Mb. Griffith et al., SECONDARY PRODUCTION OF MACROINVERTEBRATE SHREDDERS IN HEADWATER STREAMS WITH DIFFERENT BASEFLOW ALKALINITY, Journal of the North American Benthological Society, 13(3), 1994, pp. 345-356
We used the size-frequency method to calculate annual production of th
e shredder functional group in four streams on the Allegheny Plateau o
f West Virginia. These streams were characterized by different bedrock
geology, streamwater pH, and alkalinity. Mean alkalinity was 40.8, 0.
9, 0.7, and 0.0, and mean pH was 7.5, 6.1, 6.0, and 4.3 in the four st
reams. The crayfish Cambarus bartoni contributed >55% of shredder biom
ass in all streams, but contributed <20% of shredder production. Annua
l production of the other common shredder species differed among strea
ms. Gammarus minus and Tipula abdominalis contributed 77% of shredder
production in the stream with the highest pH. Tipula abdominalis, Pycn
opsyche sp., and Peltoperla arcuata together contributed 68% and 54% o
f shredder production in the two streams with intermediate pH. Leuctra
spp., Amphinemura sp., and Paracapnia angulata contributed 71% of shr
edder production in the stream with the lowest pH. Annual production o
f the shredder functional group was 3.77 g dry mass/m2 in the highest-
pH stream, 2.06 g dry mass/m2 and 1.56 g dry mass/m2 in the intermedia
te-pH streams, and 1.19 g dry mass/m2 in the lowest-pH stream. The dif
ferences in annual production of different shredder species among stre
ams paralleled the results of other studies that have found difference
s in macroinvertebrate community structure in relation to differences
in pH and alkalinity. However, the annual production of the shredder f
unctional group in these streams may also have been affected by differ
ences in the riparian vegetation and temperature among streams in addi
tion to pH and alkalinity.