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Meeting with Gemeente Haren – Green and tree policy Haren 2016/2017Bomenridders Groningen PresentationKristin McGeeMei 2017

10 POINTS

1. Yearly totals in the Urban Canopy – 30% CanopyWhy doesn’t the gemeente Haren keep records of the number of trees removed per year versus number of trees planted per year? And further since we now know that numbers don’t reflect the benefits that trees deliver based upon mass and canopy, we must begin to understand not only the total mass of green and trees, but the total tree coverage or canopy. In Haren, around 600 plus trees are removed per year (that are registered) and this average has likely increased since deregulation of the permit policy. We have about a 30% canopy, which is rather acceptable. But if we continue removing trees at the current rate of 2.5% per year, we will have no trees in 46 years. Here is an estimate the financial and environmental benefits of a 30% canopy, which is what was briefly estimated in Haren based upon the program iTreeTools using Google maps.

Figure 1: Tree Benefits of Haren’s total canopy in 2016

2. Strategy of the gemeente tree policyHow does the Gemeente plan on preserving the urban forest? Considering the many environmental challenges of the future, this should be our primary goal. It is not possible to design a policy with this goal in mind if we don’t know what our yearly canopy totals are. It is possible to map total canopy (tree cover) with the aerial photography program that the gemeente has access to (and regularly uses for building projects), but so far nothing has come of this. Bomenridders would be interested in finding someone to do this research. This is now standard practice in many municipalities throughout the world. Examples are Sydney, Toronto, Portland,

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Chicago, Birmingham and hundreds of other international cities. Many cities publish models and information that we could use in Haren1.

3. Overly liberal tree removal policy Trees are often removed at the first site of a less than full crown or a few examples of fungi. According to Hans van der Lans and Wankja Ferguson – while some of these large trees may require felling at some point, most can live safely for decades or at least another 10 years – such as the maple (esdoorn) in front of my house, which could have lived for several decades more and was not yet in danger of falling. This tree provided essential qualities for local residents and was home for many birds and insects.

Figure 2: Example of non-sustainable maintenance

1 See publications and reports at the end of this document.

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Figure 3: Overly pruned trees – putting them in danger of breakage and rot. A 2/3 crown to trunk in height ratio is advised by the International Arboreal Society.

4. Failing trees from poor maintenance: Trees begin to suffer poor health because of how they are maintained – they are aggressively and needlessly over-pruned, the trunks are damaged because of industrial grass mowing, and large living branches are removed for no apparent reason, even on trees not near streets. Also the crown is unreasonably raised forcing a tree to survive on a much smaller percentage of foliage – disrupting the balance between the root system and the above ground live foliage2.

2 Here are several sources which point to the long term damage of trees because of over pruning: "Pruning urban trees: overpruning" bij Deborah Ellis, 2013; "Het belang van bomen in de stad" in De Groene Stad, 2016; "Waarde van natuur veel groter dan bedacht" in De Vitale Groen, 2016; "Pruning maturing shade trees", CMG Garden Notes 615, Colorado State University; "Topping and lion's tailing are forbidden", National Arborist Association; “Lions by Larry Figart, University of Florida, 2009; "Pruning Affects Tree Movement in Hurricanes", Gilman et al., Arboriculture & Urban Forestry 2008: 34(1): 20–28.

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Figure 4: Damaged tree trunk from mowing

Lions Tailing and ToppingTwo other areas of consistently bad policy are ‘lions tailing’ and topping. These are common in Haren and there is apparently no penalty for such harmful and long-discredited practices.

5. Total tree canopy removed permitted by the Haren municipality in 2016Here I used iTree to estimate the C02 sequestration based upon tree size, species and health condition. This program is used to gauge the impact of urban forest and environmental climate fighting potential of existing trees.

1. 37 trees to be removed in 2017: a. 3,178 kg C02 (so the CO2 of 1/4th car if a car driving 45,000

kilometers per year emits 10,686 kg per year)3 b. 122,674 liters rain water filteredc. 86,539 kg OZ absorbedd. 500 kg Nitrogen Dioxide absorbede. 30,747 kg Large Particular Matter filtered (pollution)

2. 600 plus per year: If we extrapolate these 37 trees to the yearly average of trees removed in the last 5 years, which is 600+ trees per year - that is all previous figures multiplied times 16:

a. 50,848 kg CO2 (5 cars in one year) b. 1,962,784 liters rain water (a normal civic swimming pool4)c. 1,384,624 kg Ozone d. 8000 kg N2O (Nitrogen Oxide)e. 491,952 kg LPM (Large Particulate Matter)

6. Large trees removed and certain species – poplars, willows: 3 1 acre of trees are required to sequester 1 average car at 45,000 kilometers4 Olympic swimming pool 2,500,000

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Current policy seems to be to gradually remove all larger and older trees – yet this policy severely underestimates the need to especially sustain and maintain older, larger stature trees – which provide many more benefits (tree statistics) and are the most valuable economically and environmentally.

