritius in 1945: Their effect on exotic plantations, indigenous forest and on some timber buildings. Empire Forest. J. 24: 192–195.

Kormanik, P. 1990. Liquidambar styraciflua, sweetgum. In: Silvics of North America: 2. Hardwoods. Burns, R. M., and B. H. Honkala, Tech. Coords. (http://www.na.fs.fed.us/spfo/pubs/silvics_manual/table_of_contents.htm) Agriculture Handbook 654 Vol. 2 of the U.S.D.A. Forest Service, Washington, DC. 877 pp.

Swain, K.M. 1979. Minimizing timber damage from hurricanes. S. Lumberman 239:107–109.

Touliatos, P. and E. Roth. 1971. Hurricanes and trees: Ten lessons from Camille. J. For. 285–289.

University of Florida, Institute of Food and Agricultural Sciences. 2018. "Assessment of Non-native Plants in Florida's Natural Areas" (https://assessment.ifas.ufl.edu, 4/29/2019) Gainesville, FL, 32611-4000, USA.

Webb, S.L. 1989. Contrasting windstorm consequences in two forests, Itasca State Park, Minnesota. Ecology 70(4):1167–1180.

Tables

Table 1. 

Survival for Southeastern Coastal Plain tree species after six hurricanes.

Tree Species

Survival (%) After Each Hurricane (Wind Speed in km/h)

 

Erin (137)

Jeanne (193)

Opal (201)

Ivan (209)

Charley (233)

Andrew (265)

Dicots

       

Acer rubrum

Red maple

93

76

Acer saccharinum

Silver maple

93

Carya floridana

Florida scrub hickory

83

Carya illinoensis

Pecan

97

93

76

Carya glabra

Pignut hickory

100

Cinnamomum camphora a

Camphor

90

Cornus florida

Flowering dogwood

100

96

81

Ilex opaca

American holly

95

Lagerstroemia indica

Crape myrtle

84

Liquidambar styraciflua

Sweet gum

93

86

Liriodendron tulipifera

Tulip poplar

24

Magnolia grandifolia

Southern magnolia

96

97

92

Magnolia virginiana

Sweet bay magnolia

97

Myrica cerifera

Wax myrtle

90

Platanus occidentalis

Sycamore

92

73

Prunus caroliniana

Carolina laurelcherry

76

74

53

Prunus serotina

Black cherry

64

Pyrus calleryana

Bradford pear

68

Quercus falcata

Southern red oak

60

Quercus virginiana

Live oak

96

97

95

91

78

78

Quercus geminata

Sand live oak

96

94

96

99

Quercus laurifolia

Laurel oak

89

94

90

77

85

Quercus laevis

Turkey oak

83

89

Quercus nigra

Water oak

72

Sapium sebiferum a

Chinese tallow

97

83

73

Monocots—Palms

 

Butia capitata

Jelly palm

97

Sabal palmetto

Sabal palm

97

92

100

80

92

93

Washingtonia robusta

Washington palm

80

92

Conifers

 

Juniperus virginiana var. silicicola

Southern red cedar

92

60

61

Pinus clausa

Sand pine

61

4

58

48

Pinus elliottii var. elliottii

and var. densa

Slash pine (and south Florida slash pine)

95

90

(densa)

96

72

79

(densa)

73

(densa)

Pinus glabra

Spruce pine

46

Pinus palustris

Longleaf pine

90

94

59

57

Pinus taeda

Loblolly pine

82

66

Taxodium distichum

Baldcypress

95

a Prohibited from use in Florida.

* Survival is defined as the percentage of trees still standing after the hurricane. Numbers are only presented for tree species having a sample greater or equal to n=20 trees for each hurricane. Least Significant Differences at p=0.05 are 35% for Jeanne, 35% for Ivan, and 30% for Charley. Erin and Opal survival percentages are from Duryea 1997; Andrew survival percentages are from Duryea et al. 1996

Table 2. 

