Clearwater County Research Articles

Forestry Tour Educates Youth in North Central Idaho

The Clearwater County Sixth Grade Forestry Tour is a unique 3-day, 2-night program that provides participants an objective view of the importance and impact of natural resource-based industries while promoting an understanding of issues regarding natural resource uses. The targeted audience is 6th grade youth, but others interested in natural resources also attend. The tour is sponsored by monetary donations from the logging industry, businesses, and private individuals. Participants camp in the woods, tour the Clearwater Bioregion, and engage with natural resource professionals who use visual aids and hands-on educational approaches. Outcomes indicate a 32% increase in knowledge.

Mid-Holocene drought and lake-level change at Elk Lake, Clearwater County, Minnesota: Evidence from CHIRP seismic-reflection data

Despite many studies of Holocene paleoclimate records from small lakes in the mid-continent of North America, direct estimates of lake-level changes associated with mid-Holocene aridity are rare. Varved sediments from Elk Lake, Clearwater County, Minnesota, are among the best studied in terms of paleoenvironmental proxies, yet the sedimentary architecture of those sediments has not been previously studied and the hydrological responses of the lake – changes in level and volume – are poorly known. High-resolution seismic-reflection (CHIRP) profiles of Elk Lake reveal complex sedimentary basins in the lake, a pattern of nearshore onlap of sediments onto older substrates, and the focusing of sediments into several deep basins. Biogenic gas obscures sediments in the deepest parts of the basins, but beneath the rest of the lake, a three-part Holocene sequence is clear. The transitions between these parts are correlated with lithological changes defined in earlier core studies. Sediments of the modern stage are less focused than those of the prairie lake stage. A prominent erosional unconformity occurs within the Holocene sequence, separating sediments from the prairie and modern stages of the lake. Erosion associated with this unconformity extends to a depth of 18.2 m below the modern water surface, at which point the unconformity grades into a conformable horizon within the sequence in the deep basins of the lake. This transition is an analog of the onlap of modern sediments onto older substrates, which occurs at a depth of about 8.2 m. The configuration of the erosional unconformity and its modern analog indicates a lake-level fall in the mid Holocene of 10.0 m. At its mid-Holocene minimum, the lake was 39% of its present size and 30% of its present volume, providing quantitative evidence to aid in constraining and evaluating reconstructions of mid-Holocene aridity in the mid-continent of North America.

Two new species of Pterostichus Bonelli subgenus Pseudoferonina Ball (Coleoptera, Carabidae, Pterostichini) from the mountains of central Idaho, U.S.A.

Two new species of Pterostichus Bonelli subgenus Pseudoferonina Ball, are described from the mountains of central Idaho: Pterostichus bousqueti Bergdahl [type locality = small tributaries of South Fork of Payette River watershed, ca. 1170 m (3840 ft), 44.0675°; -115.6822°, near Lowman, Salmon River Mountains, Boise County, Idaho, U.S.A.] and Pterostichus lolo Bergdahl [type locality = Cottonwood/Orogrande Creek, ca. 870 m (2850 ft), 46.5528°; -115.5522°, North Fork of Clearwater River watershed, Clearwater Mountains, near Bungalow, Clearwater County, Idaho, U.S.A.]. Males of Pterostichus bousqueti and Pterostichus lolo are easily distinguished from each other and the seven previously described Pseudoferonina species by the form of the median lobe of the aedeagus, and from most individuals of the other species of Pseudoferonina in Idaho by features of pronotal shape and macrosculpture. Both species appear to be obligate ripicolous hygrophiles, restricted in distribution primarily to the margins of small montane streams in forested areas. Widespread intensive stream surveys for Pseudoferonina over many years indicate the geographic ranges of both species are highly localized, and additional undescribed species may occur in Idaho.

