GC33B-01 INVITED 

Data gathering and simulation of climate change impacts in mountainous areas

* Bachelet, D (dbachelet@tnc.org), The Nature Conservancy, 2505 Vista Ave SE, Olympia, WA 98501, United States Baker, B (bbaker@tnc.org), The Nature Conservancy, 2505 Vista Ave SE, Olympia, WA 98501, United States Hicke, J (jhicke@uidaho.edu), University of Idaho, McClure Hall Room 203 PO Box 443021, Moscow, ID 83844-3021, United States Conklin, D (david.conklin@oregonstate.edu), Oregon State University, 444 NW 35th Street, Corvallis, OR 98330, United States Mckelvey, K (kmckelvey@fs.fed.us), USDA Forest Service, Rocky Mountain Station, Missoula, MT 59715, United States

High mountains include species most at risk in a warming environment and are a critical link in the water supply chain for both human and natural systems. Scientists are monitoring and simulating these systems as snowpack depth changes, snowmelt timing changes, frozen soils melt and destabilize, and low elevation populations migrate upslope. Natural climate cycles and human activities interact with climate change trends and complicate the interpretation of the signal we observe. For ex. over the past 4 years in Yunnan (China), we documented that herbaceous alpine meadows are contracting as forest tree line advances and alpine shrub biomass increases. This is a result of interactions between human land use alteration and observed shifts in climate. In North America as snowpack decreases, wolverines and lynx denning conditions are jeopardized as human pressure reduces their extent. Coarse scale vegetation shift models using downscaled future climate scenarios fail to capture complex terrain features and microclimatic conditions that can either ensure critical habitat for the in-situ survival of threatened species or make things worse (ex. rockfalls) for climate migrants. Recent simulation efforts focus on high resolution models that address aspect, slope, soil types, and microclimate variations that affect local and migrating plants, their associated pollinators and insect herbivores, modifying habitat availability for birds and mammals

GC33B-02 INVITED 

Effects of Recent Climate Change on Facultative and Spontaneous Torpor in Apline Habitats

* Frank, C L (frank@fordham.edu), Fordham University, Dept. of Biological Sciences Louis Calder Center 53 Whippoorwill Road, Armonk, NY 10504, United States Hood, W R (wrhood@auburn.edu), Auburn University, Dept. of Biological Sciences Rouse Science Building, Auburn, AL 36849-5407, United States Stevens, M (ekim@cokinetic.com), Fordham University, Dept. of Biological Sciences Louis Calder Center 53 Whippoorwill Road, Armonk, NY 10504, United States Gary, G (ggary@fordham.edu), Fordham University, Dept. of Biological Sciences Louis Calder Center 53 Whippoorwill Road, Armonk, NY 10504, United States

Mean annual air temperatures have increased in North America by 1.0°C during the past 100 years, and are predicted to increase by 4-8 °C further within the next 70 years. Hibernating mammals may be particularly sensitive to climate change since body temperatures during torpor are strongly influence by ambient temperature. We conducted 3-7 year studies on the relationship between ambient (air/soil) temperature and the torpor patterns of free-ranging facultative and spontaneous hibernators. The facultative hibernation of eastern chipmunks (Tamias striatus) in New York State and the spontaneous hibernation by golden-mantled ground squirrels (Spermophilus lateralis) in the mountains of California were continuously monitored using temperature sensitive radiocollars during winters of 2000-01 through 2006-07. Mean air/soil temperatures during the winter 2001-02 were much greater than those observed during the same periods of 2000-1 and 2002-3 winters at both sites, and the winter of 2001-2 was one of the warmest measured in both New York State and California since 1895. Consequently T. striatus during the winter 2001-2 had: a) fewer individuals using torpor, b) reduced the time spent in torpor by 96%, and, c) increased energy expenditure by 100% when compared to the torpor patterns of the same population during the colder winters of 2000-1/2002-3. Likewise, S. lateralis during the winter of 2001-2 had: a) delayed the entrance into hibernation by a mean of 12.2 days, b) increased mean body temperatures by an average of 5.4 C during torpor, and, c) increased metabolic rate during torpor by 75% when compared to the torpor patterns of the same population during the winters of 2000-1/2002-3.

