Towards a history of Holocene P dynamics for the Northern Hemisphere using lake sediment geochemical records

2021 ◽  
Author(s):  
Madeleine Moyle ◽  
John Boyle ◽  
Richard Chiverrell
Keyword(s):  
Human Impact ◽  
Lake Sediment ◽  
Northern Hemisphere ◽  
Human Activity ◽  
Lake Water ◽  
Process Model ◽  
P Cycling ◽  
History Of ◽  
P Supply

<p>Present day phosphorus (P) enrichment and accelerated P cycling are changes superimposed on a dynamic Holocene history of landscape recovery from glaciation, changes in climate, and long-term low-intensity human activity. Knowledge of the changing role of human activity in driving long-term P dynamics is essential for understanding landscape P export and managing both terrestrial and aquatic environments.</p><p>Here we apply a simple process model to published lake sediment geochemical P records from 24 sites distributed across the Northern Hemisphere, producing Holocene records of landscape P yield and reconstructions of lake water TP concentrations. These records are a first attempt to produce values for average P export for the Northern Hemisphere over the Holocene, which can be used for constraining long-term landscape P cycling models.</p><p>Individual site trajectories of reconstructed Holocene landscape P yield and lake water TP varied systematically, with differences attributable to landscape development history, in turn driven by climate, human impact and other local factors. Three distinct traits are apparent across the records. Mountain sites with minimal direct human impact show falling Holocene P supply, and conform to conceptual models of natural soil development (Trait 1). Lowland sites  where substantial (pre-)historic agriculture was present show progressively increasing Holocene P supply (Trait 2). Lowland sites may also show a rapid acceleration in P supply over the last few centuries, where high intensity land use, including settlements and farming, are present (Trait 3).</p><p>This long-term perspective is pivotal to understanding drivers of change in coupled terrestrial and aquatic P cycling. Our reconstructions of long-term lake water TP are particularly useful for target-driven management of aquatic systems.</p>

scholarly journals Towards a history of Holocene P dynamics for the Northern Hemisphere using lake sediment geochemical records

2021 ◽  
Vol 18 (20) ◽  
pp. 5609-5638
Author(s):  
Madeleine Moyle ◽  
John F. Boyle ◽  
Richard C. Chiverrell
Keyword(s):  
Lake Sediment ◽  
Northern Hemisphere ◽  
Lake Water ◽  
Landscape Development ◽  
Development History ◽  
P Cycling ◽  
Sediment Records ◽  
History Of ◽  
P Supply

Abstract. Present-day lake water phosphorus (P) enrichment and accelerated P cycling are changes superimposed on a dynamic Holocene history of landscape development following glaciation, changes in climate, and long-term low-intensity human activity. Knowledge of the history of long-term P dynamics is essential for understanding present-day landscape P export and for managing both terrestrial and aquatic environments. This study is the first attempt to constrain the timing and magnitude of terrestrial changes in Holocene P dynamics across the Northern Hemisphere using lake sediment records. Here we reconstruct trajectories in terrestrial Holocene P dynamics for the Northern Hemisphere. We apply a simple process model to published lake sediment geochemical P records from 24 sites, producing records of landscape P yield and reconstructing lake water total phosphorus (TP) concentrations. Individual site trajectories of landscape P yield and lake water TP vary systematically, with differences attributable to local landscape development history. Three distinct traits are apparent. Mountain sites with minimal direct human impact show falling P supply and conform to conceptual models of natural soil development (Trait 1). Lowland sites where substantial (pre-)historic agriculture was present show progressively increasing P supply (Trait 2). Lowland sites may also show a rapid acceleration in P supply over the last few centuries, where high-intensity land use, including settlements and farming, is present (Trait 3). Where data availability permitted comparison, our reconstructed TP records agree well with monitored lake water TP data, and our sediment-inferred P yields are comparable to reported catchment export coefficients. Comparison with diatom-inferred TP reveals good agreement for recent records. Our reconstructions form the first systematic assessment of average terrestrial P export for the Northern Hemisphere over the Holocene and provide the empirical data needed for constraining long-term landscape P cycling models and values for terrestrial P export that could be used for ocean P cycling models. The long-term perspective provided by our sediment-inferred TP can be used to identify pre-disturbance baselines for lake water quality, information essential to target-driven lake management. We find the first detectable anthropogenic impacts on P cycling ca. 6000 BP, with more substantial impacts as early as 3000 BP. Consequently, to characterize pre-disturbance lake P conditions at Trait 2 and Trait 3 sites, it is necessary to consider time periods before the arrival of early farmers. Our use of trait classifications has a predictive power for sites without sediment records, allowing prediction of TP baselines and P trajectories based on regional landscape development history.

scholarly journals Towards a history of Holocene P dynamics for the northern hemisphere using lake sediment geochemical records

2021 ◽  
Author(s):  
Madeleine Moyle ◽  
John Francis Boyle ◽  
Richard Christopher Chiverrell
Keyword(s):  
Lake Sediment ◽  
Northern Hemisphere ◽  
Lake Water ◽  
Landscape Development ◽  
Development History ◽  
P Cycling ◽  
Sediment Records ◽  
History Of ◽  
P Supply

