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Remote Sensing Grassland Phenology in the Greater Yellowstone Ecosystem: Biophysical Correlates, Land Use Effects and Patch Dynamics. November 28 th , 2012 Nathan Piekielek. Phenology in Ecology. Population dynamics and migration Boone et al. 2006; Andreo et al. 2008
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Remote Sensing Grassland Phenology in the Greater Yellowstone Ecosystem: Biophysical Correlates, Land Use Effects and Patch Dynamics November 28th, 2012 Nathan Piekielek
Phenology in Ecology • Population dynamics and migration • Boone et al. 2006; Andreo et al. 2008 • Spatial patterns of plant, bird and other diversity • Phillips et al. 2008; Nightingale et al. 2008 • Fuel accumulation and drying • Westerling 2006; Littell et al. 2009 • Detection of forest insect outbreak and recovery • deBeurs and Townsend 2008; Spruce et al. 2011 • Nutrient cycling • Potter 2001; Risch and Frank 2010 • Biological response to climate change • Myneni et al. 1997; Cleland et al. 2007 • Integrated analyses with hydrologic cycle • Cayan 2001; Sun et al. 2008
Jul 28 Jan 17 May 9 Oct 16 Photo credit: Bill Berg, CoolWorks.com
Research Questions • What are the biophysical correlates and likely drivers of grassland LSP in the GYE? • How well do correlates predict LSP across the study-area? • How does land use modify grassland LSP from its natural biophysical state? • What are the seasonal patch-dynamics of green/growing grasslands in the study area?
Biophysical Correlates • SRAD outer envelope control on timing • Water or VPD in every model except SOS • Temp. only in SOS • Impact of warming mediated by seasonal water-balance • Influence of snow-dynamics is spatially-variable • EOS is not captured well by models SOS SNOWMELT
Methods • Develop land use map • Apply biophysical models of natural LSP • Compare modeled natural LSP to observed actual LSP under different land uses
SOS MAX Urb (n=9) Suburb (n=20) Exurb (n=39) Rur (n=51) Ag (n=155) EOS INDVI
Ecological Implications • Landscape context for ungulate preference for private lands that has been observed by others (Thompson and Henderson 1998) • Suggests future wildlife management challenges in GYE? • Future modification and ecological impacts of land use are highly dependent on aesthetic preferences and values of future residents (Buyantuyev and Wu 2009) Banff, Alberta (Mckenzie 2001)
Patch Dynamics Late-season important time for ungulates to graze green forage • weight gain, reproduction etc. EARLY SEPT. CURRENT
Implications 5 degree C growing season temperature increase 15 day earlier EOS on ave. 67% reduction in Sept. green forage area EARLY SEPT. FUTURE
Implications Climate and land use change in tandem: • Late-season green patches are almost exclusively on private lands • Migration a threatened ecological process in GYE? • What are the management options? GREEN FORAGE IN STUDY-AREA EARLY SEPT
Funding 1) NASA Applications Program 2) Montana Institute on Ecosystems Landscape Biodiversity Laboratory Climate Datasets provided by: 1) Forrest Melton and the NASA Ecological Forecasting Laboratory: http://ecocast.arc.nasa.gov/