Urban Forest Hurricane Recovery Program

1. This presentation is part of a series of educational initiatives from The Urban Forest Hurricane Recovery Program in the School of Forest Resources and Conservation and the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida (IFAS/UF). This presentation is part of a series of educational initiatives from The Urban Forest Hurricane Recovery Program in the School of Forest Resources and Conservation and the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida (IFAS/UF).

2. Wind-resistant urban design Dr. Edward F. Gilman and Traci Partin Dr. Edward F. Gilman, professor in Environmental Horticulture department at the University of Florida; Traci Partin is information specialist at University of Florida.Dr. Edward F. Gilman, professor in Environmental Horticulture department at the University of Florida; Traci Partin is information specialist at University of Florida.

3. Could this have been prevented? Design, soil conditions, and maintenance practices contributed to the demise of these trees during a hurricane. Could this have been prevented? Notice the trees have mostly fine roots and no larger diameter anchoring roots. Roots were deflected by the curbing; roots were cut when the sidewalk was repaired; the high water table in the soil did not allow deep rooting. These issues combined to cause blow over.Design, soil conditions, and maintenance practices contributed to the demise of these trees during a hurricane. Could this have been prevented? Notice the trees have mostly fine roots and no larger diameter anchoring roots. Roots were deflected by the curbing; roots were cut when the sidewalk was repaired; the high water table in the soil did not allow deep rooting. These issues combined to cause blow over.

4. The answer is yes! Good planning, as demonstrated in this picture, can allow trees to live to a healthy, mature age. Notice the space allowed for roots to grow. Rather than being sandwiched between the road and sidewalk, the trees on the left can send roots under the wall into the yard beyond it, to provide anchorage. The curbing is only about 6 inches deep so roots can grow under the asphalt. Deep roots can form when the water table is at least several feet below the soil surface. This provides stability for the trees. These trees are much more prepared to withstand 100 mph winds than those of the previous picture.Good planning, as demonstrated in this picture, can allow trees to live to a healthy, mature age. Notice the space allowed for roots to grow. Rather than being sandwiched between the road and sidewalk, the trees on the left can send roots under the wall into the yard beyond it, to provide anchorage. The curbing is only about 6 inches deep so roots can grow under the asphalt. Deep roots can form when the water table is at least several feet below the soil surface. This provides stability for the trees. These trees are much more prepared to withstand 100 mph winds than those of the previous picture.

5. Wind-resistant urban design Design conflicts that can cause tree failure Design solutions that promote wind  resistance - existing design situations - new design/construction How to take action This presentation will focus mainly on how to design urban environments to support trees so that they are less likely to blow over under high winds. The current problems of urban areas will be presented first so that the audience can see examples of design issues that can lead to tree failure. The discussion will conclude with suggestions for how this information can be used in your community.This presentation will focus mainly on how to design urban environments to support trees so that they are less likely to blow over under high winds. The current problems of urban areas will be presented first so that the audience can see examples of design issues that can lead to tree failure. The discussion will conclude with suggestions for how this information can be used in your community.

6. How often do trees fall down due to poor design? The pictures speak for themselves. Give the audience time to think about how the tree losses here were caused by a design issue.The pictures speak for themselves. Give the audience time to think about how the tree losses here were caused by a design issue.

7. Ask the audience: what is the common factor in all of these pictures? The answer: all of these trees are surrounded by paved surfaces. Curbing deflects the roots needed for anchorage.Ask the audience: what is the common factor in all of these pictures? The answer: all of these trees are surrounded by paved surfaces. Curbing deflects the roots needed for anchorage.

8. What design conflicts cause trees to fail? Large-maturing trees within 10 feet of a paved surface, without space designed for root growth Lack of open soil space Large roots cut during construction Poor soil conditions Single specimens (versus grouping trees) Wrong species selected for the site NOT ENOUGH ROOT SPACE! Often designers place trees in highly compromised situations that do not even vaguely resemble the conditions trees are accustomed to. It is no surprise that trees with less than half of the root space they need fall down under high winds. All of that money spent on planting is wasted once the trees blow over, and the cost of clean-up is not cheap either. The following situations are examples of poor planning.Often designers place trees in highly compromised situations that do not even vaguely resemble the conditions trees are accustomed to. It is no surprise that trees with less than half of the root space they need fall down under high winds. All of that money spent on planting is wasted once the trees blow over, and the cost of clean-up is not cheap either. The following situations are examples of poor planning.