GC33B-03 

Climate Forced Alpine Tundra Ecosystem Dynamics: A Model Approach

* Jarosch, A H (ajarosch@eos.ubc.ca), Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, BC V6T 1Z4, Canada Clarke, G K (clarke@eos.ubc.ca), Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, BC V6T 1Z4, Canada Danby, R K (rdanby@ualberta.ca), Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB T6G 2E9, Canada Hik, D S (dhik@ualberta.ca), Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB T6G 2E9, Canada

Insights concerning the future evolution of alpine ecosystems depend on understanding and simulating their response to climate change. Comprehensive studies of these regions require novel spatio-temporal computational models of climate-forced landscape/ecosystem interactions. As part of the International Polar Year (IPY) we are examining alpine tundra landscapes and ecosystems in the Kluane region of southwest Yukon, Canada. Based on the combination of long-term geophysical and ecological field studies and driven by different climate change scenarios, such a model is being used to explore the range of possible future scenarios for the region. As the first step in building such a complex model, we present a simplified, grid-based model to demonstrate potential changes in plant community distribution driven by key climate variables such as temperature and precipitation. A linear orographic precipitation model is used to downscale climate data which, in combination with a digital elevation model, forms the geophysical input for the model. Simplified ecological rules describing the potential state transition of different plant communities and land cover types are incorporated in the model in a cellular automation fashion. The response of the ecosystem to several different climate scenarios will be presented, including a set of North American Regional Reanalysis climate data. This simplified model is used to demonstrate the potential of such interdisciplinary simulations to gain deeper understanding of ecosystem evolution with climate change.

GC33B-04 

Twentieth Century Bristlecone Pine Tree Rings Near Upper Tree Limit Wider Than in Recent Millennia

* Hughes, M K (mhughes@ltrr.arizona.edu), Laboratory of Tree-Ring Research, W Stadium 105 The University of Arizona, Tucson, AZ 85721, United States Salzer, M W (msalzer@ltrr.arizona.edu), Laboratory of Tree-Ring Research, W Stadium 105 The University of Arizona, Tucson, AZ 85721, United States

Unusually wide tree-rings have been observed in recent decades in bristlecone pines from widespread locations at high elevations (3100 m.a.s.l. and above) near the upper forest border in the western USA. We present an enhanced and extended dataset from such environments, and report only results based on unmodified raw ring widths. These wide rings are unique in the context of at least the last 3700 years. Sites at similar elevations, but further below the upper tree limit, do not show this increase. The implications of these observations for possible explanations of the growth increase will be discussed, in the context of environmental changes unique to recent times. These will include the possible effects of increasing atmospheric concentrations of carbon dioxide on the trees' water use efficiency, enhanced nutrient availability related to pollution, shifts in seasonal climatic patterns, and mountain climate conditions unique to the 20th and 21st centuries. Particular attention will be given to this last explanation, and in particular to the possibility of uniquely "Anthropocene" patterns of vertical change and their consequences for tree growth.

GC33B-05 

Recent Relationships of Tree Establishment and Climate in Alpine Treelines of the Rocky Mountains

* Germino, M J (germmatt@isu.edu), Idaho State University, 921 S 8th St, Stop 8007, Pocatello, ID 83209, United States Graumlich, L J (lisag@ag.arizona.edu), University of Arizona, PO Box 3308, Tuscon, AZ 85722, United States Maher, E J (azile77@yahoo.com), Idaho State University, 921 S 8th St, Stop 8007, Pocatello, ID 83209, United States

