title: Climate change may restrict dryland forest regeneration in the 21st century.
abstract: The persistence and geographic expansion of dryland forests in the 21st century will be influenced by how climate change supports the demographic processes associated with tree regeneration. Yet, the way that climate change may alter regeneration is unclear. We developed a quantitative framework that estimates forest regeneration potential (RP) as a function of key environmental conditions for ponderosa pine, a key dryland forest species. We integrated meteorological data and climate projections for 47 ponderosa pine forest sites across the western United States, and evaluated RP using an ecosystem water balance model. Our primary goal was to contrast conditions supporting regeneration among historical, mid-21st century and late-21st century time frames. Future climatic conditions supported 50% higher RP in 2020-2059 relative to 1910-2014. As temperatures increased more substantially in 2060-2099, seedling survival decreased, RP declined by 50%, and the frequency of years with very low RP increased from 25% to 58%. Thus, climate change may initially support higher RP and increase the likelihood of successful regeneration events, yet will ultimately reduce average RP and the frequency of years with moderate climate support of regeneration. Our results suggest that climate change alone may begin to restrict the persistence and expansion of dryland forests by limiting seedling survival in the late 21st century.
authors.affiliation: US Geological Survey, Southwest Biological Science Center, Room #202, 525 S. Beaver Street #5614, Flagstaff, Arizona, 86011, USA.|Department of Plant and Environmental Sciences, New Mexico State University, MSC 3JER, Las Cruces, New Mexico, 88003, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Petrie
authors.affiliation: US Geological Survey, Southwest Biological Science Center, Room #202, 525 S. Beaver Street #5614, Flagstaff, Arizona, 86011, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Bradford
authors.affiliation: USDA Forest Service, Rocky Mountain Research Station, 240 West Prospect Road, Fort Collins, Colorado, 80526, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Hubbard
authors.affiliation: School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut, 06511, USA.
authors.forename: W K
authors.initials: WK
authors.lastname: Lauenroth
authors.affiliation: US Geological Survey, Southwest Biological Science Center, Room #202, 525 S. Beaver Street #5614, Flagstaff, Arizona, 86011, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Andrews
authors.affiliation: Section of Conservation Biology, Department of Environmental Sciences, University of Basel, St. Johanns-Vorstadt 10, CH-4056, Basel, Switzerland.
authors.forename: D R
authors.initials: DR
authors.lastname: Schlaepfer
mesh_terms: D057231:Climate Change; D017753:Ecosystem; D065928:Forests; D041604:Pinus ponderosa; D014197:Trees
keywords: climate change; demographics; persistence; ponderosa pine; regeneration