Rangeland Ecology & Management

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EFFECTS OF FERAL PIG DISTURBANCE ON NUTRIENT FLUXES IN SOUTHWEST FLORIDA DEPRESSION MARSHES
Author
Gates, Cyndi A.
Clark, Mark W.
Publisher
Society for Range Management
Publication Year
2014
Body

Intense rooting of soil by feral pigs (Sus scrofa) when foraging often results in large areas of bare ground and incorporation of litter and plant material into soil.  Research in uplands has shown higher levels of nitrate and ammonium in disturbed (rooted) soils as compared to undisturbed (unrooted) soils due to alteration of nitrogen transformation processes.  Some of these same studies indicated that phosphorus was lower in rooted soils.  Rooting disturbance by pigs has been implicated in water quality declines due to increased erosion, spread of pathogens and increased nutrient loading; however, relatively little work has been done regarding changes in nutrient flux in isolated wetlands as a result of pig disturbance. Three depression marshes were selected for our study at locations within Polk and Pasco counties in Florida.  Selection was based on similarity of the following: soil type, severity of disturbance (moderate), time since last disturbance (4-6 months), and similarity of hydrologic zone of disturbance.  We looked at the potential effects of rooting on nutrient flux by collecting 20 cm deep soil cores in 7 cm diameter tubes from areas of mounded soil, nearby ground soil (typically the source of the mounded soil), and undisturbed control sites.  Each core was flooded with 25 cm deep rain water then samples from the water column were collected at 1, 2, 5, and 7 days post-flooding to examine the flux of nitrate/nitrite (NOx-N), ammonium (NH4-N), and soluble reactive phosphorus (SRP).   Total phosphorus and total Kjeldahl nitrogen (TKN) flux rates were sampled at 1 and 7 days post-flooding.  The mounded and ground soil treatments had significantly higher cumulative flux rates than the control for NH4-N.  The mounded soil treatment was also significantly higher than the control for TKN and SRP.  Implications of our findings as well as general impacts to plant communities will be discussed.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Orlando, FL