Deer Lake Research Articles

Tournaisian volcanism associated with transtensional basin development in western Newfoundland during the amalgamation of Pangea

During the Carboniferous, the assembly of the supercontinent Pangea periodically reactivated strike-slip faults and shear zones that transect the northern Appalachian Orogen. These strike-slip deformation zones represent crustal-scale zones of structural weakness that have long-lived and complex kinematic histories. Their periodic reactivation controlled the evolution of the transtensional sedimentary basins of the region. The continuous interplay between the lithospheric plates, their subcontinental lithospheric mantle, and surficial processes (i.e. oceanic/riverine, biological, atmospheric, gravitational, erosional) controlled the development of the Deer Lake Basin in western Newfoundland. The Saltwater Cove Formation of the Deer Lake Basin is a late Tournaisian lacustrian-deltaic succession interrupted by minor eruption of basalt flows and pyroclastic deposits. The basalts have E-MORB (enriched-mid ocean ridge basalt) to OIB (ocean island basalt) chemical affinities with LREE enriched profiles, lack negative Nb and Ti anomalies and εNd(t=350 Ma) values between +2.8 to +6.4. Pyroclastic deposits include mafic lapilli tuff and intermediate tuff, and have compositions similar to CAB (continental arc basalt), having steep LREE relative to HREE patterns, negative Nb and Ti anomalies, and εNd(t=350 Ma) ranging from −6.1 to −1.0. Geochemical variation within the mafic rocks is explained by an E-MORB source variably influenced by crustal contamination processes. Lithofacies analysis coupled with geochemical and isotopic data support their eruption in a transtensional, intra-orogenic basin setting that formed during the assembly of Pangea. Their moderately primitive chemistry supports the interpretation that faulting, associated with transtensional basin development, facilitated asthenosphere upwelling via edge-driven convection.

Identifying a fly-in/fly-out source-hub community: The case of Deer Lake, Newfoundland and Labrador

Fly-in/Fly-out (FIFO) is a commuting arrangement involving the movement of employees to and from their place of work by airplane, often on a rotational basis. Extensive research on FIFO has been conducted in Australia where three community types have been identified: source (or home) communities, host (or work) communities, and hub communities (stop-over communities). An additional community type, the source-hub community, was identified in 2013. Though FIFO arrangements are important for facilitating intra- and inter-provincial ERGM, limited research on hub or source-hub communities has been conducted in Canada. Through a door-to-door census and key informant interviews, this study identified Deer Lake in Newfoundland and Labrador (NL) as a FIFO source-hub community. While airport access was an important factor influencing Deer Lake's source-hub development, as was the case in Australia, other significant factors included proximity to friend and family connections and employment. Overall, it is suggested that factors influencing the development of FIFO source-hub communities may be context-specific. While more research is needed to understand the emergence of source-hub communities, these findings contribute to dialogues around the nature of resource-dependent communities, including the study of compound community types and the relationship between FIFO workers and the communities through which they travel.

Full and Simulated Compact Polarimetry SAR Responses to Canadian Wetlands: Separability Analysis and Classification

Detailed information on spatial distribution of wetland classes is crucial for monitoring this important productive ecosystem using advanced remote sensing tools and data. Although the potential of full- and dual-polarimetric (FP and DP) Synthetic Aperture Radar (SAR) data for wetland classification has been well examined, the capability of compact polarimetric (CP) SAR data has not yet been thoroughly investigated. This is of great significance, since the upcoming RADARSAT Constellation Mission (RCM), which will soon be the main source of SAR observations in Canada, will have CP mode as one of its main SAR configurations. This also highlights the necessity to fully exploit such important Earth Observation (EO) data by examining the similarities and dissimilarities between FP and CP SAR data for wetland mapping. Accordingly, this study examines and compares the discrimination capability of extracted features from FP and simulated CP SAR data between pairs of wetland classes. In particular, 13 FP and 22 simulated CP SAR features are extracted from RADARSAT-2 data to determine their discrimination capabilities both qualitatively and quantitatively in three wetland sites, located in Newfoundland and Labrador, Canada. Seven of 13 FP and 15 of 22 CP SAR features are found to be the most discriminant, as they indicate an excellent separability for at least one pair of wetland classes. The overall accuracies of 87.89%, 80.67%, and 84.07% are achieved using the CP SAR data for the three wetland sites (Avalon, Deer Lake, and Gros Morne, respectively) in this study. Although these accuracies are lower than those of FP SAR data, they confirm the potential of CP SAR data for wetland mapping as accuracies exceed 80% in all three sites. The CP SAR data collected by RCM will significantly contribute to the efforts ongoing of conservation strategies for wetlands and monitoring changes, especially on large scales, as they have both wider swath coverage and improved temporal resolution compared to those of RADARSAT-2.

