Seasonal changes in habitat use by Maine spruce grouse

1985 ◽  
Vol 63 (12) ◽  
pp. 2738-2742 ◽  
Author(s):  
Thomas A. Allan
Keyword(s):  
Seasonal Changes ◽  
Abies Balsamea ◽  
Forest Composition ◽  
Ground Vegetation ◽  
Larix Laricina ◽  
Forest Density ◽  
Winter Diet ◽  
Open Canopy ◽  
Conifer Tree ◽  
Males And Females

Seasonal change in habitats used by spruce grouse (Dendragapus canadensis) in eastern Maine was studied from spring 1981 until autumn 1983. Forest composition averaged 88 and 90% conifer tree species for males and females, respectively. Red spruce (Picea rubens) and balsam fir (Abies balsamea) were the dominant trees present in all habitats at all seasons. Forest density of habitats used by grouse differed significantly by season and sex. During winter males and females used conifer stands that were denser than random plots. During spring and summer females used sites that were less dense than those used by males and had a more open canopy and more ground vegetation. Both sexes showed seasonal changes in the proportion of time observed in trees. By midsummer, males and nonbrood females exhibited a strong selection for larch (Larix laricina) trees. During autumn both sexes moved to habitats with an increased proportion of larch and were found in these trees greater than 75% of the time Larch needles were considered an important transition food to the winter diet of conifer needles.

SEASONAL GROWTH CHARACTERISTICS OF LONG AND SHORT SHOOTS OF TAMARACK

1967 ◽  
Vol 45 (9) ◽  
pp. 1643-1651 ◽  
Author(s):  
J. Johanna Clausen ◽  
T. T. Kozlowski
Keyword(s):  
Seasonal Changes ◽  
Stem Elongation ◽  
Growth Characteristics ◽  
Weight Increase ◽  
Stem Length ◽  
Larix Laricina ◽  
Seasonal Growth ◽  
Long Shoots ◽  
Short Shoots ◽  
Food Reserves

Tamarack (Larix laricina (DuRoi) K. Koch) produces long shoots which bear two kinds of needles. Early needles are present in the bud and elongate rapidly after budbreak. Late needles, few of which are present in the bud, elongate later than early needles. Short shoots bear early needles only, and stem length seldom exceeds 1 mm. Seasonal changes in length and weight of needles and stems of both shoot types were measured. In long shoots, 75% of stem elongation, more than 70% of stem weight increment, and 65–70% of late needle elongation occurred after early needles were full-sized. Stem and late needle elongation ceased simultaneously, after which time needle weight decreased and stem weight increased. Early needles probably drew on food reserves while developing, and then themselves contributed to stem and late needle elongation. Final stem weight increase probably used photosynthate from both late and early needles of the current year.Shading of current and last year's needles showed that shoots in which photosynthesis was interrupted in this way produced shorter, lighter-weight stems than did control shoots.

Assessing the effects of climate change and land use on northern Labrador forest stands based on paleoecological data

2016 ◽  
Vol 86 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Isabel Lemus-Lauzon ◽  
Najat Bhiry ◽  
James Woollett
Keyword(s):  
Land Use ◽  
Vegetation History ◽  
Ice Age ◽  
Tree Cover ◽  
Forest Composition ◽  
Anthropogenic Factors ◽  
Larix Laricina ◽  
Open Forest ◽  
Historic Land Use ◽  
Study Sites

AbstractWe reconstructed the late Holocene vegetation of the Nain region (northern Labrador, northeastern Canada) in order to assess the influence of climate and historic land use on past shifts in forest composition. Chronostratigraphy was used in combination with macrofossil and pollen data from monoliths sampled from four peatlands. Paleoecological reconstructions produced a vegetation history spanning 4900 years for the Nain region that is largely concordant with other studies in Labrador. An initial open forest tundra phase was followed by an increase in tree cover at around 2800 cal yr BP. Paludification began ∼200 cal yr BP. A decline in Picea and its subsequent disappearance from most of the sites occurred ∼170 cal yr BP (AD 1780) in a period of relatively mild conditions during the Little Ice Age. This event was followed by the establishment of Larix laricina in the region. Local anthropogenic factors are likely responsible for these later developments, as they were not observed in other regional studies. The period around AD 1780 corresponds to the establishment of the Moravian missionaries on the Labrador coast, which increased the need for fuel and lumber. We conclude that changes in land use are reflected in the patterns of vegetation and hydrological change at the study sites.

