Lance E. Gorham 1, Sammy L. King2,3, Bobby D. Keeland 2, and Susan Mopper 4.
Title:
EFFECTS OF CANOPY GAPS AND FLOODING ON HOMOPTERANS IN A BOTTOMLAND HARDWOOD FOREST
Abstract:
Canopy disturbance is a major factor affecting forest structure and composition and, as a result of habitat alterations, can influence insect communities. We initiated a field study to quantify the effects of canopy disturbance on aerial insect abundance and distribution within a bottomland hardwood forest along the Cache River, Arkansas, USA. We used passive flight-intercept traps to sample insects in canopy gap and forest interior habitats from May to July in 1996, 1997, and 1998. The hydrologic conditions of our study site varied among years: 1996 was relatively dry, 1997 incurred a long-duration flood, and 1998 was moderately wet. Of the 34,000+ Homopterans collected, many groups were distributed in a non-uniform manner among years and between habitats. Total Homopterans, two families of Homopterans, and six morphospecies were more abundant in canopy gaps than interior forest. Many Homopteran taxa were least abundant in 1997 following almost six months of flooding. Alternatively, relatively large Homopteran abundances were associated with the dry conditions of 1996 and the moderately wet conditions of 1998. Differences in Homopteran abundance among years and habitats may be related to differences in vegetation density. Canopy gaps supported more vegetation cover than the interior forest in all but the first sampling interval. In addition, similar to Homopteran abundance, vegetation density was lower in 1997 than in 1998. These results demonstrate that natural disturbance and flooding contribute to Homopteran abundance and distribution patterns in bottomland hardwood forests of the south central United States.
1 Johnson Controls World Services Inc. National Wetlands Research Center 700 Cajundome Blvd. Lafayette, Louisiana, USA 70506
2 U.S. Geological Survey National Wetlands Research Center 700 Cajundome Blvd. Lafayette, Louisiana, USA 70506
3 Present Address: University of Tennessee Department of Forestry, Wildlife, and Fisheries 274 Ellington Plant Sciences Building, P.O. Box 1071 Knoxville, Tennessee, USA 37901
4 Department of Biology University of Louisiana Lafayette, Louisiana, USA 70504