Subarctic Environment Research Articles

Strategies for revegetation of disturbed gravel areas in climate stressed subarctic environments with special reference to Churchill, Manitoba, Canada: a literature review

In the vicinity of Churchill, Manitoba, Canada, dry heath tundra is restncted to elevated gravel deposits such as beach ndges and eskers These sites have been utilized for gravel excavation and extraction as well as for building and road construction Vast areas of open glavel resulting from human activities scar the landscape and reduce the amount of undisturbed dry heath tundra When left alone these gravel areas inay remain devoid of vegetation for many decades due to the severity of the climate Nothing has been done to restore them to their pre-disturbance vegetation cover Their soils a re charactenzed by low nutnent availability poor moisture retention capabdities and limited seed banks The current paper reviews literature regarding manipulation of chemical and physlcal properties of gravel substrates in order to facllitate the development of cover by native plants A planned revegetation prolect is presented This project would provide ecological and aesthetic benefits as well as enhance conservation and tourism in the area

Prey capture by three Pinguicula species in a subarctic environment.

The number and biomass of prey captured were estimated for Pinguicula alpina, P. villosa and P. vulgaris in a subarctic environment. Seasonal captures were estimated for one site per species for 4-5 years. Captures were related to reproductive status (reproductive/non-reproductive) and to leaf area. For one species (P. vulgaris) the catch was also compared across a range of habitats. Of the seasonal catch, 50-75% was obtained during June and less than 5% during August. For P. alpina and P. villosa the seasonal catch varied threefold or more between years (means of 89-329 μg dry matter plant-1 season-1 for P. alpina, and 11-91 μg dry matter plant-1 season-1 for P. villosa), whereas the between-year variation for P. vulgaris was small (mean c. 600 μg plant-1 season-1). Large variations were, however, observed among habitats for P. vulgaris. Captured prey may contribute a substantial amount of nutrients to the most successful individuals (up to 85% of the mean seasonal turnover), but prey capture varied greatly and during any given season many individuals obtained only marginal amounts of nutrients through carnivory. P. vulgaris trapped almost twice as much per unit leaf area and season as the other two species (224 for P. vulgaris versus 127 μg cm-2 season-1 for the other two species). Reproductive individuals of P. vulgaris trapped almost twice as much as non-reproductive individuals (after taking differences in leaf area into account). For the other two species no differences were observed between reproductive and non-reproductive individuals.

COASTAL DUNE DEVELOPMENT IN COLD-CLIMATE ENVIRONMENTS

Many studies have been carried out on coastal dunes of mid-latitude regions, but little is known about cold-climate coastal dunes. Coastal dunes that have developed in arctic and subarctic environments usually are described as minor aeolian accumulation features, but they occur widely along arctic and subarctic coastlines. In the Arctic, aeolian deflation is a common phenomenon and coastal dunes are less developed than in subarctic environments. Short open-water duration, coarse beach sediment, and sparse vegetation cover are factors explaining the limited coastal dune development of arctic regions. In subarctic settings, niveo-aeolian sedimentation is a major process contributing to coastal dune development. Quantitative and qualitative studies still are needed for a better understanding of the mechanisms of coastal-dune development in cold-climate environments. [Key words: coastal dunes, arctic, subarctic, coastal geomorphology].

The Significance of Internal Nutrient Cycling in Branches for Growth and Reproduction of Rhododendron lapponicum

The significance of internal nitrogen and phosphorus cycling for growth and reproduction was evaluated for the evergreen dwarf shrub Rhododendron lapponicum in a subarctic environment. The evaluation was made by analysing the seasonal dynamics of branch nitrogen and phosphorus pools and studying the effects of experimentally depleting the resources available from one-year-old leaves. Resource depletion was induced by shading the old foliage or removing it entirely. Responses were measured as growth and changes in nutrient pools (N and P) in new vegetative and reproductive parts. Non-reproductive branches maintained relatively constant resource levels over the growing season (...)