Interactive effect of temperature and resources on carbon cycling by freshwater bacterioplankton communities

Planktonic heterotrophic prokaryotes play an essential role in all aquatic ecosystems due to their short generation times and access to dissolved organic carbon and nutrients. In order to understand how rising temperatures and nutrient loading affect the biogeochemistry of whole lake ecosystems, it is essential to understand the interactive effects that temperature and resources have on the metabolism of natural bacterioplankton communities. To address this question we sampled bacterial communities from 1 mesotrophic and 1 oligotrophic lake in Clearwater County, Minnesota, USA, in winter and summer. Each community was exposed to a combination of carbon, nitrogen and phosphorus additions at 4 different levels (ambient, 2 ×, 5 ×, and 10 × ambient) and 4 temperatures (4, 14, 24 and 34°C). Community metabolic response to temperature depended on the resource treat- ment, and the season when the community was sampled. Bacterial respiration increased more with temperature than bacterial growth, resulting in decreased bacterial growth efficiencies at higher temperatures. This result was most pronounced in the high resource treatments, while at lower resource levels the results were more ambiguous. In addition, differences between seasons and lakes suggested that the bacterial communities had adapted or acclimated to in situ temperature such that communities sampled from cold temperature environments had higher respiration at high tempera- tures than those sampled from warmer environments. These results suggest that the effect of temper- ature on carbon cycling mediated by the bacterial community depends on both the in situ resource pool and the extent to which the bacterial community is acclimated to a specific temperature regime.

A 1500-year record of climatic and environmental change in ElkLake Clearwater County, Minnesota II: geochemistry, mineralogy, and stableisotopes

Most of the sediment components that have accumulated in ElkLake, Clearwater County, northwestern Minnesota, over the past 1500 years areauthigenic or biogenic (CaCO3, biogenic SiO2, organicmatter, iron and manganese oxyhydroxides, and iron phosphate) and are deliveredto the sediment–water interface on a seasonal schedule where they are preservedas distinct annual laminae (varves). The annual biogeochemical cycles of thesecomponents are causally linked through the ‘carbon pump’, and are recapitulatedin longer-term cycles, most prominently with a periodicity of about 400 years.Organic carbon is fixed in the epilimnion by photosynthetic removal ofCO2, which also increases the pH, triggering the precipitation ofCaCO3. The respiration and degradation of fixed organic carbon inthe hypolimnion consumes dissolved oxygen, produces CO2, and lowersthe pH so that the hypolimnion becomes anoxic and undersaturated with respectto CaCO3 during the summer. Some of the CaCO3 produced inthe epilimnion is dissolved in the anoxic, lower pH hypolimnion and sediments.The amount of CaCO3 that is ultimately incorporated into thesediments is a function of how much is produced in the epilimnion and how muchis consumed in the hypolimnion and the sediments. Iron, manganese, andphosphate accumulate in the anoxic hypolimnion throughout the summer.Sediment-trap studies show that at fall overturn, when iron-, manganese-, andphosphate-rich bottom waters mix with carbonate- and oxygen-rich surfacewaters, precipitation of iron and manganese oxyhydroxides, iron phosphate, andmanganese carbonate begins and continues into the winter months.Detrital clastic material in the sediments of Elk Lake depositedover the last 1500 years is a minor component (<10% by weight) that ismostly wind-borne (eolian). Detailed analyses of the last 1500 years of the ElkLake sediment record show distinct cycles in eolian clastic variables (e.g.aluminum, sodium, potassium, titanium, and quartz), with a periodicity of about400 years. The 400-yr cycle in eolian clastic material does not correspond tothe 400-yr cycles in redox-sensitive authigenic components, suggesting that theclastic component is responding to external forcing (wind) whereas theauthigenic components are responding to internal forcing (productivity),although both may ultimately be forced by climate change. Variations in theoxygen and carbon isotopic composition of CaCO3 are small but appearto reflect small variations in ground water influx that are also driven byexternal forcing.

Two New Species of Imagocidal Hydromermis (Nematoda: Mermithidae) from Endochironomus subtendens (Townes) (Diptera: Chironomidae)

Hydromermis viridis n. sp. and Hydromermis gastroviridis n. sp. are described from June and August emerging imagos, respectively, of Endochironomus subtendens (Townes) in Lake Itasca, Clearwater County, Minnesota. The position of the mouth, shape of the posterior end, structure and size of the spicule, absence of an excretory pore, arrangement of male tail musculature, and measurements separate the new species form other species of Hydromermis as well as from one another. The 2 species are placed in the genus Hydromermis though having a rounded tail and only 6 hypodermal cords at midbody. An anomalous double vagina condition is reported in H. viridis.