9. Large maturing tree near curb Several trees on this street were leaning after Hurricane Charley blew through, and eventually they were all cut down. Notice the tiny soil space between the sidewalk and street. The close-up (upper right) shows how roots were blocked and deflected by the curb. Notice the density of fine roots, and the lack of any large, anchoring roots. Several trees on this street were leaning after Hurricane Charley blew through, and eventually they were all cut down. Notice the tiny soil space between the sidewalk and street. The close-up (upper right) shows how roots were blocked and deflected by the curb. Notice the density of fine roots, and the lack of any large, anchoring roots.

10. Space is needed for roots to spread Fine roots can be found well beyond the canopy of the tree at full maturity These roots help anchor the tree under high winds Roots need distance to expand in order to secure the aboveground weight of the tree. The main structural roots within 5 to 10 feet of the trunk should be straight and some should be at least three feet deep in order to develop a strong hold in soil.Roots need distance to expand in order to secure the aboveground weight of the tree. The main structural roots within 5 to 10 feet of the trunk should be straight and some should be at least three feet deep in order to develop a strong hold in soil.

11. Soil depth is necessary for root stability Roots need adequate soil depth to anchor the tree under high winds. Soil should be at least 3 feet deep for large maturing trees Here is a picture of a shallow water table, and an example of tree failure due to wet soil. Although the tree has a strong root system, it lacks the vertical sinker roots that would develop in a deeper soil. After the hurricane, this tree was found leaning. A high water table or rock near the surface usually does not provide a firm foundation for tree roots, and trees are far more likely to blow over in wet soil during a hurricane. Often, soil quality can be tested by simply smelling the sample! Sour smells indicate the soil has poor aeration due to compaction or water saturation. Special designs are needed to provide space for roots to grow in these situations.Here is a picture of a shallow water table, and an example of tree failure due to wet soil. Although the tree has a strong root system, it lacks the vertical sinker roots that would develop in a deeper soil. After the hurricane, this tree was found leaning. A high water table or rock near the surface usually does not provide a firm foundation for tree roots, and trees are far more likely to blow over in wet soil during a hurricane. Often, soil quality can be tested by simply smelling the sample! Sour smells indicate the soil has poor aeration due to compaction or water saturation. Special designs are needed to provide space for roots to grow in these situations.

12. Lack of open soil space When pavement is close to the trunk, the expanding roots lift it causing cracks.When pavement is close to the trunk, the expanding roots lift it causing cracks.

13. Open soil space allows root flare to develop The swelling at the base of the tree (where the large roots meet the trunk) is commonly referred to as the root flare or buttress The root flare provides balance and stability for the massive weight of a tree The root flare has also been referred to as trunk flare.The root flare has also been referred to as trunk flare.

14. Roots cut during construction Here, in order to make room for repair of the sidewalks, the interfering tree roots were cut close to the trunk. Cheap and easy…until the tree blows down in the next storm!Here, in order to make room for repair of the sidewalks, the interfering tree roots were cut close to the trunk. Cheap and easy…until the tree blows down in the next storm!

15. Poor soil conditions Compacted Shallow soil – rocky; high water table Drainage issues High clay content Alkaline soil/ Lime rock- inhibits uptake of  essential nutrients Little to no organic matter (i.e. builder’s sand) In building sites such as the one pictured above, good soil is often removed from the site and replaced with builder’s sand. Trees are then planted in this poor soil substitute after construction, after the area has been compacted by heavy machinery. It’s no wonder we often see trees dying in urban areas shortly after planting! In building sites such as the one pictured above, good soil is often removed from the site and replaced with builder’s sand. Trees are then planted in this poor soil substitute after construction, after the area has been compacted by heavy machinery. It’s no wonder we often see trees dying in urban areas shortly after planting!

16. This is a familiar site for many who live in South Florida. What can be done with shallow, rocky soil? Small trees for this soil…this is why some trees went over! Choose native trees adapted to these soil conditions. Recommend against planting large-maturing shade trees unless there is amply soil for lateral root expansion. Some of these rocky soils allow roots to penetrate several feet in solution holes.Small trees for this soil…this is why some trees went over! Choose native trees adapted to these soil conditions. Recommend against planting large-maturing shade trees unless there is amply soil for lateral root expansion. Some of these rocky soils allow roots to penetrate several feet in solution holes.

