scholarly journals Geese and grazing lawns: responses of the grass Festuca rubra to defoliation in a subarctic coastal marsh

2006 ◽  
Vol 84 (11) ◽  
pp. 1732-1739 ◽  
Author(s):  
P. C. O ◽  
P. M. Kotanen ◽  
K. F. Abraham
Keyword(s):  
Coastal Marsh ◽  
Hudson Bay ◽  
Festuca Rubra ◽  
Canada Geese ◽  
James Bay ◽  
Morphological Response ◽  
Chen Caerulescens ◽  
Growing Seasons ◽  
Chen Caerulescens Caerulescens ◽  
Akimiski Island

In coastal marshes on James Bay and southern Hudson Bay, Canada, the grass Festuca rubra L. is heavily used for forage by both Snow (Chen caerulescens caerulescens (Linnaeus)) and Canada Geese ( Branta canadensis (Linnaeus)). On Akimiski Island, James Bay, this grass occurs in a mosaic of short, heavily grazed patches and tall, lightly grazed patches. We investigated whether short plants are primarily a plastic morphological response to grazing by geese. Over two growing seasons, we measured growth of short patches protected from grazing and of tall patches subjected to mowing treatments, with unmanipulated short and tall controls. Protection resulted in rapid conversion from a short growth form to a tall form, similar in height and biomass to plants in tall control plots. Mowed tall plants also rapidly recovered to near tall control values for height and biomass. A single 3 week treatment episode often permitted nearly full recovery to tall form. In some cases, more sustained protection was required, but repeated mowing ultimately may have reduced growth rates. These results indicate that the morphology of individual plants of Festuca rubra plastically recovers from changes in defoliation pressure. Consequently, short patches likely represent grazing lawns maintained by intensive foraging by geese.

Egg size as a predictor of nutrient composition of eggs and neonates of Canada Geese (Branta canadensis interior) and Lesser Snow Geese (Chen caerulescens caerulescens)

2002 ◽  
Vol 80 (2) ◽  
pp. 333-341 ◽  
Author(s):  
Shannon S Badzinski ◽  
C Davison Ankney ◽  
James O Leafloor ◽  
Kenneth F Abraham
Keyword(s):  
Egg Size ◽  
Nutrient Composition ◽  
Canada Geese ◽  
Chen Caerulescens ◽  
Organ Mass ◽  
Snow Geese ◽  
Lesser Snow Geese ◽  
Branta Canadensis Interior ◽  
Chen Caerulescens Caerulescens ◽  
Goose Eggs

Fresh and pipped eggs were collected to provide data on nutrient composition of eggs and neonates, respectively, of Canada Geese (Branta canadensis interior) and Lesser Snow Geese (Chen caerulescens caerulescens). We sought to determine how well a commonly used and simple index like estimated egg volume or "egg size" predicted egg composition and neonate characteristics including body composition, structural size, and digestive-organ mass. For both species, egg constituents were positively correlated with egg size, but relations for Canada Geese consistently had higher coefficients of determination than did those for Lesser Snow Geese. These differences suggest that there is more among-female variation in nutrient composition of Lesser Snow goose eggs relative to Canada Goose eggs. Most neonatal nutrient constituents were positively correlated with egg size in both species, but the relations between nutrient constituents and egg size were consistently stronger in Lesser Snow Geese than in Canada Geese. Several measures of structural size of neonates were positively correlated with egg size in both species, but egg size was a better predictor of neonate size for Lesser Snow Geese than for Canada Geese. Egg size was a relatively poor predictor of digestive-organ mass for both species. We hypothesize that the stronger relations between neonate quality and egg size in Lesser Snow Geese are a reflection of greater stabilizing selection for embryonic metabolic rates in species that nest at high latitudes and have a short incubation period. The fact that nutrient constituents of eggs were more strongly related to egg size than were the analogous constituents of neonates suggests that variation in metabolic rates of embryos limits the utility of egg size as an accurate and precise predictor of nutrient constituents in the two study species, but especially in Canada Geese.

