Origin of a postglacial kettle-fill sequence near Georgetown, Ontario

1991 ◽  
Vol 28 (12) ◽  
pp. 1965-1974 ◽  
Author(s):  
Barry G. Warner ◽  
Helen J. Kubiw ◽  
Paul F. Karrow

Stratigraphic relationships, radiocarbon dating, and pollen and plant macrofossil analyses establish the origin and developmental history of a kettle near Georgetown, Ontario. The early inorganic sediments contain redeposited fossils, particularly from local vegetation. Fossils in peat younger than 10 000 BP largely represent past wetland plant communities in the basin. Although the fossil record probably began about 1300 years after deglaciation of the site, an additional 1700 years passed before the dead ice block melted; only then did sedimentation and biological activity stabilize in the basin and produce an accurate fossil record of past vegetation. Truncated fossil records, illustrated further here by a pollen diagram from nearby Heart Lake, should be expected from kettle-hole deposits, and the radiocarbon ages and fossils from the earliest parts of such sequences should be interpreted with caution.

2019 ◽  
Vol 11 (6) ◽  
pp. 1559 ◽  
Author(s):  
Xiaojun Zheng ◽  
Jing Fu ◽  
Noelikanto Ramamonjisoa ◽  
Weihong Zhu ◽  
Chunguang He ◽  
...  

Understanding what controls wetland vegetation community composition is vital to conservation and biodiversity management. This study investigates the factors that affect wetland plant communities and distribution in the Tumen River Basin, Northeast China, an internationally important wetland for biodiversity conservation. We recorded floristic composition of herbaceous plants, soil properties, and microclimatic variables in 177, 1 × 1 m2 quadrats at 45 sites, located upstream (26), midstream (12), and downstream (7) of the Basin. We used TWINSPAN to define vegetation communities and canonical correspondence analysis (CCA) to examine the relationships between environmental and biological factors within the wetland plant communities. We recorded 100 plant species from 93 genera and 40 families in the upstream, 100 plant species from 57 genera and 31 families in the midstream, and 85 plant species from 76 genera and 38 families in the downstream. Higher species richness was recorded upstream of the River Basin. The plant communities and distribution were influenced by elevation, soil properties (total potassium, pH, and available phosphorus), and microclimate variables (surface temperature, precipitation, average temperature, sunshine hours, and relative humidity). More than any other factor, according to our results, elevation strongly influenced the structure of wetland plant communities. These findings support prevailing models describing the distribution of wetland plants along environmental gradients. The determination of the relationship between soil and plants is a useful way to better understand the ecosystem condition and can help manage the wetland ecosystem.


2016 ◽  
Vol 25 (8) ◽  
pp. 1569-1585 ◽  
Author(s):  
David C. Deane ◽  
Damien A. Fordham ◽  
Fangliang He ◽  
Corey J. A. Bradshaw

1989 ◽  
Vol 67 (12) ◽  
pp. 3534-3544 ◽  
Author(s):  
Helen Kubiw ◽  
Michael Hickman ◽  
Dale F. Vitt

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.


2019 ◽  
Vol 104 ◽  
pp. 704-710 ◽  
Author(s):  
Hui Fu ◽  
Guixiang Yuan ◽  
Erik Jeppesen ◽  
Dabing Ge ◽  
Dongsheng Zou ◽  
...  

Wetlands ◽  
1996 ◽  
Vol 16 (2) ◽  
pp. 208-218 ◽  
Author(s):  
Evan Weiher ◽  
Irene C. Wisheu ◽  
Paul A. Keddy ◽  
Dwayne R. J. Moore

Oikos ◽  
1995 ◽  
Vol 73 (3) ◽  
pp. 323 ◽  
Author(s):  
Evan Weiher ◽  
Paul A. Keddy

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