U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2012–3144

December 2012 Printed on recycled paper

1975 1980 1985 1990 1995 2000 2005 2010

Waterfowl Songbirds Shorebirds

Date of First Arrival

Year

Collapsed permafrost block of coastal tundra on Alaska’s Arctic Coast.

Black brant goose

Trends toward earlier dates of spring arrival 

on the Arctic coast (1974–2010) for three 

types of birds. J. Helmericks and USGS data.

Changing Arctic Ecosystems

Measuring and Forecasting the Response of Alaska’s Terrestrial Ecosystem 

to a Warming Climate

The Arctic Coastal Plain of northern Alaska is a complex 

landscape of lakes, streams, and wetlands scattered across low relief 

tundra that is underlain by permafrost. This region of the Arctic has 

experienced a warming trend over the past three decades, leading to 

thawing of on-shore permafrost and the disappearance of sea ice at 

an unprecedented rate. The loss of sea ice has increased ocean wave 

action, leading to higher rates of erosion and salt water inundation of 

coastal habitats. Warming temperatures also have advanced the overall 

phenology of the region, including earlier snowmelt, lake ice thaw, 

and plant growth. As a result, many migratory species now arrive in 

the Arctic several days earlier in spring than in the 1970s. Predicted 

warming trends for the future will continue to alter plant growth, 

ice thaw, and other basic landscape processes. These changes will 

undoubtedly result in different responses by wildlife (fish, birds, and 

mammals) and the food they rely upon (plants, invertebrates, and fish). 

However, the type of response by different wildlife populations and their 

habitats—either positively or negatively—remains largely unknown.

Through the Changing Arctic Ecosystems initiative, the U.S. 

Geological Survey (USGS) strives to inform key resource management 

decisions for Arctic Alaska by providing scientific information on current 

and future ecosystem response to a warming climate. The Changing 

Arctic Ecosystems initiative includes research across three ecosystems 

found in Arctic Alaska: sea ice, terrestrial, and the tundra–boreal forest 

ecotone. Here, we describe the conceptual framework of USGS research 

within the northern tundra or terrestrial ecosystem of the Arctic Coastal 

Plain and highlight on-going and future research. Research within the 

terrestrial ecosystem objective will provide scientific data through 

conceptual models, field and laboratory projects, and 

remote-sensing assessments. This information 

will quantify effects of changing physical 

processes on the northern tundra and then 

be used to forecast the response of 

different wildlife populations 

throughout the region. 

Results of this USGS 

led research will 

assist Federal and 

State land managers, 

local residents, and 

industry by providing sound 

scientific data for decision-making on 

issues related to land use, hunting and fishing, industrial development, 

and conservation.
Wetland and low relief tundra habitats of the Arctic Coastal Plain.

USGS field research site showing shade and green houses on coastal 

sedge tundra of the Arctic Coastal Plain. Vegetation within these 

experimental plots is monitored throughout the summer to quantify how 

slight changes in temperature affect the quality and quantity of plant 

forage for migratory birds.

Theme II - The Arctic Coastal Plain

Changes in Plant Forage and Phenology and the Response of Wildlife Populations

The warming climate and loss of sea ice is altering the 

tundra habitats of the Arctic Coastal Plain. Time series photo 

imagery and field sampling by the USGS have revealed habitat 

changes resulting from thaw of tundra permafrost and flooding 

of coastal lowlands by salt water. Research also has shown that 

warmer conditions cause plants to produce more biomass that 

is of relatively lower nutrient content. The USGS is studying 

different groups of herbivorous wildlife to understand the 

potential impacts of changing northern vegetation on a broad 

array of species. Current projects focus on geese, which must 

forage on plants that are high in nutrients and low in fiber, and 

caribou (Rangifer tarandus), which feed on plants that are 

relatively higher in fiber content and lower in nutrient content. 

Further, the USGS is experimentally manipulating forage, 

using shade and green houses to determine how a warming 

Arctic will influence the quality and quantity of forage plants. 

These data will allow scientists to estimate the quality of food 

resources under future climate scenarios and project how 

these changes will impact wildlife that feed on plants to fuel 

long-distance migrations, reproduction, and molting. Several 

species of migratory geese are already responding to habitat 

change. Thousands of black brant (Branta bernicla) undergo 

their flightless molting period on the Arctic Coastal Plain 

and are shifting to new coastal habitats created by saltwater 

flooding. This shift may be related to an increase in forage 

quantity following saltwater inundation of coastal sedge and 

grass meadows (primarily Carex subspathacea and Puccinellia 

phryganodes). The white-fronted goose (Anser albifrons) also 

is responding positively to habitat changes on both coastal 

and interior portions of the Arctic Coastal Plain, increasing its 

population size seven-fold in northern Alaska since 1980. This 

dramatic growth of white-fronted geese likely also has been 

facilitated by temperature driven changes in forage quantity. 

