Nitrogen and Carbon Soil Dynamics in Response to Climate Change in a High-Elevation Ecosystem in the Rocky Mountains, U.S.A.

1998 ◽  
Vol 30 (1) ◽  
pp. 26 ◽  
Author(s):  
Mark W. Williams ◽  
Paul D. Brooks ◽  
Tim Seastedt
Keyword(s):  
Climate Change ◽  
Rocky Mountains ◽  
High Elevation ◽  
Soil Dynamics

scholarly journals Cold tolerance of mountain stoneflies (Plecoptera: Nemouridae) from the high Rocky Mountains

2020 ◽  
Author(s):  
Scott Hotaling ◽  
Alisha A. Shah ◽  
Michael E. Dillon ◽  
J. Joseph Giersch ◽  
Lusha M. Tronstad ◽  
...  
Keyword(s):  
Climate Change ◽  
Cold Tolerance ◽  
Rocky Mountains ◽  
High Elevation ◽  
Mountain Stream ◽  
Cold Temperatures ◽  
Thermal Limits ◽  
Late Instar ◽  
Stream Biodiversity ◽  
Common Association

ABSTRACTHow aquatic insects cope with cold temperatures is poorly understood. This is particularly true for high-elevation species that often experience a seasonal risk of freezing. In the Rocky Mountains, nemourid stoneflies (Plecoptera: Nemouridae) are a major component of mountain stream biodiversity and are typically found in streams fed by glaciers and snowfields, which due to climate change, are rapidly receding. Predicting the effects of climate change on mountain stoneflies is difficult because their thermal physiology is largely unknown. We investigated cold tolerance of several alpine stoneflies (Lednia tumana, Lednia tetonica, and Zapada spp.) from the Rocky Mountains, USA. We measured the supercooling point (SCP) and tolerance to ice enclosure of late-instar nymphs collected from a range of thermal regimes. SCPs varied among species and populations, with the lowest SCP measured for nymphs from an alpine pond, which is much more likely to freeze solid in winter than flowing streams. We also show that L. tumana cannot survive being enclosed in ice, even for short periods of time (less than three hours) at relatively mild temperatures (−0.5 °C). Our results indicate that high-elevation stoneflies at greater risk of freezing may have correspondingly lower SCPs, and despite their common association with glacial meltwater, they appear to be living near their lower thermal limits.

A 15,000 year record of vegetation and climate change from a treeline lake in the Rocky Mountains, Wyoming, USA

The Holocene ◽  
2011 ◽  
Vol 22 (7) ◽  
pp. 739-748 ◽  
Author(s):  
Scott Mensing ◽  
John Korfmacher ◽  
Thomas Minckley ◽  
Robert Musselman
Keyword(s):  
Climate Change ◽  
Rocky Mountains ◽  
Vegetation Change ◽  
Climatic Variability ◽  
High Elevation ◽  
Sagebrush Steppe ◽  
Climate Projections ◽  
Upward Movement ◽  
Regional Patterns ◽  
Vegetation And Climate

Future climate projections predict warming at high elevations that will impact treeline species, but complex topographic relief in mountains complicates ecologic response, and we have a limited number of long-term studies examining vegetation change related to climate. In this study, pollen and conifer stomata were analyzed from a 2.3 m sediment core extending to 15,330 cal. yr BP recovered from a treeline lake in the Rocky Mountains of Wyoming. Both pollen and stomata record a sequence of vegetation and climate change similar in most respects to other regional studies, with sagebrush steppe and lowered treeline during the Late Pleistocene, rapid upward movement of treeline beginning about 11,500 cal. yr BP, treeline above modern between ~9000 and 6000 cal. yr BP, and then moving downslope ~5000 cal. yr BP, reaching modern limits by ~3000 cal. yr BP. Between 6000 and 5000 cal. yr BP sediments become increasingly organic and sedimentation rates increase. We interpret this as evidence for lower lake levels during an extended dry period with warmer summer temperatures and treeline advance. The complex topography of the Rocky Mountains makes it challenging to identify regional patterns associated with short term climatic variability, but our results contribute to gaining a better understanding of past ecologic responses at high elevation sites.

