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Riverine community structure, biotic...

University of Calgary (Canada).

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Riverine community structure, biotic and abiotic drivers, and the modifying impact of impoundment.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Riverine community structure, biotic and abiotic drivers, and the modifying impact of impoundment./
Author:	Powell, Heather M.
Description:	220 p.
Notes:	Source: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 2735.
Contained By:	Dissertation Abstracts International69-05B.
Subject:	Biology, Ecology. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoeng/servlet/advanced?query=NR38232
ISBN:	9780494382325

Riverine community structure, biotic and abiotic drivers, and the modifying impact of impoundment.
Powell, Heather M.

Riverine community structure, biotic and abiotic drivers, and the modifying impact of impoundment. - 220 p.

Source: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 2735.

Thesis (Ph.D.)--University of Calgary (Canada), 2008.

A major goal of ecology is to understand patterns of community structure across landscapes and the processes that generate these patterns. In rivers, change in community structure is thought to be gradual over a longitudinal gradient (upstream to downstream). Under this framework, species distribution is thought to be predictable and limited by physiological tolerance to the abiotic environment and morphological adaptation to food resources. I test these predictions and further the existing paradigm by examining changes in community structure along an ecoregion gradient in multiple rivers over large spatial scales. If a river is strongly connected to the surrounding landscape, then changes in a landscape ought to be reflected by changes in a river. If community structure is unique to an ecoregion, then this offers a new framework with which ecologists may examine the relative roles of the biotic (foodweb interactions such as predation, competition, facilitation) and abiotic environment (eg. drivers) in structuring communities.

ISBN: 9780494382325Subjects--Topical Terms:

1017726
Biology, Ecology.

Riverine community structure, biotic and abiotic drivers, and the modifying impact of impoundment.
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100 1 $a Powell, Heather M. $3 1024535
245 1 0 $a Riverine community structure, biotic and abiotic drivers, and the modifying impact of impoundment.
300 $a 220 p.
500 $a Source: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 2735.
502 $a Thesis (Ph.D.)--University of Calgary (Canada), 2008.
520 $a A major goal of ecology is to understand patterns of community structure across landscapes and the processes that generate these patterns. In rivers, change in community structure is thought to be gradual over a longitudinal gradient (upstream to downstream). Under this framework, species distribution is thought to be predictable and limited by physiological tolerance to the abiotic environment and morphological adaptation to food resources. I test these predictions and further the existing paradigm by examining changes in community structure along an ecoregion gradient in multiple rivers over large spatial scales. If a river is strongly connected to the surrounding landscape, then changes in a landscape ought to be reflected by changes in a river. If community structure is unique to an ecoregion, then this offers a new framework with which ecologists may examine the relative roles of the biotic (foodweb interactions such as predation, competition, facilitation) and abiotic environment (eg. drivers) in structuring communities.
520 $a To detect patterns of community structure and how environmental drivers change over a landscape, I analysed benthic macroinvertebrate and environmental data from three, parallel rivers that flow >700 km over a landscape that changes in temperate, North America. I found that similar communities developed within similar ecoregions among rivers. The mountain and dry-grass ecoregions exhibited the most distinct communities. The relative importance of biotic and abiotic drivers changed along an ecoregion gradients. Water flow, measured as current velocity, was not always important in explaining variation in invertebrate communities in all ecoregions.
520 $a When change in invertebrate communities was examined via biomass, I found that biomass did not reflect changes in community composition across the landscape. Contrary to contemporary ecological predictions, biomass was not linearly related to abundance or diversity.
520 $a The patterns of community structure observed in lotic ecosystems may be altered by impoundment. The serial discontinuity concept maintains that biotic structure and function will recover to local, pre-impoundment conditions at some distance downstream. The concept is limited because many watersheds include multiple dams and weirs, and the surrounding landscapes are heavily managed. To test this prediction, I analysed changes in invertebrate community structure before and after impoundment in a watershed with one impoundment and altered land-use activities post-impoundment. I found that invertebrate communities were altered &sim;20 yrs after impoundment and that the ecosystem did not recover to pre-impoundment conditions over >700km.
590 $a School code: 0026.
650 4 $a Biology, Ecology. $3 1017726
650 4 $a Biology, Limnology. $3 1018638
690 $a 0329
690 $a 0793
710 2 $a University of Calgary (Canada). $3 1017619
773 0 $t Dissertation Abstracts International $g 69-05B.
790 $a 0026
791 $a Ph.D.
792 $a 2008
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoeng/servlet/advanced?query=NR38232