Abstract
ABSTRACT Plants growing at the edges of their range limits are expected to be particularly sensitive to changes in precipitation and temperature regimes associated with climatic change. However, non-climatic factors are increasingly recognized as important constraints to species’ range expansions. Therefore, we assessed the effects of soil provenance with respect to the alpine treeline on the germination, growth, and survival of Engelmann spruce (Picea engelmannii) seedlings. Seedlings were grown under controlled conditions in a growth chamber and greenhouse for ninety days in soils collected from four treeline ecotones in the Canadian Rocky Mountains. By controlling seed source and climatic conditions, and eliminating competition and predation, we attribute differences in seedling viability to soil properties that differed across elevation zones and individual treeline sites. Overall, alpine soils originating from beyond the species’ current elevational range were least amenable to growth, and there was some indication of reduced germination and survival in high-elevation soils. Forest soils, which were coarser and more nutrient rich, hosted seedlings with greater above- and below-ground biomass. Thus, the physical and chemical characteristics of alpine soils in our study region may constrain future treeline expansion, underscoring the importance of incorporating soil properties when considering species’ distributions under climate change.
Highlights
The expansion of a species’ distribution into new habitat can serve as an indicator of climate change if its establishment is enhanced by changes in air temperature or precipitation
Our objective was to determine whether differences in soils collected along treeline ecotones influence the viability of Engelmann spruce seedlings when controlling for climate, competition, and other potentially limiting factors
The results of the growth chamber and greenhouse studies support this expectation as they were indicative of greater seedling growth and survival in the forest zone relative to the alpine
Summary
The expansion of a species’ distribution into new habitat can serve as an indicator of climate change if its establishment is enhanced by changes in air temperature or precipitation. The elevational extent of alpine treelines has long been viewed as a sensitive ecological indicator of climate change (see Smith et al 2009). Throughout western Canada, paleoecological studies have been used to identify relationships between climate and tree establishment (Beaudoin 1989; Brown 2013; Kearney 1982; Laroque, Lewis, and Smith 2001; Luckman and Kavanagh 2000; Pisaric et al 2003; Roush 2009). Much of this research has provided evidence of significant upslope advance and meadow infilling by trees throughout the twentieth century as limitations imposed by temperature and precipitation have diminished.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