Comparative responses of small mammals, vegetation, and food sources to natural regeneration and conifer release treatments in boreal balsam fir stands of Quebec

1999 ◽  
Vol 29 (7) ◽  
pp. 1128-1140 ◽  
Author(s):  
Nancy Gagné ◽  
Louis Bélanger ◽  
Jean Huot
Keyword(s):  
Small Mammals ◽  
Natural Regeneration ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Rubus Idaeus ◽  
Balsam Fir ◽  
Food Sources ◽  
Ground Vegetation ◽  
Growing Seasons ◽  
Advance Regeneration

Abundance and species diversity of small mammals were compared among three regeneration methods used in boreal balsam fir (Abies balsamea (L.) Mill.) forests. Those methods were natural regeneration after "careful logging" to retain advance regeneration and planting (black spruce, Picea mariana (Mill.) BSP) followed by herbicide (Vision®) release or brushsaw cutting release. Deciduous vegetation was reduced for two growing seasons in both plantation types after treatment, and foliar arthropods decreased for one growing season. In herbicide-treated plantations, red raspberry (Rubus idaeus L.) shrub cover, near-ground vegetation, and production of berries were reduced for two growing seasons. After herbicide release, the abundance of the red-backed vole (Clethrionomys gapperi (Vigors)) was significantly lowered for two growing seasons. This negative effect was associated with reduced cover during the first two post-treatment growing seasons. In the short term, herbicide-treated plantations constitute poorer red-backed vole habitats than brushsaw plantations. In early successional boreal balsam fir stands, planting did not markedly affect small mammals probably because natural regeneration was common in these plantations.

scholarly journals Végétation tardiglaciaire et postglaciaire au sud-est du parc des Laurentides, Québec

2011 ◽  
Vol 35 (3) ◽  
pp. 345-359 ◽  
Author(s):  
Claude Labelle ◽  
Pierre J.H. Richard
Keyword(s):  
Picea Mariana ◽  
Picea Glauca ◽  
Abies Balsamea ◽  
Pinus Strobus ◽  
Larix Laricina ◽  
Betula Papyrifera ◽  
Betula Glandulosa

L’analyse pollinique des sédiments de trois lacs situés au sud-est du parc des Laurentides a permis de retracer les étapes de la recolonisation végétale post-wisconsinienne. Celle-ci s’est effectuée selon un schéma assez constant à travers le secteur à l’étude. Au début, la végétation était très ouverte, mais tout de même relativement riche en taxons herbacés et arbustifs. Cette phase initiale de végétation (sous-zone la) fut suivie, après une période de transition (sous-zone 1b), par une végétation luxuriante de type toundra (sous-zone 1c). Celle-ci fut à son tour remplacée par une végétation de type toundra arbustive (sous-zone 1d) où l’on voit s’accroître l’importance de Betula glandulosa et d’autres éléments arbustifs. Avec un certain métachronisme entre les sites, l’afforestation s’est amorcée par l’installation du Populus cf. tremuloïdes (sous-zone 2a) et s’est poursuivie par l’arrivée de Picea mariana (fin de la sous-zone 2a) puis, par celle d’une série d’arbres tels Betula papyrifera, Pinus cf. divaricata, Abies balsamea, Picea glauca et Larix laricina (sous-zone 2b). Pendant cette dernière phase de l’afforestation, l’abondance du pollen d’Alnus cf. crispa dans les spectres est maximale. Il semble qu’au moins mille ans se soient écoulés avant l’arrivée des arbres autres que le Populus cf. tremuloïdes. Par la suite, l’histoire de la végétation forestière (zone 3) a été plutôt monotone. Bien que les diagrammes révèlent des périodes de plus grande abondance de certains taxons (Pinus strobus, Picea mariana, Pinus et. divaricata), la majorité des arbres, présents actuellement dans la région, ont migré très tôt à l’Holocène.

