Presentation Outline. Urban Tree Canopy Loss. Climate Change Sustainable Forest Management Urban Tree Diversity Diversity Prioritization

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2 Presentation Outline Urban Tree Canopy Loss Climate Change Sustainable Forest Management Urban Tree Diversity Diversity Prioritization Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

3 New York and Los Angeles

4 City of Santa Monica & LA Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

5 City of Santa Monica Source: Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

6 Urban Forests by Numbers Estimated 2M Park Trees 620,000 Street Trees 6,335 Park Trees 26,813 Street Trees

7 Urban Tree Canopy Loss Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

8 Urban Tree Canopy (UTC) Area City Tree Cover (%) Atlanta, GA 37 Austin, TX 34 Boston, MA 29 Washington, DC 28 US National Average 27 Seattle, WA 25 NYC & Los Angeles 21 London, UK 20 Santa Monica, CA Jersey City, NJ Chicago, IL 11 < 10% 15% 20% 25% 30% 35% 40% 45% 50% > 50% Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

9 Urban Tree Canopy Loss Columbia University found that NYC lost 4.5% vegetative cover (9,000 acres) between A US Forest Service study found NYC lost 1.2% area of tree canopy between 2004 and 2009 (Nowak and Greenfield, 2012) 6% Drop in total UTC in 5 Years This same study discovered that 19 out of 20 US cities were losing urban tree canopy Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

10 Urban Tree Canopy Loss Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

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13 One of the biggest risks to the urban forest is, risk! Wells, 2015 Lawyers Insurance Companies Residents Urban Forest Risk Manager Consultants & Tree Companies Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

14 Urban Tree Canopy Loss Climate Change: Drought WORST IN 500 YEARS!

15 Drought: Threat to Urban Forest Reduced Water Conductivity (Hydraulic Failure) Reduced Carbon Metabolism (Starvation) Drought Stress Induced Decline Impaired Response to Biotic and Abiotic Agents A Summary of the Physiological Impacts of Drought Stress in Trees (McDowell et al., 2013; McDowell, 2011)

16 Drought Stress: Contributing Factors Soil Compaction Root Removal Installation of Impervious Surfaces Reduced Irrigation Soil Moisture Stress Insufficient Soil Volume (Modified from Connella, 2008) Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

17 Drought Stress Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

18 Source: LA Times April 2015: 14,000 dead park trees reported in last year due to drought Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

19 Drought Stress Reduced Irrigation June 2011 August % of public trees in Santa Monica have a moderate water demand and 44% are categorized as low (Xiao & McPherson, 2015)

20 Urban Tree Canopy Loss Climate Change: Extreme Weather

21 $32 Billion Damages 53 Fatalities Hurricane Sandy: 10/29/2012

22 Hurricane Sandy

23 Hurricane Sandy

24 Hurricane Sandy

25 Hurricane Sandy

26 Hurricane Sandy

27 Totals 6050 Service Requests 710 Work Orders 140 Complete Hurricane Sandy

28 Hurricane Sandy

29 Totals 10,995 Service Requests 3,687 Work Orders 551 Complete Hurricane Sandy

30 Climate Change: Extreme Weather Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

31 Climate Change: Extreme Weather Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

32 Climate Change: Extreme Weather 25,000 20,000 15,000 Three major storms in as many years. 17,219 trees lost due to these 3 storms. $24 million spent on emergency contracts. 10,000 Limbs Down Hanging Limbs Trees Down 5, /6/1998 (Labor Day Storm) 3/13/2010 (March Nor'Easter) 9/16/2010 (The Tornadoes) 8/27/2011 (Hurricane Irene) 10/29/2012 (Superstorm Sandy)

33 Climate Hurricane Sandy Change: created a Extreme 13-14ft Storm Weather Surge 47,800 trees in the inundation zone August 2011 September 2013 Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

34 Climate Change: Extreme Weather 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1, Most Affected Species by Percent Leaf Out Over 3,000 had a 25% or less leaf out $3.2 million replacement cost 20,000 mature trees destroyed in total Planetree Maple Unknown Cherry Honey locust Oak Callery Pear 75% 50% 25% 0% Pine Pin Oak Linden Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

