Projected effects of climate-induced vegetation changes on caribou (Rangifer tarandus) energetics in northern Alaska
May 2009 - September 2016
- Brad Griffith, Principal Investigator
- Caroline Lundmark, Student
- Science Support Partnership
1) Employ the existing DVM and a suite of climate scenarios (present to 2100; IPCC, 2007) to a) simulate possible future changes in the seasonal biomass of aboveground non-woody tissue of various plant functional types (e.g. lichen, sedge, Salix) that are accessible to Rangifer; b) match DVM output plant functional type seasonal biomass to input functional types used in the CARMODEL; c) match output summary seasons (currently months) to the input seasons of the CARMODEL (e.g. calving, post-calving, late summer); d) explicitly track projected changes in growing degree days (GDD) and use the GDD:digestibility relationships developed by Finstad (2008) to project the effects of warming on seasonal forage quality by plant functional type. 2) Use the projected changes in biomass and digestibility of caribou forages through time (present to 2100) derived from the DVM in (1) to estimate the implications of this suite of climate scenarios on the seasonal patterns of fat and protein deposition and use by caribou for maintenance and growth throughout the year. 3) Compare and contrast the implications of climate-induced changes in forage biomass and quality on fat and protein dynamics in two groups of caribou with characteristically different diets at calving: a) caribou that calve in the wetter portions of the coastal plain (Central Arctic, Teshekpuk), and b) caribou that calve in uplands and drier portions of the coastal plain (Western Arctic, Porcupine). 4) Collect supplemental estimates of diet and forage quality for herds as necessary. Summer diets are relatively well known for all herds. Fall, and early and late winter-spring diets are relatively unknown and will require field collection of fecal pellets and microhistological analyses. Some seasonal forage will require nutrient analyses to establish baseline conditions.