Changes in the forest structure of alpine-forest or treeline boundaries may be a significant climate response of mountainous regions in the near future. A particularly important point of climate sensitivity for treelines is the initial survival and establishment of tree seedlings - a demographic bottleneck that may be particularly suited to early detection of treeline responses to climate change. However, concise information on climate sensitivity of seedling establishment has come primarily from direct observations of seedlings over short time periods encompassing a few years. Dendrochronological approaches have revealed tree establishment patterns at more extensive time scales of decades to millenia, but at coarser temporal resolutions. Climate variations that most directly affect initial tree seedling establishment occur at annual or smaller time scales, and climate for seedlings is modulated by landscape factors such as neighboring plant cover. Our objective was to assess climate sensitivity of tree establishment at treeline at these finer temporal and spatial scales, with consideration of treeline features that alter the climate for seedlings. Our approach combined direct observations of seedling emergence and survival with dendrochronology of older seedlings and saplings that were still small and young enough (less than 25 years and 20 cm height) to allow detecting the year of establishment and associated factors. Surveys for subject seedlings and saplings were performed for 2 years across the gradient from forest into treeline alpine in the Beartooth, Teton, and Medicine Bow mountains of Wyoming USA. No seedlings or saplings were detected above the highest elevation adult trees or krummholz, but there were up to 0.3 seedlings per square meter in subalpine meadows close to forest (within the timberline zone) where changes in tree abundance appear possible in future decades. Correlations of establishment and summer temperature ranged from weak in whitebark pine (Pinus albicaulis) and Engelmann Spruce (Picea engelmannii) to significantly positive for subalpine fir (Abies lasiocarpa). Seedling establishment was consistently associated with microsite features such as resident trees and herbs that alter sunlight and temperature for small seedlings, and the effect was strongest for subalpine fir and least evident for whitebark pine. For all species and treelines, establishment in microsites with the least amount of overhead tree cover (furthest from forest in the alpine, in exposed locations) occurred in years with warmer summer temperatures. These patterns of establishment are consistent with previous and current experimental studies of terrestrial and solar radiation and temperature effects on tree seedlings at treeline. Our findings indicate that local treeline response to climate variability may vary as a function of current landscape patterns of tree and herb cover, and tree species assemblages that are unique to different treelines. Local shifts in tree species composition that are ongoing may thus pose a significant issue in forecasting future treeline change.

GC33B-06 

A Model of Temperature Inversion Across the White Mountains, California to Explain Downslope Migration of Trees

* Van de Ven, C M (cvandeven@albion.edu), Albion College, Dept. of Geological Sciences Albion College, Albion, MI 49224, United States Weiss, S B (stu@creeksidescience.com), Creekside Center for Earth Observation, 27 Bishop Ln, Menlo Park, CA 94025, United States Millar, C (cmillar@fs.fed.us AF: AF:

Shifting species distributions in montane ecosystems under a warming climate are generally assumed to be toward higher elevations, but the possibilities of lateral and downward shifts in complex terrain have received less attention. We modeled nighttime minimum temperatures across the White Mountains, eastern California based on hourly temperature recorded by inexpensive temperature loggers, a 10m Digital Elevation Model (DEM), and long-term weather station data. Thirty-five iButton Thermochrons recorded hourly temperatures from July 23 to October 6, 2006, and were distributed along elevation gradients on all aspects around a valley with strong night-time temperature inversions and a weather station. The overall lapse rate was calculated from three local weather stations: Bishop WSO Airport (1253m; 4110ft), White Mountain 1 (at 3094m; 10,151ft), and White Mountain 2 (at 3800m; 12,470ft). Using multiple least-squares regression, deviations from the local weather station were predicted by topographic position (the average elevation within 500m subtracted from the cell elevation), slope, and the absolute value of topographic position (r2 = 0.92). The results were extrapolated across the rest of the range using the same parameters embedded in the overall lapse rate. The models predict strong night-time temperature inversions (up to 7degrees C) in valleys and canyons across the range. Field observations and airphoto analysis show limber pine (Pinus flexilis) and bristlecone pine (P. longaeva) population migrating downward into the inversions. The temperature measurements and models explain this downslope migration as low temperature limitations in the cold valley bottoms are relieved under a generally warming climate. Range-wide maps provide testable hypotheses of minimum night-time temperatures.

