Changes in soil and litter arthropod abundance following tree harvesting and site preparation in a loblolly pine (Pinus taeda L.) plantation

Soil and litter arthropods are important in many forest ecosystem processes where they help to regulate nutrient dynamics and soil quality, and are useful bioindicators of ecosystem condition and change. This study was initiated in response to concerns about possible decline in site productivity due to intensive forestry practices. We investigated the effects of tree harvesting and site preparation treatments on soil and litter arthropod abundance in a loblolly pine plantation in eastern Texas, USA. Using soil and litter cores, we sampled abundance of selected arthropods over two years following tree harvesting. Response to treatments varied somewhat among arthropod taxa. Acari (mites) and Collembola (springtails), the numerically dominant taxa in core samples, were initially higher in abundance in less intensive harvesting and site preparation treatments. However, after 2 years, abundance of these arthropods was comparable in all harvesting and site preparation treatments. Fertilization with nitrogen and phosphorus had a strong positive effect on abundance of most arthropod groups in the second year of the study. The recovery of arthropod abundance through time suggests that the silvicultural practices used did not jeopardize the ecological integrity of the site. The results reported here contrast with other similar studies which suggests that soil and litter arthropod communities respond differently in different geographic locations and forest types. Further comparative and extensive studies of this nature are needed therefore for a deeper understanding of the impacts of forest management practices.