Absolute pollen frequencies and carbon-14 age of a section of Holocene Lake sediment from the Riding Mountain area of Manitoba

1969 ◽  
Vol 47 (9) ◽  
pp. 1345-1349 ◽  
Author(s):  
J. C. Ritchie
Keyword(s):  
Boreal Forest ◽  
Lake Sediment ◽  
Present Form ◽  
Accumulation Rates ◽  
Mountain Area ◽  
Carbon 14 ◽  
Pollen Accumulation Rates ◽  
Grassland Type ◽  
Aspen Parkland ◽  
Frequency Diagram

A section of Holocene lake sediment in the Southern Boreal Forest of Manitoba was re-sampled, and the sedimentation rate (0.039 cm per annum) calculated from eight carbon-14 age determinations. Pollen accumulation rates were computed, and an absolute pollen frequency diagram constructed. It suggests modifications of an earlier reconstruction of vegetation, based on relative pollen frequencies. A spruce-dominated assemblage occurred from about 11 500 to 10 000 B.P., when there was a change to a treeless vegetation of a grassland type. This persisted until about 2500 B.P., with the possible interpolation of an aspen parkland phase from 6500 to 2500 B.P. The boreal forest in its present form (dominated by spruce, birch, and aspen, with local occurrences of pine, fir, larch, and oak) returned at 2500 B.P., presumably in response to a deterioration in climate (cooler and (or) wetter).

CONTRIBUTIONS TO THE HOLOCENE PALEOECOLOGY OF WESTCENTRAL CANADA: I. THE RIDING MOUNTAIN AREA

1964 ◽  
Vol 42 (2) ◽  
pp. 181-196 ◽  
Author(s):  
J. C. Ritchie
Keyword(s):  
Boreal Forest ◽  
Lake Sediment ◽  
Pollen Analysis ◽  
Deciduous Forests ◽  
Pollen Spectrum ◽  
Spruce Forest ◽  
Mountain Area ◽  
The Holocene ◽  
Carbon 14 ◽  
Spruce Wood

The results of pollen analysis of three sections of lake sediment, sampled in the Riding Mountain area of Manitoba, suggest a tentative division of each into four zones. The lower, interpreted as representing a closed white spruce forest, is followed by an apparently treeless episode tentatively interpreted as a grassland phase; this is followed by a zone which suggests indirectly the prevalence of deciduous forests, possibly dominated by poplar, birch, and oak. The development of the mixed boreal forest, which prevails today, is marked by a rise in the spruce and alder curves. The suggestion that the sections are post-Valders in age is corroborated to some extent by a carbon-14 age measurement of 9570 years from a sample of spruce wood excavated from the bottom of a filled-in kettle in the vicinity; associated gyttja yielded a pollen spectrum very similar to the I zones of the diagrams.

Modern pollen accumulation rates at the north-western fringe of the European boreal forest

2008 ◽  
Vol 151 (3-4) ◽  
pp. 90-109 ◽  
Author(s):  
Martina Hättestrand ◽  
Christin Jensen ◽  
Margrét Hallsdóttir ◽  
Karl-Dag Vorren
Keyword(s):  
Boreal Forest ◽  
Accumulation Rates ◽  
The North ◽  
Pollen Accumulation Rates ◽  
Modern Pollen ◽  
North Western

scholarly journals Linking modern pollen accumulation rates to biomass: Quantitative vegetation reconstruction in the western Klamath Mountains, NW California, USA

The Holocene ◽  
2021 ◽  
pp. 095968362098803
Author(s):  
Clarke A Knight ◽  
Mark Baskaran ◽  
M Jane Bunting ◽  
Marie Champagne ◽  
Matthew D Potts ◽  
...  
Keyword(s):  
Mean Squared Error ◽  
Plant Biomass ◽  
Source Area ◽  
Pollen Deposition ◽  
Accumulation Rates ◽  
Klamath Mountains ◽  
Plant Abundance ◽  
Circular Area ◽  
Value Analysis ◽  
Pollen Accumulation Rates