The effects of these habitat changes on invertebrates and fish are 

unknown but are currently under study by the USGS. 

Phenology is the study of recurring ecosystem processes 

such as seasonal plant growth or bird migration. The phenology 

of an ecosystem often responds to seasonal cues, such as 

changes in temperature. Increasing spring and summer 

temperatures in the Arctic are leading to earlier snowmelt and 

plant emergence. Migratory birds and mammals time their 

arrival to Arctic breeding areas to correspond with the onset 

of habitat and food availability. Seasonal changes in forage 

quality and abundance occur rapidly at high latitudes, and 

migration and reproduction of Arctic wildlife are often timed 

so that young are born near the peak of food availability. In 

this respect, climate change may have significant consequences 

for wildlife when timing of migration and breeding is tightly 

synchronized with food availability. Populations failing to 

adapt to changing are at risk of reduced reproductive success 

White-fronted goose and goslings.
Caribou on the Arctic Coastal Plain.

Monitoring of vegetation phenology using satellite imagery (eMODIS). From http://

earthexplorer.usgs.gov/.

Yellow-billed loon.

Theme II - The Arctic Coastal Plain

Changes in Plant Forage and Phenology and the Response of Wildlife Populations (continued)

Changes in Water Resources and the Response of Wildlife Populations

and declines in abundance. Species vulnerable to this 

phenological mismatch between spring arrival and plant 

phenology are being identified by the USGS through 

the study of migration behavior, source nutrients invested 

in reproduction, timing of reproduction relative to peak 

nutrient availability, and rates of juvenile growth on 

the Arctic Coastal Plain. The USGS is using satellitebased photography to calculate Normalized Difference 

Vegetation Index (NDVI) measurements that will provide 

a broad-scale perspective of the timing of vegetation 

phenology across the Arctic Coastal Plain. NDVI has 

been shown to be strongly correlated with net primary 

production, photosynthetic activity, and biomass. From 

this information, the USGS will develop a map to 

identify areas of high and low primary production or 

“greenness” across the Arctic Coastal Plain.

Predicted increases in temperature and changes in vegetation phenology 

also are expected to lead to changes in the summer habitats used by caribou. 

Four populations of caribou (Central and Western Arctic, Teshekpuk, and 

Porcupine) roam the Arctic Coastal Plain in summer, seeking out high 

quality plants to replenish energy and protein lost during winter. The 

phenology, nutrient content, and abundance of plant forage throughout the 

short summer growing season are critical for survival and reproduction in 

caribou. Although the predominant effects of climate warming will be on the 

phenology and quality of plant forage, it is unclear whether these changes 

will result in positive or negative impacts for tundra-dwelling caribou. 

Therefore, the USGS is incorporating empirical and simulation approaches 

to quantify the bottom up effects of climate change to these and other 

mammal populations across the northern terrestrial ecosystem of Alaska. For 

example, changes in the habitats used by large mammals are being quantified 

by repeating a series of habitat transects originally conducted in 1977 that 

extend from the Brooks Range to the Arctic Ocean.

The warming of the Arctic Coastal Plain is expected to alter the dynamics of water resources 

of the region. Water is an integral part of the landscape and provides nutrients to a 

diverse array of tundra habitats. However, questions remain as to the specific 

effects increased temperatures will have on the flow, rate of permafrost thaw, 

and nutrient composition of water resources in the Arctic. These processes 

are critical to invertebrate and fish communities, which also provide food 

for other wildlife. The USGS is conducting field studies in northern 

habitats to quantify water and nutrient fluxes across the tundra and 

among lakes, and is testing how increases in temperature and nutrients 

will influence plant and invertebrate abundance. Changes in primary 

productivity may lead to increases in invertebrate grazers and, in turn, 

be beneficial to wildlife such as fish and birds. Isotopic and genetic 

analysis of birds and their prey (invertebrates and fish) will allow the 

USGS to understand how wetland resources are used by wildlife. 

Wildlife species likely to be influenced by changes to wetland 

invertebrate and fish populations include the Alaska population of the 

yellow-billed loon (Gavia adamsii), which nests almost exclusively 

on the Arctic Coastal Plain. During breeding, this species relies upon 

large, deep lakes that host fish populations. The breeding population 

of the spectacled eider (Somateria fischeri) on the Arctic Coastal 

Plain has remained stable over the past 10 years while numbers in 

western Alaska have increased, implying some localized effect that 

may be related to invertebrate forage.
2080s

2050s

2020s

Present

Flat-lobed lichen Cetraria nivalis, and Cladonia spp.

Receding distribution of the barren ground shrew, a tundra 

specialist, as the tundra-boreal forest ecotone creeps northward. 

Present and future time frames based on preliminary USGS 

genetic and climate models.

