A Stratigraphic Record of the Pollen Influx to a Lake in the Big Woods of Minnesota

Waddington, J C

doi:10.1130/spe123-p263

Cited by 78 publications

(63 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In theory, the size class method should reveal this difference better. Some authors have ignored the small particles and counted just the larger ones (Waddington 1969, Mehringer et al 1977, Green 1981. There is, however, no agreement about what is the size limit of a large charcoal particle.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of two methods of counting microscopic charcoal particles in peat

Sarmaja‐Korjonen¹

1991

Bull Geol Soc Finland

View full text Add to dashboard Cite

SARMAJA-KORJONEN, KAARINA, 1991: Comparison of two methods of counting microscopic charcoal particles in peat. Bull. Geol. Soc. Finland 63, Part 1,[41][42][43][44][45][46][47][48] A peat monolith of the topmost 92.5 cm of Slåttmossen, a bog in Helsinki/ Vantaa, S Finland, was analysed for microscopic charcoal with two methods. In the first, the number of charcoal particles was counted, irrespective of their size; in the second, the total area of charcoal was calculated in seven size classes. The peat monolith was also analysed for pollen. The results show that human activity has played an important role in vegetation changes at the site and has also influenced the fire regime, as new land for cultivation was cleared with fire up to the 18th century. The ratio for charcoal and arboreal pollen concentrations was calculated to eliminate the effect of concentration peaks in the more humified peat layers. After these corrections, both methods gave almost identical results; the size class method was not superior in any way. The distribution of larger charcoal particles provided no clear evidence of individual fires nearby.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Davis 1967, Tallis 1975, M. Tolonen 1985. However, since Waddington's (1969) study, most authors have estimated the total charcoal area lam 2 by varying numbers of size classes (e.g. Swain 1973, 1980, Cwynar 1978, M. Tolonen 1978, Amundson & Wright 1979.…”

Section: Introductionmentioning

confidence: 99%

Comparison of two methods of counting microscopic charcoal particles in peat

Sarmaja‐Korjonen¹

1991

Bull Geol Soc Finland

View full text Add to dashboard Cite

show abstract

“…It has often been assumed that large charcoal particles derive from a local source (i.e., within the catchment) while smaller ones are transported longer distances (e.g., Patterson et al, 1987). These assumptions led many charcoal analysts to tediously estimate in a time-consuming manner the charcoal area of particles in pollen slides (e.g., Waddington, 1969;Swain, 1973). However, a recent comparison between particle-area concentration (mm 2 /cm 3 ) and particle-number concentration (no./cm 3 ) for different vegetation types showed that it is unnecessary to measure charcoal areas in standard pollen slides (Tinner and Hu, 2003).…”

Section: Introductionmentioning

confidence: 99%

Minimum count sums for charcoal concentration estimates in pollen slides: accuracy and potential errors

2005

View full text Add to dashboard Cite

Charcoal particles in pollen slides are often abundant, and thus analysts are faced with the problem of setting the minimum counting sum as small as possible in order to save time. We analysed the reliability of charcoal-concentration estimates based on different counting sums, using simulated low-to high-count samples. Bootstrap simulations indicate that the variability of inferred charcoal concentrations increases progressively with decreasing sums. Below 200 items (i.e., the sum of charcoal particles and exotic marker grains), reconstructed fire incidence is either too high or too low. Statistical comparisons show that the means of bootstrap simulations stabilize after 200 counts. Moreover, a count of 200 Á/300 items is sufficient to produce a charcoal-concentration estimate with less than9/5% error if compared with high-count samples of 1000 items for charcoal/marker grain ratios 0.1 Á/0.91. If, however, this ratio is extremely high or low (/0.91 or B/0.1) and if such samples are frequent, we suggest that marker grains are reduced or added prior to new sample processing.

show abstract

“…The southern boreal tree limit moved northward on the plains as the grassland attained its maximum extent since 11 ka BP both northward (Hickman and Klarer, 1981;Hickman et al, 1984;MacDonald, 1989;Hickman and Schweger, 1996) and northeastward (McAndrews, 1966;Janssen, 1968;Waddington, 1969;Dean et al, 1984;Jacobson and Grimm, 1986;Almquist-Jacobson et al, 1992;Hu et al, 1997). Grassland expansion was accompanied by opening of the boreal forest margin in northwestern Ontario to form parkland, at least locally, accompanied by extension of the range of plains bison (Bison bison bison) (McAndrews, 1982).…”

mentioning

confidence: 99%

Late Quaternary Vegetation History of Northern North America Based on Pollen, Macrofossil, and Faunal Remains*

Dyke

2007

gpq

114

118

View full text Add to dashboard Cite

AbstractBiome maps spanning the interval from the last glacial maximum to modern times are presented. The biome distributions at 18 ka BP were probably as nearly in equilibrium with climate as are the modern distributions, but deglacial biomes were probably in disequilibrium. Ice sheet configuration was a strong control of climate until 7 ka BP. Regional climate trends can be inferred from changing biome distributions, but during periods of disequilibrium, biome distributions under-represent summer warming. Because of summer cooling by 2-4 °C during the Holocene, largely in the last 3-5 ka, middle and certain early Holocene biome distributions and species compositions are reasonable analogues of future equilibrium displacements due to equivalent warming, at least in areas that were long-since deglaciated. Past biome migration rates in response to rapid regional warming during deglaciation were mainly in the range of 100-200 m per year. If these rates pertain in the future, biomes may shift 10-20 km in most regions over the next century. A major impediment to using former Holocene conditions as a guide to future conditions is that warmer Holocene summers were accompanied by colder winters, whereas warmer future summers will be accompanied by warmer winters.

show abstract

A Stratigraphic Record of the Pollen Influx to a Lake in the Big Woods of Minnesota

Cited by 78 publications

References 0 publications

Comparison of two methods of counting microscopic charcoal particles in peat

Comparison of two methods of counting microscopic charcoal particles in peat

Minimum count sums for charcoal concentration estimates in pollen slides: accuracy and potential errors

Late Quaternary Vegetation History of Northern North America Based on Pollen, Macrofossil, and Faunal Remains*

Contact Info

Product

Resources

About