17. Single specimens vs. grouping trees Rather than creating many small islands with one tree, create larger planting islands for trees to share greater soil space.Rather than creating many small islands with one tree, create larger planting islands for trees to share greater soil space.

18. Larger groupings are less damaged This design did not suffer any tree damage when a hurricane blew through UF researchers visiting post-hurricane sites discovered that trees suffered less damage when planted in groups.UF researchers visiting post-hurricane sites discovered that trees suffered less damage when planted in groups.

19. Consider the natural setting for a tree The information is not surprising – trees naturally grow within populations, not as a single-standing specimen. Along the coast and in the south Florida region, the common habitat is a hammock of trees, grouped together with canopies touching. An urban forest design attempts to mimic the natural setting for a tree, rather than what we are accustomed to seeing, which is jamming trees into areas where they do not fit. Wind is directed over a solid canopy but can penetrate the canopy of individual trees causing damage.The information is not surprising – trees naturally grow within populations, not as a single-standing specimen. Along the coast and in the south Florida region, the common habitat is a hammock of trees, grouped together with canopies touching. An urban forest design attempts to mimic the natural setting for a tree, rather than what we are accustomed to seeing, which is jamming trees into areas where they do not fit. Wind is directed over a solid canopy but can penetrate the canopy of individual trees causing damage.

20. Notice the trees still standing Think about it this way – five trees are grouped together in this picture, and two blew down. Had the trees been planted separately, the odds are high that all five would have blown down. When trees are grouped, the ones on the outside protect the others.Think about it this way – five trees are grouped together in this picture, and two blew down. Had the trees been planted separately, the odds are high that all five would have blown down. When trees are grouped, the ones on the outside protect the others.

21. Selecting the wrong species for the site Choose small trees for sites where soil space is limited. Urban conditions are difficult for many species to thrive in: high levels of pollutants in the air, concentration of heat, poor soil – these factors affect the tree selection process. A large maturing tree can be planted in a small space and the tree can live a few years in the landscape, but evidence of decline often shows, such as yellowing leaves, dieback at the tips of branches. Note the declining mahogany in this small soil space. The tree has run out of suitable soil for root growth.Urban conditions are difficult for many species to thrive in: high levels of pollutants in the air, concentration of heat, poor soil – these factors affect the tree selection process. A large maturing tree can be planted in a small space and the tree can live a few years in the landscape, but evidence of decline often shows, such as yellowing leaves, dieback at the tips of branches. Note the declining mahogany in this small soil space. The tree has run out of suitable soil for root growth.

22. What design conflicts cause trees to fail? Large-maturing trees within 10 feet of a paved surface, without space designed for root growth Lack of open soil space Large roots cut during construction Poor soil conditions Single specimens (versus grouping trees) Wrong species selected for the site NOT ENOUGH ROOT SPACE! Often designers place trees in highly compromised situations that do not even vaguely resemble the life trees are accustomed to. It is no surprise that trees with less than half of the root space they need fall down under high winds. All of that money spent on planting is wasted when the trees blow over. The following situations are examples of poor planning.Often designers place trees in highly compromised situations that do not even vaguely resemble the life trees are accustomed to. It is no surprise that trees with less than half of the root space they need fall down under high winds. All of that money spent on planting is wasted when the trees blow over. The following situations are examples of poor planning.

23. Where do we grow now? The amount of abuse trees are capable of withstanding is truly amazing. Learn to recognize these kinds of situations around you – the problem is real, and better design can help prevent costly repairs.The amount of abuse trees are capable of withstanding is truly amazing. Learn to recognize these kinds of situations around you – the problem is real, and better design can help prevent costly repairs.

24. Wind-resistant urban design Design conflicts that can cause tree failure Design solutions that promote wind  resistance - existing design situations - new design/construction How to take action Now lets look at some solutions that have worked for a number of communities.Now lets look at some solutions that have worked for a number of communities.

25. Existing design situations Problem: Mature tree with large roots interfering with hardscape. Solutions: Install different surface material Add fill and re-pour walk Bridge over roots Re-route walk

26. Install different surface material: rock dust The dust by-product of the rock quarry industry can be used as a wearing surface. It can provide an inexpensive solution to roots lifting walks.The dust by-product of the rock quarry industry can be used as a wearing surface. It can provide an inexpensive solution to roots lifting walks.

27. Final product: This works best on level ground where erosion is minimal.This works best on level ground where erosion is minimal.

