skip to content
National Park Service

Central Alaska Network

Parks in this Network

Central Alaska Network Map
Click to see Larger
Network Map

Central Alaska Network News

Search news and events archive:

Small Mammals Resource Brief (Feb 3, 2015)

Within Denali’s ecosystems, voles of the genera Microtus and Myodes consume seeds, fungi and invertebrates and provide a key prey resource for raptors and carnivorous mammals. Although voles have short life spans, they reproduce prolifially and play an important ecological role by having the ability to inflence species above and below them in the food chain. While they are small and not highly visible in the boreal forest, • Monitor trends in population estimates of density and abundance of three target species at the Rock Creek legacy plots. • Track how oscillations in small mammal population numbers may affct other organisms in the ecosystem. • Track changes in small mammal population dynamics that represent an important prey base in the ecosystem. • Monitor fie scale climate change effcts by tracking changes in species composition, range expansions and/or hybridization among small mammals 4175 Geist Road, Fairbanks, Alaska 99709 telephone: (907) 457-5752 From 1992-2014, we have monitored small mammals annually in Denali using livetrapping and mark-recapture techniques. Park scientists, science interns, and trained student volunteers backpack all camping and scientifi equipment into the plots and conduct fild work for one week in mid-August. Estimates of population density and abundance are collected for three target species: northern red-backed vole (Myodes rutilus), tundra vole (Microtus oeconomus) and singing vole (Microtus miurus), and when suffient numbers allow, shrews (Sorex spp.). We deploy four plots at Rock Creek, a drainage located near park headquarters. Each their collective biomass contributes a larger proportion to the animal community in Denali than that of grizzly bears. Consequently, changes in the abundance or density of small mammals may affct the survival of the species that prey upon them. Data from Denali suggest that annual flctuations in small-mammal populations are strongly related to ... [Read full article]

Moving beyond the minimum: The addition of nonvascular plant inventories to vegetation research in Alaska’s national parks (Jan 5, 2015)

Alaska’s national parks encompass a wide range of habitat types and climate gradients known to support a rich and diverse flora. At such northern latitudes, nonvascular plants, particularly bryophytes and lichens, contribute a significant portion to overall biomass andbiodiversity, provide a wide range of ecosystem functions, and can serve as important indicators of air quality and climate change. A number of Alaskan parks have recently completed or are conducting comprehensive inventories that are documenting extraordinary nonvascular plant diversity. Alaska’s Inventory and Monitoring networks have also developed vegetation and air quality vital-sign monitoring programs that include nonvascular plant communities in their baseline sampling. University partnerships have played an important role in contributing to our understanding of nonvascular vegetation communities in Alaska’snational parks. Such collaboration has provided a strong foundation for future studies and has enhanced NPS efforts toward resource management goals.

Walton J and Stehn S. 2014. Moving beyond the minimum: The addition of nonvascular plant inventories to vegetation research in Alaska’s national parks. Park Science. 31(1):62-69.

Alaskan national park glaciers - status and trends (Dec 2, 2014)

This is the final technical report presenting results of a three-year project involving scientists from the National Park Service, the University of Alaska, and Alaska Pacific University. These results differ, in some cases, from preliminary results presented in four prior progress reports and take priority over them. Objectives of the project include mapping of all glaciers within Alaska’s nine glaciated national parks at two time intervals, measurement of surface elevation changes on a subset of those glaciers, and an interdisciplinary summary of the nature and impacts of glacier change on 1-3 focus glaciers in each park. Objectives one and two are addressed here; the third focus glacier component will be presented in a companion interpretive report.

Climate Exposure of US National Parks in a New Era of Change (Nov 20, 2014)

US national parks are challenged by climate and other forms of broad-scale environmental change that operate beyond administrative boundaries and in some instances are occurring at especially rapid rates. Here, we evaluate the climate change exposure of 289 natural resource parks administered by the US National Park Service (NPS), and ask which are presently (past 10 to 30 years) experiencing extreme (<5th percentile or >95th percentile) climates relative to their 1901–2012 historical range of variability (HRV). We consider parks in a landscape context (including surrounding 30 km) and evaluate both mean and inter-annual variation in 25 biologically relevant climate variables related to temperature, precipitation, frost and wet day frequencies, vapor pressure, cloud cover, and seasonality. We also consider sensitivity of findings to the moving time window of analysis (10, 20, and 30 year windows). Results show that parks are overwhelmingly at the extreme warm end of historical temperature distributions and this is true for several variables (e.g., annual mean temperature, minimum temperature of the coldest month, mean temperature of the warmest quarter). Precipitation and other moisture patterns are geographically more heterogeneous across parks and show greater variation among variables. Across climate variables, recent inter-annual variation is generally well within the range of variability observed since 1901. Moving window size has a measureable effect on these estimates, but parks with extreme climates also tend to exhibit low sensitivity to the time window of analysis. We highlight particular parks that illustrate different extremes and may facilitate understanding responses of park resources to ongoing climate change. We conclude with discussion of how results relate to anticipated future changes in climate, as well as how they can inform NPS and neighboring land management and planning in a new era of change.

Invasive plant management in Wrangell-St. Elias National Park & Preserve (Jun 25, 2014)

The National Park Service Wrangell-St. Elias National Park has published a new report titled 'Invasive plant management in Wrangell-St. Elias National Park & Preserve: 2013 Summary report'.