Fisher Linear Discriminant Analysis of coherency matrix for wetland classification using PolSAR imagery

Wetlands provide a wide variety of environmental services globally and detailed wetland inventory maps are always necessary to determine the conservation strategies and effectively monitor these productive ecosystems. During the last two decades, satellite remote sensing data have been extensively used for wetland mapping and monitoring worldwide. Polarimetric Synthetic Aperture Radar (PolSAR) imagery is a complex and multi-dimensional data, which has high potential to discriminate different land cover types. However, despite significant improvements to both information content in PolSAR imagery and advanced classification approaches, wetland classification using PolSAR data may not provide acceptable classification accuracy. This is because classification accuracy using PolSAR imagery strongly depends on the polarimetric features that are incorporated into the classification scheme. In this paper, a novel feature weighting method for PolSAR imagery is proposed to increase the classification accuracy of complex land cover. Specifically, a new coefficient is determined for each element of the coherency matrix by integration of Fisher Linear Discriminant Analysis (FLDA) and physical interpretation of the PolSAR data. The proposed methodology was applied to multi-temporal polarimetric C-band RADARSAT-2 data in the Avalon Peninsula, Deer Lake, and Gros Morne pilot sites in Newfoundland and Labrador, Canada. Different combinations of input features, including original PolSAR features, polarimetric decomposition features, and modified coherency matrix were used to evaluate the capacity of the proposed method for improving the classification accuracy using the Random Forest (RF) algorithm. The results demonstrated that the modified coherency matrix obtained by the proposed method, Van Zyl, and Freeman-Durden decomposition features were the most important features for wetland classification. The fine spatial resolution maps obtained in this study illustrate the distribution of terrestrial and aquatic habitats for the three wetland pilot sites in Newfoundland using the modified coherency matrix and other polarimetric features. The classified maps provide valuable baseline data for effectively monitoring climate and land cover changes, and support further scientific research in this area.

Chido / Map, and: Kohyang / Hometown, and: Pirobong 1 / Vairocana’s Peak 1, and: Paengnoktam / White Deer Lake, and: Changsusan 1 / Long Life Mountain 1, and: Changsusan 2 / Long Life Mountain 2, and: Kusŏngdong / Nine Forts Valley, and: Pi / Rain, and: Indongch’a / Honeysuckle Tea, and: Ch’un-sŏl / Spring Snow, and: Sapsari

