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What do snails do in ecosystems?

it is a matter of traits

Astor, Tina (2014). What do snails do in ecosystems? Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2014:67
ISBN 978-91-576-8082-2
eISBN 978-91-576-8083-9
[Doctoral thesis]

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Current environmental changes demand the ability to predict possible consequences for ecosystems performing important functions regulating the Earth system, and providing essential services for human well-being. Indirect impacts can occur through changes in biotic communities. Functional traits determine organisms' performance, and thus their fitness in a given environment. Therefore, traits can be used to assess communities' response to environmental variation (via response traits) and their effects on ecosystem processes (via effect traits).

In this thesis, I used terrestrial snails as study organisms to examine different aspects of their response to environmental and spatial factors, and their potential effects on leaf litter decomposition, as mediated by their traits. I investigated which factors determine the assembly of communities and found that trait underdispersion was more common than trait overdispersion, indicating the dominance of environmental filtering over biotic interactions. Testing the relative importance of environmental and spatial factors, I found that both environment and space significantly contributed to the variation in community trait composition, whereby the environment had the strongest effect. This indicates that intrinsic population processes (e.g. dispersal) that are independent from the environment play only a subordinate role. Moreover, I conducted microcosm experiments to measure snail traits that affect leaf litter decomposition (consumption rate, faeces production and assimilation efficiency) testing two litter types differing in quality. With the observed relationship between species specific shell size and consumption rate as proxy I assessed snail communities' potential influence on leaf litter decomposition along an acidification gradient.

Several traits responded to environmental factors in all three observational studies (shell size, number of offspring, reproduction mode, and microhabitat occurrence), or in two of the three studies (survival of dry period, and humidity preference) suggesting some generality of certain trait-environment relationships. Three traits (shell size, calcium affinity, and self-fertilization) and one measure of functional diversity (functional richness) responded both to environmental variation, and influenced the snails' potential contribution to leaf litter decomposition.

Authors/Creators:Astor, Tina
Title:What do snails do in ecosystems?
Subtitle:it is a matter of traits
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2014
Number of Pages:67
I.Astor, T., Strengbom, J., Berg, M.P., Lenoir, L., Marteinsdóttir, B., Bengtsson, J. (2014). Underdispersion and overdispersion of traits in terrestrial snail communities on islands. Ecology and Evolution 4(11), 2090-2102.
II.Astor, T., von Proschwitz, T., Strengbom, J., Lenoir, L., Berg, M.P., Bengtsson, J. Environment contributes more than space to trait composition in terrestrial snail communities (manuscript).
III.Astor, T., Lenoir, L., Berg, M.P. Measuring effect traits of a range of terrestrial snails – litter consumption, faeces production and scaling with shell size (submitted to Oecologia).
IV.Astor, T., Strengbom, J., Lenoir, L., Bengtsson, J. Testing the response-and-effect trait framework on macro-invertebrate communities: land snail effects on litter consumption (manuscript)
Place of Publication:Uppsala
Publisher:Department of Ecology, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8082-2
ISBN for electronic version:978-91-576-8083-9
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L20 Animal ecology
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Ecology
Agrovoc terms:gastropoda, snails, indicator organisms, ecosystems, environmental factors, biodiversity, soil fauna, invertebrates, degradation
Keywords:functional traits, functional diversity, ecosystem functioning, decomposition, macro-detritivores, gastropods
Permanent URL:
ID Code:11552
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
External funders:Swedish Research Council
Deposited By: Tina Astor
Deposited On:01 Oct 2014 10:41
Metadata Last Modified:14 Dec 2014 05:05

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