Associations of watershed and instream environmental factors with aquatic macrofauna in tributaries of the Pedernales River, Texas

Show simple item record


dc.contributor.advisor Winemiller , Kirk O . en_US
dc.contributor.committeeMember Abbott , John C . en_US
dc.creator Birnbaum , Jenny Sue en_US
dc.date.accessioned 2005 -08 -29T14 :41 :04Z
dc.date.accessioned 2014 -02 -19T19 :21 :36Z
dc.date.available 2005 -08 -29T14 :41 :04Z
dc.date.available 2014 -02 -19T19 :21 :36Z
dc.date.created 2006 -05 en_US
dc.date.issued 2005 -08 -29T14 :41 :04Z
dc.identifier.uri http : / /hdl .handle .net /1969 .1 /2411
dc.description.abstract Intermittent headwater streams serve important functions in semi -arid rangelands , both for humans and wildlife . However , few studies have assessed species -environment relationships for fish and benthic macroinvertebrate assemblages in these systems . Additionally , no published studies could be found that addressed the influence of juniper coverage in watersheds on assemblage structure of these taxa . Increased juniper coverage in recent decades is believed to be associated with decreased water yields in central Texas streams . During summer 2003 and spring 2004 , I examined potential effects of juniper cover on aquatic ecology . Fishes , benthic macroinvertebrates , and the physicochemical habitat were investigated in spring -fed headwater tributaries of the Pedernales River . My objectives were to : 1 ) describe the typical fish and benthic macroinvertebrate assemblages in headwater creeks of the Pedernales River basin ; 2 ) compare seasonal variability of fish and benthic macroinvertebrate assemblages ; 3 ) identify species -environment relationships in this river basin ; and 4 ) evaluate the influence of juniper coverage in the watershed , relative tolocal and landscape -level environmental factors , on the structure of fish and benthic macroinvertebrate assemblages . A total of 4 ,181 individual fish were collected in summer 2003 samples , 551 fish were collected in spring 2004 , 59 ,555 macroinvertebrates were captured in summer 2003 samples , and 51 ,500 macroinvertebrates were collected in spring 2004 . Assemblages were typical for the area and habitat conditions . Faunal richness was lower in spring than in summer , possibly due to a combination of sampling after a relatively dry period in the spring , and lack of winter refugia in the form of deep pools . Fish assemblages may structure based principally on abiotic factors in spring , the harsher season (less available water ) , whereas predation pressure may influence structure in summer . Another important environmental gradient for both fish and invertebrate assemblages contrasts pool and run mesohabitats . In general , juniper cover was weakly associated with fish and invertebrate assemblages , although it tended to be associated with relatively high quality habitat for sensitive taxa (flowing runs with coarse substrate ; deep , connected pools ) . In these intermittent streams , local -scale environmental factors probably are the dominant influences on fish and benthic macroinvertebrate assemblages . Implications for future studies are discussed . en_US
dc.format.extent 1996161 bytes
dc.format.medium electronic en_US
dc.format.mimetype application /pdf
dc.language.iso en _US en_US
dc.publisher Texas A &M University en_US
dc.subject juniper en_US
dc.title Associations of watershed and instream environmental factors with aquatic macrofauna in tributaries of the Pedernales River , Texas en_US
dc.type Book en
dc.type.genre Electronic Thesis en_US
dc.type.material text en_US
dc.format.digitalOrigin born digital en_US

Citation

Associations of watershed and instream environmental factors with aquatic macrofauna in tributaries of the Pedernales River, Texas. Available electronically from http : / /hdl .handle .net /1969 .1 /2411 .

Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record

Search DSpace

Advanced Search

Browse