Forage variation in brood-rearing areas used by pacific black brant geese on the Yukon-Kuskokwim delta, Alaska
-
-
Authors: B. T. Person, C. A. Babcock, and R. W. Ruess
Date: 1998
Journal: Journal of Ecology
Volume: 86
Number: 2
Pages: 243-259
Summary of Methods: The effect of grazing by black brant geese (Branta bernicla nigricans) on Carex subspathacea lawns was investigated on the Yukon-Kuskokwim delta, Alaska for two years. Six grazing treatments (grazed for 21 days, 42 days; no grazing for 21 days, 42 days; grazed for 21 days followed by no grazing for 21 days, no grazing for 21 days followed by 21 days of grazing) were tested using 10 replicated exclosures across 4 landscapes (Tutakoke, Lower Kashunuk, Onumtuk Bend and Emperor Bend). During the second year of the study the sites of Kokechick West and Kolomak River were added along with two additional grazing treatments (grazed for 54 days, and no grazing for 40 days followed by 14 of grazing). Standing biomass, nitrogen content, stem density, apparent take off, standing crop nitrogen (SCN) and carbon to nitrogen ratio (C:N) of Carex were measured.
Article Summary / Main Points: At landscape level there was no effect of grazing on net above-ground primary productivity (NAPP) over the different levels of grazing intensity. There was no difference between the two colonies with respect to the response of C. subspathacea growth rates, NAPP, or forage quality in response to grazing pressures. Nitrogen concentrations, availability of forage per sampled area, and quality of vegetation had greater spatial variation than seasonal variation. Goose grazing apparently does not have deleterious effects on the C. subspathacea ecosystem.
Vegetation Types: Riparian and Wetlands
MLRA Ecoregions: Not Applicable
Agrovoc Control Words: Riparian zones Grazing Wildlife
Article Review Type: Refereed
Article Type: Experimental Research
Keywords: graminoids, grazing lawns, plant-animal interactions, salt marsh, subarctic
Annotation: This is a replicated study over two years and is applicable to coastal salt marsh areas in Alaska influenced by geese grazing intensity. The results suggest that long-term grazing by geese does not have deleterious effects in the subarctic salt marsh ecosystems. The present study can be used as an approach for long-term grazing management studies, since both spatial and temporal changes were examined. Additionally, Person et al. (2003, Oecologia 135:583-592) studied grazing effects by Black Brant geese on plant communities and gosling growth in southwestern Alaska, also availalable on the RSIS website.
-
Get article
Cite article with DOI
-