U. S. Department of the Interior

Bureau of Land Management

BLM Alaska Open File Report 120 

BLM/AK/GI-08/012+6518+025

June 2008

McCarthys Marsh Caribou Winter Range Transects: 

Vegetative Changes from 1997 to 2006

Kyle Joly and Randi R. Jandt

BLM

Alaska
The BLM Mission

The Bureau of Land Management sustains the health, diversity and productivity of the public lands for the 

use and enjoyment of present and future generations.

Cover Photo

Tundra near Transect 3 and the 1977 Wagon Wheel burn with the Bendeleben Mountains in the background.

BLM photo by the author. 

Author

Kyle Joly was until April 2008 a wildlife biologist at the BLM Fairbanks District Office in Fairbanks, Alaska. 

He now works for the National Park Service in Fairbanks. Randi R. Jandt is a fire ecologist for BLM’s 

Alaska Fire Service in Fairbanks, Alaska.

Disclaimer

The mention of trade names or commercial products in this report does not constitute endorsement or recommendation for use by the federal government.

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A bibliography of scientific reports is online at www.blm.gov/ak. 
McCarthys Marsh Caribou Winter Range Transects:

Vegetative Changes from 1997 to 2006

Kyle Joly and Randi R. Jandt 

BLM-Alaska Open File Report 120

June 2008

U. S. Department of the Interior

Bureau of Land Management

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Methods ................................................................................ 1 

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Unburned Transects: 1997 versus 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Paired Transects: Burned versus Unburned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Repeat Photography: Lava Creek and Death Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figures

Figure 1. Locations of permanent vegetation transects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Researcher quantifying vegetation cover at the Death Valley transect using the 

sampling frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Figure 3. Changes in percent cover of different vegetative classes from 1997 to 2006 on eight 

permanent transects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 4. Observed differences in percent cover of different vegetative classes between paired 

burned and unburned transects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 5. Lava Creek in 1997 (left) and 2006 (right) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Figure 6. Death Valley in 1997 (left) and 2006 (right) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Figure 7. Quick recovery of vascular vegetation, Oregon Creek burn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Tables

Table 1. Coordinates of transects (NAD 83 datum). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

iii

B E N D E L E B E N M O U N TA I N S

Fish

River

Koyuk River

N

Seward Peninsula

.

.

NOME

Kotzebue

9 0 9 18 km

Bering 

Sea

McCarthys Marsh

1

INTRODUCTION

The Bureau of Land Management (BLM) began 

studies of the winter range of the Western Arctic 

Caribou Herd (WACH) in 1981. Twenty permanent 

vegetation transects were deployed within the Buckland River valley on the northeastern side of the 

Seward Peninsula. Additional sites added in 1996 and 

1997 included eight located in and around the 

McCarthys Marsh area of the southcentral region of 

the Seward Peninsula (Table 1 and Figure 1). All relocatable transects (two transects deployed in 1981 

were not found again) were monitored during 1981, 

the mid-1990s, and again in 2005 and 2006. Jandt et 

al. (2008) compared all paired burn and unburned 

transects, while Joly et al. (2007) compared the

vegetative changes over the three time periods

in the Buckland Valley region. This report presents 

the changes in vegetation within the McCarthys

Marsh area between 1997 and 2006 detected using 

these permanent transects. Two of the eight transects 

had paired burned transects, and these results

will be presented here to retain a central location for 

McCarthys Marsh data even though these data

previously were reported by Jandt et al. (2008).

The WACH numbered 490,000 caribou (Rangifer 

tarandus) as of 2003 (Dau 2005). Lichens are the primary winter forage for caribou. Lichen cover has been 

declining in the Buckland Valley, which is within 

the herd’s core winter range, since 1981 (Joly et al.

2007). In 1997 the BLM chose McCarthys Marsh,

an area outside the range of the WACH until the

mid-1990s, as a site for deploying new transects primarily to document the rate and magnitude 

of caribou disturbance in a recently invaded range 

that had high initial lichen cover. It was assumed that 

once the caribou had “discovered” this relatively

pristine winter range, they would heavily utilize it.

