Succession of Coleoptera on Freshly Killed Loblolly Pine (Pinus taeda L.) and Southern Red Oak (Quercus falcata Michaux) in Louisiana
Wood is important in forest ecology because its large biomass serves as a nutritional substrate and habitat for many organisms, including Coleoptera, and beetles contribute greatly to nutrient recycling in forests. Overlapping complexes of beetles invade dead wood according to the species of tree, ambient conditions, and most importantly, stage of decomposition. Beetle succession was studied in loblolly pines (Pinus taeda L.) and southern red oaks (Quercus falcata Michx.) by documenting beetle arrival and residency in cut, reassembled, and standing bolts. Twelve trees of each species at Feliciana Preserve in West Feliciana parish, LA were felled during October 2004 and April 2005 for a total of 24 trees sampled from October 2004 September 2005. Four 48-inch bolts were cut from each felled tree. Each bolt was further cut into eight six-inch sections, reassembled in proper order, and positioned standing upright. Beetles were aspirated from section interfaces weekly the first month and then monthly for the duration of the study.
A total 51,119 specimens from 190 taxa were collected from 3822 samples during 18 sampling events. Species richness and abundance were higher on southern red oak wood (144 taxa, 40874 specimens) than loblolly pine (122 taxa, 10245 specimens); abundance was significantly higher. Colonization and species composition patterns of coleoptera were significantly affected by host tree species, the season in which the tree died, the period of decay, the position or height along the woody substrate and many complex interactions of these effects. Loblolly pine bolts showed a slightly more rapid turnover of taxa than southern red oak bolts. Wood characteristics such as loss of moisture, which caused bark to loosen on pines, and higher quality substrate hardwood in oaks presumably account for the greater number of taxa and specimens collected from southern red oak than loblolly pine. This study has increased the number of species known to inhabit recently dead loblolly pine and southern red oak, two economically important tree species. Studies of this nature supplement investigations into the importance of coarse woody debris in forests by documenting ecological patterns of saproxylic coleoptera.
Advisor:Christopher Carlton; Dorothy Prowell; Timothy Schowalter
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Date of Publication:04/17/2008