Results of survey of arborists, scientists, and urban foresters in Florida.*

Scientific Name

Common Name

Wind Resistance

p-value

Total N

High

Medium

Low

N

%

N

%

N

%

Dicots and Pines

Acer negundo

boxelder

1

8

6

50

5

42

n.s.

12

Acer palmatum

Japanese maple

6

50

6

50

0

0

n.s.

12

Acer rubrum

red maple

12

20

32

52

17

28

0.0049

61

Acer saccharinum

silver maple

0

0

10

45

12

55

n.s.

22

Acer saccharum subsp floridanum

Florida sugar maple

2

11

11

61

5

28

0.0302

18

Betula nigra

river birch

11

39

16

57

1

4

0.0019

28

Carpinus caroliniana

ironwood

7

50

6

43

1

7

n.s.

14

Carya glabra

pignut hickory

11

41

14

52

2

7

0.0131

27

Carya illinoinensis

pecan

6

21

9

32

13

47

n.s.

28

Carya tomentosa

mockernut hickory

6

50

6

50

0

0

n.s.

12

Celtis laevigata

sugarberry

4

15

18

70

4

15

0.0005

26

Celtis occidentalis

common hackberry

2

18

5

46

4

36

n.s.

11

Cercis canadensis

red bud

14

48

8

28

7

24

n.s.

29

Chionanthus virginicus

fringe tree

7

50

5

36

2

14

n.s.

14

Cornus florida

flowering dogwood

9

60

6

40

0

0

n.s.

15

x Cupressocyparis leylandii

leyland cypress

7

22

13

41

12

37

n.s.

32

Diospyros virginiana

common persimmon

14

56

9

36

2

8

0.0128

25

Eucalyptus cinerea

silver dollar eucalyptus

2

13

9

56

5

31

n.s.

16

Eriobotrya japonica c

loquat

9

24

24

63

5

13

0.0004

38

Fraxinus americana

white ash

3

30

6

60

1

10

n.s.

10

Fraxinus pennsylvanica

green ash

3

24

5

38

5

38

n.s.

13

Ilex cassine

dahoon holly

34

76

10

22

1

2

0.0001

46

Ilex opaca

American holly

21

75

6

21

1

4

0.0001

28

Ilex vomitoria

yaupon holly

28

81

7

19

0

0

0.0004

37

Juniperus virginiana var. silicicola

southern red cedar

14

28

18

35

19

37

n.s.

51

Lagerstroemia indica

crape myrtle

55

83

11

17

0

0

0.0001

66

Liriodendron tulipifera

tulip poplar

2

8

14

58

8

33

0.0111

24

Liquidambar styraciflua

sweetgum

18

43

21

50

3

7

0.0013

42

Magnolia grandiflora

southern magnolia

45

82

9

16

1

2

0.0001

55

Magnolia virginiana

sweetbay magnolia

15

42

17

47

4

11

0.0169

36

Magnolia x soulangiana

saucer magnolia

8

44

9

50

1

6

0.0421

18

Morus rubra

red mulberry

6

23

14

54

6

23

n.s.

26

Myrica cerifera

wax myrtle

18

33

15

28

21

39

n.s.

54

Nyssa aquatica

water tupelo

7

58

5

42

0

0

n.s.

12

Nyssa sylvatica

black tupelo

14

58

9

38

1

4

0.0469

24

Ostrya virginiana

American hophornbeam

8

67

4

33

0

0

n.s.

12

Pinus glabra

spruce pine

7

54

1

8

5

38

n.s.

13

Pinus elliottii var. elliottii

slash pine

16

25

36

57

11

18

0.0002

63

Pinus palustris

longleaf pine

23

56

13

32

5

12

0.0017

41

Pinus taeda

loblolly pine

7

20

19

54

9

26

0.0289

35

Platanus occidentalis

sycamore

17

38

21

48

6

14

n.s.