Chido / Map, and: Kohyang / Hometown, and: Pirobong 1 / Vairocana’s Peak 1, and: Paengnoktam / White Deer Lake, and: Changsusan 1 / Long Life Mountain 1, and: Changsusan 2 / Long Life Mountain 2, and: Kusŏngdong / Nine Forts Valley, and: Pi / Rain, and: Indongch’a / Honeysuckle Tea, and: Ch’un-sŏl / Spring Snow, and: Sapsari Eleven Poems by Chŏng Chiyong Translated by Emily Yoon (bio) Translator’s Note Chŏng Chiyong is known today as one of the greatest modernist poets in Korean history, but scholarship on his poetry began to flourish only after 1988, when South Korea lifted the ban on literature by writers who defected to North Korea. Chŏng was born in Okch’ŏn, North Ch’ungch’ŏng Province, in 1902. He attended Hwimun High School in Seoul (1918-1922), where he started his literary activities by publishing the literary magazine Yoram and composing his first fiction and poetry. He studied English literature at Doshisha University in Kyoto (1923-1929); while at Doshisha, in 1926, he made his debut as a poet with nine poems including “K’ap’e P’ŭransŭ” [Cafe France] in the inaugural issue of Hakcho. After graduating from Doshisha, he returned to Hwimun High School to teach English, where he taught until Korea’s independence from the Japanese occupation in 1945. Then he taught English and Latin at Ewha Women’s University and assumed the role of chief editor for the Kyŏnghyang newspaper. With the onslaught of the Korean War and the confusion that followed, Chŏng became a member of the leftist National Guidance Alliance (or Bodo League; Kungmin bodo yŏnmaeng) against his will along with other writers from Chŏson Writers Alliance (Chŏson munhakka tongmaeng). He was abducted to North Korea [End Page 65] in 1950 and is rumored to have died in 1953. Until 1988 his name nonetheless had the bad reputation of a writer who voluntarily went to the North. Even though his life after 1950 remains mysterious, thankfully one can now glimpse Chŏng’s and colonial-era Korea’s histories through the poetry he left behind. 1920s Korea was a time of turmoil and change. After Japan occupied Korea in 1910, poetry explicitly criticizing the state became scarcer; the 1920s saw poets writing works concerning despair and destruction, expressing poets’ social responsibility to transcribe the people’s struggles, and asking for the revival of sijo. Modernist poets in the mid-1930s focused on visual imagery, exploration of the psyche, and illustration of urban life. Chŏng is often referred to as a modernist poet, largely due to his imagistic poems. His affinity for novel imagery and diction does seem to stray from the poetic traditions of the previous decade. Still, he does not strictly adhere to Western modernist ideals. He also retains traditional elements of Korean poetry; many of his poems illustrate the speaker’s solitude, quest for spiritual awakening, and reverence for nature. Also, Chŏng’s poems in his second collection Paengnokdam [White Deer Lake] (1941) mostly portray landscape, suggesting the symbolic significance of the land to a colonial subject. Therefore, to call Chŏng a modernist poet is not quite accurate. Chŏng’s poetry seems deceptively easy to read. His language is not cryptic and the sceneries he paints are exquisite and familiar. His lines seep into the mind effortlessly, and one feels nostalgic for a place and time one has not experienced, due to his ability to capture the landscape and sense of longing ingrained in Korea’s collective memory. For instance, Korea is a mountainous country, and it is difficult to picture a Korean landscape devoid of mountains or hills, which inhabit many of Chŏng’s poems; he yearns for home and childhood with images of his hometown, thereby presenting a universal sentiment coupled with specifically [End Page 66] Korean scenes. Although many of his best-known poems involve nostalgia and/or the natural world, it is an oversimplification to limit Chŏng’s poetry to the themes of nature and longing; some poems specifically illustrate human interaction and urbanity, and many reflect his contemplation of spirituality, religious faith, endurance, civilization, and more. Further complicating one’s...

Strategi Pengembangan Ekowisata di Kawasan Waduk Pembangkit Listrik Tenaga Air (PLTA) Koto Panjang Kabupaten Kampar

The aims of this study are to determine the general condition of the HydroelectricDam area at Koto Panjang as a tourism , analyzing the potential of ecotourism to support theuse of Hydroelectric dam Koto Panjang and formulate the ecotourism development strategyof hydroelectric dam Koto Panjang by using descriptive qualitative method. The studyinvolved 76 people consist of 30 local people, 30 tourists , 6 businesses, and 10 officialsassociated with the utilization of hydroelectric dam Koto Panjang, to obtain the informationfrom the society in the hydroelectric dam area of Koto Panjang and from the tourist wasdistributed the questioners Randomly. The study was conducted from April to October 2012 atKampar regency that divided in several related institutions at Kampar Regency and in thePekanbaru city. The object and appeal of ecotourism that was potential to developed in thehydroelectric dams area at Koto Panjang were : 1) Dam with beautiful scenery floating netcages and small islands located in the dam, with fishing, boating, swimming, eating at afloating restaurant and watching the unloading of fish cages, 2) Deer Lake was located on thebanks of the dam with beautiful scenery, equipped playground for children that used as amotocross arena, 3) Aquari Beach was in the middle of the dam has a beautiful view of thewater tourism activities such as jet skis and canoes, and also the venue to routine cultureevent, Balimau Kasai. 4) The Peak Panorama was transitory (resting area) and strategicallylocated at the cross-roads between provinces with the very beautiful scenery towards the dam.5) Ketangka island has a gently sloping coastal island which overlooking the dam withbeautiful scenery was very suitable to be developed as a tourist hiking, camping, fishing,swimming and boating. 6) First bridge across the province road were on used to be atransitory because of the beautiful scenery under the bridge which was the dam with floatingnet attraction. The ecotourism development strategies in the hydroelectric Dam, KotoPanjang were: 1) Keeping our environment by setting zoning conservation and zoningdesignation of the activities in the dam, through the dam area authorities were authorized todetermine the rules.2)Conducting a variety of cultural events and activities in thehydroelectric Dam area, Koto Panjang which supported the availability of sufficient financialresources to completing the infrastructure. 3) Increasing the government's commitment toestablish authorities of hydroelectric dam area, Koto Panjang. 4) Implementing theRegulation in the Ecotourism area by involving the local communities, it supported by thefinancial support to completed adequate facilities and infrastructures, thus attracted touriststo open up new business opportunities for the local community.

