Picia glauca

Description:

Picea glauca, is also known as: white spruce, cat spruce, Canadian spruce, Black Hills spruce. The observed organism is growing in a shared space with another white spruce that has missing needles and lower branches on west side (facing north) looking bare and sickly. The tree under my observation is the east tree. This tree has areas around its mid-line that is changing colour from normal green for this species, to a faded green changing to yellow. On the lower east side of the tree near its trunk, the tree is also losing needles similar to the tree to the west. It is clearly evident this dual grouping of trees is experiencing an "unhealthy condition". The tree, from its middle to top appears to be normal and healthy.

Habitat:

This tree is located in an open space planted with another identical pica glauca tree. Both trees are planted and covered under a layer of wood chip mulch. Outside of the mulch area is lush green grass. The trees are native to the Olds, Alberta, Canada climate, able to handle the harder climate conditions for this region (1). The trees are under the supervision of an experienced horticulturalist.

Notes:

(Diagnosis). It is clearly evident that this dual grouping of trees is experiencing an issue that is making the needles turn yellow and lose its needles, in clusters, towards the bottom of the tree. Since this same set of conditions is occurring in both trees, it seems that there is the same condition affecting both trees. This would suggest to me that this condition is being spread through its roots. And, if the problem is being transmitted and shared to infect the neighbouring tree, then is this a disease (2)? Could the issue turning the needles yellow and causing them to fall off entire branches due to a virus, fungus, bacteria? What if there is a problem with the root system to prevent nutrients from moving to these sickly areas? The same website reference (from the University of Florida - Environmental Horticultural Department), identifies the potential of spider mites (only visible under identifying glass). This reference suggests the yellowing of needles from infested branches, which is occurring. Without getting specific into the roots or able to investigate the tree and its needles to determine cause of effects, the diagnosis remains speculative.