44

Prunus angustifolia

chickasaw plum

12

50

8

33

4

17

n.s.

24

Prunus caroliniana

Carolina laurelcherry

5

16

15

48

11

36

n.s.

31

Prunus serotina

black cherry

4

18

10

46

8

36

n.s.

22

Pyrus calleryana

Bradford pear

5

21

5

21

14

58

0.0342

24

Quercus alba

white oak

6

55

5

45

0

0

0.0539

11

Quercus falcata

southern red oak

4

20

15

75

1

5

0.0003

20

Quercus geminata

sand live oak

36

92

2

5

1

3

0.0001

39

Quercus laevis

turkey oak

17

47

16

45

3

8

0.0062

36

Quercus laurifolia

laurel oak

3

4

27

39

39

57

0.0001

69

Quercus michauxii

swamp chestnut oak

8

50

8

50

0

0

n.s.

16

Quercus myrtifolia

myrtle oak

13

76

4

24

0

0

0.0290

17

Quercus nigra

water oak

3

8

14

36

22

56

0.0009

39

Quercus phellos

willow oak

1

8

8

67

3

25

0.0388

12

Quercus shumardii

shumard oak

13

52

10

40

2

8

0.0207

25

Quercus stellata

post oak

5

33

10

67

0

0

n.s.

15

Quercus virginiana

live oak

64

89

8

11

0

0

0.0001

72

Salix x sepulcralis

weeping willow

2

12

8

50

6

38

n.s.

16

Taxodium distichum

baldcypress

59

91

6

9

0

0

0.0001

65

Taxodium ascendens

pondcypress

41

91

4

9

0

0

0.0001

45

Tilia americana

basswood

5

38

4

31

4

31

n.s.

13

Ulmus alata

winged elm

15

53

12

43

1

4

0.0030

28

Ulmus americana

American elm

6

30

12

60

2

10

0.0224

20

Ulmus parvifolia

Chinese elm

7

23

11

35

13

42

n.s.

31

Vaccinium arboreum

sparkleberry

11

85

2

15

0

0

0.0126

13

Palms

Butia capitata

pindo, jelly

34

79

7

16

2

5

0.0001

43

Phoenix canariensis

Canary Island date palm

49

89

4

7

2

4

0.0001

55

Phoenix dactylifera

date palm

33

94

2

6

0

0

0.0001

35

Sabal palmetto

cabbage, sabal palm

71

99

1

1

0

0

0.0001

72

Washingtonia robusta

Washington fan palm

29

54

16

29

9

17

0.0033

54

c Caution: may be used but must be managed to prevent escape in Florida (UF/IFAS, 2018)

* Rankings for wind resistance of southeastern US coastal plain tree species. N is the number of respondents for each species, out of a total of eighty-five experts. P-values from the chi-square test for equal proportions indicate the significance level for one or more of the categories being different from the others; n.s. means that there is no significant difference between the categories of high, medium and low (p>0.05).

Table 3. 

