The History of Human Impacts in the Clear Lake Watershed ( California) as Deduced from Lake Sediment Cores*

1999 ◽  
Author(s):  
Douglas Nelson ◽  
Alan Heyvaert ◽  
Laurent Meillier ◽  
Jae Kim ◽  
Xiaoping Li ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Human Impacts ◽  
Sediment Cores ◽  
Clear Lake ◽  
History Of

The History Of Human Impacts In The Clear Lake Watershed (California) As Deduced From Lake Sediment Cores *

2019 ◽  
pp. 119-148 ◽  
Author(s):  
Peter J. Richerson ◽  
Thomas H. Suchanek ◽  
Jesse C. Becker ◽  
Alan C. Heyvaert ◽  
Darell G. Slotton ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Human Impacts ◽  
Sediment Cores ◽  
Clear Lake ◽  
History Of

scholarly journals Postglacial Fire Frequency and its Relation to Long-Term Vegetational and Climatic Changes in Yellowstone Park

1993 ◽  
Vol 17 ◽  
pp. 146-152
Author(s):  
Cathy Whitlock
Keyword(s):  
Lake Sediment ◽  
Sediment Cores ◽  
Natural Disturbance ◽  
Plant Macrofossils ◽  
Fire Frequency ◽  
Environmental Perturbations ◽  
Human Perturbation ◽  
Long Term Effect ◽  
History Of

The Paleoecologic recod provides unique insights into the response of communities to environmental perturbations of different duration and intensity. Climate is a primary agent of environmental change and its long-term effect on the vegetation of the Yellowstone/Grand Teton region is revealed in a network of pollen records (Whitlock, 1993). Fire frequency is controlled by climate, and as climate changes so too does the importance of fire in shaping spatial patterns of vegetation. The prehistoric record of Yellowstone's Northern Range, for example, shows the response of vegetation to the absence of major fires in the last 150 years (Whitlock et al., 1991; Engstrom et al., 1991). In longer records spanning the last 14,000 years, periods of frequent fire are suggested by sediments containing high percentages of fire-adapted trees, including lodgepole pine and Douglas-fir, and high amounts of charcoal (Bamosky et al., 1987; Millspaugh and Whitlock, 1993; Whitlock, 1993). The primary research objective has been to study the vegetational history of Yellowstone and its sensitivity to hanges in climate and fire frequency. This information is necessary to understand better the relative effects of climate, natural disturbance, and human perturbation on the Yellowstone landscape. Fossil pollen and plant macrofossils from dated-lake sediment cores provide information on past vegetation and climate. The frequency of charcoal particles and other fire indicators in dated lake-sediment cores offer evidence of past fires.

Multi-stage Holocene evolution of the River Murray Estuary, South Australia

The Holocene ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 50-65
Author(s):  
Thomas Job ◽  
Dan Penny ◽  
Bree Morgan ◽  
Quan Hua ◽  
Patricia Gadd ◽  
...  
Keyword(s):  
Sea Level ◽  
Human Impacts ◽  
Sediment Cores ◽  
South Australia ◽  
Estuarine System ◽  
Central Basin ◽  
Base Level ◽  
Multi Stage ◽  
History Of ◽  
Anthropogenic Modifications

The River Murray Estuary, South Australia exhibits a morphology typical of a wave-dominated estuary and comprises two large, shallow central basin lakes – Lakes Alexandrina and Albert. Contested interpretations of the estuary’s limnological history and uncertainty surrounding the sustainability of current basin water usage practice warrant a robust investigation into how the system has evolved. Here we combine lithostratigraphic, geochemical and sedimentological evidence from a transect of sediment cores to reconstruct the sediment infill history of the system. We uncover multiple stages of sediment infill over the history of the system, associated with (1) the low gradient morphology of the estuary and lower river channel, (2) the mid- to late-Holocene sea-level regression and (3) anthropogenic modifications to the fluvio-estuarine system. We show that while estuarine conditions in the system were fully established during the mid-Holocene highstand (~6.4 kyr BP), central basin facies sedimentation was focussed further inland before prograding with the lowering of base level and shifting of tidal influence as sea-level fell. Central basin facies sedimentation within northern Lake Albert occurred from 5.4 to 4.0 cal kyr BP at ~0.25 cm yr-1. The uppermost accumulation of this unit was eroded by continued reduction in base level until sea-level regression concluded at 3.5 cal kyr BP. Barrage and weir installation (1940 CE) re-initiated and expanded central basin facies sedimentation in the estuary (~0.32 cm yr-1). Recently deposited sediments exhibit geochemical markers of increased trophy and more frequent acid sulfate soil acidification, exposing human impacts on the estuary.