Late Quaternary climates and limnology of the Lake Winnebago basin, Wisconsin, based on ostracodes

Ostracodes document a series of late Quaternary climatic and limnologic changes within the Lake Winnebago basin of east-central Wisconsin. Using a 14 C, 137Cs, and 210Pb-based geochronology, Lake Winnebago ostracode abundances were compared to regional patterns of ostracode biogeography and the paleontological, sedimentological, and geochemical records of Elk Lake (Clearwater County), Minnesota, in order to interpret past temperature and hydrochemical changes in Lake Winnebago. Lake Winnebago sediments contain five major ostracode species, Candona ohioensis, Candona rawsoni, Cytherissa lacustris, Limnocythere verrucosa, and Physocypria pustulosa. In combination with sedimentology and geochronology, variations in the abundances of these species allow the late Quaternary record of the Lake Winnebago basin to be subdivided into five major climatic intervals: (1) glacial to post-glacial (15.5–11.0 ka), (2) cold and variable immediate post-glacial (11.0–10.4 ka), (3) warmer and wet early Holocene (10.4–7.8 ka), (4) warm but not particularly dry middle Holocene (7.8–4.2 ka), and (5) warm and moist late Holocene (4.2 ka-present).

Strelkovimermis acuticauda n. sp. and Strelkovimermis buccalis n. sp. (Nematoda: Mermithidae) from Adult Chironomids (Diptera: Chironomidae) from Lake Itasca, Minnesota

Specimens of 2 mermithid species were obtained from adults of undetermined species of chironomids emerging from Lake Itasca (Clearwater County), Minnesota. Both species have the characteristics of species in the genus Strelkovimermis. The new species are distinguishable from one another and from the 8 currently accepted species in the genus by their small size, shape of the posterior end, length of the buccal funnel, length of the cephalic papillae, location of the mouth, and morphology of the spicule region and vagina. Strelkovimrmis acuticauda n. sp. is unique in possessing an acute posterior end, an auxiliary protractor muscle, and a relatively long vagina, whereas Strelkovimermis buccalis n. sp. is distinguishable from other Strelkovimermis species by its thick cuticle and exceptionally long buccal funnel. The significance of the tail muscles is emphasized as a taxonomic feature to be used in describing future species of Strelkovimermis. A key to the 10 species of Strelkovimermis is provided.

Chrysophycean stomatocyst flora from Elk Lake, Clearwater County, Minnesota

The paleoecological record preserved in the varved sediments of Elk Lake, Clearwater County, Minnesota, has been used by a large number of researchers to reconstruct past environmental and climatic conditions that have occurred at this important reference site. As part of this interdisciplinary effort, we used the International Statospore Working Group (ISWG) taxonomic guidelines to describe the chrysophycean flora that Elk Lake supported over the last 10 400 years. In total, we identified 56 stomatocyst morphotypes using scanning electron and light microscopy. Over one-third of these morphotypes had not been previously recorded. Key words: stomatocyst, Chrysophyceae, paleolimnology, Minnesota, climatic change.

Two New Species of Larvicidal Nematodes (Mermithidae) from Larvae of Chironomus plumosus (Diptera: Chironomidae) in Minnesota, U.S.A.

Telomermis amphiorchis n. gen., n. sp. and Gastromermis plumosus n. sp. are described from the larvae of Chironomus plumosus in the north arm of Lake Itasca, Clearwater County, Minnesota. Telomermis is distinguished from other mermithid genera in having a terminal mouth, four head papillae, a short S-shaped vagina, no visible cuticular cross-fibers, amphidal opening posterior to head papillae, two simple spicules, and a rounded posterior terminus. The post-parasitic juvenile lacks a larval horn. Gastromermis plumosus is distinguishable from most species of the genus by the mouth opening, amphidal opening and head papillae being at the same level. Four other adequately described species of Gastromermis have those characteristics. The length and shape of the spicule, amphids, and vagina is used to separate G. plumosus from the four species. Octomyomermis itascensis heavily infected the larvae of Chironomus plumosus from 1959 through 1962. In 1969-1970, it was replaced by the two new species. The 1969-1970 condition also existed