Wind resistance of southeastern US coastal plain tree species.*

Highest Wind Resistance

DICOTS

Carya floridana, Florida scrub hickory

Cornus florida, dogwood

Ilex cassine, dahoon holly

Ilex glabra, inkberry

Ilex opaca, American holly

Ilex vomitoria, yaupon holly

Lagerstroemia indica, crape myrtle

Magnolia grandiflora, southern magnolia

Podocarpus spp, podocarpus

Quercus geminata, sand live oak

Quercus laevis, turkey oak

Quercus myrtiflora, myrtle oak

Quercus virginiana, live oak

Vaccinium arboreum, sparkleberry

CONIFERS

Taxodium ascendens, pondcypress

Taxodium distichum, baldcypress

Medium-High Wind Resistance

DICOTS

Acer saccharum, Florida sugar maple

Acer palmatum, Japanese maple

Betula nigra, river birch

Carpinus caroliniana, ironwood

Carya glabra, pignut hickory

Carya tomentosa, mockernut hickory

Cercis canadensis, red bud

Chionanthus virginicus, fringe tree

Diospyros virginiana, common persimmon

Fraxinus americana, white ash

Liquidambar styraciflua, sweetgum

Magnolia virginiana, sweetbay magnolia

Magnolia x soulangiana, saucer magnolia

Nyssa aquatica, water tupelo

Nyssa sylvatica, black tupelo

Ostrya virginiana, American hophonbeam

Prunus angustifolia, chickasaw plum

Quercus michauxii, swamp chestnut oak

Quercus shumardii, Shumard oak

Quercus stellata, post oak

Ulmus alata, winged elm

Medium-low Wind Resistance

DICOTS

Acer negundo, boxelder

Acer rubrum, red maple

Acer saccharinum, silver maple

Celtis laevigata, sugarberry

Celtis occidentalis, hackberry

Cinnamomum camphora, camphorb

Eriobotrya japonica, loquatc

Eucalyptus cinerea, silverdollar eucalyptus

Fraxinus pennsylvanica, green ash

Morus rubra, red mulberry

Myrica cerifera, wax myrtle

Persea borbonia, redbay

Platanus occidentalis, sycamore

Prunus serotina, black cherry

Quercus alba, white oak

Quercus phellos, willow oak

Salix x sepulcralis, weeping willow

Ulmus americana, American elm

CONIFERS

Pinus elliottii, slash pine

Pinus palustris, longleaf pine

Pinus taeda, loblolly pine

Lowest Wind Resistance

DICOTS

Carya illinoensis, pecan

Liriodendron tulipifera, tulip poplar

Prunus caroliniana, Carolina laurelcherry

Pyrus calleryana, Bradford pear

Quercus falcata, southern red oak

Quercus laurifolia, laurel oak

Quercus nigra, water oak

Sapium sebiferum, Chinese tallowa

Ulmus parvifolia, Chinese elm

CONIFERS

Juniperus virginiana var. silicicola, southern red cedar

x Cupressocyparis leylandii, Leyland cypress

Pinus clausa, sand pine

Pinus glabra, spruce pine

PALMS

Washingtonia robusta, Washington fan palm

a Prohibited from use in Florida

b Invasive and not recommended for use in Florida

c Caution: may be used but must be managed to prevent escape in Florida (UF/IFAS 2018)

* Wind resistance of southeastern coastal plain species as estimated utilizing the hurricane measurements and the survey results in this study, and the scientific literature cited throughout this publication.

Table 4. 

New Trees

To promote a healthy and more wind- resistant urban forest, additional recommendations for establishing new trees include:

Plant a mixture of species, ages, and layers (shrubs and trees) to maintain diversity in your community.

Plant trees from the "Highest" and "Medium-High" Wind Resistance lists and match these to local site conditions.

Give trees adequate rooting space with no obstructions (e.g., sidewalks, buildings, and streets): for small trees, provide at least 3 meters by 3 meters; for large trees, provide at least 10 meters by 10 meters.

Consider planting trees in groups as opposed to individually.

Consider soil properties when deciding what to plant (e.g. soil depth, water table depth, and compaction).

Give trees adequate aerial space considering their crown size when mature.

Plant high quality trees with good structure.

Establish a structural pruning program early on.

Table 5. 

Established Trees

Likewise, recommendations for managing established trees include:

Have tree health evaluated and remove hazard trees.

Consider removing trees that are on the "Lowest Wind Resistance" list, especially if they are over-mature and endangering life or property.

Establish a regular structural pruning program (especially for dicots).

Consult with a certified arborist.

Do not over-prune palms especially before a hurricane; palms only need to have dead or dying leaves removed.

Be aware of possible root damage and lack of anchoring when construction has resulted in sidewalks or trenches near the roots of trees.

Avoid damage to the trunk of the tree (e.g., mechanical weed control damage).