Parasites of Two Native Fishes in Adjacent Adirondack Lakes

This survey of parasites in 2 adjacent lakes is the first of its kind in the Adirondack Park of New York State. Wolf Lake is designated as a heritage lake whereas nearby Deer Lake is limnologically similar but has at least 5 introduced fish species. Both lakes have 2 native species, i.e., white sucker (Catostomus commersoni) and redbreast sunfish (Lepomis auritus), which were the focus of this study. Parasite communities of both hosts were surveyed and compared between each lake and were statistically evaluated for differences in species similarity, prevalence, mean intensity, and mean abundance. Between lakes, white suckers had significant differences in the prevalence of 4 parasite species (Myxobolus sp. 2, Myxobolus bibulatus, Octospinifer macilentis, and Pomphorhynchus bulbocoli) and mean abundances of 4 parasites (neascus larvae, Octospinifer macilentis, Pomphorhynchus bulbocoli, and Glaridacris confusus). Redbreast sunfish had significant differences in the prevalence of 3 species (Myxobolus uvuliferis, a coccidian species, and Spinitectus carolini) and differences in parasite mean abundance of 5 species (neascus larvae, Clinostomum marginatum , Leptorhynchoides thecatus, Spinitectus carolini, and Eustrongylides sp.). Differences in component communities between lakes were found and, although the exact causes cannot be determined by this study, we speculate on several possible explanations.

Cousins at Deer Lake on Whidbey Island, Washington, August 2009

Cousins at Deer Lake on Whidbey Island, Washington, August 2009

Assessing the natural recovery of a lake contaminated with Hg using estimated recovery rates determined by sediment chronologies

Abstract Deer Lake is an impoundment located near Ishpeming, Michigan, USA. Iron mining assay laboratories located in Ishpeming disposed of Hg salts to the city sewer whose outfall was located along an inlet to Deer Lake. An effort to remediate the system in the mid 1980s which consisted of drawing down water in the impoundment in order to volatize Hg from the sediments did not result in recovery of the system. Since the mid 1990s, the remediation strategy has been to allow the continual burial of the contaminated sediments, i.e., natural recovery. The goal of this study was to assess the effectiveness of this strategy. This was accomplished by investigating the state of the system in terms of its recovery and estimating the time frame for recovery. Sediment cores were collected in 2000 to determine historical trends in accumulation rates and concentrations of Hg and other metals. Sedimentation rates and sediment ages were estimated using 210 Pb. Event-based dating (e.g., peak of 137 Cs in 1963) was used to supplement 210 Pb data due to non-monotonic features in the 210 Pb profile and activities that were not at supported levels at the base of the core. Selected results are that: (1) drawdown significantly influenced sedimentation patterns causing slopes for 210 Pb profiles that reflected the influx of older sediment, (2) periods of Fe production correlate to Hg loading indicating the point source for contamination, a relationship not previously identified, (3) Hg:Al ratios indicate a recent change to a watershed pathway for Hg loading and (4) Hg concentrations had decreased from their peak, remain elevated, and were increasing after 1997. The cause of the recent Hg concentrations may be related to influx of contaminated watershed soils or sediments. Estimating the time frame for recovery is challenging in this system because the process of natural recovery seems to have been arrested and deeper, uncontaminated sediments, were not recovered as a basis for reference. However, a recovery to background conditions is likely not achievable since rates of Hg loading to nearby lakes and the current rate of atmospheric deposition are greater than an estimate of background conditions for Deer Lake. Assuming recovery continued after 2000, estimates of the time required for recovery varied based on the system state used to define it (e.g., recent rates of wet Hg deposition or Hg surface concentrations/fluxes from similar systems), but were less than 12 a. However, the recent increasing values of recovery indicators (e.g., Hg concentrations) suggests that these estimates are conservative and will be longer if recovery remains arrested, which may in part be due to the legacy of Hg contamination on the landscape. This study shows that estimates of recovery of highly disturbed lake systems can be made in the absence of within lake reference conditions by using comparisons to reference systems and challenges of estimating ages from atypical 210 Pb activity profiles can be overcome in part using event-based dating techniques.