28. Install different surface material: porous pavers To protect the root zone around the existing trees in this parking space at a botanical garden, porous pavers were selected A coarse sand would work nicely as a sub-base for the porous pavers because it compacts yet allows for enough air space between particles for air movement. This parking lot for a large botanical garden was constructed near existing large trees Porous pavers were used to help preserve the root system and soil structure Be sure that the soil grade is not lowered during the construction process because this will damage roots Soil can be added around the roots to prepare a base for the pavers, but be sure it is coarser than the existing soil A coarse sand would work nicely as a sub-base for the porous pavers because it compacts yet allows for enough air space between particles for air movement. This parking lot for a large botanical garden was constructed near existing large trees Porous pavers were used to help preserve the root system and soil structure Be sure that the soil grade is not lowered during the construction process because this will damage roots Soil can be added around the roots to prepare a base for the pavers, but be sure it is coarser than the existing soil

29. Soil or gravel can be added over the existing roots and the walk re-poured.Soil or gravel can be added over the existing roots and the walk re-poured.

30. Roots can remain intact if a bridging system is designed. Here the roots were not cut. Instead, diamond plate was used to craft a bridge for pedestrians.Roots can remain intact if a bridging system is designed. Here the roots were not cut. Instead, diamond plate was used to craft a bridge for pedestrians.

31. Re-routing walk around tree When damaged sidewalks are repaired they can be re-routed around the tree trunks This can eliminate the need to prune roots that caused the walk to lift Many trees in urban areas are treated like this. Be sure to put a mechanism in place that prevents contractors from damaging main roots during sidewalk repair.Many trees in urban areas are treated like this. Be sure to put a mechanism in place that prevents contractors from damaging main roots during sidewalk repair.

32. Do not cut roots! Within 5 X trunk diameter i.e. 2 ft. trunk diameter = do not cut within 10 ft.Within 5 X trunk diameter i.e. 2 ft. trunk diameter = do not cut within 10 ft.

33. New design situations How do we make trees fit? Parking lots Planting islands Road medians Sidewalks Streets Buildings The solutions to these different design situations revolve around one central, simplistic concept – allow space for tree roots! Often trees are planted with just enough space for the root ball size at planting, without any account for the space needed for roots to grow. Obviously, it follows that these trees can blow down under 100 mph winds! Roots provide a necessary anchor for the tree.The solutions to these different design situations revolve around one central, simplistic concept – allow space for tree roots! Often trees are planted with just enough space for the root ball size at planting, without any account for the space needed for roots to grow. Obviously, it follows that these trees can blow down under 100 mph winds! Roots provide a necessary anchor for the tree.

34. Good design happens in two ways… Choose the right tree for the conditions of the site Design the right place to fit the trees you want The problem is that many trees in urban areas have two choices: a short life span in which they begin to decline a few years after planting, or the more stalwart trees can send out aggressive roots that disrupt the hardscape. The solution, therefore, is to either design more soil space or pick smaller trees.The problem is that many trees in urban areas have two choices: a short life span in which they begin to decline a few years after planting, or the more stalwart trees can send out aggressive roots that disrupt the hardscape. The solution, therefore, is to either design more soil space or pick smaller trees.

35. Designing the right place Plant trees in the open soil space available If this is not possible, direct roots toward the open soil If there is not open space for root growth, design appropriate soil space Consider groupings vs. individual plantings This first solution may sound a bit obvious, but it is surprising how often this is not done.This first solution may sound a bit obvious, but it is surprising how often this is not done.

36. “Appropriate” soil space Plan on providing about 9-10 feet between curb and sidewalk to accommodate large maturing trees. What’s wrong with this picture? (back tree near curb) Plan on providing about 9-10 feet between curb and sidewalk to accommodate large maturing trees. What’s wrong with this picture? (back tree near curb)

37. Planting strips in successful designs Planting strips are wide enough to support these trees.Planting strips are wide enough to support these trees.