Abstract. Present day lake water phosphorus (P) enrichment and accelerated P cycling are changes superimposed on a dynamic Holocene history of landscape recovery from glaciation, changes in climate, and long-term low-intensity human activity. Knowledge of the history of long-term P dynamics is essential for understanding present-day landscape P export and for managing both terrestrial and aquatic environments. This study is the first attempt to constrain the timing and magnitude of terrestrial changes in Holocene P dynamics across the Northern Hemisphere using lake sediment records. Here we reconstruct trajectories in terrestrial Holocene P dynamics for the Northern Hemisphere. We apply a simple process model to published lake sediment geochemical P records from 24 sites, producing records of landscape P yield and reconstructing lake water total phosphorus (TP) concentrations. Individual site trajectories of landscape P yield and lake water TP vary systematically, with differences attributable to local landscape development history. Three distinct traits are apparent. Mountain sites with minimal direct human impact show falling P supply and conform to conceptual models of natural soil development (Trait 1). Lowland sites where substantial (pre-)historic agriculture was present show progressively increasing P supply (Trait 2). Lowland sites may also show a rapid acceleration in P supply over the last few centuries, where high intensity land use, including settlements and farming, are present (Trait 3). Where data availability permitted comparison, our reconstructed TP records agree well with both monitored lake water TP data and diatom inferred TP, and our sediment inferred P yields are comparable to reported catchment export coefficients. Our reconstructions form the first systematic assessment of average terrestrial P export for the Northern Hemisphere over the Holocene and provide the empirical data needed for constraining long-term landscape P cycling models and values for terrestrial P export that could be used for ocean P cycling models. The long-term perspective provided by our sediment-inferred TP can be used to identify pre-disturbance baselines for lake water quality, information essential to target-driven lake management. We find the first detectable anthropogenic impacts on P cycling ca. 6000 BP, with more substantial impacts as early as 3000 BP. Consequently, to characterise pre-disturbance lake P conditions at Trait 2 and Trait 3 sites it is necessary to consider time periods before the arrival of early farmers. Our use of trait classifications has a predictive power for sites without sediment records, allowing prediction of TP baselines and P trajectories based on regional landscape development history.

scholarly journals Is the Anthropause a useful symbol and metaphor for raising environmental awareness and promoting reform?

2021 ◽  
pp. 1-4
Author(s):  
Nathan Young ◽  
Andrew N Kadykalo ◽  
Christine Beaudoin ◽  
Diana M Hackenburg ◽  
Steven J Cooke
Keyword(s):  
Human Impact ◽  
Human Activity ◽  
Public History ◽  
Research Interest ◽  
The Public ◽  
Cultural Symbol ◽  
History Of ◽  
Ecological Event ◽  
The Impact

Summary Lockdowns associated with the COVID-19 pandemic temporarily restricted human activity and removed people from many places of work and recreation. The resulting ‘Anthropause’ generated much media and research interest and has become an important storyline in the public history of the pandemic. As an ecological event, the Anthropause is fleeting and unlikely to alter the long-term human impact on the planet. But the Anthropause is also a cultural symbol whose effects may be more enduring. Will the Anthropause inspire people and governments to mobilize for meaningful reform, or does it present a misleading and too-comforting portrayal of resilient nature and wildlife that could ultimately discourage action? While it is too early to gauge the impact of the Anthropause on human behaviour and politics, we use existing research on environmental symbols and metaphors to identify factors that may influence long-term behavioural and political responses to this globally significant period of time.

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

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.

scholarly journals History on Mona Island

2015 ◽  
Vol 89 (1-2) ◽  
pp. 30-60 ◽  
Author(s):  
Alice V.M. Samson ◽  
Jago Cooper
Keyword(s):  
Human Activity ◽  
Small Island ◽  
Historical Sources ◽  
Archaeological Evidence ◽  
Historical Landscape ◽  
Regional Dynamics ◽  
Mona Island ◽  
History Of ◽  
The Caribbean

The history of Mona Island and her transitory and permanent communities provides an interesting perspective on the role this small island has played over the long-term in spheres of maritime interaction in the Caribbean and further afield. In particular, we examine the role that the extraordinary cave systems have played in attracting people to the island and into the subterranean realm within. Through a recent study of the extant historical sources and archaeological evidence for past human activity on the island, we trace this historical landscape and seascape in order to review the importance of Mona in wider regional dynamics through time.

scholarly journals Millennial-scale change on a Caribbean reef system that experiences hypoxia

2021 ◽  
Author(s):  
Blanca Figuerola ◽  
Ethan L Grossman ◽  
Noelle Lucey ◽  
Nicole D Leonard ◽  
Aaron O'Dea
Keyword(s):  
Coral Reefs ◽  
Carbon Isotope ◽  
Human Activity ◽  
Water Depth ◽  
Human Impacts ◽  
Reef System ◽  
Caribbean Reef ◽  
History Of ◽  
Shallow Part

Coastal hypoxia has become an increasingly acknowledged threat to coral reefs that is potentially intensifying because of increased input of anthropogenic nutrients. Almirante Bay (Caribbean Panama) is a semi-enclosed system that experiences hypoxia in deeper waters which occasionally expand into shallow coral reefs, suffocating most aerobic benthic life. To explore the long-term history of reefs in the bay we extracted reef matrix cores from two reefs that today experience contrasting patterns of oxygenation. We constructed a 1800-year-long record of gastropod assemblages and isotope compositions from six U-Th chronologically-constrained reef matrix cores. We extracted two cores from each reef at 3 m water depth and two additional cores from a deeper part (4.8 m) of the hypoxia-exposed reef. Results show that the deeper part of the hypoxic reef slowed in growth and stopped accreting approximately 1500 years BP while the shallow part of the reef continued to accrete to the present day, in agreement with a model of expanding hypoxia at this time. Our proxy-based approach suggests that differences among these palaeoindicators in the two reefs may have been driven by an increase in hypoxia via eutrophication caused by either natural changes or human impacts. Similar patterns of increasing herbivores and decreasing carbon isotope values occurred in the shallow part of the hypoxic reef during the last few decades. This suggests that hypoxia may be expanding to depths as shallow as 3 m and that shallow reefs are experiencing greater risk due to increased human activity.

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).

Sign in / Sign up

Export Citation Format

Share Document