C. Picea mariana (black spruce) atsk This specimen was collected trom a ling tree (bark date A .0.1975 locaied near Dubant late, in Nanawt, the largest and newest (1995) teriaty in Canada. (w istront) 18. This tree indicates extremely slow growth, except for the first few years. The few large rings are due to complacency (little or no growth stress) at youth. How many years was the tree growing in complacency? 19. This mature black spruce tree was growing to the west of Hudson Bay, and it was cut in 1975. The rings of the northern boreal forest are too narrow to see without magnification, so you will have to estimate. Approximately when did this tree start to grow? 20. Explain why a tree of this age has such small annual rings. Answer in terms of the environment within which it grew. Realize that this tree was growing at the northernmost part of the boreal forest, i.e., just south of the tundra..