Effets de coupes de dimensions restreintes sur l'abondance des populations d'oiseaux nicheurs en milieu boréal

1991 ◽  
Vol 67 (4) ◽  
pp. 397-402
Author(s):  
Patrick Beauchesne ◽  
Pierre Larue ◽  
Louis Bélanger ◽  
Jean Huot
Keyword(s):  
Food Source ◽  
Bird Communities ◽  
Balsam Fir ◽  
Total Abundance ◽  
Forest Stands ◽  
Yellow Birch ◽  
Breeding Bird ◽  
Additional Food ◽  
White Cedar ◽  
Northern White Cedar

The objective of this study was to evaluate the effects of small clearcuts on breeding bird communities found in adjacent forest stands. The study was conducted in a deer yard of the Duchenier Wildlife Preserve located in the boreal balsam fir-yellow birch ecological domain of eastern Quebec. The balsam fir-northern white cedar stands of the deer yard had been treated by strip cutting 2 years before the study. Total abundance of nesting passerines in stands adjacent to 60-m-wide strip cuttings was greater (P = 0.10) than in similar control unlogged stands. The establishment of shrub strata within the strip probably provided an additional food source for shrub- and ground-feeding species without significantly affecting canopy-feeding species.

Hydrology and microtopography effects on northern white-cedar regeneration in Michigan's Upper Peninsula

1996 ◽  
Vol 26 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Rodney A. Chimner ◽  
James B. Hart
Keyword(s):  
Unsaturated Soil ◽  
Growing Season ◽  
Shallow Depth ◽  
Balsam Fir ◽  
Stem Density ◽  
Soil Thickness ◽  
Upper Peninsula ◽  
White Cedar ◽  
Northern White Cedar

Many harvested northern white-cedar (Thujaoccidentalis L.) sites have not regenerated to cedar but have become dominated by other species such as balsam fir (Abiesbalsamea (L.) Mill.) and tag alder (Alnusrugosa (Du Roi) Spreng.) A regenerating cedar fen near Escanaba, Mich., was used to study factors related to regeneration success and failure. Twelve plots (6.1 × 6.1 m) were established on the site to collect data on hydrology, microtopography, stand composition, and stem density. Abundance of cedar regeneration was positively correlated with percentage of hummocks. There were more cedar on microsites with drier conditions (numerous hummocks) while more shrubs and hardwoods were found on the wetter areas (fewer hummocks) of the fen. The shallow depth to groundwater and unsaturated soil thickness early in the growing season are suggested to be factors.

scholarly journals Influence of Soil Site Class on Growth and Decay of Northern White-Cedar and Two Associates in Maine

2009 ◽  
Vol 26 (2) ◽  
pp. 68-75 ◽  
Author(s):  
Philip V. Hofmeyer ◽  
Robert S. Seymour ◽  
Laura S. Kenefic
Keyword(s):  
Light Exposure ◽  
Basal Area ◽  
Site Index ◽  
Red Spruce ◽  
Balsam Fir ◽  
White Cedar ◽  
Basal Area Growth ◽  
Area Growth ◽  
Northern White Cedar ◽  
Mineral Soils

Abstract Basal area growth of outwardly sound northern white-cedar (Thuja occidentalis L.) was compared with that of balsam fir (Abies balsamea [L.] Mill.) and red spruce (Picea rubens Sarg.) across site and light exposure class gradients on 60 sites throughout northern Maine. Once adjusted for sapwood area, northern white-cedar basal area growth was not strongly affected by site or light exposure class; growth was similar to that of red spruce but generally lower than that of balsam fir. Site index did not differ appreciably among soil drainage classes for red spruce and northern white-cedar, although small sample size limited analysis on upland site classes. Incidence of central decay was higher in northern white-cedar than balsam fir, which was higher than red spruce. Incidence of decay in outwardly sound northern white-cedar and balsam fir was highest on well-drained mineral soils, and mean proportion of basal area decayed at breast height increased in outwardly sound northern white-cedar as drainage improved from poorly drained to well-drained soils. These data suggest that northern white-cedar on lowland organic and poorly drained mineral soils in Maine have less decay, similar basal area growth, and similar site index relative to upland northern white-cedar communities.

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

Rare forest types in northeastern Ontario: a classification and analysis of representation in protected areas

2010 ◽  
Vol 40 (3) ◽  
pp. 423-435 ◽  
Author(s):  
Charles R. Drever ◽  
James Snider ◽  
Mark C. Drever
Keyword(s):  
Protected Areas ◽  
Local Population ◽  
Red Oak ◽  
Betula Alleghaniensis ◽  
White Pine ◽  
Yellow Birch ◽  
Eastern White Pine ◽  
Habitat Specificity ◽  
White Cedar ◽  
Eastern White Cedar

Our objective was to assess the relative rarity and representation within protected areas of Standard Forest Units (SFUs) in northeastern Ontario by applying the concepts of geographic range, habitat specificity, and local population size. SFUs are stand type classifications, routinely employed by forest managers, based on tree composition, disturbance history, and prescribed silvicultural system. We identified several SFUs as rare because of a narrow distribution, association with only one landform type, or lack of at least one stand larger than an ecoregion-specific threshold. In the Boreal forest, rare SFUs comprised stands dominated by eastern hemlock ( Tsuga canadensis (L.) Carrière), red oak ( Quercus rubra L.), yellow birch ( Betula alleghaniensis Britt.), or eastern white-cedar ( Thuja occidentalis L.). Rare SFUs also included eastern white pine ( Pinus strobus L.) and (or) red pine ( Pinus resinosa Ait.) leading stands managed by shelterwood or seed tree silviculture as well as low-lying deciduous stands and selection-managed stands of shade-tolerant species. In the Great Lakes – St. Lawrence forest, rare SFUs were yellow birch stands, stands dominated by conifer species abundant in the Boreal, and shelterwood-managed hardwood stands. Several rare SFUs had <12% of their total area in protection, i.e., stands dominated by eastern white pine, yellow birch, eastern white pine – red oak, or eastern white-cedar. These rare stand types require increased protection in reserves and tailored silvicultural practices to maintain their probability of persistence.

THE FUTURE OF BIRCH FROM THE VIEWPOINT OF DISEASES AND INSECTS

1957 ◽  
Vol 33 (1) ◽  
pp. 25-30 ◽  
Author(s):  
D. R. Redmond
Keyword(s):  
Soil Temperature ◽  
High Grade ◽  
Forest Stands ◽  
Yellow Birch ◽  
Virus Diseases ◽  
Maritime Provinces ◽  
Eastern Canada ◽  
Important Species ◽  
Intensive Silviculture ◽  
Bronze Birch Borer

Yellow birch was once the most important species of hardwood in Eastern Canada. During the last 20 to 25 years, "birch dieback" has caused losses in the three Maritime Provinces estimated at 2,400 million cu. ft. A considerable number of species of insects feed normally on birch foliage, but none was found responsible for the disease. The bronze birch borer played a very important role in that its presence may have determined whether a tree succumbed to or recovered from decline. No fungi or bacteria found on twigs, leaves or roots were virulent enough to be considered the cause. No permanent or temporary stoppages were found in water-conducting tissues and occurrence of dieback has not been related to drought. Slight increases in soil temperature caused mortality of rootlets, which resulted in bare twigs, and small, slightly curled and chlorotic foliage. Several symptoms characteristic of virus diseases are being investigated. It is predicted that birch will form a substantial component of future forest stands, but high-grade products will be obtained only through application of intensive silviculture. Some recommended treatments are given.

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