Seasonal changes in aggression, hunger, and curiosity in ranch mink

1969 ◽  
Vol 47 (6) ◽  
pp. 1395-1404 ◽  
Author(s):  
R. R. MacLennan ◽  
E. D. Bailey
Keyword(s):  
Breeding Season ◽  
Seasonal Changes ◽  
Environmental Temperature ◽  
Gonadal Hormones ◽  
Corpora Lutea ◽  
Field Situation ◽  
Body Weights ◽  
Males And Females ◽  
And Storage ◽  
Ranch Mink

Aggression, hunger, and curiosity of ranch mink (Mustela vison) were examined. The animals were divided into socialized animals (those visually isolated at 1 year of age) and unsocialized animals (those visually isolated at 10 weeks of age).Aggression was measured by placing two mink in a special cage and measuring the time until a fight or confrontation occurred. The effects of 0, 24, and 48 hours of food deprivation were measured in summer, fall, and winter. The number of trips made by each mink up a vertical cage to get food was used as an indicator of hunger. Levels of curiosity were determined by measuring the speed and pattern of exploration of a novel open-field situation. The breeding behaviors of experienced and inexperienced male mink were compared.Aggression in mink consisted of at least two offensive threats and, as in other animals, fighting was ritualized to a great extent. All young mink showed some adult aggressive patterns by 20 weeks of age. Aggression in males reached a peak at breeding season (March) and declined throughout the summer and fall, to a low point in November. Socialized males had lower aggressive levels than unsocialized males. Aggression in female mink reached a peak after the breeding season and declined to a low in winter. These cycles were likely caused by gonadal hormones in males and hormones from the corpora lutea in females.Both consumption and storage of food must be considered in determining hunger in mink. Hunger varied inversely with environmental temperature, reaching a peak in the winter and a low point in the summer. Immature animals had lower hunger drives than adult animals. Changes in body weights of mink centered around the breeding season.Curiosity decreased from summer to fall as did aggression. Unsocialized males had higher levels of curiosity than socialized males and females. Immature mink showed incomplete exploratory behavior and had lower curiosity scores than adult animals.

Survival and growth of eastern larch, balsam fir, and black spruce six years after winter browning in northeastern Ontario, Canada

2013 ◽  
Vol 89 (06) ◽  
pp. 777-782 ◽  
Author(s):  
Rongzhou Man ◽  
Gordon J. Kayahara ◽  
Stephen Foley ◽  
Cory Wiseman
Keyword(s):  
Cold Hardiness ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Weather Data ◽  
Larix Laricina ◽  
Stem Analysis ◽  
Growing Seasons ◽  
Survival And Growth ◽  
Needle Loss

In spring 2007, young conifers suffered extensive needle and bud injury near Hearst, Kapuskasing, and Cochrane in northeastern Ontario, Canada. Analysis of weather data revealed that the damage was likely caused by earlier than normal loss of cold hardiness during higher than normal temperatures in late April and early May. The dehardened trees were damaged in the cold days that followed. We report the survival and growth of eastern larch (Larix laricina), balsam fir (Abies balsamea), and black spruce (Picea mariana) in the affected area based on field assessments and stem analysis of affected trees following the event. Total survival through six growing seasons following damage was 98% in eastern larch but only about 70% in balsam fir and black spruce. The effect of the damage on tree growth was greater and longer lasting for diameter than height. Both survival and growth reductions were associated with high levels of mature needle loss and bud damage. Implications of these findings for forest management are discussed in light of expected climate change.

scholarly journals Long-term compositional changes following partial disturbance revealed by the resurvey of logging concession limits in the northern temperate forest of eastern Canada

2016 ◽  
Vol 46 (7) ◽  
pp. 943-949 ◽  
Author(s):  
Victor Danneyrolles ◽  
Dominique Arseneault ◽  
Yves Bergeron
Keyword(s):  
Acer Saccharum ◽  
Temperate Forest ◽  
Land Use Changes ◽  
Abies Balsamea ◽  
Forest Composition ◽  
Betula Alleghaniensis ◽  
Eastern Canada ◽  
Partial Cutting ◽  
Compositional Changes

Land use changes that are linked to European settlement of North America have transformed northeastern temperate forest landscapes. Many studies report a regional increase of young early-successional forests due to high disturbance rates since the preindustrial era (fire, land clearing, and clear-cuts). In this study, we document specific compositional changes to present-day mature forest landscapes, which have only been managed with partial cutting (high-grading and diameter-limit cuts) since the preindustrial era in southwestern Quebec. We resurveyed 108 forest observations that were extracted from logbooks of former logging concession limits (surveyed between 1870 and 1890). Results highlight an increase in mid- to late-successional shade-tolerant taxa (Betula alleghaniensis Britton, Thuja occidentalis L., Acer saccharum Marsh.) at the expense of preindustrial dominant conifers (Abies balsamea (L.) Mill., Pinus strobus L.). Former logging activities and spruce budworm (Choristoneura fumiferana Clemens) outbreaks appear to be the main drivers of these changes, which were also strongly structured across the topographic gradient. To some extent, these results highlight the relevance of partial cutting management, as it has allowed long-term maintenance of a mid- to late-successional forest composition, while also pointing the need for P. strobus restoration. We conclude that by allowing site-specific comparisons, the resurvey of historical observations greatly improve the analytical strengths of historical reconstruction.