Decomposition and nitrogen mineralization from legume and non-legume crop residues in a subarctic agricultural soil

An understanding of the C and N dynamics of crop residues is important for efficient nutrient management. The present experiment was conducted to determine the rate of mass and N loss from alfalfa, faba bean, barley, and rape crop residues in a subarctic agricultural soil. Mass, C, and N losses were measured from residues contained in mesh bags and placed on the soil surface or buried 15 cm below the surface. The mass loss from October, 1988, to May, 1989, was the same for surface and buried alfalfa, barley, and rape residues, averaging 40, 20, and 61%, respectively, while surface and buried faba bean residue sustained 30 and 40% mass loss, respectively. The mass loss of the buried residues continued over the summer but not of those placed on the soil surface, resulting in an average 23% greater mass loss of the buried materials after 1 year. The N loss from October to May was similar from the surface and from the buried placements for the alfalfa, faba bean, and rape residues, averaging 11.3, 10.3 and 38.4 g N kg-1 residue, respectively, while the surface and buried barley lost 2.9 and 4.2 g N kg-1, respectively. The C:N ratio of all of the residues increased during the winter. These data indicate that the rate of decomposition and N mineralization from crop residues in subarctic environments can equal that measured in temperate climates. Furthermore, the concurrent loss of mass and N combined with an increase in the C:N ratio of the residues suggests that physical rather than biological processes were functioning during the winter. Most of the mass and N loss from these residues occurred during the winter, out of phase with crop demand, thereby creating the potential for N loss from the system and inefficient use of crop residue N.

Foredune development along a subarctic emerging coastline, eastern Hudson Bay, Canada

A study of sedimentary processes and evolution of subarctic foredunes along a rapidly emerging coastline in southeastern Hudson Bay showed that niveo-eolian sedimentation is a significant process contributing to the formation of these foredunes. The fall storm berm and the sand-laden ice foot are the prime sedimentary sources for the niveoeolian deposits, which are generally coarser grained than the eolian sand deposited during summer. The annual sedimentation in the backshore zone is less than in typical mid-latitude regions. The development of established foredunes in this subarctic environment seems to require a longer period of time than in other climatic zones. The short-term backshore evolution (1954–1990) shows that sediment supply appears to be a major factor controlling foredune morphology and dynamics. Phases of sediment surplus seem to correspond to rapid seaward progradation and formation of low foredune terraces or low foredune ridges with a beach ridge-like morphology.Conversely, high foredunes probably develop during periods of lower sediment supply and slower beach progradation. On a longer time scale, the relative sea-level fall controls coastline progradation and results in the formation of raised, coast-parallel, relict foredune ridges.

Herbage yield and nitrogen accumulation by seven legume crops on acid and neutral soils in a subarctic environment

Alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), yellow sweet-clover (Medicago officinalis L.), fababean (Vicia faba L.), lentil (Lens culinaris Medik.), pea (Pisum sativum L.), and white lupin (Lupinus albus L.) were evaluated as annual crops in central Alaska on neutral and acid soils for their potential herbage productivity and N accumulation. Herbage dry matter yields were high on the neutral soil, with an overall average yield of 6927 kg ha−1. Yields were much lower at the cooler, acid soil site with an overall average yield of 3743 kg ha−1 for inoculated legumes. Herbage N concentrations ranged from 14 to 36 mg g−1. Amounts of N-fixation, as estimated by the total N difference method, ranged from < 50 kgha−1 for some legumes on the acid soil to > 200 kg ha−1 for fababean on the neutral soil. Inoculation resulted in increases in nodulation, growth and apparent N-fixation on the acid soil where legumes had not previously been grown, but were usually not significant on the neutral soil where legumes had been grown for many years. Liming the acid soil resulted in significant increases in soil pH and in nodulation, herbage yield, and herbage N yield. Key words: Forage legume crops, Alaska, liming, N-fixation

Optimizing bioventing in shallow vadose zones and cold climates

Abstract This paper describes a bioventing study design and initial activities applied to a JP-4 jet fuel spill at Eielson Air Force Base, Alaska. The primary objectives of the project were to investigate the feasibility of using bioventing technology to remediate JP-4 jet fuel contamination in a sub-arctic environment and to determine to what degree the biodegradation rate of JP-4 soil contaminants could be enhanced by increasing soil temperature, both actively by circulating heated groundwater and passively by utilizing solar energy. Biodegradation rates at the bioventing site remained relatively high during the winter months in the active-warming test plot and were consistently higher than those observed in the passive-warming and control test plots. These studies suggest that an active-warming system operated in conjunction with bioventing is a useful method for remediating fuel-contaminated areas in cold climates.

Observations on anthophilous Muscidae and other Diptera (Insecta) in Abisko National Park, Sweden

Muscidae are the dominant anthophilous insects in arctic and subarctic environments. In Abisko National Park, North Sweden, five genera were found to visit blossoms regularly for feeding. Species of Thricops and Phaonia fed extensively on pollen and nectar, and some specialized modes of gathering pollen are described. Morphological adaptations, abundance, activity, periodicity, and flower fidelity are discussed. Muscidae are the leading group of pollinators of open blossoms in arctic and subarctic ecosystems. Brief notes are given on other flower-visiting Diptera.