38. Structural soilSmall aggregate material (angular rocks ~ 1 in. diameter) with enough soil to almost fill the space between the rocks. Roots grow well in the soil between the aggregates. In normal design, the soil and sub-base under a walk or pavement is compacted to 95% proctor density. This reduces air exchange below the critical level needed for root growth. As a result, roots are unable to grow into this compacted soil. In structural soil, weight is transferred from one aggregate to another aggregate then into the soil below the aggregate. Soil between the aggregates is not compacted because load is transferred to the aggregates. Typical aggregates are stones about one inch in diameter. Structural soil is designed to support the weight of walks, roads, pedestrians and vehicles as well as provide a well-aerated soil substrate for tree root growth Weight is transferred from aggregate to aggregate then to the soil under the aggregate; no weight is borne by the soil between aggregates. Remember that only 20% of the volume is soil; the rest is rock. In normal design, the soil and sub-base under a walk or pavement is compacted to 95% proctor density. This reduces air exchange below the critical level needed for root growth. As a result, roots are unable to grow into this compacted soil. In structural soil, weight is transferred from one aggregate to another aggregate then into the soil below the aggregate. Soil between the aggregates is not compacted because load is transferred to the aggregates. Typical aggregates are stones about one inch in diameter. Structural soil is designed to support the weight of walks, roads, pedestrians and vehicles as well as provide a well-aerated soil substrate for tree root growth Weight is transferred from aggregate to aggregate then to the soil under the aggregate; no weight is borne by the soil between aggregates. Remember that only 20% of the volume is soil; the rest is rock.

39. Tree growth in structural soil These trees were planted into a strip of structural soil installed in this retrofitted parking lot between the blue arrows They have performed quite well This is a typical urban scene that appears to have no space for tree roots. However, below the surface, provisions have been made to allow for root growth. If you look closely you can see the light colored structural soil at the right-hand side of the parking lot (right arrow), near the railroad tracks. The structural soil extends below the asphalt to the rear of the front tire on the white car in this photo (left arrow). Even the most challenging urban sites can be designed to include trees!This is a typical urban scene that appears to have no space for tree roots. However, below the surface, provisions have been made to allow for root growth. If you look closely you can see the light colored structural soil at the right-hand side of the parking lot (right arrow), near the railroad tracks. The structural soil extends below the asphalt to the rear of the front tire on the white car in this photo (left arrow). Even the most challenging urban sites can be designed to include trees!

40. Suspended sidewalk Suspending the sidewalk avoids issues with soil compaction so that roots can spread without interrupting the hardscape There is no contact between the bottom of the slab and the soil; the slabs rest on lateral supports and pilings This allows the soil to be placed loosely in the 100 foot long planting hole which promotes root growth and healthy trees There is no contact between the bottom of the slab and the soil; the slabs rest on lateral supports and pilings This allows the soil to be placed loosely in the 100 foot long planting hole which promotes root growth and healthy trees

41. This particular system provides structure to support the hardscape, filling in the remaining space with quality soil. Structure Soil Example of elevated sidewalkExample of elevated sidewalk

42. Use alternate surface materials Materials other than concrete can be used as a wearing surface: crushed granite gravel wood decking brick-in-sand porous pavers porous asphalt These materials allow oxygen to penetrate the soil and may encourage root growth Choose materials that allow water to permeate for more even distribution, to avoid runoff and flooding issues in urban areas. An additional benefit to these other surfaces is that they provide aeration to the ground below, as opposed to concrete, which traps water and moisture below, attracting roots that will disturb the surface.Choose materials that allow water to permeate for more even distribution, to avoid runoff and flooding issues in urban areas. An additional benefit to these other surfaces is that they provide aeration to the ground below, as opposed to concrete, which traps water and moisture below, attracting roots that will disturb the surface.

43. Porous paving surfaces Porous surfaces are a good design idea for areas prone to flooding: reduce runoff provide aeration to the soil This is an especially important design detail for Florida, which is prone to heavy tropical rains and post-hurricane water surge. The top picture shows a parking lot for a large zoo in the southern U.S. that used traditional pavement for the travel lanes, and cars stalls were constructed of porous paver blocks. The bottom picture shows the parking lot for a garden, where porous asphalt was used as a paving surface. Porous asphalt should be power-washed twice/year to remain porous. This is an especially important design detail for Florida, which is prone to heavy tropical rains and post-hurricane water surge. The top picture shows a parking lot for a large zoo in the southern U.S. that used traditional pavement for the travel lanes, and cars stalls were constructed of porous paver blocks. The bottom picture shows the parking lot for a garden, where porous asphalt was used as a paving surface. Porous asphalt should be power-washed twice/year to remain porous.

44. Designing the right place Plant trees in the open soil space available If this is not possible, direct roots toward the open soil If there is not open space for root growth, design appropriate soil space Consider groupings vs. individual plantings This concept is key to the development of the urban forest.This concept is key to the development of the urban forest.