Figure 5: These two healthy oak trees removed last year and labeled “life threatening” when in reality only their inner trunk began to soften - an absolutely ordinary process for a mature oak tree. This does not make it dangerous.

7. Large tree comparison If you compare the sustainability and pollution removing benefits of large trees to small trees the differences are immense. Here is one comparison between 1. Poplar (127 centimeters) versus 2. A small maple (esdoorn) (13 centimeters). The results: The Poplar is more than 13 TIMES MORE VALUABLE.

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Figure 6: benefits of a 13-centimeter maple with picture

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13 centimeter diameter maple on Waterhuizerweg 1. 18.27 CO22. 680 liters rainfall 3. 163 grams ozone 4. 4. 5 grams nitrogen dioxide 5. 172 grams large particulate matter

Figure 7: Tree benefits of a 127-centimeter Poplar tree with picture

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127-centimeter diameter poplar on Waterhuizerweg (13 times more valuable): 1. 209 kg CO2 (12 times more)2. 9857 liters rainfall (15 times more) 3. 2073 grams ozone (13 times more)4. 59 nitrogen dioxide (13 times more)5. 2218 grams large particulate matter (13 times more).

8. Current focus of green policy The current strategy is on tree removal and pruning and not on tree maintenance and planting. Total average canopy removed per year is 2.5%. Tree permit is ca. 90% and 10% rejection – this should be reversed. We need to completely reverse or policy to prioritize tree coverage preservation and tree planting – to preserve and extend the urban forest.

Example of my street (Waterhuizerweg) Within three blocks (but I cannot see the back yards), I measured the trees cut in the front yards and street and compared this to 2 years ago. 13 trees were removed in the last year. All were the most beneficial sort – large stature, healthy trees with large canopies for our urban forest. This is more than 50% of our current canopy, even though only 25% of total trees. However, two new trees were planted on the Cantersveen.

9. Permits given and refused for 2016 and 2017Trees permitted to be removed in less than 3 months in 2017: 117 (see excel chart). If we double this because of deregulation for trees in backyards, we come to an average of 117 (for 4 months) x 3 (for entire year) x 2 (doubling for backyard trees) = 702 which is an increase of 100 trees or about 15% increase in tree removals.

Trees permitted to cut in 2016: 411 (and ca. 616 total)Since the deregulation in September 2016 all trees under 100 centimeters no longer are registered. Therefor we add at least 50% more (205) of unannounced trees so likely 616 trees were removed in 2016 – maintaining the average from earlier years. In reality because the barrier to remove a tree is now removed, we must assume that the number increased.

Totals permits refused: 88 refused (10%) since 2016 – it should be more like 80%. Only sick and dangerous or trees totally blocking light, but this is an increase in 9% from last year.

Permits given from Jan – April 2017: 117 (702 yearly total)Private117 trees (in 4 months) x 3 = 351 x 2 (for trees without permits in backyard) = 702

Current Gemeente Projects21 fietsplusDe Vork

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New train station – Heritage Linde treeSBB – dozens if not hundreds of trees removed in small park areas and in the houdwallen

10. Total reduction in canopy – 2.5% in 2016Gemeente says it has 28,000 so if it didn’t replant any trees of equal mass it reduced the total canopy ca. 2.5% this year.

Sources“Every Tree counts: A Portrait of Toronto’s Urban Forest.” 2007. Toronto Parks,

Forestry and Recreation (study using iTree tools to calculation tree worth and related compensation values)

iTree tools: https://www.itreetools.org/Fleming, Amy. 2016. “The importance of urban forests: why money really does grow

on trees” in The Guardian.Jacobs, Brent, Nicholas Mikhailovich, and Candice Delaney. 2014. Final Report

Benchmarking Australia’s Urban Tree Canopy: An i-Tree Assessment. Institute for Sustainable Futures, University of Technology, Sydney.

Li, Xiaojiang, Chuanrong Zhang, Weidong Li, Robert Ricard, Qingyan Meng and Weixing Zhang “Assessing street-level urban greenery using Google Street View and a modified green view index” in Urban Forestry & Urban Greening 14 (3), 2015: 675-685.

McPherson, E. Gregory, David Nowak, Gordon Heisler, Sue Grimmond, Catherine Souch, Rich Grant, and Rowan Rowntree. 1997. “Quantifying urban forest structure, function, and value: the Chicago Urban Forest Climate Project” in Urban Ecosystems 1/1.

Nowak, Crane and Dwyer. 2002. “Compensatory Value of Urban Trees in the United States”.

Nowak and Dwyer. 2007. “Understanding the benefits and costs of urban forests ecosystems” in Urban and Community Forests in the Northeast.

Plant, Lyndal and Neil Sipe. “Adapting and applying evidence gathering techniques for planning and investment in street trees: A case study from Brisbane, Australia” in Urban Forestry & Urban Greening, 19/1, 2016: 79-87.

“Portland’s Urban Forest Canopy: Assessment and Public Tree Evaluation , ” October 2007, prepared by Portland Parks and Recreation. Report outlines the economic, environmental and cultural benefits of urban trees in monetary terms.