Bonner County, Idaho
Okanogan Highlands Section (M333A) Ecoregion
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Hager Lake is a seepage pond with no apparent inlet or outlet. The basin of Hager Lake is enclosed and underlain by ice-contact fluvial gravels. The depression likely formed as a result of an ice block melting near the terminus of the glacier that occupied this portion of the Priest River Valley; a depression commonly referred to as a "glacial kettle". The origin of the basin dates between 11,500 and 12,000 years before present based on the presence of Glacier Peak tephra near the base of peat cores extracted in 1992 (Bursik and Moseley 1992). |
Several distinct plant communities are found at Hager Lake Fen. The most extensive is a shrub carr dominated by a dense stand of Spiraea douglasii (spiraea). Pinus contorta (Lodgepole pine) and Pinus monticola (western white pine) trees are scattered throughout the shrub carr. The middle of the fen basin north of Hager Lake is covered by a rich fen codominated by Carex lasiocarpa (slender sedge ) and Spiraea douglasii. An extensive (one-hectare) floating mat encroaches on the south side of the lake. The floating mat is covered by a poor fen community dominated by Sphagnum angustifolium, S. subsecundum, and S. centrale. Common vascular species include Carex limosa (mud sedge) and Kalmia microphylla (alpine laurel). Between the floating mat and the Spiraea douglasii shrub carr to the south is a fixed mat zone. The fixed mat also occurs around the east, west, and north lake margins. The fixed mat is characterized by intermediate fen vegetation codominated by Sphagnum subsecundum,
| C. lasiocarpa, and Dulichium arundinaceum (three-way sedge). A narrow, shallow littoral zone is found on the east, west, and north lake margins. It is characterized by Nuphar polysepalum (pond lily), Brasenia schreberi (water-shield), Potamogeton natans (floating-leaved pondweed), and Scirpus acutus (hardstem bulrush). |  |
Hager Lake Fen is located in the Priest River Valley of northern Idaho in Bonner County.
Hager Lake is a high priority peatland in northern Idaho that is partially protected by a conservation easement.
Numerous studies have taken place at Hager Lake Fen since the 1940's which provide an important baseline for current and future studies.
Hager Lake Fen supports 75 vascular and bryophyte plant species, including six considered rare in Idaho. Four additional other rare species were previously documented from Hager Lake Fen and are now believed extirpated: Epilobium palustre (swamp willow weed), Dryopteris cristata (crested shield fern), Carex leptalea (bristle stalk sedge), and Lycopodium dendroidium (groundpine). Hager Lake contains one of the more extensive floating mats in Idaho and the poor fen community on the mat is exceptional.
Hay harvesting is occurring in the northeastern portion of Hager Lake Fen, and pasture development has included drainage ditches. A ditch was constructed in the 1950's through the morraine to the north of Hager Lake. This moraine acted as a natural dam between Hager Lake and the shallower fen basin to the north. Construction of the ditch lowered the potential high water of Hager Lake by approximately 30 cm and excess water flowed out of Hager Lake in the spring rather than seasonally flooding the fixed mat and Spiraea shrub carr habitats around the lake. The flooding was apparently important for maintaining the habitat for several of the extirpated species, including the rare Dryopteris cristata, Carex leptalea, and Lycopodium dendroidium. A log weir was constructed in 1996 to maintain more consistent water levels.
Some timber harvest has occurred in the recent past just north of Hager Lake Fen. Logging and road construction and maintenance present offsite threats that could lead to enhanced eutrophication within the lake and changes in the composition of the fen and aquatic plant communities, which could ultimately threaten the viability of rare plant populations. The analysis of 40-year changes in the vegetation of Hager Lake Fen showed that fen communities were significantly affected by enhanced eutrophication from land clearing surrounding the lake during the first half of the 20th century (Bursik and Moseley 1992).
Major Science and Stewardship Activities
Five peizometers have been installed around the lake to monitor water table changes as a result of the installation of the log weir in 1996. Preliminary monitoring results indicate that the water table is higher than prior to construction of the weir.
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Numerous paleocological studies have taken place at Hagar Lake Fen analyzing post-glacial succession (Hansen 1939, Rumely 1956, Mack et al. 1978, Bursik and Moseley 1992). |
Forty-year changes in the flora and vegetation at Hager Lake Fen were analyzed in 1992 by Bursik and Moseley based on comparison with data collected by Rumely (1956). The 1992 study laid the foundation for continuing a long-term monitoring program at HLF to learn more about Idaho peatlands and to evaluate the effects that management activities in surrounding forests can have on sensitive ecosystems such as peatlands.
Macroinvertebrate and zooplankton communities of HLF have been inventoried and studied for more than a decade (Rabe et al. 1986).
For more information, please contact:
The Nature
Conservancy of Idaho
Box 165
Sun Valley,
ID
(208)726-3007
or contact:
Idaho Conservation
Data Center
600 South
Walnut, P.O. Box 25
Boise, ID
(208)344-9273
or email:
mjankovs@idfg.state.id.us
Bursik, R. J., and R. K. Moseley. 1992. Forty-year changes in Hager Lake Fen, Bonner County, Idaho. Cooperative Challenge Cost-share Project, Idaho Panhandle National Forests and Idaho Conservation Data Center, Idaho Department of Fish and Game. 31 pp.
Hansen, H. P. 1939. Pollen analysis of a bog in northern Idaho. American Journal of Botany 26: 225-228.
Mack, R. N., N. W. Rutter, V. M. Bryant, Jr., and S. Valastro. 1978. Reexamination of postglacial vegetation history in northern Idaho: Hager Pond, Bonner Co. Quaternary Research 10: 241-255.
Rabe, F. W., R. Biggham, R. Breckenridge, and R. Naskali. 1986. A limnological description of selected peatland lakes in Idaho. Journal of the Idaho Academy of Science 22(2):63-90.
Rumely, J. H. 1956. Plant ecology of a bog in
northern Idaho. Unpublished dissertation, Washington State University,
Pullman. 85 pp.