However, groups of caribou used the area only sporadically between 1996 and 2006, although as many as 

10,000 animals were observed on occasion. Serendipitously, lower than expected use did not render the

monitoring valueless. Changes in vegetation on these 

transects also helped shed light on the effects of 

lighter grazing pressure, climate change, wildfire, and 

the interactions of these factors (Joly and Jandt 2007), 

illustrating how monitoring efforts may yield unexpected, yet important, findings.

MetHODS

Permanent vegetation transects were deployed in 

the McCarthys Marsh and Death Valley area in 1997 

at eight sites. Two of these sites had an additional 

transect located within a nearby burned area so as to 

Figure 1. Locations of permanent vegetation transects in the McCarthys Marsh region of 

the Seward Peninsula, Alaska. For transect names and coordinates, see Table 1.
2

 

create paired burned and unburned transects. All 

transects were read in 1997 and in 2006. A 1-m x 0.5-m 

sampling frame (see Figure 2) was placed along the 

50-m transect at 4-m intervals (12 total). Each frame 

was divided into 0.1-m x 0.1-m sections to develop 50 

point-intercept locations. Species was determined for 

each intercept. The first “hit” for each intercept was 

used to determine percent cover. While multiple “hits” 

were recorded through the canopy, these data were not 

part of this analysis. Only the first hit was recorded for 

the Buckland transects (Joly et al. 2007). Percent cover 

was then calculated for the entire transect for each of 

the following vegetative classes: lichens, graminoids, 

shrubs, mosses, forbs, and non-vegetated. The lichen 

class was further subdivided into primary, secondary, 

and non-forage lichens based on published literature 

and the authors’ field experience (see Joly et al. 2007). 

T-tests were employed for dependent samples to statistically compare differences in vegetative cover between 1997 and 2006. Repeat photography was also 

used to document changes in vegetative cover.

RESULTS

Unburned Transects: 1997 versus 2006

The relative 54.0% decline in lichen cover over the 

last decade was significant (T = - 7.89, df = 7, P < 0.001). 

Similarly, primary lichens suffered a 57.5 % relative 

decline, which was also significant (T = - 5.59, df = 7, 

P < 0.001). The large decline in lichen cover was offset 

by increases in graminoids, shrubs, and forbs. Graminoid cover more than doubled during the study, which 

was significant (T = 3.64, df = 7, P = 0.008). 

Shrub cover significantly increased by a 

relative 30.0 % (T = 3.80, df = 7, P = 0.007). The 

relative 63.0 % increase forb cover was also 

significant (T = 2.96, df = 7, P = 0.021). The 

changes in cover for both moss (P = 0.123) 

and non-vegetated (P = 0.628) were not significant. Changes in absolute percent coverage 

are depicted in Figure 3.

Paired Transects: Burned versus 

Unburned

The data comparing the two paired burned 

and unburned transects is presented in 

Figure 4. Wildland fires burned these areas in 

1972 and 1977, so the burns were 34 and 29 

years old at the time of the last (2006) reading.

Although the absolute percent coverages vary 

between the two decades, the relative patterns 

of vegetative cover between burned and unburned transects are very similar.

Table 1. Coordinates of transects (NAD 83 datum).

# Transect name Latitude (N) Longitude (W)

1 Wagon Wheel Airstrip 65°10.875' 163°04.718'

2 Upper Pargon 65°04.588' 163°35.392'

3B 1977 Wagon Wheel Burn 65°01.713' 162°50.602'

3UB 1977 Wagon Wheel Unburned 65°01.545' 162°50.577'

4 Lava Creek 65°11.096' 162°53.968'

5 Darby Mountains 65°01.374' 162°27.266'

6 Etehepuk 64°58.789' 162°53.406'

7 Death Valley 65°12.410' 162°20.295'

8B 1972 Pargon Burn 65°02.910' 163°19.494'

8UB 1972 Pargon Unburned 65°02.895' 163°19.419'

