title: Climate Change Across Seasons Experiment (CCASE): A new method for simulating future climate in seasonally snow-covered ecosystems.
abstract: Climate models project an increase in mean annual air temperatures and a reduction in the depth and duration of winter snowpack for many mid and high latitude and high elevation seasonally snow-covered ecosystems over the next century. The combined effects of these changes in climate will lead to warmer soils in the growing season and increased frequency of soil freeze-thaw cycles (FTCs) in winter due to the loss of a continuous, insulating snowpack. Previous experiments have warmed soils or removed snow via shoveling or with shelters to mimic projected declines in the winter snowpack. To our knowledge, no experiment has examined the interactive effects of declining snowpack and increased frequency of soil FTCs, combined with soil warming in the snow-free season on terrestrial ecosystems. In addition, none have mimicked directly the projected increase in soil FTC frequency in tall statured forests that is expected as a result of a loss of insulating snow in winter. We established the Climate Change Across Seasons Experiment (CCASE) at Hubbard Brook Experimental Forest in the White Mountains of New Hampshire in 2012 to assess the combined effects of these changes in climate on a variety of pedoclimate conditions, biogeochemical processes, and ecology of northern hardwood forests. This paper demonstrates the feasibility of creating soil FTC events in a tall statured ecosystem in winter to simulate the projected increase in soil FTC frequency over the next century and combines this projected change in winter climate with ecosystem warming throughout the snow-free season. Together, this experiment provides a new and more comprehensive approach for climate change experiments that can be adopted in other seasonally snow-covered ecosystems to simulate expected changes resulting from global air temperature rise.
authors.affiliation: Boston University, Department of Biology, Boston, Massachusetts, United States of America.
authors.forename: Pamela H
authors.initials: PH
authors.lastname: Templer
authors.affiliation: Boston University, Department of Biology, Boston, Massachusetts, United States of America.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Reinmann
authors.affiliation: Boston University, Department of Biology, Boston, Massachusetts, United States of America.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Sanders-DeMott
authors.affiliation: Boston University, Department of Biology, Boston, Massachusetts, United States of America.
authors.forename: Patrick O
authors.initials: PO
authors.lastname: Sorensen
authors.affiliation: Boston University, Department of Biology, Boston, Massachusetts, United States of America.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Juice
authors.affiliation: Research Designs, Lyme, New Hampshire, United States of America.
authors.forename: Francis
authors.initials: F
authors.lastname: Bowles
authors.affiliation: Boston University, Department of Biology, Boston, Massachusetts, United States of America.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Sofen
authors.affiliation: Boston University, Department of Biology, Boston, Massachusetts, United States of America.
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Harrison
authors.affiliation: US Forest Service, Hubbard Brook Experimental Forest, Woodstock, New Hampshire, United States of America.
authors.forename: Ian
authors.initials: I
authors.lastname: Halm
authors.affiliation: US Forest Service, Hubbard Brook Experimental Forest, Woodstock, New Hampshire, United States of America.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Rustad
authors.affiliation: University New Hampshire, Institute for the Study of Earth, Oceans, and Space, Durham, New Hampshire, United States of America.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Martin
authors.affiliation: US Forest Service, Hubbard Brook Experimental Forest, Woodstock, New Hampshire, United States of America.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Grant
mesh_terms: D057231:Climate Change; D003198:Computer Simulation; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D012621:Seasons; D012914:Snow; D013696:Temperature