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Tree Valuation Assignment

Report on the Condition of a Sugar Maple Tree at 23 Westwood Court, Lindsay, Ontario

by: Marie-Andrée Crothers

for: Paul Bell

Contents

Appendix (detailed calculations)

Over the course of the summer and fall of 2001, extensive renovations were made to the apartment building found at 23 Westwood Court, Lindsay, Ontario. During this time, I was able to observe how the construction workers treated the natural environment around the building and was witness to the decline of several sugar maple (Acer saccharum) trees. One tree, in particular, was cause for concern because of its vulnerability to pests and diseases, and its placement on the property.

Condition:

The species range for Acer saccharum is from 75%-82%. As this is a specimen of Acer saccharum that is 8.3 metres tall and approximately 50 years old, and which has been experiencing decline and low vigour over the past few years, I give it a species rating of 75%.

At present, some of the visible problems with the tree are the following:

Presence of Parmelia spp. (see figure 1)
This lichen is not a problem for the maple, but, rather, the indicator of a potential problem. Parmelia prefers to grow in damp/wet conditions (Licheni). Damp conditions, in combination with the number of open wounds on the tree, increase the potential for fungal infection such as:
Maple Tar Spot caused by Rhytisma;
Purple Eye caused by Phyllostica minima (Pirone, p. 109);
Leaf Blister caused by Taphrina sacchari (Pirone, p. 110); and
Gloeosporium apocryptum, which causes the leaf killing condition Anthracnose (Maple).

Figure 1. Parmelia spp. (digital photograph by M-A Crothers)

Improper Pruning (see figures 2, 3, and 4 for a few examples)
Figure 4 presents particular cause for concern. As can be seen in the photograph, the stump left after pruning is dead wood. This is the perfect habitat for wood boring insects, including the flat headed borer (Chrysobothris femorata) that generally attacks trees of low vigour and the sugar maple borer (Glycobius speciosus) (Pirone, pp. 116-117), as well as their predators, including woodpeckers. Other potential pests include sapstreak (Ceratocystis coerulescens), the forest tent caterpillar (Mala cosomadistria), the maple leaf cutter (Paraclemensia acerifoliella), bladder-gall mites (Vasates quadripedes), maple phenacoccus (Phenacoccus acericola) (Pirone, pp. 113-116), maple trumpet skeletonizer (Epitriotia aceriella), and orange humped mapleworm (Symmerista leucitys) (Johnson, pp. 212 and 154).

Figures 2, 3, and 4. Pruning has left stubs and open wounds on the tree, all of which have been left untreated. (digital photographs by M-A Crothers)

Frost Crack/Sun Scald (see figure 5)
A wound of this nature leaves the tree susceptible to rot because of the disruption of sap flow. Additionally, the damaged bark around this area is an attraction to numerous insects, examples listed above. (Green Thumb).

Figure 5. Frost Crack/Sun Scald (digital photograph by M-A Crothers)

Damage of Bark (see figures 6, 7, 8, 9, and 10)
Damage to the bark of this maple includes holes (potentially from wood boring pests such as woodpeckers), lesions, and even a nail. If too much of the bark continues to be damaged, girdling is a probable result.

Figures 6, 7, 8, 9, and 10. Damages to the bark (digital photographs by M-A Crothers)

Root Pounding and Erosion (see figures 11, 12, and 13)
This tree is unfortunate enough to be located right next to the apartment building (see figures 14 and 15). It is evident from the photographs that there has been excessive wear on the area around the tree. In fact, all the maples on the property show signs of root pounding and erosion. In theory, this tree, and those around it, should have been protected from the construction process; for example, by putting up a barrier around them (SCFC). However, there is literally no way around the building other than by impeding on the tree's space because the tree is so close to the building. This is why, over the course of the summer and fall, I have seen cement mixers and other heavy equipment parked right under the tree.

Figures 11, 12, and 13. Root Pounding and Erosion (digital photographs by M-A Crothers)

Figures 14 and 15. Proximity of the sugar maple to the building (digital photograph by M-A Crothers)

Root Girdling
As can be seen in figure 16, rather than being flared, the base of the tree is concave. This is a sign that the tree is suffering from root girdling, the probability of which is increased by the proximity of the root system to the foundation of the building. If the root girdling is not dealt with immediately, the tree will die.

Figure 16. Trunk indicating probable root girdling. (digital photograph by M-A Crothers)

Squirrel Damage
Red squirrels bite maple bark to drink the sap, leaving lesions that can develop cankers (see figure 17) (Pirone, p. 117).

Figure 17. Probable squirrel damage (digital photgraph by M-A Crothers)

Because the sugar maple is likely to develop serious problems in the next few years, I am attributing to it a condition rating of 50%.

Location:

This sugar maple tree has grown in a favoured residential area where properties are worth at least $100,000-$300,000. This is an older neighbourhood with properties having several mature trees on them. I examined a weekly flyer advertising homes in the area and then went to each home to see if I could correlate value and number of trees. Indeed, the older homes with more trees had a higher value than the new homes with fewer trees. It can be concluded that having mature, healthy trees on one's property in this area is a definite asset. In addition, the dwelling on this site is an apartment building. The treed lot, with picnic tables and a place to play with your dog or throw a ball with your children is a definite attraction to potential renters. Other trees on the site include more sugar maples (see figures 18 and 19), and several red pines (also in decline, see figure 20), as well as cedar.

Figures 18 and 19. Other sugar maple trees within proximity (digital photograph by M-A Crothers)

Figure20. Red Pines showing dieback (digital photograph by M-A Crothers)

While the neighbourhood does offer attractive treed lots, it has very little in the way of services (only one convenience store and no gas station, for example). However, it is very close to numerous parks, playgrounds, and schools, all things families with young children look for when shopping for a home. I therefore give this location a rating of 75%.

Recommendations

During the construction process, heavy equipment should have been kept away from the tree and parked in the nearby parking lots, which would have helped mitigate the erosion and root pounding problems. However, while this tree does not yet appear to have been seriously infected by any insects or pathogens, it has potential for attack from numerous sources, and this not just because of the construction work. The work served to accelerate the tree's decline, but was not its cause. Because of this, I do not believe the construction company should be held liable for the whole amount the tree is worth, $2,300 (see appendix).

I recommend considering the the removal of the tree in the near future. Its root system is showing signs of girdling, which will eventually kill the tree if problematic roots are not removed. In addition, removing this tree would also eliminate the threat of numerous infections and infestations that could propagate to infect nearby maples that are in better condition and more likely to survive the effects of the construction process.

Shortly after the tree was examined, grass seed was planted around the eroded area at its base. This is a good solution to the erosion problem, but will most likely prove ineffective in the long run because the tree is in such a high traffic area.

Appendix

Species: Acer saccharum L. Sugar (Hard) Maple

Species Rating: 75%

Condition: 50%

Trunk Diameter: 43.5 cm

Location: 75%

Replacement Tree Area: 20 cm2

Replacement Tree Cost: $500.00

Installation Cost: $600.00

Total Cost: #6+#7= $1,100.00

Unit Cost Value: $5.00/cm2.

#10