Responses of arctic sedges to release from grazing: leaf demography of Carex × flavicans

1989 ◽  
Vol 67 (5) ◽  
pp. 1408-1413 ◽  
Author(s):  
P. M. Kotanen ◽  
R. L. Jefferies
Keyword(s):  
Growing Season ◽  
Hudson Bay ◽  
Snow Goose ◽  
Chen Caerulescens ◽  
Leaf Demography ◽  
Lesser Snow Goose ◽  
Chen Caerulescens Caerulescens ◽  
Demographic Techniques

The responses to herbivory of shoots of the sedge, Carex × flavicans, were investigated at La Pérouse Bay on the Hudson Bay coast in northern Manitoba. Demographic techniques were used to compare the production and turnover of leaves between plants of swards on which adults and goslings of the Lesser Snow Goose (Chen caerulescens caerulescens (L.)) fed and plants of swards from which geese were excluded. Within a growing season, release from grazing resulted in decreased production and turnover, and increased lifespans of leaves. The data indicate that plants of this species have the ability to modify patterns of leaf demography in response to the absence or presence of foraging by geese.

Vegetation patterns in James Bay coastal marshes. II. Effects of hydrology on salinity and vegetation

1988 ◽  
Vol 66 (12) ◽  
pp. 2586-2594 ◽  
Author(s):  
Jonathan S. Price ◽  
Kern Ewing ◽  
Ming-ko Woo ◽  
Kenneth A. Kershaw
Keyword(s):  
Salt Marshes ◽  
Saline Water ◽  
Coastal Marsh ◽  
Hudson Bay ◽  
James Bay ◽  
Stream Channels ◽  
Surface Salinity ◽  
Rooting Zone ◽  
Hydrologic Gradients ◽  
Freshwater Budget

The vegetation of a coastal marsh in southern James Bay was examined in reference to the salinity and hydrological processes. Regional hydrologic influences related to the freshwater budget of James Bay reduce the local salinity so that the vegetation typifies that of a fresh to brackish marsh system, in contrast to the Hudson Bay salt marshes reported in the literature. Thus species that thrive in areas of higher salinity have only limited occurrence at the study site. Infrequent tidal inundation of low salinity bay water diminishes surface salinity, which is primarily controlled by the interaction of marsh hydrology with fossil salt diffusing upward from postglacial deposits. The soil water salinity increases with depth and distance inland. However, local hydrologic gradients near raised beach ridges and incised stream channels affect surface runoff and groundwater recharge and discharge, producing further distinct spatial variations in salinity. These processes thus control the distribution of saline water in the rooting zone and hence the patterns of vegetation.

Morphological and isozyme variation in Salicornia europaea (s.l.) (Chenopodiaceae) in northeastern North America

1987 ◽  
Vol 65 (7) ◽  
pp. 1410-1419 ◽  
Author(s):  
S. L. Wolff ◽  
R. L. Jefferies
Keyword(s):  
North America ◽  
Atlantic Coast ◽  
Hudson Bay ◽  
Salicornia Europaea ◽  
Electrophoretic Variation ◽  
James Bay ◽  
Northeastern North America ◽  
Electrophoretic Patterns ◽  
Anther Length ◽  
Vegetative Characters

Morphological and electrophoretic variation has been documented within and among populations of Salicornia europaea L. (s.l.) in northeastern North America. Univariate and multivariate analyses (discriminant analyses) of measurements of floral and vegetative characters delimited three morphologically distinct groups of populations: Atlantic coast tetraploids (2n = 36), Hudson Bay diploids, and Atlantic coast and James Bay diploids (2n = 18). The two diploid groups were morphologically distinct from the midwestern diploid, S. rubra Nels., based on anther length, width of the scarious border of the fertile segment, and the overall width of the fertile segment. Electrophoretic evidence supported the delimitation of the three distinct morphological groups of populations of S. europaea with the exception of the population from James Bay, which had electrophoretic patterns identical with those of plants from Hudson Bay but resembled the Atlantic coast diploids morphologically. Most enzyme systems assayed were monomorphic. Only homozygous banding patterns were detected in diploid plants and electrophoretic variation was not observed within populations of S. europaea or S. rubra but was detected between groups of populations. Four multilocus phenotypes were evident; these corresponded to the major groups recognized on the basis of ploidy level and morphology. Reasons that may account for the paucity of isozymic variation are discussed.

scholarly journals Distribution and use of brood-rearing and moulting sites of the Atlantic population of Canada Geese (Branta canadensis) in Nunavik, Quebec

