Vegetation characteristics of Snow Goose nest sites

1979 ◽  
Vol 57 (14) ◽  
pp. 1502-1504 ◽  
Author(s):  
M. I. Heagy ◽  
F. Cooke
Keyword(s):  
Discriminant Analysis ◽  
Plant Species ◽  
Stepwise Discriminant Analysis ◽  
Breeding Colony ◽  
Snow Goose ◽  
Nest Sites ◽  
Ecological Requirements ◽  
Nesting Site ◽  
Lesser Snow Goose ◽  
Vegetation Characteristics

The vegetation at a Lesser Snow Goose breeding colony was examined to determine if particular plant species or species associations were characteristic of the nest sites of the geese. A stepwise discriminant analysis revealed that nest sites could be satisfactorily distinguished from the ambient vegetation using 2 of the 29 plant species growing in the quadrats. These two species, lyme grass (Elymus arenarius ssp. mollis) and arctic daisy (Chrysanthemum arcticum ssp. polare) were strongly associated with Snow Goose nest sites.Possible explanations for the association are examined. It is suggested that rather than a cause and effect relationship between plants and nest sites, E. arenarius and C. arcticum have similar ecological requirements to those of the geese for a nesting site.

The influence of nesting habitat on reproductive success of the lesser snow goose

1988 ◽  
Vol 66 (7) ◽  
pp. 1699-1703 ◽  
Author(s):  
Sandra L. Jackson ◽  
David S. Hik ◽  
R. F. Rockwell
Keyword(s):  
Reproductive Success ◽  
Nesting Habitat ◽  
Snow Goose ◽  
Chen Caerulescens ◽  
Vegetation Height ◽  
Nest Sites ◽  
Lesser Snow Goose ◽  
Habitat Effect ◽  
Chen Caerulescens Caerulescens

The quality of nesting habitat and the influence of vegetation height on reproductive success of the lesser snow goose (Chen caerulescens caerulescens) were examined. In 1984, geese nesting in tall willow bushes (Salix ssp.) were more successful than individuals nesting in shorter willows, or in areas with no willows at all. In particular, individuals nesting in tall willows lost fewer eggs to depredation or abandonment, resulting in a greater number of goslings leaving the nest after hatch. The effect of willow height on reproductive success was independent of female age and relative nest initiation date, both of which are known to affect reproductive success. The degree of the habitat effect was not as great in 1986, but the geese nesting in willow bushes did tend to have greater reproductive success. Since spring environmental conditions influence both the availability and quality of nest sites, the potential importance of the effect of nesting habitat on reproductive success probably varies among years.

scholarly journals Improving the knowledge of plant potential biodiversity-ecosystem services links using maps at the regional level in Southern Patagonia

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yamina Micaela Rosas ◽  
Pablo L. Peri ◽  
María Vanessa Lencinas ◽  
Romina Lasagno ◽  
Guillermo J. Martínez Pastur
Keyword(s):  
Ecosystem Services ◽  
Plant Species ◽  
Vegetation Index ◽  
Vascular Plant ◽  
Conservation Strategies ◽  
Cultural Ecosystem Services ◽  
Important Indicator ◽  
Ecological Requirements ◽  
Trade Offs ◽  
Southern Patagonia

Abstract Background Biodiversity supports multiple ecosystem services, whereas species loss endangers the provision of many services and affects ecosystem resilience and resistance capacity. The increase of remote sensing techniques allows to estimate biodiversity and ecosystem services supply at the landscape level in areas with low available data (e.g. Southern Patagonia). This paper evaluates the potential biodiversity and how it links with ecosystem services, based on vascular plant species across eight ecological areas. We also evaluated the habitat plant requirements and their relation with natural gradients. A total of 977 plots were used to develop habitat suitability maps based on an environmental niche factor analysis of 15 more important indicator species for each ecological area (n = 53 species) using 40 explanatory variables. Finally, these maps were combined into a single potential biodiversity map, which was linked with environmental variables and ecosystem services supply. For comparisons, data were extracted and compared through analyses of variance. Results The plant habitat requirements varied greatly among the different ecological areas, and it was possible to define groups according to its specialization and marginality indexes. The potential biodiversity map allowed us to detect coldspots in the western mountains and hotspots in southern and eastern areas. Higher biodiversity was associated to higher temperatures and normalized difference vegetation index, while lower biodiversity was related to elevation and rainfall. Potential biodiversity was closely associated with supporting and provisioning ecosystem services in shrublands and grasslands in the humid steppe, while the lowest values were related to cultural ecosystem services in Nothofagus forests. Conclusions The present study showed that plant species present remarkable differences in spatial distributions and ecological requirements, being a useful proxy for potential biodiversity modelling. Potential biodiversity values change across ecological areas allowing to identify hotspots and coldspots, a useful tool for landscape management and conservation strategies. In addition, links with ecosystem services detect potential synergies and trade-offs, where areas with the lowest potential biodiversity are related to cultural ecosystem services (e.g. aesthetic values) and areas with the greatest potential biodiversity showed threats related to productive activities (e.g. livestock).

scholarly journals Growth of black brant and lesser snow goose goslings in northern alaska

2017 ◽  
Vol 81 (5) ◽  
pp. 846-857 ◽  
Author(s):  
Jerry W. Hupp ◽  
David H. Ward ◽  
Kyle R. Hogrefe ◽  
James S. Sedinger ◽  
Philip D. Martin ◽  
...  
Keyword(s):  
Snow Goose ◽  
Black Brant ◽  
Lesser Snow Goose ◽  
Northern Alaska

scholarly journals Occurrence of Citropsis articulata in Tropical Forests in Uganda: Implication for Ex Situ Conservation

