Canadian Forest Service Publications
Growth, shoot phenology and physiology of diverse seed sources of black spruce: II. 23-year-old field trees. 1996. Johnsen, K.H.; Seiler, J.R.; Major, J.E. Tree Physiology 16: 375-380.
Issued by: Atlantic Forestry Centre
Catalog ID: 27458
Availability: PDF (download)
Four sources of 23-year-old black spruce (Picea mariana (Mill.) B.S.P.) from a provenance test at the Petawawa National Forestry Institute (46° N, 77°30’ W) were assessed for height growth, shoot phenology and seasonal gas exchange. The provenances were designated 7000 (Yukon, 63°34’ N, 135°55’ W), 6979 (Alberta 52°22’ N, 115°15’ W), 6908 (Ontario, 48°59’ N, 80°38’ W) and 6901 (Ontario, 45°10’ N, 77°10’ W). Trees of southern provenances (6901 and 6908) were considerably taller, and broke bud and ceased growth later than trees of northern provenances (6979 and 7000). In early spring, trees of northern provenances had higher net photosynthetic rates (Pn) than trees of southern provenances (6908 and 6901). During midsummer, trees of Provenance 7000 generally had the highest Pn as a result of low rates of shoot dark respiration (Rd). Trees of northern provenances displayed an earlier autumn decline in Pn than trees of southern provenances. Provenance differences in growth, shoot phenology and physiology agreed well with results from a greenhouse study of seedlings from the same provenances. We conclude that the poor growth performance of trees of northern provenances in Ontario was associated with: (1) a short period of shoot growth, (2) a high rate of dry matter partitioning to roots, (3) low rates of late-season Pn in response to decreasing photoperiod, and possibly, (4) a high rate of root Rd.