2015 ◽  
Vol 129 (3) ◽  
pp. 229
Author(s):  
Richard C. Cotter
Keyword(s):  
Branta Canadensis ◽  
Hudson Bay ◽  
Canada Geese ◽  
Nesting Ecology ◽  
Brood Rearing ◽  
Atlantic Population ◽  
The Mean ◽  
Shallow Bay ◽  
Over Time ◽  
Coastal Lowlands

The Atlantic population of Canada Geese (Branta canadensis) nests in the coastal lowlands of eastern Hudson Bay and southwestern Ungava Bay in Nunavik, Quebec. Although many aspects of the nesting ecology of this and other northern populations of Canada Geese have been studied and published, there is a paucity of information on the use of brood-rearing and moulting sites. Based on 18 years of band and recapture data from an ongoing banding program, this paper presents the distribution of brood-rearing and moulting sites and the use of these sites over time. Along Hudson Bay and Ungava Bay, the most important brood-rearing and moulting areas are the stretch of coastal lowlands between the Mariet River and Shallow Bay and between Rivière aux Feuilles and Virgin Lake, respectively. Of all adult geese captured during the banding program (n = 41 924), 7.5% (standard error [SE] 0.13%) were recaptures, that is, birds that had previously been caught and banded; annual recapture rates ranged from 5.1% to 11.4%. The mean and median distances between the site of first recapture and the original site of capture were 4.3 km (SE 0.22 km) and 1.5 km, respectively. Juveniles moved, on average, 5.4 km farther than adults and males moved 1.4 km farther than females. Among geese banded as juveniles, males moved twice as far as females: 11.5 km versus 5.7 km.

Vegetation patterns in James Bay coastal marshes. III. Salinity and elevation as factors influencing plant zonations

1989 ◽  
Vol 67 (10) ◽  
pp. 2967-2974 ◽  
Author(s):  
J. C. Earle ◽  
K. A. Kershaw
Keyword(s):  
Salt Marsh ◽  
Salinity Gradient ◽  
Detrended Correspondence Analysis ◽  
Distribution Patterns ◽  
Environmental Data ◽  
Plant Distribution ◽  
Coastal Marsh ◽  
James Bay ◽  
Factors Influencing ◽  
Community Types

Plant zonations and selected environmental variables were studied in a subarctic coastal marsh at Ekwan Point, James Bay, Ont. Eight distinct community types were identified using two-way indicator species analysis classification (TWINSPAN). These were interpreted as a primary successional sequence. The eight communities were found to conform closely to the classical marsh zonations based on elevation and tidal influence: (1) lower salt marsh, (2) middle salt marsh, (3) upper salt marsh, (4) saline meadow, (5) freshwater meadow, and (6) freshwater fen. Environmental data collected along the vegetation transects indicated that changes in elevation and soil-water salinity probably influence species distributions. A species ordination using detrended correspondence analysis (DECORANA) revealed several trends in plant distribution patterns. Consideration of the environmental affinities of species separated along three ordination axes suggested that salinity and elevation, water content, and soil texture were probably important factors influencing successional processes in the marsh during at least the last century. An inverse salinity gradient, which has been reported at many sites along the west coast of Hudson and James bays, was not found at Ekwan Point.

BIOLOGICAL AND OCEANOGRAPHIC CONDITIONS IN HUDSON BAY: 6. THE GENERAL HYDROGRAPHY AND HYDRODYNAMICS OF THE WATERS OF THE HUDSON BAY REGION

1932 ◽  
Vol 7 (1) ◽  
pp. 91-118 ◽  
Author(s):  
H. B. HACHEY
Keyword(s):  
Fresh Water ◽  
Water Movement ◽  
Open Ocean ◽  
Hudson Bay ◽  
Water Drainage ◽  
James Bay ◽  
Bay Area ◽  
Hydrographic Conditions ◽  
The Many ◽  
Oceanographic Conditions

The waters of Hudson bay differ markedly from the waters of Hudson strait and the waters of the open ocean. Intense stratification in the upper twenty-five metres, decreasing as the waters of the open ocean are approached, gives Hudson bay the character of a large estuary. Below fifty metres the waters are for all purposes dynamically dead, thus resulting in a cold saline body of water which probably undergoes very little change from season to season. The movements of the waters at various levels are dealt with to show that the inflow of waters from Fox channel and the many fresh-water drainage areas control the hydrographic conditions as found. The main water movement is from the James bay area to Hudson strait and thence to the open ocean.

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