I did a tree inventory of the trees on Glenholme Ave. in Toronto. I wanted to know how many trees are on Glenholme, and of what type.
Glenholme is a street in mid-town Toronto. The street stretches north from Davenport Rd. to Eglinton Ave., a length of 2.67km. The majority of development on Glenholme was post WWI, post WWII the neighbourhood was an Italian enclave.
1907 City of Toronto Map, from the Toronto Public Library
I entered the trees into the OpenStreetMap, they appear as green circles.
I noted all the trees on Glenholme Ave., in Toronto;
-from Regal Rd., to Eglinton Ave., W.
-trees in front yards
-trees in side yards, if the yard was adjacent to a perpendicular street, and clearly visible (when little distinction could be made between a side and front yard)
-trees with a Glenholme addresses.
I estimated the size of the tree. This was done comparing the size of the tree and the closet house. The size is recorded in storeys of a house. Each house storey is assumed to be 3 meters.
There are 456 properties on Glenholme Ave., of which 227 properties have at least one tree, and 229properties do not have any tree.
There are 456 Glenholme addresses on the street. Those 458 addresses have 300 trees; 229 addresses have 0 trees, 179 addresses have 1 tree, 32 addresses have 2 trees, 12 addresses have 3 trees, 2 addresses have 4 trees, 1 address has 5 trees, 1 address has 8 trees
The addresses that had the most amount of trees, 8 trees and 5 trees, where the two schools on the street. 4 front/side yard trees on a residential property is the most trees a non-institutional property an address has.
|Type Of Tree||Count|
Deciduous trees outnumber coniferous trees on Glenholme Ave., with 217 deciduous trees and 83 coniferous trees.
Total amount of storeys, of trees, on Glenholme is 732.5. Each story is 3 meters. Therefore there are 2206.5 meters of tree on Glenholme, or aprox. 2.2km.
The Total length of Glenholme is aprox. 2.67km, if the total length of all trees combined is 2.2km, than there is less tree than road.
The average amount of trees per address on Glenholme is .6572
There is some speculation that tree coverage in a neighbourhood is associated with wealth. Here we will look at the difference between the north portion of Glenholme aprox. above Rogers Rd., and the south portion of tree coverage approx. below Rogers.
|North Part Of Glenholme||South Part Of Glenholme|
|Yes, property has a tree||88||140|
|No, property does not have a tree||141||87|
There are 456 addresses. 456/2 is 228. The 228th address, halfway up the street, is 288 Glenholme Ave. It should be reasoned that half the trees are below 288 Glenhome Ave., and half the trees above that address. But that is not the case there are 191 trees below that address and a 110 above that address.
Examining, only, if a property had a tree or not. For the addresses until and including 288; 140 had trees and 88 addresses did not have trees. For the addresses 289 and above; 87 addresses had trees and 141 did not have trees.
Running a Chi-Square Test, at Alpha of .05, and 1 degree of freedom. The critical value is 3.8414, and my calculated value is 24.6408. We can reject the Null hypothesis that there is no difference between the north half and south half of the street. The south half of Glenholme has more trees planted than the north half, that is most likely not by random chance.
The northern part of Glenholme Ave., has significantly less trees than the southern half of the street. The hypothesis that wealthier neighbourhoods have more trees suggests to be true in this case.
Southern exposure for plants is best for exposure to light, west facing is the next best for total light, with east and north facing yards trailing. Would we therefor tend to find more trees on the west side of a street than on the east side of a tree?
Even numbered houses are on the west side of the street. Odd numbered housed are on the east side of the street.
|Property has a tree.||121||106|
|Property does not have a tree.||119||110|
Running a Chi-Square Test, at Alpha of .05, and 1 degree of freedom. The critical value is 3.8414, and my calculated value is 0.08197. We cannot reject the Null hypothesis that there is no difference between the west half and east half of the street. The variation of amount of trees planted, between the east and west side, of Glenholme Ave., can be attributed to random chance. It may be inconsequential for trees if they are planted on a west facing yard, or on a east facing yard.
Arthur Gron, January 2020.