scholarly journals Late Holocene summer temperatures in the central Andes reconstructed from the sediments of high-elevation Laguna Chepical, Chile (32° S)

2013 ◽  
Vol 9 (3) ◽  
pp. 2277-2308
Author(s):  
R. de Jong ◽  
L. von Gunten ◽  
A. Maldonado ◽  
M. Grosjean
Keyword(s):  
Climate Change ◽  
South America ◽  
Temperature Reconstruction ◽  
High Elevation ◽  
Ice Age ◽  
Central Chile ◽  
Southern South America ◽  
Calibration Period ◽  
The Past ◽  
Insight Into

Abstract. High-resolution reconstructions of climate variability that cover the past millennia are necessary to improve the understanding of natural and anthropogenic climate change across the globe. Although numerous records are available for the mid- and high-latitudes of the Northern Hemisphere, global assessments are still compromised by the scarcity of data from the Southern Hemisphere. This is particularly the case for the tropical and subtropical areas. In addition, high elevation sites in the South American Andes may provide insight into the vertical structure of climate change in the mid-troposphere. This study presents a 3000 yr long austral summer (November to February) temperature reconstruction derived from the 210Pb and 14C dated organic sediments of Laguna Chepical (32°16' S/70°30' W, 3050 m a.s.l.), a high-elevation glacial lake in the subtropical Andes of central Chile. Scanning reflectance spectroscopy in the visible light range provided the spectral index R570/R630, which reflects the clay mineral content in lake sediments. For the calibration period (AD 1901–2006), the R570/R630 data were regressed against monthly meteorological reanalysis data, showing that this proxy was strongly and significantly correlated with mean summer (NDJF) temperatures (R3yr = −0.63, padj = 0.01). This calibration model was used to make a quantitative temperature reconstruction back to 1000 BC. The reconstruction (with a model error RMSEPboot of 0.33 °C) shows that the warmest decades of the past 3000 yr occurred during the calibration period. The 19th century (end of the Little Ice Age (LIA)) was cool. The prominent warmth reconstructed for the 18th century, which was also observed in other records from this area, seems systematic for subtropical and southern South America but remains difficult to explain. Except for this warm period, the LIA was generally characterized by cool summers. Back to AD 1400, the results from this study compare remarkably well to low altitude records from the Chilean Central Valley and Southern South America. However, the reconstruction from Laguna Chepical does not show a warm Medieval Climate Anomaly during the 12–13th century, which is consistent with records from tropical South America. The Chepical record also indicates substantial cooling prior to 800 BC. This coincides with well-known regional as well as global glacier advances which have been attributed to a grand solar minimum. This study thus provides insight into the climatic drivers and temperature patterns in a region for which currently very few data are available. It also shows that since ca AD 1400, long term temperature patterns were generally similar at low and high altitudes in central Chile.

scholarly journals Dendrochronological Assessment of Whitebark Pine Response to Past Climate Change: Implications for a Threatened Species in Grand Teton National Park

2014 ◽  
Vol 37 ◽  
pp. 58-64
Author(s):  
Kendra McLauchlan ◽  
Kyleen Kelly
Keyword(s):  
Climate Change ◽  
National Park ◽  
Fire History ◽  
Multiple Stressors ◽  
Fire Suppression ◽  
Climatic Variability ◽  
High Elevation ◽  
Whitebark Pine ◽  
Grand Teton National Park ◽  
Pine Trees