Wireworm and White Grub Control in Potato, 1987

Abstract Wireworm control trials were established at 3 locations in Minnesota: Staples (Wadena County), Itasca (Clearwater County), and Woodbury (Washington County). All sites had either old alfalfa-grass or pasture as the previous crop. Soils were sandy loam and irrigated at Wadena County, clay loam and very moist in Clearwater County, and sandy loam with a spring drouth in Washington County. Severe white grub infestations developed at the Washington and Clearwater locations. A large wireworm population was present in Washington; neither was found in Wadena. The latter permitted evaluation of uncomplicated chemical effects on the potato itself. Insecticides were applied in the furrow with the seed piece in Wadena and Clearwater and over the planted row and then lightly covered in Washington. Plots were single rows 50 ft long, replicated 6 times at each site, and arranged in a randomized complete block design. A different design was used at each location. Fungicide and foliar insecticides were broadcast on all plots at least 3 times at each location to protect the growing potato throughout the season. Plots were hand dug and all tubers were examined and separated according to grub damage, wireworm damage, damage by both, and no damage. Percent effect for each case was calculated and transformed by ARCSINE, and the means were compared.

Summer Foods of the Cyprinid Fish Semotilus atromaculatus

Abstract Aquatic larvae and pupae, fishes, and molluscs together contributed 95% of the stomach contents of creek chubs from headwaters of the Mississippi River, Clearwater County, Minnesota, during the summer of 1965. As fish grew the changes in food items were from ephemeropteran nymphs and smaller dipterans to larger caddisfly and dipteran larvae, and then fishes. Chubs feed generally in proportion to availability of food organisms. Fishes fed most intensively during early evening and least in the morning. As summer progressed, a reduction in feeding intensity occurred.

The Life Cycle and Larval Development of Octospinifer macilentis (Acanthocephala: Neoechinorhynchidae)

The Life Cycle and Larval Development of Octospinifer macilentis (Acanthocephala: Neoechinorhynchidae)

Summer Weights of Raccoons in Northern Minnesota

During the summers of 1948 through 1955, weight data on live-trapped raccoons ( Procyon lotor hirtus Nelson and Goldman) were obtained at three localities in northern Minnesota. Whitney and Underwood (the eaccoon, 1952, pp. 1–177) state “The largest coons are still said to come from the north-central states, but as yet we have no authentic weights” (p. 15). All data presented are live-weights obtained at first capture of the individual. Much of the information was obtained during the period 1950 through 1955 at the Lake Itasca Forestry and Biological Station in Clearwater County. Grants for field studies from the Graduate School of the University of Minnesota made this work possible. Other data are from the Mud Lake National Waterfowl Refuge in …

An Ecological Study of the Microbenthic Fauna of Two Minnesota Lakes

This report is based on a general study of a neglected and poorly-known ecological group, the lacustrine microbenthos. The microbenthos may be defined as the whole assemblage of microscopic organisms living within and on the surface of the bottom sediments. Further definition is based on limnological sampIing procedure, the microbenthos being that part of the bottom community which is not retained by the coarse metal screens usedl in ordinary bottom-fauna studies. In this sense the microbenthos is analogous to the nannoplankton, while the macroscopic bottom animals, collectively termed macrobenthos, are analogous to the net plankton. Results of the only previous detailed and intensive ecological study concerned primarily with the microbenthos were published by Moore (1939). His paper included an historical bibliography to which should be added at least the papers of Imel (1915), Berg (1938), and Lindeman (1941). The data for the present paper were obtained from two Minnesota lakes. Twelve collections were made in the north arm of Lake Itasca, Clearwater County (R 36 W, T 143 N) during July and August, 1948. Eighty-six benthic collections were made from midwinter, 1948, to midsummer, 1949, in Crystal Lake, Hennepin County (R 21 W, T 29 N, Section 15). Of the total collections, 55 were qualitative, involving 73 ooze-sucker samples, and 43 were quantitative, based on 112 core samples. The molluscs, insects, malacostracans, and larger annelid worms were noted when found, but were considered macroscopic and beyond the realm of this investiagtion. Special emphasis was placed on species distribution with respect to physicochemical factors in the lacustrine environment throughout the seasons. An appraisal of the relationships of the microbenthic assemblage to other lake biota was attempted by examining occasional plankton samples and correlating them with data from bottom collections.

Description of vivianite encrusting a fossil tusk from gold placers of Clearwater County, Idaho

Description of vivianite encrusting a fossil tusk from gold placers of Clearwater County, Idaho