Stratigraphy and genesis of the Lake Sixteen peatland, northern Michigan

1986 ◽  
Vol 64 (12) ◽  
pp. 3008-3019 ◽  
Author(s):  
Richard P. Futyma ◽  
Norton G. Miller
Keyword(s):  
Basal Layer ◽  
Developmental History ◽  
Peat Accumulation ◽  
Hydrological Changes ◽  
Alkaline Lake ◽  
Temporal Relationships ◽  
History Of ◽  
Northern Michigan

The Lake Sixteen peatland is a 400-ha mire consisting principally of low-shrub (Chamaedaphne) bog and lesser areas of tree-covered (Picea – Larix) bog and sedge fen adjacent to a 55-ha alkaline lake. The sediments consist of the following superimposed deposits: gyttja, sedge peat, and Sphagnum–ericad–sedge peat. Near the edges of the peatland, highly humified, sometimes woody peat is present as the basal layer instead of gyttja. Radiocarbon-dated pollen stratigraphies from the lake and four sites in the peatland have elucidated the temporal relationships of the various sediment units and the developmental history of the peatland. During the mid-Holocene, probably in response to a change to cooler, moister climate, early Lake Sixteen underwent an expansion resulting in the deposition of gyttja over an increasingly larger area. About 3000 years BP, a sedge fen developed on the edge of the lake. Low-shrub bog replaced the sedge vegetation as the fen mat expanded into the lake. Swamping of bordering forests also allowed expansion of bog vegetation outward from the basin. Hydrological changes accompanying peat accumulation probably promoted vegetational changes within the peatland and the centrifugal spread of bog vegetation through swamping.

The developmental history of peatlands at Muskiki and Marguerite lakes, Alberta

1989 ◽  
Vol 67 (12) ◽  
pp. 3534-3544 ◽  
Author(s):  
Helen Kubiw ◽  
Michael Hickman ◽  
Dale F. Vitt
Keyword(s):  
Species Composition ◽  
Radiocarbon Dating ◽  
Environmental Changes ◽  
Warm Period ◽  
Vegetation Changes ◽  
Developmental History ◽  
Peat Accumulation ◽  
Fire Activity ◽  
History Of ◽  
Peat Stratigraphy

The peat stratigraphy of fens at Muskiki Lake (52°50′N, 116°51′W) and Marguerite Lake (54°38′N, 110°43′W) in central Alberta was examined to determine the developmental history of the fens on the basis of radiocarbon dating and bryophyte macrofossil analyses. Peat accumulation at Muskiki Lake peatland began about 9000 years BP via lake filling. Expansion of the peatland by paludification and vegetation changes, including string and flark formation, are secondary occurrences, the latter occurring subsequent to environmental changes, including mid-Holocene thermal events. Peat inception at Marguerite Lake began about 2400 years BP via paludification. This delay, relative to Muskiki Lake peatland, may be related to the mid-Holocene warm period. Fire activity and increased wetness, as well as autogenic successional processes, altered species composition and abundance.

The role of climate on the developmental history of Frontenac Peatland, southern Quebec

2000 ◽  
Vol 78 (5) ◽  
pp. 668-684 ◽  
Author(s):  
Martin Lavoie ◽  
Pierre JH Richard
Keyword(s):  
Lake Level ◽  
Elevated Temperatures ◽  
Accumulation Rate ◽  
Critical Factor ◽  
Accumulation Rates ◽  
Developmental History ◽  
Peat Accumulation ◽  
Lake Water Level ◽  
History Of

The developmental stages, hydrological conditions, and net peat accumulation rates at three coring sites of Parc de Frontenac Peatland (Quebec) were reconstructed to examine the role of climate on peat accumulation. During the early to mid-Holocene, elevated temperatures proved to be a more critical factor for sustained peat production than precipitation, because peatland development occurred mostly under a dry climate according to a low lake-level stage lasting from 11 000 to 7000 calibrated (cal.) BP in a nearby lake. Between 7000 and 6000 cal. BP, elevated net peat accumulation rates roughly correspond with a rise in lake water level, suggesting that higher precipitation and (or) less evapotranspiration then favored peat growth. A decrease in peat accumulation occurred from 5000 to 2500-1500 cal. BP, while the lake level was high from 4400 cal. BP. An important increase in net peat accumulation rate is recorded for this entire peatland from 1500 cal. BP. Lack of close timing between lake level changes and changes in peat accumulation rates or surface hydrology suggest that temperature and autogenic processes were often more important than regional water balance in the developmental history of the peatland.Key words: peatlands, paleohydrology, pollen, plant macrofossils, rhizopods, Quebec.

Greater Right Hemisphericity is Associated with Lower Self-Esteem in Adults

1991 ◽  
Vol 73 (3_suppl) ◽  
pp. 1244-1246 ◽  
Author(s):  
M. A. Persinger ◽  
Katherine Makarec
Keyword(s):  
Negative Affect ◽  
Sense Of Self ◽  
Self Esteem ◽  
The Self ◽  
Self Concept ◽  
Developmental History ◽  
Men And Women ◽  
History Of

28 men and 32 women were given Vingiano's Hemisphericity Questionnaire and the Coopersmith Self-esteem Inventory. People who reported the greatest numbers of right hemispheric indicators displayed the lowest self-esteem; the correlations were moderately strong ( r>.50) for both men and women. These results support the hypothesis that the sense of self is primarily a linguistic, left-hemispheric phenomenon and that a developmental history of frequent intrusion from right-hemispheric processes can infuse the self-concept with negative affect.

Group Psychotherapy in Private Practice

1970 ◽  
Vol 4 (1) ◽  
pp. 43-48 ◽  
Author(s):  
George L. Christie
Keyword(s):  
Clinical Practice ◽  
Group Psychotherapy ◽  
Patient Selection ◽  
Private Practice ◽  
Group Leader ◽  
Developmental History ◽  
Individual Form ◽  
Organization And Management ◽  
History Of ◽  
The Individual

Some tentative conclusions about the organization and management of relatively closed psychotherapeutic groups are illustrated by examples culled from private clinical practice. After reviewing the rationale of group psychotherapy and its advantages over the individual form, the paper deals mainly with patient selection, the developmental history of the group and group leader technique.

Response of Diatoms and Other Siliceous Indicators to the Developmental History of a Peatland in the Tiksi Forest, Siberia, Russia

2000 ◽  
Vol 32 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Kathleen Rühland ◽  
John P. Smol ◽  
J. P. Paul Jasinski ◽  
Barry G. Warner
Keyword(s):  
Developmental History ◽  
History Of

scholarly journals Some aspects of the history and population ecology of the tsessebe damaliscus lunatus lunatus in the Kruger National Park

Koedoe ◽  
1977 ◽  
Vol 20 (1) ◽  
Author(s):  
S.C.J. Joubert ◽  
P.J.L. Bronkhorst
Keyword(s):  
Sex Ratio ◽  
Population Ecology ◽  
Age Structure ◽  
National Park ◽  
Kruger National Park ◽  
Population Trends ◽  
Social Organisation ◽  
Developmental History ◽  
The Social ◽  
History Of

The population trends and distribution of the tsessebe population of the Kruger National Park are evaluated in terms of the available data derived from records compiled in the developmental history of the Kruger National Park (KNP). The recent numerical status of the population is also given. A description of the habitats favoured by tsessebe in the KNP is presented as well as an analysis of the age structure and sex-ratio of the population. Aspects of the social organisation of tsessebe affecting the interpretation of the age structure and sex-ratio phenomena of the population, are also discussed.

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