One of the keystone tree species in subalpine forests of the western United States – whitebark pine (Pinus albicaulis, hereafter whitebark pine) – is experiencing a significant mortality event (Millar et al. 2012). Whitebark pine occupies a relatively restricted range in the high-elevation ecosystems in the northern Rockies and its future is uncertain. The current decline of whitebark pine populations has been attributed to pine beetle infestations, blister rust infections, anthropogenic fire suppression, and climate change (Millar et al. 2012). Despite the knowledge that whitebark pine is severely threatened by multiple stressors, little is known about the historic capacity of this species to handle these stressors. More specifically, it is unknown how whitebark pine has dealt with past climatic variability, particularly variation in the type of precipitation (rain vs. snow) available for soil moisture, and how differences in quantity of precipitation have influenced the establishment and growth of modern stands. We propose to study the past responses of whitebark pine to paleoclimatic conditions, which would be useful to park ecologists in developing new conservation and regeneration plans to prevent the extinction of this already severely threatened high-elevation resource. The purpose of this study is to determine in great temporal and spatial detail the demographics of the current stand of whitebark pine trees in the watershed surrounding an unnamed, high-altitude pond (known informally as Whitebark Pine Moraine Pond) located approximately 3.06 miles NW of Jenny Lake in Grand Teton National Park (GTNP). The main objectives of this study were: 1.) To obtain the precise GPS locations of the current stand of whitebark pine trees in the watershed to generate a GIS map detailing their locations. 2.) To obtain increment cores of a subset of the trees in the watershed to estimate age and date of establishment for the current stand of whitebark pines, with particular attention to fire history. 3.) To analyze ring widths from core samples to identify climatic indicators that may influence the regeneration and survival of whitebark pine.

scholarly journals Post-LGM glacial retreat drives aggradation in the interiors of the Kashmir Himalaya

2021 ◽  
Author(s):  
Saptarshi Dey ◽  
Naveen Chauhan ◽  
Anushka Vashistha ◽  
Vikrant Jain
Keyword(s):  
Climate Change ◽  
Foreland Basin ◽  
High Elevation ◽  
Sediment Supply ◽  
Kashmir Himalaya ◽  
Glacial Retreat ◽  
Valley Fill ◽  
Mean Grain Size ◽  
Exposure Ages ◽  
Semi Arid

Understanding the response of glaciated catchments to climate change is fundamental for assessing sediment transport from the high-elevation, semi-arid to arid sectors in the Himalaya to the foreland basin. The fluvioglacial sediments stored in the semi-arid Padder valley in the Kashmir Himalaya record valley aggradation during ~19-11 ka. We relate the valley aggradation to increased sediment supply from the deglaciated catchment during the glacial-to-interglacial phase transition. Previously-published bedrock-exposure ages in the upper Chenab valley suggest ~180 km retreat of the valley glacier during ~20-15 ka. Increasing roundness of sand-grains and reducing mean grain-size from the bottom to the top of the valley-fill sequence hint about increasing fluvial transport with time and corroborate with the glacial retreat history. Our result also correlates well with late Pleistocene-early Holocene sediment aggradation observed across most Western Himalayan valleys. It highlights the spatiotemporal synchronicity of sediment transfer from the Himalayas triggered by climate change.

scholarly journals Alpine limnology of the Rocky Mountains of Canada and the USA in the context of environmental change

2018 ◽  
Vol 26 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Laura E. Redmond
Keyword(s):  
Climate Change ◽  
Rocky Mountains ◽  
Multiple Stressors ◽  
Ultra Violet ◽  
Future Climate Change ◽  
Monitoring Methods ◽  
Freshwater Biodiversity ◽  
Nutrient Deposition ◽  
Alpine Regions ◽  
The Usa

The cumulative impacts of multiple environmental and anthropogenic stressors on freshwater biodiversity have been studied in systems across the globe. The magnitude of multiple interdependent stressors on alpine systems may lead to increased primary productivity and jeopardize these unique communities. In this review, the consequences of individual stressors on alpine lake and pond ecology are synthesized, as well as the cumulative and potentially synergistic or antagonistic effects of multiple stressors. Beside temperature variability, other stressors reviewed include ultra violet (UV) radiation, organic pollutants, nutrient deposition, and biological invasions. Each stressor was evaluated individually and in combination with increasing water temperatures. In alpine environments, climatic warming is anticipated to increase with elevation, therefore amplifying the effects of temperature-related responses. The purpose of this review is to highlight the ecological effects of climate change on alpine lakes and ponds in the Rocky Mountains of North America and fill knowledge gaps between disciplines of aquatic studies. This work underscores that to better understand and face the overall effects of climate change on alpine biota, investigations must continue to assess the compounded impacts of multiple stressors. Emphasis must be put on the standardization of monitoring methods across alpine regions to aid in consistent trend and prediction analysis within the context of both current and future climate change.

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