View Full Document

Effects of grazing minnows and crayfish



View the full content.
View Full Document
View Full Document

3 views

Unformatted text preview:

J N Am Benthol Soc 2008 27 3 772 782 2008 by The North American Benthological Society DOI 10 1899 07 136 1 Published online 22 July 2008 Effects of grazing minnows and crayfish on stream ecosystem structure and function Justin R Bengtson1 Michelle A Evans White2 AND Keith B Gido3 Division of Biology Kansas State University Manhattan Kansas 66502 USA Abstract We compared the effects of 2 common grazers southern redbelly dace Phoxinus erythrogaster and crayfish Orconectes spp on ecosystem structure and function in experimental streams with pool and riffle habitats Our goal was to identify potentially overlapping roles of these grazers in these systems Measures of ecosystem structure included algal filament length particulate organic matter POM densities of invertebrate taxa and algal biomass Ecosystem function was measured as gross primary productivity GPP Biomass dependent effects of crayfish and dace on ecosystem properties were compared in autumn 2005 when mean water temperature was 12 98C range 7 6 27 98C Increasing crayfish biomass did not influence ecosystem properties but increasing dace biomass negatively affected algal filament length and chironomid abundance and positively affected chydorid abundance Effects of moderately high biomasses of dace and crayfish were compared in spring 2006 when mean water temperature was 21 48C range 17 5 29 98C Algal filament lengths were generally low relative to values obtained in autumn 2005 in both dace and crayfish treatments In addition algal filament length was shorter and chironomid density was lower in crayfish than in dace streams The contrasting effects of dace and crayfish across sampling days seasons and habitats led us to hypothesize that physiological and behavioral traits of these species might limit the redundancy of their effects on ecosystems across broad spatial and temporal scales Key words primary production context dependent effects experimental streams prairie stream periphyton temperature physiology



Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Effects of grazing minnows and crayfish and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Effects of grazing minnows and crayfish and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?