Figure 2. Researcher quantifying vegetation cover at the Death Valley 

transect using the sampling frame.
0

10

20

30

40

50

Percent Cover

1997 45.9 30.8 13.8 25.3 2.7 2.4 10

2006 21.1 13.1 29.4 32.9 4.4 3.4 8.7

Lichen PrimLich Gram Shrub Forb Moss Nonveg

0

10

20

30

40

50

60

Percent Cover

Unburned 18.9 15 38.7 29.6 2.9 3 7.1

Burned 1.1 0.5 52.2 34.5 8 0.7 3.7

Lichen PrimLich Gram Shrub Forb Moss Nonveg

0

10

20

30

40

50

Percent Cover 

Unburned 43.9 33.1 18.1 23.6 2.1 2.7 9.7

Burned 3.7 1.8 36.2 36.7 4.4 1.1 18

Lichen PrimLich Gram Shrub Forb Moss Nonveg

3

Figure 3. Changes in percent cover of different vegetative classes from 1997 

to 2006 on eight permanent transects in the McCarthys Marsh area of the 

Seward Peninsula, Alaska. “PrimLich” represents cover of primary caribou 

forage lichens—a subcategory of all lichens.

Figure 4. Observed differences in percent cover of different vegetative 

classes between paired burned and unburned transects. Sampling was conducted in 1997 and 2006 on two permanent transects in the McCarthys 

Marsh area of the Seward Peninsula, Alaska. “PrimLich” represents cover 

of primary caribou forage lichens—a subcategory of all lichens.

2006 

Data

1997 

Data
4

 Repeat Photography: Lava Creek and Death

Valley

Photos taken at the same place on the east side of 

Lava Creek show obvious signs of substantial increases 

in shrub cover (Figure 5). The bright ground cover in 

the 1997 photo is replaced by low evergreen shrubs in 

the 2006 photo. Also, the extent of alder (Alnus spp.) 

clusters is much greater in the 2006 photo than in the 

1997 photo. Notice the large boulder in the middle of 

the 1997 photo that is almost totally obscured in 2006.

Also note size increases in individual shrubs and expansion of shrub cover extent.

The photo-point pair from Death Valley shows obvious signs of substantial increases in graminoid cover 

(Figure 6). This area was used by a large group of 

caribou and lichens were mined out. There are damaged 

tussocks (bright spots), but low-lying moss (orange 

areas) is still visible in 1997. Nine years later, the site 

is a field of vigorous tussocks. Ankle-deep tussocks are 

Figure 5. Lava Creek in 1997 (left) and 2006 (right), McCarthys Marsh area of the Seward Peninsula, Alaska.

Figure 6. Death Valley in 1997 (left) and 2006 (right), McCarthys Marsh area of the Seward Peninsula, Alaska.

now knee-high, and the moss is no longer visible. This 

area did not burn.

DISCUSSION

Results from the McCarthys Marsh permanent 

transect data agree with, and reinforce, other research 

(Jandt et al. 2008, Joly et al. 2007) that has documented 

the large and rapid changes occurring in tundra ecosystems within the range of the WACH in northwest 

Alaska. Lichen cover has declined significantly in 

the McCarthys Marsh area, with declines in primary 

caribou forage species leading the way. Grazing and 

trampling were likely the primary factors contributing to this very rapid decline. However, it is remarkable that such significant changes were documented with

limited caribou use occurring in only about 4 of the 

9 years between monitoring efforts. Graminoid (grass 

and sedge) cover has more than doubled from 1997 to 

2006. Shrub cover and forb cover have also increased 

significantly over this period within the study area.
5

Lichen cover, including specifically 

primary forage lichens, was much 

lower on burned transects than on 

unburned transects. There has been 

little recovery of lichen cover 30–35 

years post-fire, with less than 2% 

cover in 2006. In fact, relative cover 

of lichen actually declined between 

1997 and 2006. Lichens are highly 

susceptible to burns and take decades 

to recover, though graminoids can 

recover very quickly (see Figure 7; 

white area is dead lichens, but grasses have returned). Unlike lichens,

graminoid, shrub, and forb cover 

were all greater in the burned transects than in the paired unburned 

transects. The absolute percent cover 

of graminoids increased markedly.

On individual transects, such as 

Death Valley, the increase in graminoid cover was remarkable and obvious on photo-plot comparisons. We hypothesize this 

response to be an indirect effect of grazing; the site 

experiences warming due to surface albedo changes 

when the highly reflective, insulating lichen cover is 

removed. Alternatively, the marked growth response 

in vascular species—primarily cottongrass (Eriophorum

spp.)—may be stimulation due to warming climate.