The Response of Alaska’s Wildlife in a Global Context

Forecasting Future Wildlife Population Sizes and Distributions

Publications

Theme II - The Arctic Coastal Plain

Authors: John Pearce, Tony DeGange, Paul Flint, Tom Fondell, David 

Gustine, Leslie Holland-Bartels, Andrew Hope, Jerry Hupp, 

Josh Koch, Joel Schmutz, Sandra Talbot, David Ward, and 

Mary Whalen

For more information: U.S. Geological Survey

 4210 University Drive, Anchorage, AK 99508

 http://alaska.usgs.gov

Publishing support provided by the U.S. Geological Survey

Tacoma Publishing Service Center

Many wildlife species that occur on the Arctic Coastal Plain in summer 

are highly migratory. Birds migrate to Alaska each spring from wintering 

areas as far away as South America and Asia, whereas caribou undertake 

migrations from winter ranges in the Brooks Range to the Arctic Coast each 

year. Wintering areas of these Arctic migrants include the open ocean and 

coastal and terrestrial habitats. Climate change also is affecting environmental 

and forage conditions in these diverse winter habitats. As a result, migratory 

wildlife carry the positive or negative influences of wintering area conditions 

with them to the Arctic. Thus, population trends of many wildlife species in 

the Arctic result from a combination of breeding and wintering area effects. 

For example, expected increases in the frequency and intensity of wildfires as 

a result of climate change will reduce the area of lichen-producing vegetation 

within the winter ranges of northern caribou. Increased ocean temperatures 

at wintering areas of black brant geese are linked with reduced breeding the 

following summer in Alaska. The USGS is using tracking devices, genetics, 

and studies of wildlife physiology to determine how changes to wintering 

areas are impacting reproductive success of species that migrate to the Arctic 

in summer.

Through the Changing Arctic Ecosystem initiative, the USGS is 

building new expertise in several novel analytical techniques to combine 

relevant climate data, expert knowledge, and scientific information 

to forecast the future response of wildlife populations to terrestrial 

ecosystem change on the Arctic Coastal Plain. Bayesian conceptual 

models are being used to determine the most critical information 

needed to predict the response of wildlife populations to climate 

change. Structured decision making is being used to assist resource 

managers with complex issues in the Arctic. The USGS also is adding 

new capabilities in molecular genetics to provide information on how 

wildlife species across Alaska responded to past changes in the earth’s 

climate. By combining evolutionary genetic data with current and 

predicted climate scenarios, the USGS is modeling the predicted future 

distributions of wildlife populations in the Arctic and identifying key 

environmental variables that determine important animal habitat.

Flint, P.L., Mallek E.J., King, R.J., Schmutz, J.A., Bollinger, K.S., and 

Derksen, D.V., 2008, Changes in abundance and spatial distribution of 

geese molting near Teshekpuk Lake, Alaska: interspecific competition 

or ecological change? Polar Biology, v. 31, p. 549-556, doi:10.1007/

s00300-007-0386-8.

Geiselman, J.A., DeGange, A.R., Oakley, K.L., Derksen, D.V., and Whalen, 

M.E., 2012, Changing Arctic Ecosystems—Research to understand and 

project changes in marine and terrestrial ecosystems of the Arctic: U.S. 

Geological Survey Fact Sheet 2011-3136, 4 p. (Also available at http://

pubs.er.usgs.gov/publication/fs20113136.)

Hope, A.G., Speer, K.A., Demboski, J.R., Talbot, S.L., and Cook, J.A., 

2012, A climate for speciation—Rapid spatial diversification within 

the Sorex cinereus complex of shrews: Molecular Phylogenetics and 

Evolution, v. 64, p. 671–684, doi:10.1016/j.ympev.2012.05.021.

Lewis, T.L., Flint, P.L., Derksen, D.V., and Schmutz, J.A., 2011, 

Fine scale movements and habitat use of black brant during the 

flightless wing molt in Arctic Alaska: Waterbirds, v. 34, p. 177-185, 

doi:10.1675/063.034.0206.

Lewis, T.L., Flint, P.L., Derksen, D.V., Schmutz, J.A., Taylor, E.J., and Bollinger, 

K.S., 2011, Using body mass dynamics to explain long-term shifts in habitat 

use of arctic-molting geese: evidence for ecological change: Polar Biology, 

v. 34, p. 1751-1762, doi:10L1007/s00300-011-1025-y.

Ravens, T.M., Jones, B.M., Zhang, J., Arp, C.D., and Schmutz, J.A., 2012, 

Process-based coastal erosion modeling for Drew Point, North Slope, Alaska: 

Journal of Waterway, Port, Coastal and Ocean Engineering, v. 138, 

p. 122-130, doi: 10.1061/(ASCE)WW.1943-5460.0000106.