Effects of gonadectomy on seasonal changes in plasma LH and prolactin concentrations in male and female starlings (Sturnus vulgaris)

1984 ◽  
Vol 100 (2) ◽  
pp. 213-218 ◽  
Author(s):  
A. Dawson ◽  
A. R. Goldsmith
Keyword(s):  
Seasonal Changes ◽  
Seasonal Pattern ◽  
Maximum Size ◽  
Sturnus Vulgaris ◽  
Prolactin Secretion ◽  
Testis Size ◽  
Gonadal Steroid ◽  
Male And Female ◽  
Males And Females

ABSTRACT Intact and gonadectomized male and female starlings (Sturnus vulgaris) were held in outdoor aviaries for 1 year. Blood samples were taken frequently and assayed for LH and prolactin, and intact males were laparotomized to determine testis size. Changes in testis size in intact males were similar to those in wild starlings with maximum size during April. Hormone levels in intact males and females also followed a similar pattern to those in wild birds although absolute levels were somewhat lower. Levels of LH increased during spring, were highest in early May and then declined rapidly as birds became photorefractory. Prolactin levels did not begin to increase until April, reached a peak in late May and then declined. In gonadectomized males and females, high levels of LH were maintained throughout the early part of the year when birds were photosensitive, but declined rapidly as they became photorefractory. This occurred at the same time as in intact birds. During photorefractoriness, LH levels in gonadectomized birds were similar to those in intact birds. Prolactin showed the same seasonal pattern in gonadectomized birds as that in intact birds. These results demonstrate that gonadal steroid feedback is unimportant in initiating and maintaining photorefractoriness and confirm that increased prolactin secretion coincides with the onset of photorefractoriness. J. Endocr. (1984) 100, 213–218

Gradient analysis of Larix laricina dominated wetlands in Canada's southeastern boreal forest

2001 ◽  
Vol 79 (4) ◽  
pp. 444-456 ◽  
Author(s):  
Martin-Philippe Girardin ◽  
Jacques Tardif ◽  
Yves Bergeron
Keyword(s):  
Boreal Forest ◽  
Abies Balsamea ◽  
Hierarchical Classification ◽  
Canopy Cover ◽  
Larix Laricina ◽  
Betula Papyrifera ◽  
Kalmia Angustifolia ◽  
Fraxinus Nigra ◽  
Hierarchical Classification Analysis ◽  
Substrate Ph

With the objective of understanding how vegetation was structured in four Larix laricina (Du Roi) K. Koch dominated wetlands in north-western Quebec, 186 point-centred quarters were sampled in four stands. For each point, both biotic and abiotic variables were collected and species cover was recorded. Divisive hierarchical classification analysis (Twinspan) identified nine vegetation clusters: i) Larix laricina & Spiraea alba, ii) Larix laricina & Kalmia angustifolia, iii) Larix laricina, Picea mariana & Alnus rugosa, iv) Larix laricina & Betula pumila, v) Thuja occidentalis & Trientalis borealis, vi) Abies balsamea & Betula papyrifera, vii) Fraxinus nigra & Onoclea sensibilis, viii) Alnus rugosa, and ix) Eleocharis smallii. Results of the canonical correspondence analyses indicated that the distribution of these clusters was mainly related to (i) distance from shore, (ii) shade (canopy cover), (iii) substrate nitrate concentration (in relation to the abundance of Kalmia angustifolia and Alnus rugosa), (iv) substrate pH (in relation to the abundance of Sphagnum spp.), and (v) substrate conductivity. Several characteristics of the water table also affected species distribution, including pH, depth, and carbon concentration. Further studies should address the effect of the presence of Kalmia angustifolia and Alnus rugosa on larch growth.Key words: larch, wetland, vegetation analysis, flooding, boreal forest.

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