45. The goal: A healthy urban forest This is an aerial view of Gainesville, Florida. Although this neighborhood is near the downtown area, development preserved existing trees rather than cutting them down. This is an aerial view of Gainesville, Florida. Although this neighborhood is near the downtown area, development preserved existing trees rather than cutting them down.

46. Plant trees closer for canopy closure Trees planted 60-70 feet apart grow large lower limbs due to wide spacing, and require pruning to allow clearance. Group trees 30 ft. apart to encourage an upright form. These ficus trees have plenty of soil space for root expansion, which accounts for their large and healthy size. However, because they are spaced further apart, the sun exposure allows growth of the lower branches. The lower limbs must be pruned or removed to allow passage. Not only does this increase maintenance costs, but it can also initiate decay from the large pruning cuts. Plant trees closer than this in order to create a healthy urban forest design that is more resistant to wind damage. St. Augustine, Florida planted these live oaks along the street in the lawns of homes on the right and between the curb and a wall on the left. The natural upright form of the trees is encouraged by close spacing, and helps to minimize maintenance needs by reducing the pruning required to keep trees clear of pedestrians, vehicles and buildings. This is a good way to develop an urban forest because the closed canopy tends to deflect wind. These ficus trees have plenty of soil space for root expansion, which accounts for their large and healthy size. However, because they are spaced further apart, the sun exposure allows growth of the lower branches. The lower limbs must be pruned or removed to allow passage. Not only does this increase maintenance costs, but it can also initiate decay from the large pruning cuts. Plant trees closer than this in order to create a healthy urban forest design that is more resistant to wind damage. St. Augustine, Florida planted these live oaks along the street in the lawns of homes on the right and between the curb and a wall on the left. The natural upright form of the trees is encouraged by close spacing, and helps to minimize maintenance needs by reducing the pruning required to keep trees clear of pedestrians, vehicles and buildings. This is a good way to develop an urban forest because the closed canopy tends to deflect wind.

47. Grouping vs. individual planting This is a sustainable design that will last many years. When large maturing trees are planted in small islands as in the picture on the right, the design has a short life span. Either the pavement will crack from root growth, or the tree will struggle due to lack of space. Either way, the system breaks down.When large maturing trees are planted in small islands as in the picture on the right, the design has a short life span. Either the pavement will crack from root growth, or the tree will struggle due to lack of space. Either way, the system breaks down.

48. Example of sustainable parking lot design Trees are located only in the buffer strips surrounding this parking lot – trees are not in small islands scattered throughout parking lot. This provides adequate space for tree roots to grow. Large healthy trees will shade a large portion of this parking lot. Lots of small islands with small trees or short-lived trees provide little shade.Large healthy trees will shade a large portion of this parking lot. Lots of small islands with small trees or short-lived trees provide little shade.

49. Remember: small spaces do not support large trees! Most of the trees in the design on the right came down after Hurricane Wilma. The large trees were planted in soil spaces that were too small.Most of the trees in the design on the right came down after Hurricane Wilma. The large trees were planted in soil spaces that were too small.

50. Solutions can happen in two ways… Choose the right tree for the conditions of the site Design the right place to fit the trees you want In addition to good design, tree selection is critical to the success of any planting project. When choosing a tree for a site, aesthetic considerations should come last, after a list has been compiled based on what trees can best survive the conditions of the site. The ability of the species to tolerate high winds is critical.In addition to good design, tree selection is critical to the success of any planting project. When choosing a tree for a site, aesthetic considerations should come last, after a list has been compiled based on what trees can best survive the conditions of the site. The ability of the species to tolerate high winds is critical.

51. Small trees for small spaces Matching species to the site conditions in this case means evaluating the volume of soil space available for root growth and choosing trees that are likely to grow well in this space. The soil space for root growth is very limited here so small maturing, drought tolerant trees are l well suited.Matching species to the site conditions in this case means evaluating the volume of soil space available for root growth and choosing trees that are likely to grow well in this space. The soil space for root growth is very limited here so small maturing, drought tolerant trees are l well suited.

52. Wind resistant species To get a comprehensive list of wind-resistant species, refer to our website: (http://treesandhurricanes.ifas.ufl.edu/index.html The species list is a result of 10 years of UF researchers tracking hurricanes and statistically analyzing which trees remain standing and recover best after a hurricane. The species list is a result of 10 years of UF researchers tracking hurricanes and statistically analyzing which trees remain standing and recover best after a hurricane.

