Felicia Woods EEOS 660 November 13, 2014 Google Maps (2014)

Geochemical processes (nutrient cycling) effect the functions of microbial processes and primary production. [2] Nearly every process in ecosystem linked to elemental cycling. [2] Environmental management complications arise from too much or too little nutrients. [2]

Google Maps (2014)

Dredge material from ditching Increases marsh elevation and decreases natural flushing of water. Increased nutrient loading from runoff Increases above ground biomass production and decreases stability of roots. This leads to bank erosion.

Increased nutrients increase aboveground biomass which reduce the stability of belowground biomass. [8] Changes root-shoot ratio: Vegetation becomes top-heavy. More susceptible to uprooting. Increased erosion. Most elements follow the came path as nutrient cycling. [2] Accumulation of harmful substances (PCBs) and elements (heavy metals) in soils are taken by plants and cycled through the food web. [9]

Increases biomass accumulation and plant density The increased N demand of Phragmites benefits from nutrient loading. Increases rate of primary productivity Phragmites australis is less tolerant to salt water than Spartina spp.

Phragmites stems trap sediment further increase the elevation of the marsh platform. [4] The increased elevation of the marsh platform prevents regular flushing of the system by salt water [3] Decreases impact of salinity on vegetation Reduces water flow and decreases flood retention Reduced water flow impacts nutrient cycling [1]

Changes in nutrient cycling can result from plant dominance because affected area can become a monocrop Changes in nutrient cycling may result in changes in the microbial community because of the quantity and quality of the inputs. Carbon fluxes associated with litter deposition can be controlled by the high stem-leaf biomass ratio [1] Leaves decompose faster but stems decompose slower

Changes in carbon and other nutrient cycling can lead to changes in microbial enzyme activity in areas that it has replaced Spartina alterniflora. [1] High nitrogen demand leads to decreased pools of NH 4 + in pore water. [1] Changes in soil pH may result from high rates of NH 4 + Increased denitrification rates in brackish marshes. [1] Changes in soil salinity [1] Decrease salinity because of physical and physiological differences of Spartina spp.

2005 Great Meadows, LLC Increased elevation lead to an increase in Phragmites australis, which is less tolerant to salt water. Removal of dredge spoil that had accumulated and increased the elevation of the marsh. Restore effect of salt water flushing Newenglandwetlands.com

Removal of Phragmites australis would decrease the rate of sediment accumulation that currently results from it being trapped by the dense stems of the plant. Increase light transmission to soil surface Increase plant diversity and therefore increase nutrient cycling. But… it may decrease primary production

Not a lot of published information on geochemistry in the Neponset River. Dr. Chen’s work on CDOM in Neponset River [6] More available on water chemistry than soil chemistry. Although the water chemistry is important in the Neponset Marsh, more information on the soil chemistry may be needed to help with restoration Research on how changes in vegetation effect nutrient cycling may be outdated (Ehrenfeld, 2003 meta- analysis). Invasion may increase Denitrification rates

Test soil composition More research!

1. Ehrenfeld, J. (2003). Effects of Exotic Plant Invasion on Soil Nutrient Cycling Processes. Ecosystems, (6), Retrieved from Weathers, K., & Ewing, H. (2013). Element Cycling. In Fundamentals of Ecosystem Science (pp ). Amsterdam: Academic Press/Elsevier &t=i2g0acls&s=de46d33ad8a371db be4f12c2d73dafb 1&t=i2g0acls&s=de46d33ad8a371db be4f12c2d73dafb 7. bowen.wikispaces.umb.edu/file/view/Limnol%20Oceanogr%202009%20Turner. pdf/ /Limnol%20Oceanogr%202009%20Turner.pdf bowen.wikispaces.umb.edu/file/view/Limnol%20Oceanogr%202009%20Turner. pdf/ /Limnol%20Oceanogr%202009%20Turner.pdf 8. bowen.wikispaces.umb.edu/file/view/Nature%202012%20Deegan- 1.pdf/ /Nature%202012%20Deegan-1.pdf bowen.wikispaces.umb.edu/file/view/Nature%202012%20Deegan- 1.pdf/ /Nature%202012%20Deegan-1.pdf 9. bowen.wikispaces.umb.edu/file/view/USGS%20Chem%20Neponset.pdf/ /USGS%20Chem%20Neponset.pdf bowen.wikispaces.umb.edu/file/view/USGS%20Chem%20Neponset.pdf/ /USGS%20Chem%20Neponset.pdf