GC33B-07 

Effects of Climate and Fire on Thermal Habitats Within Mountain Stream Networks: An Example With a Native Charr Species

* Isaak, D (disaak@fs.fed.us), US Forest Service - Research, 322 E. Front St., Suite 401, Boise, ID 83702, United States Luce, C (cluce@fs.fed.us), US Forest Service - Research, 322 E. Front St., Suite 401, Boise, ID 83702, United States Rieman, B (brieman@fs.fed.us), US Forest Service - Research, 322 E. Front St., Suite 401, Boise, ID 83702, United States Nagel, D (dnagel@fs.fed.us), US Forest Service - Research, 322 E. Front St., Suite 401, Boise, ID 83702, United States Peterson, E (disaak@fs.fed.us), CSIRO, 120 Meiers Road, Indooroopilly, QLD 4068, Australia

Climatic trends associated with warming air temperatures, changing hydrology, and increasing fire activity will affect thermal regimes in mountain streams. Because most aquatic species are ectotherms, disruptions of these ecosystems will be significant as the distributions of thermal habitats change. Although local stream temperature models have frequently been developed, network-scale models necessary for conservation are generally lacking. Using a new class of spatial statistical model that accommodates network topology and multiple types of spatial autocorrelation based on instream and Euclidean distance, we modeled the effects of geomorphology, climate, and fire on stream temperatures across a 6th-order network in central Idaho. Satellite imagery of riparian vegetation pre- and postfire was used to quantify the amount of solar radiation reaching the stream and consequent effects on temperature. Climate covariates were derived from weather and flow gauging stations and relevant geomorphic features were derived from digital elevation models. The spatial models yielded more accurate parameter estimates than traditional regression models and offered improved predictive ability for the temperature metrics examined (e.g., R² ~ 0.60 vs. 0.85). Upon completion, the spatial models were used to assess changes in the distribution of thermally suitable habitats for bull charr (Salvelinus confluentus) over a 15 year period with extensive fire activity. Habitat losses were spatially variable, as were the relative effects of the covariates. In general, the greatest habitat loss was attributable to the effects of fire and recent trends of increasing air temperatures and decreasing flows played lesser roles. Our results suggest that impairment and loss of aquatic habitats due to climate change can be caused by direct or indirect effects and may occur as gradual trends or during episodic disturbances. If future efforts to conserve aquatic species are to succeed, models that incorporate the spatial complexity of landscape responses to ongoing climate trends are needed. http://www.fs.fed.us/rm/boise

GC33B-08 

Glacier Retreat in the Southern Peruvian Andes: Climate Change, Environmental Impacts, Human Perception and Social Response

* Orlove, B (bsorlove@ucdavis.edu), Department of Environmental Science & Policy, One Shields Way UCDavis, Davis, CA 95616,

This paper presents results from recent environmental and anthropological research near glacierized areas in the department of Cusco, Peru, home to the well-known Quelccaya Ice Cap and to the peak of Ausangate (6384 m). Glaciers in the region are in negative mass balance, losing volume and area, with upslope movement of the glacier fronts. Somewhat paradoxically, flows in many streams close to the glaciers are reduced, particularly in the dry season, due to a shift in the seasonal distribution of melting, to increased evaporation and to increased percolation into newly-exposed sands and gravels. Associated with this reduction in flow is a desiccation of some anthropogenic and natural wetlands, reducing the availability of dry season forage to wild (vicuna) and domesticated (alpaca, llama) ruminants. Interviews and ethnographic observations with local populations of Quechua-speaking herders at elevations of 4500-5200 meters provide detailed comments on these changes. They have an extensive vocabulary of terms for glacial features associated with retreat. They link this treat with environmental factors (higher temperatures, greater winds that deposit dust on lower portions of glaciers) and with religious factors (divine punishment for human wrong-doing, failure of humans to respect mountain spirits). They describe a variety of economic and extra-economic impacts of this retreat on different spatial, social and temporal scales. Though they face other issues as well (threats of pollution from new mining projects, inadequacy of government services), glacier retreat is their principal concern. Many herders express extreme distress over this unprecedented threat to their livelihoods and communities, though a few propose responses - out-migration, the formation of an association of neighboring communities, development of irrigation works - that could serve as adaptations.

Author(s) (2007), Title, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract #####-##.