Quantitative reconstructions of vegetation abundance from sediment-derived pollen systems provide unique insights into past ecological conditions. Recently, the use of pollen accumulation rates (PAR, grains cm−2 year−1) has shown promise as a bioproxy for plant abundance. However, successfully reconstructing region-specific vegetation dynamics using PAR requires that accurate assessments of pollen deposition processes be quantitatively linked to spatially-explicit measures of plant abundance. Our study addressed these methodological challenges. Modern PAR and vegetation data were obtained from seven lakes in the western Klamath Mountains, California. To determine how to best calibrate our PAR-biomass model, we first calculated the spatial area of vegetation where vegetation composition and patterning is recorded by changes in the pollen signal using two metrics. These metrics were an assemblage-level relevant source area of pollen (aRSAP) derived from extended R-value analysis ( sensu Sugita, 1993) and a taxon-specific relevant source area of pollen (tRSAP) derived from PAR regression ( sensu Jackson, 1990). To the best of our knowledge, aRSAP and tRSAP have not been directly compared. We found that the tRSAP estimated a smaller area for some taxa (e.g. a circular area with a 225 m radius for Pinus) than the aRSAP (a circular area with a 625 m radius). We fit linear models to relate PAR values from modern lake sediments with empirical, distance-weighted estimates of aboveground live biomass (AGLdw) for both the aRSAP and tRSAP distances. In both cases, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus, and TCT (Taxodiaceae, Cupressaceae, and Taxaceae families) – were statistically significant and reasonably precise estimators of contemporary AGLdw. However, predictions weighted by the distance defined by aRSAP tended to be more precise. The relative root-mean squared error for the aRSAP biomass estimates was 9% compared to 12% for tRSAP. Our results demonstrate that calibrated PAR-biomass relationships provide a robust method to infer changes in past plant biomass.

scholarly journals Tracking Open Versus Closed‐Canopy Boreal Forest Using the Geochemistry of Lake Sediment Deposits

2019 ◽  
Vol 124 (5) ◽  
pp. 1278-1289
Author(s):  
C. Bastianelli ◽  
A. A. Ali ◽  
Y. Bergeron ◽  
C. Hély ◽  
D. Paré
Keyword(s):  
Boreal Forest ◽  
Lake Sediment ◽  
Sediment Deposits ◽  
Closed Canopy ◽  
Open Versus

Seasonal dynamics of the bat stomach worm, Longibucca lasiura (Nematoda: Rhabditoidea), in Alberta

1994 ◽  
Vol 72 (5) ◽  
pp. 791-794 ◽  
Author(s):  
Lena N. Measures
Keyword(s):  
Boreal Forest ◽  
Sample Size ◽  
Seasonal Dynamics ◽  
Eptesicus Fuscus ◽  
Myotis Lucifugus ◽  
Lasiurus Cinereus ◽  
Mean Intensity ◽  
Ecological Zones ◽  
Aspen Parkland ◽  
Lasionycteris Noctivagans

One hundred and sixty-nine bats belonging to 6 different species and collected from 4 ecological zones (aspen parkland, boreal forest, grassland, and montane) in Alberta, Canada, during 1988 and 1989 were examined for helminths. Forty bats were infected with the stomach nematode Longibucca lasiura McIntosh and Chitwood, 1934. Sample size, prevalence, and mean intensity (with range in parentheses) of L. lasiura for the 6 species of bat were as follows: Myotis lucifugus, N = 130, 27%, 39 (1–121); Myotis ciliolabrum, N = 10, 10%, 1; Eptesicus fuscus, N = 6, 33%, 12 (2–22); Lasionycteris noctivagans, N = 2, 100%, 22 (5–39). Myotis evotis (N = 9) and Lasiurus cinereus (N = 3) were not infected. Longibucca lasiura was found in bats from all ecological zones except the boreal forest. This parasite was found in bats active during summer (June to August) and in hibernating M. lucifugus collected in September and April.

scholarly journals Signals of tree volume and temperature in a high-resolution record of pollen accumulation rates in northern Finland

2012 ◽  
Vol 27 (6) ◽  
pp. 564-574 ◽  
Author(s):  
F. Mazier ◽  
A. B. Nielsen ◽  
A. Broström ◽  
S. Sugita ◽  
S. Hicks
Keyword(s):  
High Resolution ◽  
Accumulation Rates ◽  
Pollen Accumulation Rates

Reconstructing the Rate of Accumulation of Lake Sediment: The Effect of Sediment Focusing

1975 ◽  
Vol 5 (4) ◽  
pp. 541-550 ◽  
Author(s):  
John T. Lehman
Keyword(s):  
Temporal Variation ◽  
Lake Sediment ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Maximum Depth ◽  
Accumulation Rates ◽  
Sediment Focusing ◽  
Regional History ◽  
Rate Of Accumulation

Use of accumulation rates of pollen or minerals to infer regional history is complicated by nonuniform deposition of lake sediment. Sediment focusing, direction of sediment to the deepest part of a basin, can introduce a discrepancy between changes in accumulation rates measured directly from sediment cores and actual changes in influx of sediment or pollen to a lake. This difference depends on values and temporal variation of the ratio of mean depth to maximum depth in a basin as it fills. Several models of sediment accumulation show how measurements from a single core can be transformed to yield basinwide influx rates, and how the distortion due to sediment focusing can be assessed. Basins shaped like hyperboloids or frustums may introduce much greater distortions than basins conforming to ellipsoid or sinusoid shapes.

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