Claire Alix

Changes in forest productivity across Alaska consistent with biome shift

Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biomes margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biomes southern edge. We evaluated changes in forest productivity since 1982 across boreal Alaska by linking satellite estimates of primary productivity and a large tree-ring data set. Trends in both records show consistent growth increases at the boreal-tundra ecotones that contrast with drought-induced productivity declines throughout interior Alaska. These patterns support the hypothesized effects of an initiating biome shift. Ultimately, tree dispersal rates, habitat availability and the rate of future climate change, and how it changes disturbance regimes, are expected to determine where the boreal biome will undergo a gradual geographic range shift, and where a more rapid decline.

Frozen: The Potential and Pitfalls of Ground-Penetrating Radar for Archaeology in the Alaskan Arctic

Ground-penetrating radar (GPR) offers many advantages for assessing archaeological potential in frozen and partially frozen contexts in high latitude and alpine regions. These settings pose several challenges for GPR, including extreme velocity changes at the interface of frozen and active layers, cryogenic patterns resulting in anomalies that can easily be mistaken for cultural features, and the difficulty in accessing sites and deploying equipment in remote settings. In this study we discuss some of these challenges while highlighting the potential for this method by describing recent successful investigations with GPR in the region. We draw on cases from Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Kobuk Valley National Park, and Gates of the Arctic National Park and Preserve. The sites required small aircraft accessibility with light equipment loads and minimal personnel. The substrates we investigate include coastal saturated active layer over permafrost, interior well-drained active layer over permafrost, a frozen thermo-karst lake, and an alpine ice patch. These examples demonstrate that GPR is effective at mapping semi-subterranean house remains in several contexts, including houses with no surface manifestation. GPR is also shown to be effective at mapping anomalies from the skeletal remains of a late Pleistocene mammoth frozen in ice. The potential for using GPR in ice and snow patch archaeology, an area of increasing interest with global environmental change exposing new material each year, is also demonstrated.

An Early Inupiaq Occupation: Observations on a Thule House From Cape Espenberg, Alaska

Abstract This paper describes and interprets a well-preserved early Thule semi-subterranean dwelling from Cape Espenberg, Alaska. The house architecture is similar in many respects to other early Thule dwellings with a sub-rectangular main room, long sunken entrance tunnel, and associated kitchen area. However, the presence of narrow side benches and associated flooring differences adds significantly to the variability present in Thule house form. Radiocarbon dates indicate occupations spanning 1300 to 1450 cal CE. Wood analysis suggests that the house underwent at least one rebuilding episode, which seems to have extended the house occupation into the early 15th century. People acquired mostly small seals for their subsistence, but supplemented their diets in the spring and fall with migrating birds, fish, terrestrial mammals, and other marine mammals. This house represents a fairly typical early Thule coastal winter occupation, but careful excavation of a well-preserved house reveals interesting details in house form, wood use, and subsistence patterns.

Ethnoarchaeology of Fuel Use in Northern Forests: Towards a Better Characterization of Prehistoric Fire-Related Activities

ABSTRACT Prehistoric fuel management and hearth functions are key research issues that have benefitted from the development of experimental and ethnoarchaeogical approaches aimed at providing interpretative models for archaeological fire and fuel studies. In this paper, we present a selection of ethnographic, ethnoarchaeological and ethnohistorical data mostly collected among Evenks and Athabascans of East Siberia and North America. Our aim is to question and discuss the relationship between fuel and hearth functions from an ethnoarchaeobotanical perspective: what are the criteria for selecting plant fuels? How archaeologically visible can these diverse fuel types be and what do they tell us about past fire-related activities? Our data shows that the contents of combustion structures result from multiple people-environment interactions at different levels, few of which are accessible to the archaeologist. Nevertheless, ethnoarchaeology, by fostering a reflection on taphonomy issues in the broad sense, actively contributes to methodological developments leading to a better understanding of complex technical fire-related processes.