Hydroclimatic variability drives episodic expansion of a floating peat mat in a North American kettlehole basin

Ecology ◽  
2011 ◽  
Vol 92 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Alex W. Ireland ◽  
Robert K. Booth
Keyword(s):  
North American ◽  
Hydroclimatic Variability ◽  
Floating Peat Mat ◽  
Floating Peat

Pollinator limitaton in a deceptive orchid, Pogonia japonica, on a floating peat mat

2001 ◽  
Vol 16 (3) ◽  
pp. 231-235 ◽  
Author(s):  
KIYOSHI MATSUI ◽  
TSUSHI USHIMARU ◽  
NOBORU FUJITA
Keyword(s):  
Floating Peat Mat ◽  
Floating Peat

scholarly journals Autogenic and allogenic factors affecting development of a floating Sphagnum-dominated peat mat in a karst pond basin

The Holocene ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 120-129 ◽  
Author(s):  
Andrey N Tsyganov ◽  
Dmitry A Kupriyanov ◽  
Kirill V Babeshko ◽  
Tamara V Borisova ◽  
Viktor A Chernyshov ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Hydrological Regime ◽  
Water Levels ◽  
Factors Affecting ◽  
Surface Wetness ◽  
Kettle Hole ◽  
Peatland Development ◽  
Floating Vegetation ◽  
Floating Peat Mat ◽  
Floating Peat

Lateral expansion of floating vegetation mats over the surface of aquatic ecosystems (terrestrialization) is one of the ways of peatland development. This process was commonly studied in kettle-hole lakes, whereas karst ponds have received less attention. We used a suite of palaeoecological analyses at Karstovoe mire (Mordovia, Russia) to reconstruct the formation of a floating Sphagnum-dominated peat mat over the karst pond. The results show that the floating peat mat had covered the central part of the pond by ca. AD 1600. Remains of Scirpus sp. and Calamagrostis sp. in the basal layers indicate that these plants might form a framework on which Sphagnum mosses and sedges were established. The terrestrialization could be triggered by the ‘Medieval Warm Period’ (AD 950–1250) as droughts reduce water levels and allow the pioneering plants to colonize exposed bottom sediments on the margins of lakes. Later, the development of the mire was mainly driven by autogenic factors that could be explained by the relatively stable hydrological regime in freely floating or poorly attached vegetation mats. In the mid 19th century, the surface wetness of the mire started to decline that can be related to both increased human activity associated with fires and to a greater thickness of the mat so that autogenic and allogenic effects were difficult to disentangle. In less than a century after that, the fen transformed to a pioneer raised mire. Our results show complex and context-dependent effect of autogenic and allogenic factors on the development of floating peat mats.

Adaptation of the Connected Speech Test: Rerecording and Passage Equivalency

2020 ◽  
Vol 29 (2) ◽  
pp. 259-264 ◽  
Author(s):  
Hasan K. Saleh ◽  
Paula Folkeard ◽  
Ewan Macpherson ◽  
Susan Scollie
Keyword(s):  
Speech Perception ◽  
North American ◽  
First Language ◽  
Intraclass Correlation ◽  
Normal Hearing ◽  
Connected Speech ◽  
Internal Reliability ◽  
Speech Test ◽  
The Mean ◽  
Unit Standard

Purpose The original Connected Speech Test (CST; Cox et al., 1987) is a well-regarded and often utilized speech perception test. The aim of this study was to develop a new version of the CST using a neutral North American accent and to assess the use of this updated CST on participants with normal hearing. Method A female English speaker was recruited to read the original CST passages, which were recorded as the new CST stimuli. A study was designed to assess the newly recorded CST passages' equivalence and conduct normalization. The study included 19 Western University students (11 females and eight males) with normal hearing and with English as a first language. Results Raw scores for the 48 tested passages were converted to rationalized arcsine units, and average passage scores more than 1 rationalized arcsine unit standard deviation from the mean were excluded. The internal reliability of the 32 remaining passages was assessed, and the two-way random effects intraclass correlation was .944. Conclusion The aim of our study was to create new CST stimuli with a more general North American accent in order to minimize accent effects on the speech perception scores. The study resulted in 32 passages of equivalent difficulty for listeners with normal hearing.

Sign in / Sign up

Export Citation Format

Share Document