Forest range shifts under climate change: microenvironment impacts to tree recruitment at a climatic ecotone
dc.contributor.author | Foster, Alison Connolly, author | |
dc.contributor.author | Redmond, Miranda, advisor | |
dc.contributor.author | Martin, Patrick, advisor | |
dc.contributor.author | Battaglia, Michael, committee member | |
dc.contributor.author | Rocca, Monique, committee member | |
dc.date.accessioned | 2019-09-10T14:36:27Z | |
dc.date.available | 2019-09-10T14:36:27Z | |
dc.date.issued | 2019 | |
dc.description.abstract | Warming across the western United States is projected to cause dramatic shifts in tree species recruitment, with the most pronounced changes in composition at range edges where species are at their thresholds of reproductive tolerance. Yet microenvironments experienced by juvenile trees can be decoupled from regional climate due to variations in canopy cover, microtopography, and organic matter. As a result, tree recruitment may be strongly controlled by microenvironments and not follow species range projections based on regional climate, even at ecotone boundaries in which species at their upper range distributions are predicted to increase in density. This is likely especially pronounced in undisturbed forests with dense canopy cover in which microclimate is more strongly de-coupled from regional climate. To address these hypotheses of tree recruitment at species range margins we conducted a field experiment and observational study at the upper montane – subalpine ecotone on the Colorado Front Range. We characterized site microenvironment and observed germination and survival of six common conifer species, Douglas-fir, ponderosa pine, lodgepole pine, subalpine fir, Engelmann spruce, and limber pine. To quantify water availability and wildlife limitations, we sowed seeds from five study species and applied treatments of simulated precipitation and wildlife exclusion. Strong recruitment limitations were observed for nearly all species in experimental and observational studies, with strong negative effects of low soil moisture and maximum temperature. Notably, only subalpine fir exhibited increased seedling dominance, likely due to the limited light availability and cooler temperatures associated with shaded microenvironments. Recruitment success was unrelated to range position and do not match established migration predictions for these species. This research further illustrates the complexity of recruitment dynamics and the need to study regeneration at multiple scales. | |
dc.format.medium | born digital | |
dc.format.medium | masters theses | |
dc.identifier | Foster_colostate_0053N_15638.pdf | |
dc.identifier.uri | https://hdl.handle.net/10217/197408 | |
dc.language | English | |
dc.language.iso | eng | |
dc.publisher | Colorado State University. Libraries | |
dc.relation.ispartof | 2000-2019 | |
dc.rights | Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright. | |
dc.title | Forest range shifts under climate change: microenvironment impacts to tree recruitment at a climatic ecotone | |
dc.type | Text | |
dcterms.rights.dpla | This Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). | |
thesis.degree.discipline | Forest and Rangeland Stewardship | |
thesis.degree.grantor | Colorado State University | |
thesis.degree.level | Masters | |
thesis.degree.name | Master of Science (M.S.) |