Rock magnetic evidence for inclination shallowing in the early Carboniferous Deer Lake Group red beds of western Newfoundland

SUMMARY A paleomagnetic and rock magnetic study of the Carboniferous Deer Lake Group red beds of Newfoundland was performed to detect and correct for inclination shallowing. Results indicate a primary remanence carried by magnetite, with a mean direction of D = 179.7 ◦ , I = 33.7 ◦ , α95 = 7.2 ◦ which corresponds to a paleopole position of 22.2 ◦ N, 122.3 ◦ E,A95 = 7.6 ◦ . Correcting the inclination using anisotropy of anhysteretic remanence and the measured individual particle anisotropy gives a corrected direction of D = 178.8 ◦ , I = 50.9 ◦ , α95 = 6.3 ◦ corresponding to a paleopole position at 8.4 ◦ N, 122.7 ◦ E, A95 = 7.2 ◦ . This correction is larger than that of other red beds from the Maritime Provinces of Canada, but is consistent with paleoenvironmental reconstructions, placing North America in a more arid climate zone. Our inclination-corrected results have important implications for this portion of North America’s apparent polar wander path and suggest a correction is needed for other red bed-derived APWPs. We have determined the range of flattening factors f , defined as the proportionality constant between the tangents of the measured (I m) and field (I o) inclinations, tan(I m) = f tan(I 0), from this study and previous inclination correction studies to estimate inclination corrections. Using the range of haematite f factors observed in this study to correct the Neogene red bed inclinations from the Vall` es-Pened` es Basin (NE Spain) yields inclinations consistent with the known geomagnetic field inclination in the Neogene, thus indicating that the range of f factors reported here may be used to estimate the magnitude of inclination shallowing in red beds.

Palynostratigraphy and lithostratigraphy of Carboniferous Upper Codroy Group and Barachois Group, southwestern Newfoundland

A new zone, the Reticulatisporites carnosus Assemblage Zone of late Pendleian to Arnsbergian age, is proposed for miospore assemblages in the Searston Formation of the Barachois Group and in unnamed coal-bearing strata in higher portions of the group. The beds containing the zone can be correlated with those in other parts of the Euramerican floral province in western Europe (including the North Sea), where the climate was semi-humid. Temporal relationships suggested by these new biostratigraphic data indicate that a reassessment of the regional lithostratigraphy of southwestern Newfoundland is required. The Overfall Brook Member of the Robinsons River Formation, formerly assigned with its correlative, the Brow Pond Lentil, to the Codroy Group, is here identified as a basal unit of the Searston Formation. It lies unconformably on Codroy Group beds of Brigantian age. Elsewhere, the basal beds of the Barachois Group lie unconformably on pre-Carboniferous rocks. The Barachois Group in the Codroy and St. George’s Bay lowlands correlates with the Humber Falls and Howley formations of the Deer Lake Subbasin of western Newfoundland and with the Pomquet Formation of the Mabou Group, Nova Scotia. The Pendleian–Arnsbergian coal-bearing strata high in the undivided Barachois Group predate the post-Arnsbergian major floral crisis and, with their correlatives, represent the youngest known rock units of Mississippian age in Atlantic Canada. They are significantly older than the Pennsylvanian coal measures of Moscovian (Bolsovian) age in a small outlier near Stephenville, and we recommend the latter be removed from the Barachois Group.

Effects of aerobic and anaerobic conditions on P, N, Fe, Mn, and Hg accumulation in waters overlaying profundal sediments of an oligo-mesotrophic lake

Concentrations of key nutrients and metals in water overlaying profundal sediments were evaluated in replicate experimental chambers containing undisturbed sediment–water interface samples from Deer Lake, an oligo-mesotrophic lake in eastern Washington. Chambers were incubated under three sequential phases: aerobic (21 d), anaerobic (27 d), and second aerobic (14 d). In general, nutrients and metals in chamber water were lower under aerobic versus anaerobic conditions. However, in some cases compounds anticipated to appear only under anaerobic conditions, including ammonia, phosphate, and manganese, were observed during aerobic conditions. Correlation analysis elucidated a number of interactions between compounds. Phosphate correlated significantly ( p<0.05) with iron during all incubation phases, suggesting that phosphorus cycling was controlled by iron. Cycling of nitrate and ammonia was tightly and significantly coupled under aerobic conditions. During both aerobic phases, nitrate increased while ammonia decreased, likely as a result of biological nitrification. Finally, mercury appeared during mildly reducing conditions and showed a significant correlation with manganese during the anaerobic phase, suggesting that Mn oxide reduction was the source of Hg in chamber water.

