Reconstruction of a high-resolution late holocene arctic paleoclimate record from Colville River delta sediments.

Schreiner, K. M.; Lowry, Thomas Stephen

doi:10.2172/1096495

Cited by 1 publication

(2 citation statements)

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“…Multiple lines of evidence, when combined, show that substantial changes have occurred in tundra riparian ecosystems. The outset of the 20th century would have witnessed riparian ecosystems with much later snowmelt and peak discharge dates, shorter summers, and correspondingly shorter, less extensive riparian shrubs (Schreiner & Lowry, ). Those smaller shrub patches would not have hosted snowshoe hares, moose, and possibly other species whose former absence (or presence) may have been overlooked.…”

Section: Discussionmentioning

confidence: 99%

“…Moose and snowshoe hare distributions in the Arctic reach the coast in only a few locations (Telfer, ; MacDonald & Cook, ), probably due to longer winters and correspondingly shorter shrubs coastward (Walker, ; Bhatt et al ., ). These climatic constraints on habitat and distribution appear to have loosened, though; for example, the northward establishment of moose c. 1940 along riparian corridors in the Alaskan Arctic (LeResche et al ., ; Coady, ) may be the result of longer growing seasons and the resulting taller and more extensive floodplain shrubs after 1880 (onset of warming; Kaufman et al ., ; Schreiner & Lowry, ). Snowshoe hares, whose North American distribution is very similar to that of moose (Boer, ), were also previously undocumented on the North Slope and rare in the Brooks Range (Rausch, ; MacDonald & Cook, ).…”

Section: Introductionmentioning

confidence: 99%

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Novel wildlife in theArctic: the influence of changing riparian ecosystems and shrub habitat expansion on snowshoe hares

Tape

Christie

Carroll

et al. 2015

Global Change Biology

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Warming during the 20th century has changed the arctic landscape, including aspects of the hydrology, vegetation, permafrost, and glaciers, but effects on wildlife have been difficult to detect. The primary aim of this study is to examine the physical and biological processes contributing to the expanded riparian habitat and range of snowshoe hares (Lepus americanus) in northern Alaska. We explore linkages between components of the riparian ecosystem in Arctic Alaska since the 1960s, including seasonality of stream flow, air temperature, floodplain shrub habitat, and snowshoe hare distributions. Our analyses show that the peak discharge during spring snowmelt has occurred on average 3.4 days per decade earlier over the last 30 years and has contributed to a longer growing season in floodplain ecosystems. We use empirical correlations between cumulative summer warmth and riparian shrub height to reconstruct annual changes in shrub height from the 1960s to the present. The effects of longer and warmer growing seasons are estimated to have stimulated a 78% increase in the height of riparian shrubs. Earlier spring discharge and the estimated increase in riparian shrub height are consistent with observed riparian shrub expansion in the region. Our browsing measurements show that snowshoe hares require a mean riparian shrub height of at least 1.24-1.36 m, a threshold which our hindcasting indicates was met between 1964 and 1989. This generally coincides with observational evidence we present suggesting that snowshoe hares became established in 1977 or 1978. Warming and expanded shrub habitat is the most plausible reason for recent snowshoe hare establishment in Arctic Alaska. The establishment of snowshoe hares and other shrub herbivores in the Arctic in response to increasing shrub habitat is a contrasting terrestrial counterpart to the decline in marine mammals reliant on decreasing sea ice.

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Section: Discussionmentioning

confidence: 99%