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Rapheal Wangalwa ◽  
Eunice Apio Olet ◽  
Grace Kagoro-Rugunda ◽  
Casim Umba Tolo ◽  
Patrick E. Ogwang ◽  
...  
Keyword(s):  
Plant Species ◽  
National Park ◽  
Ex Situ Conservation ◽  
Habitat Degradation ◽  
Kibale National Park ◽  
Ex Situ ◽  
Forest Reserves ◽  
Ecological Requirements ◽  
Shade Tolerant Species ◽  
Alternative Sources

Citropsis articulata is a medicinal plant that is increasingly threatened by unsustainable methods of harvesting and habitat degradation. Owing to the fact that this plant species is highly utilized for herbal medicine and is currently restricted to a few forest reserves in Uganda, this has significant implications for ex situ conservation. Therefore, the aim of this study was to assess how physiographical factors influence the occurrence and distribution of C. articulata in the three forest reserves in Uganda, namely, Budongo, Mabira, and Kibale National Park. The study was carried out in 15 compartmental sites in each of the three forests. In each compartmental site, 4 plots of 60 m × 60 m were systematically established, and within each plot, 4 subplots each of size 20 m × 20 m were randomly setup. A total of 240 subplots were assessed for occurrence of Citropsis articulata in each forest. The results indicated a significant ( p < 0.05 ) variation in the density of C. articulata with the highest recorded in Kibale National Park. Citropsis articulata generally occurred at moderate altitudinal landscapes (overall elevation = 1200.0 ± 20.73 m) with soils that are moderately acidic (overall pH = 5.7 ± 0.10), low in salinity (overall salinity = 84.0 ± 3.84 mg/l), and moderate levels of macro- and micronutrients. Citropsis articulata was generally associated with plant communities dominated by canopy tree species of genera such as Chryosphyllum, Celtis, Markhamia, Cynometra, Lasiodiscus, Trilepisium, Funtumia, and Diospyros, thus suggesting that C. articulata is a shade-tolerant species. Establishing the ecological requirements of this plant species among other things informs the potential for ex situ production of this plant. This will not only provide alternative sources of plant harvest but also go a long way in relieving the current harvest pressures exerted on the conserved wild populations of this plant species.

scholarly journals BETTER ALTERNATIVES FOR STEPWISE DISCRIMINANT ANALYSIS

2015 ◽  
Vol 1 (311) ◽  
Author(s):  
Katarzyna Stąpor
Keyword(s):  
Feature Selection ◽  
Discriminant Analysis ◽  
Tabu Search ◽  
Stepwise Discriminant Analysis ◽  
Selection Methods ◽  
Discrimination Power ◽  
Statistical Software ◽  
Software Packages ◽  
Benchmark Datasets

Discriminant Analysis can best be defined as a technique which allows the classification of an individual into several dictinctive populations on the basis of a set of measurements. Stepwise discriminant analysis (SDA) is concerned with selecting the most important variables whilst retaining the highest discrimination power possible. The process of selecting a smaller number of variables is often necessary for a variety number of reasons. In the existing statistical software packages SDA is based on the classic feature selection methods. Many problems with such stepwise procedures have been identified. In this work the new method based on the metaheuristic strategy tabu search will be presented together with the experimental results conducted on the selected benchmark datasets. The results are promising.

DNA marker analysis detects multiple maternity and paternity in single broods of the lesser snow goose

Nature ◽  
1987 ◽  
Vol 326 (6111) ◽  
pp. 392-394 ◽  
Author(s):  
Thomas W. Quinn ◽  
James S. Quinn ◽  
Fred Cooke ◽  
Bradley N. White
Keyword(s):  
Dna Marker ◽  
Snow Goose ◽  
Marker Analysis ◽  
Lesser Snow Goose

The Blue Goose and Lesser Snow Goose on Southampton Island, Hudson Bay

The Auk ◽  
1931 ◽  
Vol 48 (3) ◽  
pp. 335-364 ◽  
Author(s):  
George Miksch Sutton
Keyword(s):  
Hudson Bay ◽  
Snow Goose ◽  
Lesser Snow Goose

Long-term vegetation changes in a Snow Goose nesting habitat

1996 ◽  
Vol 74 (5) ◽  
pp. 965-969 ◽  
Author(s):  
Barbara Ganter ◽  
Fred Cooke ◽  
Pierre Mineau
Keyword(s):  
Salt Marsh ◽  
Ground Cover ◽  
Habitat Destruction ◽  
Food Plants ◽  
Nesting Habitat ◽  
Snow Goose ◽  
Brood Rearing ◽  
Nest Sites ◽  
Bare Sediment ◽  
Snow Geese

Vegetation in a small section of nesting habitat in a Lesser Snow Goose colony was mapped in 1976 and again in 1993. During the 17-year period, ground cover changed dramatically from being dominated by salt-marsh graminoids and short grasses to being dominated by willows and areas of bare sediment. Lyme grass, Elymus arenarius, a plant strongly favoured by Snow Geese when selecting their nest sites, which covered 15% of the ground in 1976, had completely disappeared by 1993. Although the area had contained 79 Snow Goose nests in 1976, no nests remained in 1993. Degradation of the nesting habitat is caused by foraging activities of the geese themselves during the prenesting and nesting phase: salt-marsh graminoids and short grasses are removed by grubbing and the sediment is exposed; E. arenarius plants are removed by shoot pulling. Both clutch size and hatching success can be negatively affected by the decline in available food plants, and, presumably as a consequence, the area was abandoned by breeding geese. This habitat destruction and subsequent abandonment of nesting areas by breeding geese is a process similar to that documented for brood-rearing areas of Lesser Snow Geese.

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