scholarly journals Postglacial Fire Frequency and its Relation to Long-Term Vegetational and Climatic Changes in Yellowstone Park

1994 ◽  
Vol 18 ◽  
pp. 160-165
Author(s):  
Cathy Whitlock
Keyword(s):  
Carbon Dioxide ◽  
Time Scales ◽  
Lake Sediment ◽  
Sediment Cores ◽  
Fire Frequency ◽  
Response Surfaces ◽  
Potential Range ◽  
Final Report ◽  
History Of

The paleoecologic record provides unique insights into the response of communities to environmental perturbations of different duration and intensity. Climate is a primary agent of environmental change and its long-term effect on the vegetation of the Yellowstone/Grand Teton region is revealed in a network of pollen records. Fire frequency is controlled by climate, and as climate changes so too does the importance of fire in shaping spatial patterns of vegetation. The prehistoric record of Yellowstone's Northern Range, for example, shows the response of vegetation to the absence of major fires in the last 150 years (Whitlock et al., 1991; Engstrom et al., 1991, 1994). In longer records spanning the last 14,000 years, periods of frequent fire are suggested by sediments containing high percentages of fire-adapted trees, including lodgepole pine and Douglas-fir, and high amounts of charcoal (Whitlock, 1993; Whitlock and Bartlein, 1993; Whitlock et al., 1995; Millspaugh and Whitlock, 1995). The primary research objective has been to study the vegetational history of the Yellowstone region and examine the sensitivity of vegetation to changes in climate and fire frequency on different time scales. This information is necessary to understand better the relative effects of climate, natural disturbance, and human perturbation in the present and future. Fossil pollen and plant macrofossils from dated-lake sediment cores provide information on past vegetation and climate. The frequency of charcoal particles and other fire indicators in dated lake-sediment cores offer evidence of past fires. Studies of future climate and vegetation in the Yellowstone region were based on climate simulations produced by general circulation models that incorporate a doubling of carbon dioxide and an equilibrium model to project potential range displacement of selected tree taxa. Relations between present distributions of tree taxa and climate were established by the use of response surfaces. The study has been divided into three parts: (1) an investigation of the vegetation history of Yellowstone National Park (YNP), (2) an analysis of charcoal accumulation in lakes following the 1988 fires and a reconstruction of fire history in central YNP on long time scales, and (3) a study of the potential ranges of tree taxa in the future with global increases in atmospheric carbon dioxide. A final report to the UW-NPS Research Center describes the methodology and findings in detail (Whitlock et al., 1994).

scholarly journals Holocene polynya dynamics and their interaction with oceanic heat transport in northernmost Baffin Bay

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rebecca Jackson ◽  
Anna Bang Kvorning ◽  
Audrey Limoges ◽  
Eleanor Georgiadis ◽  
Steffen M. Olsen ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Active Role ◽  
Atlantic Water ◽  
The Arctic ◽  
Negative Consequences ◽  
Baffin Bay ◽  
The North ◽  
North Water ◽  
History Of ◽  
Ocean Conditions

