Canadian Forest Service Publications

Past and projected future changes in moisture conditions in the Canadian boreal forest. 2014. Wang, Y.; Hogg, E.H.; Price, D.T.; Edwards, J.; Williamson, T. The Forestry Chronicle 90(5):678-691.

Year: 2014

Issued by: Northern Forestry Centre

Catalog ID: 35762

Language: English

Availability: PDF (request by e-mail)

Available from the Journal's Web site.
DOI: 10.5558/tfc2014-134

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Mark record


Spatial data for the Climate Moisture Index and the Palmer Drought Severity Index were generated from gridded temperature and precipitation data for the Canadian boreal zone over the period 1951‒2010. Annual values for the indices for 2011–2100 were generated from projections of future climate derived from four general circulation models forced by three greenhouse gas emissions scenarios. Linear regression models between the indices and time were fitted to examine long-term trends. Results indicated that several large regions of the Canadian boreal forest experienced substantial drying during 1951–2010. Future projections indicated a general trend toward drier conditions during the 21st century. Overall, the analysis indicated more frequent and/or more severe droughts across managed western and central portions of the boreal forest in coming decades. These projections of indices are relevant to forest management because soil moisture availability is an important determinant of forest distribution, tree health, and regeneration success. Knowledge of the range of potential future changes in drought occurrence and intensity will aid forest managers and decisionmakers in incorporating climate change considerations into forest management planning and practices.

Plain Language Summary

The study investigated how climate change might affect soil moisture in the boreal forest, over time and across geographic regions of Canada. The authors used the Climate Moisture Index and the Palmer Drought Severity Index to examine how moisture conditions changed from 1951 to 2010. They then estimated how conditions would change in the future (from 2011 to 2100) under several different climate change scenarios. The analysis showed that warming in the Canadian boreal region is expected to occur twice as fast as the global average. Also, soil moisture will probably become inadequate in the northwestern region of the Canadian boreal forest. Scenario analysis, like the one presented in this paper, can help forest managers to understand future moisture conditions and to identify areas where droughts may become more frequent and more severe. They can use this knowledge and understanding to adapt forest management practices in the changing climate.