Lawn Lake, a high montane hunting camp in the Colorado (USA) rocky mountains: Insights into early Holocene Late Paleoindian hunter-gatherer adaptations and paleo-landscapes

2020 ◽  
Vol 42 (1) ◽  
pp. 5-44
Author(s):  
Robert H Brunswig ◽  
James P Doerner
Keyword(s):  
High Altitude ◽  
Rocky Mountain ◽  
Subalpine Forest ◽  
Forest Zone ◽  
Lake Outlet ◽  
Plant Processing ◽  
Sediment Data ◽  
Late Paleoindian ◽  
Camp Levels

The Lawn Lake site is a stratified hunting camp situated on a glacial lake outlet river terrace in Rocky Mountain National Park’s upper subalpine forest zone. Its archaeological assemblage represents 9,000 years of hunter-gatherer use as a summer game and plant processing camp for subalpine forest and nearby alpine tundra resource areas. This article’s focus is on the site’s earliest camp levels which contain artifacts and AMS radiocarbon dated hearth charcoal between 8,900 and 7,900 cal yr BP, placing them among the region’s earliest high montane (3,353 m ASL) Paleoindian hunting camps, once part of a network of such sites designed to support systematic high altitude procurement of summer migratory game animals and plant foods in Southern Rocky Mountain subalpine forest and tundra ecosystems. Lawn Lake paleoclimate and paleoecology studies produced long-term pollen records and climate-proxy sediment data for modeling the site’s prehistoric climate and ecology history, useful for interpreting its high-altitude Late Paleoindian hunter-gatherer adaptations.

scholarly journals Low-Altitude Boundary of Abies faxoniana Is More Susceptible to Long-Term Open-Top Chamber Warming in the Eastern Tibetan Plateau

2021 ◽  
Vol 12 ◽  
Author(s):  
Haifeng Song ◽  
Qingquan Han ◽  
Sheng Zhang
Keyword(s):  
High Altitude ◽  
Global Climate ◽  
Subalpine Forest ◽  
Nutrient Concentrations ◽  
Open Top Chamber ◽  
Soil P ◽  
Abies Faxoniana ◽  
Low Altitude ◽  
Different Altitudes

With global climate change, for evaluating warming effect on subalpine forest distribution, the substantial effects of long-term warming on tree growth and soil nutrients need to be explored. In this study, we focused on different responses in the boundaries of trees and soils to warming. Using the open-top chamber (OTC), a 10-year artificial warming experiment was conducted to evaluate the impacts of warming on Abies faxoniana at three different altitudes. We determined metabolites and nutrient concentrations in needles of A. faxoniana and characterized the soil chemistries. Many kinds of sugars, amino acids, and organic acids showed higher contents at high altitude (3,500 m) compared with low altitude (2,600 m), which could have been due to the temperature differences. Warming significantly decreased needle sugar and amino acid concentrations at high altitude but increased them at low altitude. These results indicated contrasting physiological and metabolic responses of A. faxoniana to long-term warming at different altitudes. Furthermore, we found that OTC warming significantly increased the concentrations of soil extractable sodium, aluminum (Al), and manganese (Mn), while decreased potassium (K) and phosphorus (P) concentrations and pH values at low altitude rather than at middle (3,000 m) or high altitude. The soil carbon and nitrogen contents were increased only at the middle altitude. In A. faxoniana at low altitudes, more mineral nutrients iron, K, and P were demand, and a mass of Al, Mn, and zinc was accumulated under warming. Soil P limitation and heavy metals accumulation are disadvantageous for trees at low altitudes with warming. Therefore, compared with high altitudes, A. faxoniana growing at low boundary in alpine regions is expected to be more susceptible to warming.

scholarly journals Simultaneous generalized and low-layer SCIDAR turbulence profiles at san pedro mártir observatory

2019 ◽  
Vol 490 (1) ◽  
pp. 1397-1405 ◽  
Author(s):  
R Avila ◽  
O Valdés-Hernández ◽  
L J Sánchez ◽  
I Cruz-González ◽  
J L Avilés ◽  
...  
Keyword(s):  
High Altitude ◽  
Wind Direction ◽  
Close Agreement ◽  
Baja California ◽  
Ground Level ◽  
Combined Effect ◽  
Moderate Altitude ◽  
San Pedro ◽  
Simultaneous Measurements