Satellite, planned resource communities: Deer Lake, Newfoundland, 1923–35

Historians neglect the role of planned industrial satellite towns in the wider history of single‐industry communities. Starting in the early 1920s, the Humber Project on the west coast of Newfoundland was an industrial mega‐project of the first order. Undertaken by a British firm wishing to tap the growing North American newsprint market, top planning and engineering contractors were hired to design a sprawling industrial network powered by a massive hydroelectric station at Deer Lake. Officials altered the plan significantly and, by early 1924, the Deer Lake development was made secondary to the paper mill at Corner Brook. Company town construction mimicked industry; Corner Brook became the main planned settlement while Deer Lake was the smaller satellite community for power plant operators. Two years later, most residents of Deer Lake were loggers living on the fringes of company control. Yet, despite their role as suppliers of essential raw material, loggers were excluded from the otherwise extensive system of company welfare. Similar entrenched and scaled dependencies shaped worker and resident experiences on the ground for years after. In the Humber Valley, company‐imposed privilege and vulnerability planned uneven development within an industrial network, highlighting a more complex relationship between corporations, planners and residents than stock ‘social control’ or ‘boosterist’ interpretations allow.

Topographically-controlled Deglacial History of the Humber River Basin, Western Newfoundland

The Humber River in western Newfoundland flows through a large interior basin, that influenced Late Wisconsinan ice flow from major dispersal centres to the north, in the Long Range Mountains, and to the east in The Topsails. An early southward ice flow from a source to the north covered coastal areas in the western part of the basin. Subsequent regional ice flow was southwestward to northwestward from The Topsails, while south to southwestward flowing ice from the Long Range Mountains occupied the upper Humber River valley. This flow was confluent with ice from The Topsails and moved northwestward toward Bonne Bay. Regional deglaciation began about 13 ka from the inner coast. Ice occupying the Deer Lake valley dammed glacial Lake Howley in the adjacent Grand Lake and Sandy Lake basins to an elevation up to 85 m above present lake levels, which were controlled by drainage through a western outlet feeding into St. George’s Bay. The lake was lowered by exposure of the South Brook valley outlet, and finally drained catastrophically through a spillway at Junction Brook. Marine limit at the coast was 60 m asl. Inland deltas at the head of Deer Lake and fine-grained sediment exposed in the Deer Lake valley show inundation below 45 m present elevation. This produced a narrow embayment extending at least 50 km inland from the modern coast and is named here as ‘Jukes Arm’. Dated marine macrofossils in the Humber Arm and lower Humber River valley, indicate the deltas at the head of Deer Lake formed about 12.5 ka.

Corn heat unit variability and potential of corn (Zea mays L.) production in a cool climate ecosystem

Recent interest in corn (Zea mays L.) production among forage producers in Newfoundland, Canada, raises questions of risk, scale and impact of seasonal heat accumulation for attaining maturity. The objectives of this paper were to present the results of corn performance in a short-term trial at three selected sites (St. John’s, Deer Lake and Stephenville), calculate corn heat unit (CHU) probability levels of these sites to assess the long-term risks, and determine CHU values of locations across Newfoundland to describe their suitability for corn production. Daily values of CHU were accumulated from the conversion of daily maximum (Tmax) and minimum (Tmin) air temperature for each location using the last day of 3 consecutive days in the spring with mean daily air temperatures (Tmean) ≥ 12.8°C as the starting date and the first date of a killing frost in the autumn (Tmin ≤ -2°C) or 30 September, whichever was earlier, as the ending date. Corn grown for silage at the three selected sites was within the desired level of 250–350 g kg-1 DM at 50% kernel milk line (R5.5) stage. Corn reached harvesting stage (R5.5) before the occurrence of a killing frost at Deer Lake and Stephenville. To protect seedlings against killing frost, mulching with transparent polyethylene film is recommended at St. John ’s. There was considerable year-to-year variability in CHU at each of the three sites. Differences in seasonal CHU for St. John’s were identified over two periods: from 1945–1989 and 1990–2001. The most recent period (1990–2001) has generally been warmer than the earlier period. A warming trend, as indicated by the CHU trends at the three sites, holds the prospect of some significant longer-term benefits for Newfoundland agriculture. Across Newfoundland, average (1956–1990) seasonal CHU accumulations (CHUave) based on STARTave and ENDend) ranged from 1686 at St. Lawrence to 2695 at Gander. Using the 80% probability (START80% and END80%) dates, the CHU80% ranged from 1486 at Port aux Basques to 2382 at Gander. The CHU values would help producers select what corn hybrid(s) to grow in their area. Overall, these analyses underline the potential for successful corn production in Newfoundland. Key words: Corn (Zea mays L.) maturity, corn heat units, cool climate region, 50% kernel milk line (R5.5), temperature