Water Use, Intercepted Radiation, and Soil Temperature of Skip‐Row and Equidistant‐Row Barley

AbstractCropping systems are sought in the subarctic that improve the plant growing environment for sustained and diversified production of crops. This study assessed whether microclimate and water use of barley (Hordeum vulgare L.) could be altered in the subarctic by crop row configuration and fertilizer placement. Treatments established at Fairbanks, AK, included equidistant‐row planting (0.18‐m equidistant rows) with N banded between alternate rows or broadcast, and skiprow planting (skipping every third row of equidistant rows) with N banded between the closely spaced rows or broadcast. Crop water use, net and reflected radiation, interception of photon flux density (PFD), and soil temperatures were monitored during 1987 through 1989. Banding N resulted in a higher water‐use efficiency (WUE) than did broadcasting N in 1989 but not 1988. Seasonal water use was equal among treatments, although higher leaf area index (LAI) for equidistant‐ row barley suggested less evaporation and greater transpiration than for skip‐row barley. Equidistant‐row barley intercepted 5% more PFD at heading, resulting in part from higher canopy reflectance. Skip‐row barley, however, intercepted more PFD per unit leaf area. Midday net radiation was 3% higher and midday soil temperatures at 0.01 m in the interrow were as much as 5 °C higher for skip‐row barley. In this subarctic environment, barley grown in equidistant rows appeared to utilize water more effectively in transpirational processes and to intercept more PFD for improving production efficiency compared to skip‐row planting.

Holocene Relict Woodlands at the Eastern Canadian Treeline

We present direct evidence for the relict nature of lichenspruce woodlands thriving at treeline, using 14C-dated stands growing in the humid climate of eastern Hudson Bay in northern Québec. Black spruce, Picea mariana (Mill.) BSP, forms two groups of relict stands: a Neoglacial group of postfire origin dating between 2000 and 900 yr B.P. and a pre-Neoglacial group most likely established between 4500 and 3200 yr B.P. The latter group shows no evidence of fire (absence of charcoal under topsoil organic horizon). The stands are exceptional because they probably are the direct lineages of the primeval forests that colonized the land sometime after deglaciation. The structure of the relict lichen-spruce communities gives strong support to the current thesis that considers lichen-spruce woodland as a self-perpetuating open forest, typical of the subarctic environment.

Heading Synchrony and Yield Components of Barley Grown in Subarctic Environments

Synchronous heading is an important characteristic of barley (Hordeum vulgare L.) grown in subarctic conditions, in which short growing seasons, cool temperatures, and the potential of early snowfall necessitate timely harvest. Kernels on late‐developing spikes often fail to mature under these conditions, resulting in harvest delay and reduced grain quality. This study was conducted to determine the influence of seeding rate on heading synchrony and yield components of barley grown in subarctic environments. Three spring barley cultivars were evaluated at seeding rates of 22, 65, 108 kg ha−1 at Palmer and Fairbanks, AK, in 1990 and 1991. Heading synchrony was assessed by determining the range and standard deviation for the interval from sowing to spike appearance. for all cultivars at both locations, growing degree days (GDD) to spike appearance had a narrower range and a reduced standard deviation with higher seeding rates. Averaged across cultivars and environments, seeding rates of 22, 65, and 108 kg ha−1 resulted in standard deviations of GDD to spike appearance of 80, 68, and 64, respectively. Earliest maturity was obtained with the 108 kg ha−1 seeding rate, and grain yield was nearly identical to the 65 kg ha−1 rate. Increasing seeding rate from 65 to 108 kg ha−1 caused a greater compensatory decrease in kernels per spike than kernel weight. In similar environments, use of relatively high rates of seeding is recommended to reduce time to maturity, minimize number of late developing tillers, and optimize grain yield.

