RESULTS & DISCUSSION

General Genetic Differentiation

Hierarchical cluster analysis was done using the provenance of climatic variables to observe general genetic differentiation among the provenances (Figure 11). The resulting dendrogram was divided into seven groups based on the height of the fusion. The results show a wide range of genetic distinctions within the seed sources, however, provenance ten from E1 region appears to be different from all the other provenances. Since the 19^th century, foresters have acknowledged that plant populations are genetically differentiated in a way that matches the variation of the environment in which the species naturally occur (McKenney et. al., 2017). The wide range of genetic variation among the provenances may mean an increased ability to adapt to change when transferred to other geographical locations as trees usually show adaptations to their local environments because of natural selection (Frank et. al., 2017).

Figure 11: (A) Dendrogram showing general genetic similarities among provenances, provenance was colored by region to facilitate their locations on the map. As we move up the tree, objects that are similar to each other are combined into branches. The height / distance of the fusion, provided on the vertical axis, indicates the similarity between the provenances. The higher the height of the fusion, the less similar the objects are. The Mahalanobis distance was used for this analysis because some of the climate variables are correlated (B) Alberta white spruce breeding region showing the provenances as blue points and multi-sites as red triangles.

General Provenance Performance at Multi-sites

The principal component analysis of the height measurements revealed there were some differences in the height measured in all the multi-sites. Most of the provenances performed relatively well in the multi-sites (Figure 12). Seeds sourced from regions E1 and E2 faired relatively well in H, E, D1, and G. Seeds from regions D and G1 performed well in regions E1, E2, NM and G1. Populations from Cypress hills did averagely well in all the sites, possibly as a result of the high elevations in the local climate as slower growth is expected for trees in high-altitude forests (Coomes and Allen,2007). Also, the result showed that provenances from Southern and northern montane regions did fairly poorly in all the sites mostly due to coming from poorly developed soils( Willoughby et. al,2017). This poor performance must be the reason seed sources from the Northern montane regions of Alberta are not usually used in reforestation programs.

The barplot in figure 13 shows seed populations faired relatively well planted in their localities supporting the claim that local sources are better adapted to the local climate (Native plant working group,2001). The seed sources from D1 and G2 had a very good performance in all the sites. G1 did best in region E despite being non-local but also had a good growth rate in all the other planting sites. and E2 also did best in its locality but also did not show any visible growth reduction across the multiple planting sites. G1 did better when planted in Cypress Hills but it did poorly in the Southern Montane region possibly because of the very dry and warm climate in the Montane region (Willoughby et al.,2017).

Seeds Planted in region D performed well on the average except for E1 which did not do so well. Also, all the regions did relatively well in region E2 but populations for Cypress Hills had the best performance in that region even though it did not originate from the locality. The seed sources from Northern Montane did not do well in all the regions while populations from region D seem to perform excellently no matter where they were planted across the regions. Generally, the trees in all the trees performed best in region I again with the exception of Nothern and Southern montane regions mostly because it was coming from colder climatic conditions.

Summary

We can conclude from this research that a wide range of genetic differences exist among the provenances and the local populations generally performed well when transferred to their region of origin. The research also revealed that seed sources from region D generally performed well in all regions. Most populations performed best in region I and seed sourced from the montane region generally perform poorly wherever they were planted. The next steps for this project include assessing climate change vulnerability by identifying which regions and /or provenances do worst when transferred to warmer locations (southward) compared to the local provenances. Also which regions and or provenances do best when transferred to colder locations also compared to the locals.

References

Coomes, D. A., & Allen, R. B. (2007). Effects of size, competition and altitude on tree growth. Journal of Ecology, 95(5), 1084-1097.

Frank, A., Howe, G. T., Sperisen, C., Brang, P., Clair, J. B. S., Schmatz, D. R., & Heiri, C. (2017). Risk of genetic maladaptation due to climate change in three major European tree species. Global Change Biology, 23(12), 5358-5371.

Lu, P., Parker, W. H., Cherry, M., Colombo, S., Parker, W. C., Man, R., & Roubal, N. (2014). Survival and growth patterns of white spruce (Picea glauca [M oench] Voss) rangewide provenances and their implications for climate change adaptation. Ecology and Evolution, 4(12), 2360-2374.

Mueller, J. M., & Hellmann, J. J. (2008). An assessment of invasion risk from assisted migration. Conservation Biology, 22(3), 562-567.

McKenney, D., Pedlar, J., Glenn, L., Yang, J., & Weersink, A. (2017). Species migration and choices under a changing climate: Opportunities & challenges.

M.G. Willoughby, J.H. Archibald, G.D. Klappstein, I.G.W. Corns, J.D. Beckingham, B.E. Wilson and D.J. Downing (2017)

Ecological Sites of The Montane Subregion.

Native Plant Working Group. (2001). Native plant revegetation guidelines for Alberta. Alberta Agriculture, Food and Rural Development.