35 Sustainable Forest Management PLANTING MAINTENANCE PRESERVATION RISK MANAGEMENT EMERGENCY RESPONSE Source: Adapted from USDA Forest Service

36 Sustainable Forest Management a dynamic and evolving concept, aims to maintain and enhance the economic, social and environmental value of all types of forests, for the benefit of present and future generations. (United Nations Forum on Forests) Environmental URBAN FOREST Social Economic

37 Urban Forest Sustainability Metrics Urban Tree Canopy % i-tree Ecosystem Benefits Net Tree Gain/loss Sustainable Urban Forest Management Tree Diversity Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

38 i-tree: Ecosystem Benefits Trees Need to be in Good Functional Health to Deliver Benefits (Rahman et al., 2011) Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

39 Urban Forest Sustainability Metrics: Urban Tree Diversity Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

40 Diversity A range of many people or things that are very different from each other (Oxford Learner s Dictionary, 2014) Resilience The ability to become strong, healthy, or successful again after something bad happens (Merriam- Webster, 2014) Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

41 Urban Tree Diversity Species Planned, Systematic & Integrated Age Location (Need) Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

42 Urban Tree Diversity What Level? Street Neighborhood Borough City Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

43 Urban Tree Diversity What Level? 38% 22% 41%

44 Urban Tree Diversity Planning Everyone has a plan til they get punched in the mouth. Mike Tyson Policies of 49 California municipalities were accessed 82% indicated that species diversity was an objective (Muller and Bornstein, 2010) Only 48% had codified this objective in a management plan

45 Urban Tree Diversity - Species Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

46 Species Diversity Recommendations Authors Miller and Miller (1991); Smiley, Kielbaso and Proffer (1986) Kielbaso (1989) Santamour (2002) Diversity Recommendations No species shall exceed 10% of the population No species should exceed 5% and no genus should exceed 10% Plant no more than 10% of any species, no more than 20% of any genus and no more than 30% of any family 10 Genus and 20 Species Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

47 Genus Count Species Count Genus Diversity Target Species Diversity Target 0 City Of Santa Monica: 35,000 Public Trees Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

48 Planting 20,000 street trees a year 10 year funding allowed for procurement contracts 3 nurseries contract grew for NYC Parks Species Planted

49 Once more unto the breach, dear friends, once more William Shakespeare, Henry V Urban Forest Managers overly rely on tried and tested species (Sjoman, 2012) As growing conditions become more challenging, diversity decreases (Pauleit et al., 2002)

50 Introducing New Species 2ND STREET - 59 Ginkgo Trees 7, 12% 15, 25% Empty Dead 1 - Worse 20, 34% 3, 5% 2 - Bad 3 - Fair 9, 15% 5, 9% 4 - Good 5 - Excellent 2 nd Street = 46% Successful Establishment Baseline = 80% Successful Establishment

51 Introducing New Species Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

52 Bring Back the Old (Natives) Quercus agrifolia (133) Platanus racemosa (374) Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

53 Species Based Pruning Cycles Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

54 Urban Tree Diversity - Age Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

55 Urban Tree Diversity - Age Juvenile Semi Mature Mature Senescent USDA FS City of LA Metric Santa Monica Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

56 Diversify Through Removal 311 Year Cycle

57 Urban Tree Diversity Location (Need) Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

58 Urban Tree Diversity Location (Need) Parks traditionally ran a request based street tree planting program Environmental need based street tree planting (stocking level x population density) Highest Priority Lowest Priority

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67 Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

68 Tree Diversity Prioritization Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

69 Tree Diversity Prioritization 400 Management Units Single Species per Unit Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

70 Tree Diversity Priority Model Per Management Unit Stocking Level or Canopy Cover Age Diversity Rating Potential Ecosystem Benefits Planting Priority

71 Urban Forest Sustainability Metrics Urban Tree Canopy % i-tree Ecosystem Benefits Net Tree Gain/loss Sustainable Urban Forest Management Tree Diversity Tree Diversity to Build a Sustainable Urban Forest: Matt Wells

72 Use Research and Planning to Strive for a Sustainable Urban Forest

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74 Thank You Matthew P. Wells Urban Forester City of Santa Monica