A Fifty-Year Record of Historical Sedimentation at Deer Lake, North Carolina*

Although many once-deforested areas of the eastern United States are now revegetated, impacts of this disturbance on watershed processes may persist. In this study, lake sediment stratigraphy and magnetism were used to assess the recovery of a small watershed in the southern Blue Ridge Mountains following abrupt reduction of human impacts. Average sediment yields were found to be higher than those of less disturbed basins nearby, and lower than those reported from the early twentieth-century Piedmont Province. Temporal trends in sediment yield appear to reflect both meteorological and land-use histories. Although most of the lake sediment is magnetically similar to bottomland sources, two instances of local upland sediment input, possibly related to human activities, are evident in the record. Interpreting relationships between sediment yield and changing environmental influences is impeded by poor temporal control in the methodology as well as by the intrinsic dynamics of the fluvial system. *I thank Henry McNabb and the U.S. Forest Service at Bent Creek Experimental Forest for resources, useful discussion, historical information, and other means of facilitating this research. I am also indebted to I. L. Larsen, Oak Ridge National Laboratory, Environmental Sciences Division, for crucial assistance with Cs-137 counting.

Effects of Length Limits on Muskellunge in Bone Lake, Wisconsin

Minimum length limits are a commonly used management tool for protecting fisheries from exploitation and for improving population size structure. However, little is known about the effects of minimum length limits on populations of muskellunge Esox masquinongy. We monitored changes in the muskellunge population in Bone Lake, a 1,781-acre lake in northwest Wisconsin over a 31-year period (1964–1995) during which time length limits were changed from 30 in to 34 in and from 34 in to 40 in. These changes were compared with population changes in nearby Deer Lake (807 acres), where the length limit remained at the statewide minimum of 32 in. Mean length of adult muskellunge in Bone Lake increased from 31.3 in in 1964 to 36.0 in in 1995. Adult (≥30-in) muskellunge abundance in Bone Lake increased more than five-fold during the study and reached a density of 0.99 fish/acre. Abundance of larger (≥38-in) muskellunge increased 269% following minimum length limit increases between 1982 and 1995. Relative weight (Wr) of Bone Lake muskellunge decreased during the study, suggesting intraspecific competition for food resources. The muskellunge population in Deer Lake also had positive increases in size structure, but the increases were not as great as those in Bone Lake, and population abundance did not change. Results from this study suggest that high minimum length limits can increase abundance and mean length of a muskellunge population, but biologists need to consider long-term effects on the fish community if high densities are achieved.

Stratigraphy, Palynology and Source Rock Potential of Lacustrine Deposits of the Lower Carboniferous (Visean) Rocky Brook Formation, Deer Lake Subbasin, Newfoundland

Stratigraphy, Palynology and Source Rock Potential of Lacustrine Deposits of the Lower Carboniferous (Visean) Rocky Brook Formation, Deer Lake Subbasin, Newfoundland

Leucodon andrewsianus comb. et stat. nov.