Yield and yield component response of barley in subarctic and temperate environments

Plant breeders are continually searching for new sources of genetically diverse germplasm from which superior genotypes might be developed. The objective of this study was to assess the performance of subarctic- and temperate-adapted barley cultivars when grown in reciprocal areas of adaptation to determine their potential for use in breeding programs. Four subarctic-adapted and four temperature-adapted barley (Hordeum vulgare L.) cultivars were grown at two environments each in Alaska (subarctic) and Nebraska (temperate) for 2 yr. Subarctic-adapted cultivars were earlier heading and earlier maturing in both environments, although differences were larger in subarctic environments. Grain yield of the two classes of cultivars was similar in subarctic environments, but temperate-adapted cultivars were far superior when grown intemperate environments. Kernel weight of all cultivars was higher in subarctic environments than in temperate environments. Maturity differences alone did not account for the poor performance of subarctic-adapted cultivars in temperate environments. Yield was positively correlated with all three yield components in temperate environments, but only with spikes per square meter in subarctic environments. Results from this study suggest that greater potential exists for the utilization of temperate-adapted germplasm to favourably increase the genetic diversity of subarctic-adapted germplasm than vice versa.Key words: Barley, Hordeum vulgare L., adaptation, yield components

Pigment analysis of phytoplankton during a subarctic spring bloom: xanthophyll cycling

The objective in this study of the spring bloom in Auke Bay, Alaska, was to determine if light-dependent xanthophyll cycling can be used to estimate the rate of vertical mixing in a subarctic environment. This was done by measuring the concentration of the xanthophylls diadinoxanthin (DD) and diatoxanthin (DT) in phytoplankton samples collected from different depths and different times of the day and in samples incubated in situ. We sampled throughout the photic zone weekly from 16 March until 9 May 1989. Pigments typical diatom assemblages (e.g., Chl a and c, fucoxanthin, DT, DD, and ß-carotene) were found throughout the sampling period. In situ incubations between dawn and early afternoon showed large differences in xanthophyll composition between incubated samples and those from the water column. Differences between samples collected in early morning and early afternoon were also found, as well as between samples collected at different depths. However, the technique was not found satisfactory to describe mixing events in this environment. Other factors besides light seemed to affect the concentrations of the xanthophyls, DT and DD. These findings cast doubt on the ability of DT: DD ratios to infer the vertical mixing history of field assemblages.

Effects of Defoliation on Radial Stem Growth and Photosynthesis in the Mountain Birch (Betula pubescens ssp. tortuosa)

Effects of herbivory on radial growth of mountain birch (Betula pubescens ssp. tortuosa) were investigated in defoliation experiments in a subarctic environment in northern Sweden. The effects of foliage loss on the rate of photosynthesis and the annual radial increment were assessed to test whether compensation had occurred. Fifty per cent defoliation had no significant effect on ring width. In trees defoliated 100%, rings formed during the treatment year and each of the following 3 years were only 15-25% as wide as the corresponding rings in control trees (...)

Competition Among Threadleaf Sundews for Limited Insect Resources

Previous articleNext article No AccessNotes and CommentsCompetition Among Threadleaf Sundews for Limited Insect ResourcesThomas C. GibsonThomas C. Gibson Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 138, Number 3Sep., 1991 Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/285251 Views: 12Total views on this site Citations: 8Citations are reported from Crossref Copyright 1991 The University of ChicagoPDF download Crossref reports the following articles citing this article:Thilo Krueger, Adam T. Cross, Jeremy Hübner, Jérôme Morinière, Axel Hausmann, Andreas Fleischmann A novel approach for reliable qualitative and quantitative prey spectra identification of carnivorous plants combining DNA metabarcoding and macro photography, Scientific Reports 12, no.11 (Mar 2022).https://doi.org/10.1038/s41598-022-08580-8J. Stephen Brewer Inter- and intraspecific competition and shade avoidance in the carnivorous pale pitcher plant in a nutrient-poor savanna, American Journal of Botany 106, no.11 (Jan 2019): 81–89.https://doi.org/10.1002/ajb2.1219Philip H. Crowley, Kevin R. Hopper, and James J. Krupa An Insect-Feeding Guild of Carnivorous Plants and Spiders: Does Optimal Foraging Lead to Competition or Facilitation?, The American Naturalist 182, no.66 (Jul 2015): 801–819.https://doi.org/10.1086/673477Andreas Jürgens, Amber Sciligo, Taina Witt, Ashraf M. El-Sayed, D. Max Suckling Pollinator-prey conflict in carnivorous plants, Biological Reviews 87, no.33 (Dec 2011): 602–615.https://doi.org/10.1111/j.1469-185X.2011.00213.xThomas C. Gibson, Donald M. Waller Evolving Darwin's ‘most wonderful’ plant: ecological steps to a snap‐trap, New Phytologist 183, no.33 (Jul 2009): 575–587.https://doi.org/10.1111/j.1469-8137.2009.02935.x Jonathan A. Moran and Alison J. Moran Foliar Reflectance and Vector Analysis Reveal Nutrient Stress in Prey‐Deprived Pitcher Plants (Nepenthes rafflesiana) Moran & Moran, International Journal of Plant Sciences 159, no.66 (Jul 2015): 996–1001.https://doi.org/10.1086/314086L. Magnus Thorén, P. Staffan Karlsson Effects of supplementary feeding on growth and reproduction of three carnivorous plant species in a subarctic environment, Journal of Ecology 86, no.33 (Jan 2002): 501–510.https://doi.org/10.1046/j.1365-2745.1998.00276.xPaul Wilson Variation in the intensity of pollination inDrosera tracyi: Selection is strongest when resources are intermediate, Evolutionary Ecology 9, no.44 (Jul 1995): 382–396.https://doi.org/10.1007/BF01237761

