Climate Action and Sustainability Plan June 2021 | Page 39

As for ecosystem benefits , imagine a heavy downpour . Tree canopies help slow down the initial rush of water . The understory vegetation reduces storm water sheetflow and its power to overwhelm catch basins , which causes erosion and negatively impacts wildlife habitat . According to iTree , Mount Auburn ’ s trees avoid 94,770ft3 of runoff , which is equivalent to emptying about 24,000 bathtubs each filled with 30 gallons of water . Fortunately , storm water percolates down through the soil and recharges the aquifer . Based on a 2002 study by Emery & Garret Groundwater 3 , the perviousness of Mount Auburn ’ s landscape recharges the aquifer at an estimated 92 million gallons in one year of average rainfall . So , the trees slow down the rain , the understory reduces sheetflow , and the ground layer absorbs water . Natural systems are amazing .
Maintaining these natural systems , in this case starting with the trees , requires innovative landscape maintenance and long-term planning ensuring plant health . Adding new plants and diversifying species through wise policies with an eye on the impact of climate change will ensure long-term successful carbon storage and sequestration as well as oxygen-rich air to breath and a beautiful , in fact , priceless landscape .
SAMPLE USED WITH iTREE
Ecosystem Benefits of Trees Across Mount Auburn ' s 175 Acres iTree Categories Ecosystem Benefits iTree Sample units $ All MAC units $
Number of Trees
1,047
4,968
Acreage
32.57
175
Hort Sections
10 , 14 , 16 , 43 , 53 , 54 , 55
1-60
Tree Cover
42.50 %
48.15 %
Sugar maple ( Acer saccharum ), Dogwood ( Cornus
Sugar maple ( Acer saccharum ), Northern red oak ,
florida ), Eastern white pine ( Pinus strobus ), Northern
Most Common Species Pct of trees less than 6 "
( Quercus rubra ), Eastern white pine ( Pinus strobus )
41.20 %
red oak , ( Quercus rubra )
Pollution Removal
703.7 lbs / year
$
17,900
year
3,170.0 lbs / yr
$
80,600
yr
Oxygen Production
46.82 tons / year
211 tons / yr
Avoided Runoff
21,400 ft3
$
1,410 year
94,770 ft3
Structural values
$
3,260,000
$
14,700,000
Carbon Storage
816.1 tons
$
139,000
year
3,680.0 tons
$
626,000
yr
conversion t to mt
740.6 mt
3,339.4 mt
C to CO2 conversion
2,715.4
mtCO2e
12,244.5
mtCO2e
Carbon Sequestration
17.56 tons / year
$
2,990
year
79.1 tons / year
$
13,500
yr
conversion t to mt
15.9 mt / year
71.8 mt / year
C to CO2 conversion
58.4
mtCO2e / year
263.2
mtCO2e / year
The total carbon stored in the tree trunks is the 3,339.4 metric tonnes of carbon ( mtC ). To get a sense of the magnitude of carbon storage when compared with Mount Auburn ’ net carbon footprint of 614.52 mtCO2e , this carbon ( C ) storage figure is the equivalent of 12,244.5 mtCO2e . These figures are enormous , however they are a grand total ; they have not been annualized . In order to determine the potential carbon offset per year , tree growth between two periods need to be compared , then the yearly offset amount could be calculated , based on new plantings and tree
3
Consultant to Mount Auburn on permitting and pumping water from the aquifer required by MA DEP .
Mount Auburn Cemetery | Climate Action & Sustainability Plan 34