Role of brown bears (Ursus arctos) in the flow of marine nitrogen into a terrestrial ecosystem

@article{Hilderbrand1999RoleOB,
  title={Role of brown bears (Ursus arctos) in the flow of marine nitrogen into a terrestrial ecosystem},
  author={Grant V. Hilderbrand and Thomas A. Hanley and Charles T. Robbins and Charles C. Schwartz},
  journal={Oecologia},
  year={1999},
  volume={121},
  pages={546-550}
}
Abstract We quantified the amount, spatial distribution, and importance of salmon (Oncorhynchus spp.)-derived nitrogen (N) by brown bears (Ursus arctos) on the Kenai Peninsula, Alaska. We tested and confirmed the hypothesis that the stable isotope signature (δ15N) of N in foliage of white spruce (Picea glauca) was inversely proportional to the distance from salmon-spawning streams (r=–0.99 and P<0.05 in two separate watersheds). Locations of radio-collared brown bears, relative to their… Expand
Major decline in marine and terrestrial animal consumption by brown bears (Ursus arctos)
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Positive relationships between δ15N and δ13C in fall-grown feathers and fecal samples below the falls but not above the falls are observed, and large positive shifts (as high as... Expand
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Variation in Maize Consumption by Brown Bears (Ursus arctos) in Two Coastal Areas of Hokkaido, Japan
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Terrestrial and marine ecosystems are linked by the annual migration of salmonids. We examined the contribution of anadromous fish to foliar nitrogen (N) in central Idaho riparian forests whereExpand
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The term “keystone species” is used to describe organisms that exert a disproportionately important influence on the ecosystems in which they live. Analogous concepts such as “keystone mutualism” andExpand
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References

SHOWING 1-10 OF 51 REFERENCES
Trophic relations of brown and black bears in several western North American Ecosystems
TLDR
Adult male brown bears were more carnivorous than any other age or sex class within these ecosystems, and long-dead bears can be compared to living bears to evaluate historical changes in ecosystems. Expand
Fertilization of terrestrial vegetation by spawning Pacific salmon : the role of flooding and predator activity
Spawning Pacific salmon (Onchorhynchus) transport marine-derived nutrients into streams and rivers. Subsequently, these marine-derived nutrients are incorporated into freshwater and terrestrial foodExpand
The importance of meat, particularly salmon, to body size, population productivity, and conservation of North American brown bears
TLDR
The proportion of meat in the diet was significantly correlated with mean adult female body mass, mean litter size, and mean population density, and salmon was the most important source of meat for the largest, largest brown bear populations. Expand
USE OF STABLE ISOTOPES TO DETERMINE DIETS OF LIVING AND EXTINCT BEARS
TLDR
The potential use of stable-isotope analyses (δ13C and δ15N) to estimate bear diets was assessed in 40-day feeding trials using American black bears (Ursus americanus) and brown bears of Chichagof and Admiralty islands, Alaska. Expand
FISHES AND THE FOREST
TLDR
E very year, millions upon millions of anadromous fish come from the oceans to spawn in freshwater streams, and these teeming hordes of fish fall prey not only to marine hunters, such as other fish, whales, and sea lions, but also to numerous terrestrial predators and scavengers. Expand
Recycling of elements transported upstream by runs of Pacific Salmon. I: δ15N and δ13C evidence in Sashin Creek, southeastern Alaska
Values of δ15N and δ13C (the per mil deviation from the recognized isotope standard) from biota of a southeastern Alaska stream (Sashin Creek) that receives an annual run of 30 000 anadromous pink ...
Terrestrial plant ecology and 15N natural abundance : The present limits to interpretation for uncultivated systems with original data from a Scottish old field
Publisher Summary This chapter discusses the present limits to interpretation for uncultivated systems with original data from Scottish old fields in reference to terrestrial plant ecology and I5 NExpand
Development of two methods to estimate body composition of bears
TLDR
The measurement of body composition in black bears, brown bears, and polar bears was investigated by means of isotopic water dilution and bioelectrical impedance analysis (BIA), and the basic relationships between body lipid, water, protein, and ash were determined. Expand
THERMODYNAMIC CONSTRAINTS ON NITROGEN TRANSFORMATIONS AND OTHER BIOGEOCHEMICAL PROCESSES AT SOIL-STREAM INTERFACES
There is much interest in biogeochemical processes that occur at the interface between soils and streams since, at the scale of landscapes, these habitats may function as control points for fluxes ofExpand
Stable isotopes in ecology and environmental science
Contributors. Abbreviations. Introduction. 1. Stable isotope chemistry and measurement: a primer. Elizabeth W. Sulzman. Introduction. What isotopes are, what makes them distinct. Properties ofExpand
...
1
2
3
4
5
...