Experimental studies (Walker et al. 2006) have documented substantial plant community shifts associated 

with changes in temperature and growing season— 

even when those changes are as small as or even smaller than those experienced on the Seward Peninsula 

since the 1970s. The trend of increasing graminoids 

was also noted in the Buckland Valley transects, where 

this class had the largest increases in percent cover 

(Joly et al. 2007). Significant changes in moss cover 

between the mid-1990s and 2006 were not detected on 

either the Buckland Valley or these McCarthys Marsh 

transects (Joly et al. 2007, this study). At Lava Creek 

the photo-pairs show substantial increases in shrub 

cover, which has been documented by Sturm et al.

(2001) in other Arctic regions.

These results provide additional evidence that factors other than high caribou numbers and fire, such as 

climate warming, are affecting vegetative cover in 

tundra ecosystems. Lichen cover declined in unburned 

transects despite the fact that the WACH did not utilize the area frequently during the study period.

Furthermore, relative lichen cover declined on burned 

transects where lichen cover was too low to attract 

caribou use (see Joly et al. 2007). Increased graminoid 

cover and shrub cover, observed on both burned and 

unburned transects, is a predicted effect of climate 

warming (Chapin et al. 1995, Sturm et al. 2001, Walker 

et al. 2006). Increased moss cover has been a common 

indicator of overgrazed ranges (Klein 1987, van der 

Wal 2006), but it was not noted in this study.

The McCarthys Marsh and Buckland Valley transects 

should continue to be monitored every 7–10 years. We 

recommend that additional transects be established in 

the Nulato Hills, a heavily utilized portion of the 

WACH’s winter range. Additional information, especially in older age-classes, is needed to determine a 

reasonable recovery curve for lichens within the range 

of the WACH. Lastly, further investigations into the 

area’s fire regime and the extent of potential winter 

range for the herd would help in the development of 

specific fire management recommendations to protect 

remaining productive, old-growth lichen communities.

ACKNOWLEDGEMENTS

Randy Meyers, who retired from the BLM in 

March 2007, has been an integral member of the 

team studying the winter range of the WACH for more 

than a decade. Her botanical expertise, from which the 

authors benefited on this and many other projects, will 

be missed. Also appreciated was the fieldwork assistance provided by Ann Claerbout in 2006 and Jeanie 

Cole in 1997.

Figure 7. Quick recovery of vascular vegetation, Oregon Creek burn. White 

vegetation is fire-killed lichens. 
6

 references

Chapin, F.S., III, et al. 1995. Responses of arctic tundra to experimental and observed changes in climate.

Ecology 76:694–711.

Dau, J. 2005. Western Arctic Herd. In: Brown, C., ed.

Caribou management report of survey and inventory 

activities, 1 July 2002–30 June 2004. Alaska Department of Fish and Game. Juneau, Alaska. pp. 177–218.

Jandt, R.R., Joly, K., Meyers, C.R., and Racine, C.

2008. Slow recovery of lichen on burned caribou winter range in Alaska tundra: potential influences of climate warming and other disturbance factors. Arctic, 

Antarctic, and Alpine Research 40: (In press).

Jandt, R. R., Meyers, C. R., and Cole, M. J. 2003. Western Arctic Caribou Herd Winter Habitat Monitoring 

and Utilization, 1995–1996. BLM-Alaska Open File 

Report 88. U.S. Department of the Interior, Bureau of 

Land Management, Anchorage, Alaska. 25 pp.

Joly, K. and R. R. Jandt. 2007. The unidirectional influences of wildfire, disturbance by caribou, global climate change and shrub expansion on arctic ecosystems.

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of grazing and climate change. Rangifer Special Issue 

17:199–207.

Klein, D.R. 1987. Vegetation recovery patterns following overgrazing by reindeer on St. Matthew Island.

Journal of Range Management 40:336–338.

Sturm, M., et al. 2001. Increasing shrub abundance in 

the Arctic. Nature 411:546–547.

van der Wal, R., 2006. Do herbivores cause habitat degradation or vegetation state transition? Evidence from 

the tundra. Oikos 114:177–186.

Walker, M. D., et al. 2006. Plant community responses 

to experimental warming across the tundra biome.

Proceedings of the National Academy of Science 

103:1342–1346.