Document: NIC-3-71-5

Community structure in bison wallows and intermittent streams in tallgrass prairie.

GERLANC, N.M.*, R.J.BERNOT and W.K.DODDS

Kansas State University, Manhattan, Kansas 66506 USA ¹

Abstract:
Ephemeral aquatic habitats support a variety of aquatic life, including plants, invertebrates, and anurans. Community structure in temporary aquatic habitats is constrained by hydroperiod and is further mediated by biotic interactions. We monitored bison wallows and intermittent streams on the Konza Prairie Research Natural Area in northeastern Kansas, to study mechanisms structuring animal communities in ephemeral aquatic habitats, which varied across a gradient of hydroperiods and physiochemical properties. We collected animals by using a 0.7mm mesh dip net and measured water temperature, pH, ammonium, dissolved oxygen, water volume and hydroperiod in the spring from nine bison wallows and ten intermittent streams in 1997 and 1998. The most common invertebrates in wallows were predators including adult Hemiptera and Coleoptera. However, invertebrates present varied among wallows and between years. Ephemeroptera was the most common invertebrate order in intermittent streams, but again invertebrates present varied among stream sites and between years. Pseudacris triseriata and Acris cripitans tadpoles were the only vertebrates to occur in bison wallows and intermittent streams although they were not at all sites in all years. Other common invertebrates in both wallows and streams included Diptera and Odonata. Gastropods were also present in bison wallows and intermittent streams, but Physidae was found only in intermittent streams while Lymnaeidae was found only in bison wallows. Presence of crayfish in intermittent streams may account for the absence of Lymnaeidae at stream sites. We suggest that differences in community structure between bison wallows and intermittent streams are linked to differences in pathways of invertebrate colonization, hydrologic regime and seasonal timing of drying and rewetting events.

Keywords: community, ephemeral, invertebrates, tadpoles, bison wallows, intermittent streams

This abstract is being presented at: 10:30 AM in session:
RIPARIAN ECOLOGY