AbstractBaffin Bay hosts the largest and most productive of the Arctic polynyas: the North Water (NOW). Despite its significance and active role in water mass formation, the history of the NOW beyond the observational era remains poorly known. We reconcile the previously unassessed relationship between long-term NOW dynamics and ocean conditions by applying a multiproxy approach to two marine sediment cores from the region that, together, span the Holocene. Declining influence of Atlantic Water in the NOW is coeval with regional records that indicate the inception of a strong and recurrent polynya from ~ 4400 yrs BP, in line with Neoglacial cooling. During warmer Holocene intervals such as the Roman Warm Period, a weaker NOW is evident, and its reduced capacity to influence bottom ocean conditions facilitated northward penetration of Atlantic Water. Future warming in the Arctic may have negative consequences for this vital biological oasis, with the potential knock-on effect of warm water penetration further north and intensified melt of the marine-terminating glaciers that flank the coast of northwest Greenland.

James C. Knox (1977) Human impacts on Wisconsin stream channels. Annals of the Association of American Geographers 67: 224–244.

2013 ◽  
Vol 37 (3) ◽  
pp. 422-431 ◽  
Author(s):  
William L. Graf
Keyword(s):  
Mississippi River ◽  
Human Impacts ◽  
Professional Community ◽  
River System ◽  
Stream Channels ◽  
Early 19Th Century ◽  
Driftless Area ◽  
University Of Wisconsin ◽  
History Of ◽  
Floodplain Deposits

James C. Knox’s 1977 paper “Human Impacts on Wisconsin Stream Channels,” published in the Annals of the Association of American Geographers, was a key component of a suite of three papers by him defining the response of rivers to the introduction and management of agriculture and to climate change. In this paper he used the Driftless Area of southwest Wisconsin as a laboratory where he could define fluvial responses by their sedimentary signatures in floodplain deposits. Land-use records dating back to the early 19th century along with shorter climate records provided his understanding of the drivers of change. He found that floods increased as an outcome of land-cover change. Upstream tributaries became wider and shallower as coarse deposits limited their adjustments, while main stem channels became narrower and deeper. His paper reflected the influence of his graduate advisor and especially of prominent faculty colleagues at the University of Wisconsin from fields ranging from soils and climatology to geomorphology and history. The paper was the subject of considerable debate in the professional community, but it remains a much-cited example of Knox’s work in unraveling the Quaternary and Holocene history of rivers of the Driftless Area and by extension the upper Mississippi River system.

Using a lake sediment record to infer the long-term history of cyanobacteria and the recent rise of an anatoxin producing Dolichospermum sp.

Harmful Algae ◽  
2021 ◽  
Vol 101 ◽  
pp. 101971
Author(s):  
William O. Hobbs ◽  
Theo W. Dreher ◽  
Edward W. Davis ◽  
Rolf D. Vinebrooke ◽  
Siana Wong ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Sediment Record ◽  
History Of

Straw Boats and the Proverbial Sea: A Response to ‘Island Archaeology: In Search of a New Horizon’

2007 ◽  
Vol 2 (2) ◽  
pp. 229-238
Author(s):  
Scott M. Fitzpatrick ◽  
Jon M. Erlandson ◽  
Atholl Anderson ◽  
Patrick V. Kirch
Keyword(s):  
Historical Ecology ◽  
Human Impacts ◽  
Coastal Zones ◽  
Comparative Framework ◽  
The World ◽  
History Of ◽  
Island Archaeology ◽  
Cultural Developments

In a recent ISJ paper, “Island Archaeology: In Search of a New Horizon”, Boomert and Bright (2007) argue that the field of “island archaeology” should be replaced by an “archaeology of maritime identity”. We disagree and counter that although islands share many physical, biological, and cultural similarities with continental coasts, coastal zones also grade uninterruptedly into riverine, lacustrine, and terrestrial landscapes, raising questions about the validity of their concept of the archaeology of maritime identity. In our view, island archaeology (the application of archaeology to island settings), regardless of past biogeographical underpinnings, has made major contributions to understanding the historical ecology, human impacts, and cultural developments of islands around the world. A focus on islands by archaeologists has encouraged scholars to study the history of island and maritime societies within a comparative framework that is useful for breaking out of the often provincial focus on a single island or archipelago.

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