Soil Properties Associated with Cogongrass Infested and Noninfested Loblolly Pine Stands in Mississippi.

The non-native, invasive grass, Imperata cylindrica (L.) Beauv. (cogongrass) is becoming an increasing threat to the diversity of native plant and wildlife species of the southeastern United States.  Imperata cylindrica infestations have also been found to affect pine ecosystems by altering fire regimes and limiting regeneration by forming extensive monocultures through rhizomatous growth.  The net result is the presence of a major threat to forest reproduction.  A study was established in southern Mississippi in 2010 to evaluate the impact of cogongrass on soil resources and loblolly pine (Pinus taeda L.) productivity.  Physical and chemical soil measurements were conducted on 20 plots: 10 with cogongrass infestation and 10 without cogongrass. Chemical measures related to total carbon, total nitrogen, exchangeable bases, phosphorus and manganese were elevated in infested plots.  Physical measures related to bulk density and soil strength were slightly lower in infested plots while total porosity was slightly higher in cogongrass plots.  Cogongrass appeared to have an effect on soil resources that may affect long term pine productivity in addition to its impact on intense fires and limiting regeneration.