Evaluating the suitability of nine shelterbelt species for dendrochronological purposes in the Canadian Prairies

Abstract

Shelterbelts have played an important role in prairie agriculture since the late 1800s; however, little is known about how these shelterbelts may be affected by climate change. The objective of this study was to determine if shelterbelt species, which are heavily influenced by human activity, express a common radial-growth signal within and between trees. The study focused on the annual tree-ring growth of the nine most common shelterbelt species of the Canadian Prairies: Salix acutifolia (Acute willow), Caragana arborescens (caragana, or Siberian pea shrub), Picea pungens (Colorado spruce), Fraxinus pennsylvanica (green ash), Populus sp. (hybrid poplar), Acer negundo (Manitoba maple), Pinus sylvestris (Scots pine), Ulmus pumila (Siberian elm) and Picea glauca (white spruce). Tree core samples were collected near Saskatoon, Saskatchewan using traditional dendrochronological methods. The standardized growth of each species was compared with historical homogenized climate data in order to determine the key monthly climate variables impacting each species. Prior to this analysis, little was known about the suitability of six of these nine species for dendrochronological purposes. It was found that all species crossdate at a significant level, and that the three most significantly correlated climate factors are able to account for up to 37 % of the annual variation in tree-ring growth. The findings of this study suggest that all nine species are suitable, to varying degrees, for future dendrochronological research in the Canadian Prairies as well as having implications for shelterbelt systems elsewhere in the world. The top four species based on four ranking criteria (interseries correlation, mean sensitivity, climate explanatory power, and commonality) were white spruce, acute willow, caragana, and Manitoba maple, and initial results suggest that all species have the potential to be investigated in greater depth.