ABSTRACT We present optical turbulence profiles obtained with a Generalized SCIDAR (G-SCIDAR) and a low-layer SCIDAR (LOLAS) at the Observatorio Astronómico Nacional in San Pedro Mártir (OAN-SPM), Baja California, Mexico, during three observing campaigns in 2013, 2014, and 2015. The G-SCIDAR delivers profiles with moderate altitude-resolution (a few hundred metres) along the entire turbulent section of the atmosphere, while the LOLAS gives high altitude resolution (on the order of tens of metres) but only within the first few hundred metres. Simultaneous measurements were obtained on 2014 and allowed us to characterize in detail the combined effect of the local orography and wind direction on the turbulence distribution close to the ground. At the beginning of several nights, the LOLAS profiles show that turbulence peaks between 25 and 50 m above the ground, not at ground level as was expected. The G-SCIDAR profiles exhibit a peak within the first kilometre. In 55 per cent and 36 per cent of the nights stable layers are detected between 10 and 15 km and at 3 km, respectively. This distribution is consistent with the results obtained with a G-SCIDAR in 1997 and 2000 observing campaigns. Statistics computed with the 7891 profiles that have been measured at the OAN-SPM with a G-SCIDAR in 1997, 2000, 2014, and 2015 campaigns are presented. The seeing values calculated with each of those profiles have a median of 0.79, first and third quartiles of 0.51 and 1.08 arcsec, which are in close agreement with other long term seeing monitoring performed at the OAN-SPM.

Long-Term Sequelae of Rocky Mountain Spotted Fever

1995 ◽  
Vol 20 (5) ◽  
pp. 1122-1125 ◽  
Author(s):  
L. K. Archibald ◽  
D. J. Sexton
Keyword(s):  
Spotted Fever ◽  
Rocky Mountain ◽  
Rocky Mountain Spotted Fever

scholarly journals Thin Air Resulting in High Pressure: Mountain Sickness and Hypoxia-Induced Pulmonary Hypertension

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Jan Grimminger ◽  
Manuel Richter ◽  
Khodr Tello ◽  
Natascha Sommer ◽  
Henning Gall ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
High Altitude ◽  
Hypobaric Hypoxia ◽  
Current Knowledge ◽  
Treatment Options ◽  
Acute Response ◽  
Mechanisms Of Adaptation ◽  
Mountain Sickness

With rising altitude the partial pressure of oxygen falls. This phenomenon leads to hypobaric hypoxia at high altitude. Since more than 140 million people permanently live at heights above 2500 m and more than 35 million travel to these heights each year, understanding the mechanisms resulting in acute or chronic maladaptation of the human body to these circumstances is crucial. This review summarizes current knowledge of the body’s acute response to these circumstances, possible complications and their treatment, and health care issues resulting from long-term exposure to high altitude. It furthermore describes the characteristic mechanisms of adaptation to life in hypobaric hypoxia expressed by the three major ethnic groups permanently dwelling at high altitude. We additionally summarize current knowledge regarding possible treatment options for hypoxia-induced pulmonary hypertension by reviewing in vitro, rodent, and human studies in this area of research.

Adaptations to High-Altitude Hypoxia

2021 ◽  
Author(s):  
Cynthia M. Beall ◽  
Kingman P. Strohl
Keyword(s):  
High Altitude ◽  
Oxygen Delivery ◽  
Hemoglobin Concentration ◽  
Barometric Pressure ◽  
Ambient Air ◽  
Extreme Environment ◽  
Indigenous Populations ◽  
East African ◽  
Short Term

Biological anthropologists aim to explain the hows and whys of human biological variation using the concepts of evolution and adaptation. High-altitude environments provide informative natural laboratories with the unique stress of hypobaric hypoxia, which is less than usual oxygen in the ambient air arising from lower barometric pressure. Indigenous populations have adapted biologically to their extreme environment with acclimatization, developmental adaptation, and genetic adaptation. People have used the East African and Tibetan Plateaus above 3,000 m for at least 30,000 years and the Andean Plateau for at least 12,000 years. Ancient DNA shows evidence that the ancestors of modern highlanders have used all three high-altitude areas for at least 3,000 years. It is necessary to examine the differences in biological processes involved in oxygen exchange, transport, and use among these populations. Such an approach compares oxygen delivery traits reported for East African Amhara, Tibetans, and Andean highlanders with one another and with short-term visitors and long-term upward migrants in the early or later stages of acclimatization to hypoxia. Tibetan and Andean highlanders provide most of the data and differ quantitatively in biological characteristics. The best supported difference is the unelevated hemoglobin concentration of Tibetans and Amhara compared with Andean highlanders as well as short- and long-term upward migrants. Moreover, among Tibetans, several features of oxygen transfer and oxygen delivery resemble those of short-term acclimatization, while several features of Andean highlanders resemble the long-term responses. Genes and molecules of the oxygen homeostasis pathways contribute to some of the differences.

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