An Assembly Rule for Functional Groups Applied to North American Soricid Communities

1992 ◽  
Vol 73 (3) ◽  
pp. 491-503 ◽  
Author(s):  
B. J. Fox ◽  
G. L. Kirkland
Keyword(s):  
Functional Groups ◽  
North American ◽  
Assembly Rule

scholarly journals Do Invasive Earthworms Affect the Functional Traits of Native Plants?

2021 ◽  
Vol 12 ◽  
Author(s):  
Lise Thouvenot ◽  
Olga Ferlian ◽  
Rémy Beugnon ◽  
Tom Künne ◽  
Alfred Lochner ◽  
...  
Keyword(s):  
Functional Groups ◽  
Plant Community ◽  
Functional Traits ◽  
North American ◽  
Native Plants ◽  
Plant Biomass ◽  
Grass Species ◽  
Earthworm Invasion ◽  
Invasive Earthworms ◽  
Community Changes

As ecosystem engineers, invasive earthworms are one of the main drivers of plant community changes in North American forests previously devoid of earthworms. One explanation for these community changes is the effects of earthworms on the reproduction, recruitment, and development of plant species. However, few studies have investigated functional trait responses of native plants to earthworm invasion to explain the mechanisms underlying community changes. In a mesocosm (Ecotron) experiment, we set up a plant community composed of two herb and two grass species commonly found in northern North American forests under two earthworm treatments (presence vs. absence). We measured earthworm effects on above- and belowground plant biomass and functional traits after 3 months of experiment. Our results showed that earthworm presence did not significantly affect plant community biomass and cover. Furthermore, only four out of the fifteen above- and belowground traits measured were affected by earthworm presence. While some traits, such as the production of ramets, the carbon and nitrogen content of leaves, responded similarly between and within functional groups in the presence or absence of earthworms, we observed opposite responses for other traits, such as height, specific leaf area, and root length within some functional groups in the presence of earthworms. Plant trait responses were thus species-specific, although the two grass species showed a more pronounced response to earthworm presence with changes in their leaf traits than herb species. Overall, earthworms affected some functional traits related to resource uptake abilities of plants and thus could change plant competition outcomes over time, which could be an explanation of plant community changes observed in invaded ecosystems.

Assembly rules for functional groups of North American shrews: effects of geographic range and habitat partitioning

Oikos ◽  
2004 ◽  
Vol 107 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Timothy S. McCay ◽  
Matthew J. Lovallo ◽  
W. Mark Ford ◽  
Michael A. Menzel
Keyword(s):  
Functional Groups ◽  
North American ◽  
Geographic Range ◽  
Habitat Partitioning ◽  
Assembly Rules

Reaffirming the Validity of the Assembly Rule for Functional Groups or Guilds: A Reply to Wilson

Oikos ◽  
1995 ◽  
Vol 73 (1) ◽  
pp. 125 ◽  
Author(s):  
Barry J. Fox ◽  
James H. Brown
Keyword(s):  
Functional Groups ◽  
Assembly Rule

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.

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