Ongoing Research
Change happens from the ground up: long-term prospects for soil carbon storage using targeted tallgrass prairie restorations in agroecosystems - Funded by Canada First Research Excellence Fund (CFREF)
Soil carbon is twice the amount of atmospheric C and plays a key role in nutrient cycling and provides critical ecosystem services. The intensification of agriculture, covering 40% of the earth’s terrestrial surface, is one of the biggest problems facing soil carbon loss. An observational study on 11 farms with cropping systems and restored prairie on marginal land was conducted. The effect of cover, restoration age, sampling depth and aboveground tissue quality and quantity on soil organic carbon (SOC) was examined. My work revealed two findings: that cover type had minimal influences on several key soil properties, with SOC, respiration and ammonia, and several other key factors associated with SOC diverged with prairies having higher root and litter biomass and lower nitrate, phosphorus, bulk density and tissue quality. Overall, no response for SOC or respiration between covers and within the prairie chronosequence demonstrates that these systems require larger timescales.
Previous Research
On Solidago Simplex (Asteraceae: Astereae): A Multivariate Study Including S. Glutinosa, S. Leiocarpa, S. Multiradiata, and S. Spathulata
Solidago simplex from the Sierra Madre Oriental of Mexico is included in a multivariate study with S. glutinosa and S. spathulata of subsect. Humiles and S. leiocarpa and S. multiradiata of subsect. Multiradiatae in order to assess statistical support for recognizing S. simplex as a separate species from S. glutinosa of the Rocky Mts and Great Plains and westerm boreal forest east to disjunct areas in Michigan and Ontario. Solidago simplex is statistically distinct and intermediate in a number of traits between S. glutinosa and S. multiradiata. The analyses indicate that S. glutinosa, S. simplex, and S. spathulata (subsect. Humiles) and S. leiocarpa and S. multiradiata (subsect. Multiradiatae) should be recognized as species.
Comparison of Three Methods for Extracting Sediment Porewater
Many factors influence the response of aquatic organisms to toxicants. One factor is the location of an organism within an aquatic environment. Organisms that occupy both the sediment and the sediment/water interface are popular test organisms for assessing contamination of sediment. These organisms can be directly associated with porewater or interstitial water, water that lies in between the spaces of particles in sediment. This water is in constant contact with the sediment and the overlying water. Interstitial water also has the ability to partition out of the sediment into the aquatic system and reach equilibrium with the surface water or ground water. There currently is little guidance on how to collect/extract porewater from sediment samples. This study examined how different approaches of collecting porewater influence measured pH, ammonia, and contaminants of concern. Three different extraction protocols were conducted on three different sediments, stored for three different periods of time. The extraction techniques included centrifugation, removal of settled water, and removal of settled water followed by centrifugation. The results indicated no difference among pH and ammonia results across all treatments, while there was high variability among measured metal and polycyclic aromatic hyrdocarbons (PAH) levels. Most notably there were elevated levels of PAH compounds in both of the centrifuged treatments compared to the settled water. Results suggest that among the three different extraction protocols examined, there is little impact on pH and ammonia measurements. However, if it is of interest to examine contaminants of concern in the porewater, the extraction method should be taken into consideration.
Change happens from the ground up: long-term prospects for soil carbon storage using targeted tallgrass prairie restorations in agroecosystems - Funded by Canada First Research Excellence Fund (CFREF)
Soil carbon is twice the amount of atmospheric C and plays a key role in nutrient cycling and provides critical ecosystem services. The intensification of agriculture, covering 40% of the earth’s terrestrial surface, is one of the biggest problems facing soil carbon loss. An observational study on 11 farms with cropping systems and restored prairie on marginal land was conducted. The effect of cover, restoration age, sampling depth and aboveground tissue quality and quantity on soil organic carbon (SOC) was examined. My work revealed two findings: that cover type had minimal influences on several key soil properties, with SOC, respiration and ammonia, and several other key factors associated with SOC diverged with prairies having higher root and litter biomass and lower nitrate, phosphorus, bulk density and tissue quality. Overall, no response for SOC or respiration between covers and within the prairie chronosequence demonstrates that these systems require larger timescales.
Previous Research
On Solidago Simplex (Asteraceae: Astereae): A Multivariate Study Including S. Glutinosa, S. Leiocarpa, S. Multiradiata, and S. Spathulata
Solidago simplex from the Sierra Madre Oriental of Mexico is included in a multivariate study with S. glutinosa and S. spathulata of subsect. Humiles and S. leiocarpa and S. multiradiata of subsect. Multiradiatae in order to assess statistical support for recognizing S. simplex as a separate species from S. glutinosa of the Rocky Mts and Great Plains and westerm boreal forest east to disjunct areas in Michigan and Ontario. Solidago simplex is statistically distinct and intermediate in a number of traits between S. glutinosa and S. multiradiata. The analyses indicate that S. glutinosa, S. simplex, and S. spathulata (subsect. Humiles) and S. leiocarpa and S. multiradiata (subsect. Multiradiatae) should be recognized as species.
Comparison of Three Methods for Extracting Sediment Porewater
Many factors influence the response of aquatic organisms to toxicants. One factor is the location of an organism within an aquatic environment. Organisms that occupy both the sediment and the sediment/water interface are popular test organisms for assessing contamination of sediment. These organisms can be directly associated with porewater or interstitial water, water that lies in between the spaces of particles in sediment. This water is in constant contact with the sediment and the overlying water. Interstitial water also has the ability to partition out of the sediment into the aquatic system and reach equilibrium with the surface water or ground water. There currently is little guidance on how to collect/extract porewater from sediment samples. This study examined how different approaches of collecting porewater influence measured pH, ammonia, and contaminants of concern. Three different extraction protocols were conducted on three different sediments, stored for three different periods of time. The extraction techniques included centrifugation, removal of settled water, and removal of settled water followed by centrifugation. The results indicated no difference among pH and ammonia results across all treatments, while there was high variability among measured metal and polycyclic aromatic hyrdocarbons (PAH) levels. Most notably there were elevated levels of PAH compounds in both of the centrifuged treatments compared to the settled water. Results suggest that among the three different extraction protocols examined, there is little impact on pH and ammonia measurements. However, if it is of interest to examine contaminants of concern in the porewater, the extraction method should be taken into consideration.