High-resolution permafrost modeling in Wrangell-St. Elias National Park and Preserve and Denali National Park and Preserve (Apr 16, 2014)

The National Park Service Central Alaska Inventory and Monitoring Network has published two new permafrost modeling reports from Wrangell-St. Elias National Park and Preserve and Denali National Park and Preserve. The authors, Santosh K. Panda, Sergey S. Marchenko and Vladimir E. Romanovsky modeled the presence or absence of near-surface permafrost, temperature at the bottom of seasonal freeze-thaw layer and thickness of seasonal freeze-thaw layer within the parks. The project resulted in maps with a much finer resolution than previously existed. The maps show the impact of changing climate on near-surface permafrost temperature and its distribution and how it may evolve in the future with changing climate. The maps also identify (vulnerable) sites at higher risk of permafrost thawing, with concurrent changes in wildlife habitats and populations allowing park managers to make informed decision on resource management and design of monitoring programs.

The maps are available for WRST at and DENA at

Potential effects of warming climate on visitor use in three Alaskan national parks (Sep 6, 2013)

Alaska’s national parks draw millions of people annually to enjoy wildlife, breathtaking scenery, and recreational adventure. Visitor use is highly seasonal and occurs primarily during the summer months when temperatures are warm and daylight is long. Climate is an important consideration when planning a trip to Alaska’snational parks because of the great distances and associatedcosts of travel for many visitors. As a result of projected climatewarming, peak visitor season of use in Alaska’s national parksmay expand. To examine the potential effects of warming climate on park visitor season of use, we used regression analyses to quantify the relationship between historical (1980–2009) visitoruse and monthly temperatures for three Alaskan national parks and identi? ed the monthly mean temperatures at which the peakvisitor season of use occurred in each park. We compared thesecontemporary temperatures with projected future average monthlymean temperatures for 2040–2049 and 2090–2099 to providecontext for how visitation might be affected by warming climate.Based on historical relationships among temperature, visitor use, and increased temperatures associated with climate change, ouranalysis suggests that peak season of visitor use could expand into May and September depending on the park, the climate scenario,and the time period. As a consequence of a warming climate, planning by the National Park Service and other stakeholders mayneed to consider this transition in temperatures and the potentialfor an extended peak season of visitor use, along with otherclimate-related changes (e.g., extreme weather), climate-inducedenvironmental changes, and shifts in recreational opportunities that will likely accompany climate change.

Monitoring Dall’s sheep in the Central Alaska Network (Jul 30, 2013)

The Central Alaska (CAKN) and Arctic Networks are collaborating to monitor the abundance, composition, and distribution of Dall’s sheep in six of Alaska’s largest park units, including Denali and Wrangell-St. Elias. In 2010-2011, surveys were completed for most sheep habitat across the Network for the first time in 30 years. Estimates from those surveys shownumbers similar to the abundance estimates from the 1980s. In Denali, the population is approximately 2,252 sheep (1,871 – 2,765, CV = 10%), and is composed of approximately 16% lambs, 50% ewe-like (including ewes and immature rams), 26% less than full-curl rams, and 8% full-curl rams. In Wrangell-St. Elias, the population is approximately 12,428 sheep (10,780 – 14,470, CV = 8%) and is composed of approximately 18% lambs, 55% ewe-like, 21% less than full-curl rams, and 6% full-curl rams.

New Approach to Dall’s Sheep Monitoring Better, Cheaper (Jul 8, 2013)

FAIRBANKS, AK— Scientists with the National Park Service have developed new methods for monitoring Dall’s sheep in Alaska that are providing better information while reducing costs by as much as 80% over existing survey approaches.

The methods and survey results are described in an article published in the current issue of the Journal of Wildlife Management (Schmidt and Rattenbury 2013) as well as in an article published in the same journal last year (Schmidt et al. 2012).

The majority of sheep habitat in seven national park units, including Denali, Gates of the Arctic, Noatak, Kobuk Valley, Cape Krusenstern, Wrangell-St. Elias, and Lake Clark, was surveyed in 2010-12 using the new technique, and the estimated population for the surveyed park units is currently 27,000-28,000 individuals—similar to the number present in the early 1980s when many of the park units were formed.

“Designing a monitoring program that provides accurate results in these large, remote areas is a challenge,” said Kumi Rattenbury, Ecologist with the National Park Service in Fairbanks. “We’re excited about this new approach because it means we can do a better job tracking the status of this iconic species over a huge area.

”The approach uses aerial distance sampling techniques to estimate overall population size as well as the composition (lambs, ewes, full curl rams, and < full-curl rams) of each population. It was first implemented by the National Park Service in Gates of the Arctic National Park and Preserve in 2009 where park-wide surveys were completed for the first time in nearly 30 years.

“This is one of the few ways to get a rigorous estimate of both abundance and composition from the same survey,” said Joshua Schmidt, National Park Service Biometrician and lead author on the two articles describing the new methods. “The higher quality data and lower costs will allow us to more consistently monitor populations and improve sheep ... [Read full article]

Reducing Effort While Improving Inference: Estimating Dall’s Sheep Abundance and Composition in Small Areas. (Jun 26, 2013)

National Park Service wildlife biologist Kumi Rattenbury and Biometrician Josh Schmidt recently published a new article in the Journal of Wildlife Management titled 'Reducing Effort While Improving Inference: Estimating Dall’s Sheep Abundance and Composition in Small Areas'.

Last Updated: June 30, 2014 Contact Webmaster