The eastern North American endemic moss Leucodon andrewsianus (Crum & Anderson) Reese & Anderson (basionym: Leucodon brachypus var. andrewsianus Crum & Anderson) is recognized at the rank of species. Although perichaetia are present rarely in this moss, it is not known to produce perigonia or sporophytes; it evidently reproduces and disperses by caducous branchlets. A key is provided for the three species of Leucodon known to occur in North America, north of Mexico. Leucodon C. E Schwaigrichen is a genus of dioicous pleurocarpous mosses with wide distribution around the world. Two species and one variety were attributed to North America north of Mexico by Anderson et al. (1990): Leucodon brachypus Bridel, L. brachypus var. andrewsianus Crum & Anderson, and L. julaceus (Hedwig) Sullivant. On the basis of new information discovered during a review of the genus for the Flora of North America project, we here recognize L. brachypus var. andrewsianus at the rank of species. Nomenclature for mosses mentioned in this article is mostly based on Anderson et al. (1990). LEUCODON ANDREWSIANUS (Crum & Anderson) Reese & Anderson comb. et stat. nov. Leucodon brachypus Bridel var. andrewsianus Crum & Anderson, THE BRYOLOGIST 75: 101. 1972. TYPE: U.S.A. NEW JERSEY. Palisades, on red cedars, C. E Austin, Musci Appalachiani 260, sub nom. Leucodon julaceus forma stolonifera, nom. nud., (holotype MICH!; isotypes CANM!, DUKE!, MO!, NY!). Plants mostly medium sized, rarely robust, dull to somewhat glossy. Primary stems rhizome-like, usually inconspicuous, bearing often crowded ascending branches. Branches mostly elongate and curved, rarely straight, simple or branched, commonly with conspicuous clusters of short fragile branchlets in upper leaf axils and at tips. Branch leaves erect-appressed, plicate, concave, rarely secund, mostly 1.41.9 mm long, lanceolate-acuminate, ecostate, commonly with the terminal cell hyaline and narrowly elongate (mostly 34-60 jxm long) on young leaves, and with the distal end of the terminal cell often curved or even uncinate. Leaf cells thick-walled, somewhat elongate in the interior of the lamina, mostly more or less isodiametric in the marginal rows at midleaf and in the basal angles, rarely somewhat papillose-roughened abaxially near leaf tip. Perichaetia rarely present, axillary, gemmiform; perigonia and sporophytes unknown. Habitat.--On logs, tree trunks, and rocks in forests; sea level to 2,100 m. Leucodon andrewsianus occurs at or near sea level in the northern part of its range, but only in the mountains in the southern part. Ra ge.---CANADA. NEW BRUNSWICK. Albert Co., Ireland 11637 CANM, DUKE, NY. NEWFOUNDLAND. Ca 10 km N of Deer Lake community, Belland 3983 CANM, MICH, MO, TENN. NOVA SCOTIA. Cape Breton Island, Victoria Co., Schofield 6017 CANM, DUKE, MICH. ONTARIO. Bruce Co., Colpoy Bay, Crum 11476 LAF. PRINCE EDWARD ISLAND. Macoun 6211 DUKE. QUEBEC. Rimouski Co., Lepage 1202 DUKE. U.S.A. ARIZONA. Coconino Co., Mack's Crossing, Haring & Haskell 22762 MO. CONNECTICUT. East Haven, J.B.H. s.n., 12 Nov 1883 NY. ILLINOIS. Dr. Vasey, sin. loc. NY. MAINE. Penobscot Co., Hermann 19213 DUKE. MASSACHUSETrS. Amesbury, Huntington s.n., 31 Jan 1902 DUKE. MICHIGAN. Alger Co., Steere 590 FH. NEW HAMPSHIRE. Plymouth, Grout s.n., 7 Mar 1898, DUKE, FH, NY. NEW JERSEY. The type material of Leucodon andrewsianus. NEW YORK. Essex Co., Smith et al. 38743 FH. NORTH CAROLINA. Jackson Co., Soco Gap, Anderson 25283 DUKE. PENNSYLVANIA. Centre Co., State College, Roberts s.n., 11-22-24 DUKE, TENN. TENNESSEE. Sevier Co., Sharp 35122 MICH, NY, TENN. VERMONT. Newfane, Grout, N. Amer. Musci Pleurocarpi 81 CANM, DUKE, FH, MO, NY. VIRGINIA. Giles Co., Mountain Lake, Blomquist 3407 DUKE, FH. WEST VIRGINIA. Fairmont, Roberts s.n., 4/16/36 MO. WISCONSIN. Lander s.n., 7/16/32, sin. loc. NY. DIFFERENTIATION OF LEUCODON ANDREWSIANUS FROM

The Deer Lake Basin, Newfoundland: Structural Constraints from New Seismic Data

The Deer Lake Basin, Newfoundland: Structural Constraints from New Seismic Data