Brown fat-specific mitochondrial uncoupling protein in adipose tissues of newborn reindeer

Reindeer inhabit a severe arctic or subarctic environment, with the young born in early spring under adverse weather conditions. The extreme northern climate imposes a major thermal challenge to the newborn, and in the present study we have examined fetal, neonatal, and young (from 2 wk before birth to 16 mo postpartum) semidomesticated reindeer from northern Finland for the presence of thermogenic brown adipose tissue. Adipose tissues were removed, mitochondria were prepared, and the proteins were separated by molecular weight and blotted onto nitrocellulose membranes. The membranes were then probed for the presence of the 32,000-relative molecular weight mitochondrial uncoupling protein (UCP) unique to brown fat by use of a rabbit anti-(ground squirrel UCP) serum. Immunoreactivity at the molecular weight characteristic of UCP was present in perirenal, abdominal, inter(pre)scapular, sternal, intralumbar, vertebral, tracheal, inguinal, and omental-mesenteral adipose tissues of newborn reindeer (0-2 days of age). No immunoreactivity was detected in coronary adipose tissue. UCP was found at high levels in interscapular and perirenal adipose tissues of fetal reindeer at 2 wk before birth. Although the protein was present during the first few days postpartum, little immunoreactivity was found at 1 mo of age, and none was evident by 2 mo. UCP and its mRNA were also apparent in perirenal adipose tissue of the newborn of another species of Cervidae, the red deer. It is concluded, on the basis of the immunologic identification of UCP, that most adipose tissues of newborn reindeer represent functional brown fat but that there is a subsequent conversion to white adipose tissue by the 2nd mo of life.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of soil nutrient status on prey utilization in four carnivorous plants.

The hypothesis that carnivorous plants are less responsive to prey at high soil nutrient levels than at lower levels (Givnish et al. 1984) is tested on four plant species (Drosera rotundifolia, Pinguicula alpina, P. villosa and P. vulgaris) from a subarctic environment. The response, measured in terms of seven characteristics (winter bud weight, winter bud nitrogen and phosphorus content, flowering frequency, total seed weight, seed number and weight per seed), was analysed. Although all species responded to prey supply the response varied depending on the characteristic and species concerned. In 5 cases (out of 28 tests) the hypothesis was supported, whereas in 1 case it was refuted, i.e. the response to prey was higher for plants supplied with soil nutrients. In the remaining three-quarters of the tests, responses to prey were not significantly different between the two nutrient levels. Thus, the hypothesis that the response to prey diminishes as soil nutrient availability increases was not supported by our findings. A modification of the model presented by Givnish et al. (1984) is therefore suggested. This modified model measures the cost of carnivory as loss in growth rate and assumes that responses to prey remain unchanged as the soil nutrient content increases. Although the distribution of carnivorous plants is still predicted to be limited mainly to wet and sunny but nutrient-poor sites, the modified model also allows for their occurrence in richer habitats, provided competition is low.

Corrosion and Cathodic Protection of Ice Going Vessels in Subarctic and Arctic Environment

Corrosion and Cathodic Protection of Ice Going Vessels in Subarctic and Arctic Environment

Resource Investment in Reproduction and Its Consequences in Three Pinguicula Species

Resource investment in reproduction and its consequences were compared for three iteroparous plant species, Pinguicula alpina, P. villosa and P. vulgaris, in a subarctic environment. Resource investment (dry matter, nitrogen and phosphorus) was estimated as reproductive effort, RE, and the consequences as relative somatic cost of reproduction, RSC, and as decreased post-breeding survival and reproduction. The relative reproductive allocation varied from 0.2 (N & P in large P. alpina plants) to 0.7 (dry matter of small P. villosa) (...)