53. Do not over-plant one species Restrict one genera or species to < 20% for a few years Develop a list of alternatives for each commonly planted tree Examples of alternatives to live oak: Swamp chestnut, redbay, trident maple, sugarberry, ash, sweetgum, american elm, cedar elm, overcup oak A sustainable urban forest should have diversity. There are other native tree species that offer different strengths and advantages than live oak, and should be incorporated into design. Diversity provides defense against the outbreak of a pest or disease that could devastate a tree population. Refer to our presentation on wind-tolerant trees to get ideas for other strong species for Florida.A sustainable urban forest should have diversity. There are other native tree species that offer different strengths and advantages than live oak, and should be incorporated into design. Diversity provides defense against the outbreak of a pest or disease that could devastate a tree population. Refer to our presentation on wind-tolerant trees to get ideas for other strong species for Florida.

54. Wind-resistant urban design Design conflicts that can cause tree failure Design solutions that promote wind  resistance - existing design situations - new design/construction How to take action Some suggestions for how to bring these ideas for better design into reality will conclude this presentation. Some suggestions for how to bring these ideas for better design into reality will conclude this presentation.

55. Where to begin… Get the right people involved Set new building ordinances for the community Become a Tree City USA Designs that involve trees should have longevity. Too often planting projects have instant gratification, but decline over time because of lack of planning. Planning may take some extra time and money at the outset, but over the long term the benefit of having large, healthy trees will pay off. Also, money often is spent on repairing poor design, which can be avoided by putting effort into planning. For information about planning, see the presentation “Developing an Urban Forest Management Plan for Hurricane-Prone Communities”Designs that involve trees should have longevity. Too often planting projects have instant gratification, but decline over time because of lack of planning. Planning may take some extra time and money at the outset, but over the long term the benefit of having large, healthy trees will pay off. Also, money often is spent on repairing poor design, which can be avoided by putting effort into planning. For information about planning, see the presentation “Developing an Urban Forest Management Plan for Hurricane-Prone Communities”

56. Who should be involved in the planning process? City engineer Landscape architect Urban forester/arborists Builders & developers Planners Parks and Recreation Power companies Homeowner’s Association City or county commissioners Not all of these characters can be present when planning a good design, but as many experts as possible should be consulted during this process. At the political level, city ordinances can be changed when commissioners are involved. Power companies should be consulted so that trees do not interfere with utilities. Tree experts like foresters and horticulturists should work closely with landscape architects to assure that the right tree species are selected. Other professionals – engineers, planners, architects, landscape architects, urban foresters, arborists Species selection and spacing Creative design solutions Ordinance and code changes Not all of these characters can be present when planning a good design, but as many experts as possible should be consulted during this process. At the political level, city ordinances can be changed when commissioners are involved. Power companies should be consulted so that trees do not interfere with utilities. Tree experts like foresters and horticulturists should work closely with landscape architects to assure that the right tree species are selected. Other professionals – engineers, planners, architects, landscape architects, urban foresters, arborists Species selection and spacing Creative design solutions Ordinance and code changes

57. What is Tree City USA? Program started by The National Arbor Day Foundation to promote communities that take care of their trees  Provides a framework for starting a tree management program. One way to start an urban forest in your community is to get involved with the Tree City USA program started by the National Arbor Day Foundation. Hundreds of cities are already involved, and it is a good way to get the community involved. To meet the standards for becoming a Tree City requires taking the first steps toward having a tree management plan, of which good design is a crucial part. The requirements that must be met for a community to receive recognition are the beginning steps for starting any tree management program. One way to start an urban forest in your community is to get involved with the Tree City USA program started by the National Arbor Day Foundation. Hundreds of cities are already involved, and it is a good way to get the community involved. To meet the standards for becoming a Tree City requires taking the first steps toward having a tree management plan, of which good design is a crucial part. The requirements that must be met for a community to receive recognition are the beginning steps for starting any tree management program.

58. Contact your local county extension! Get information specific to counties across the state i.e. tree species that grow well in the area,  local soil conditions, etc. Cuts time spent on looking up information in half! The local county extension offices are a great resource. Time and effort for finding the right information on growing trees in your area can be cut in half with one short trip to the extension office!The local county extension offices are a great resource. Time and effort for finding the right information on growing trees in your area can be cut in half with one short trip to the extension office!