Changing precipitation regimes and soil carbon
There is evidence to suggest that mineral-associated organic carbon (MAOC) may increase, while particulate organic carbon (POC) may decrease, under increased precipitation, leading to no change in total soil carbon but with important restructuring of this globally important carbon pool. To investigate this, we have sampled soils at a long-term irrigation experiment at an annually burned prairie in northeastern Kansas (Konza LTER) and are investigating the soil organic carbon and pyrogenic carbon dynamics and their controls. We are writing up this project.
Project partners: Dr. Francesca Cotrufo (CSU), Dr. John Blair (KSU), Dr. Alan Knapp (CSU), Dr. Michael Bird (JCU), Dr. Chao Liang (CAS)
Local nitrogen pollution in Rocky Mountain National Park (RMNP)
National parks are both places of exploration and places of conservation. Thus, it is important to understand how visitation affects park ecosystems. We are researching whether local N pollution from cars driving through the RMNP is affecting roadside ecosystems. We performed a proof-of-concept test in summer 2020 and are executed a complete project in summer 2021. This work is under review at Water, Air, & Soil Pollution.
Project partners: Dr. Francesca Cotrufo (CSU) & Dr. Jill Baron (CSU)
Summarizing soil carbon responses to global environmental change
Soils hold the largest terrestrial store of C and thus, understanding their responses to global changes is crucial for predicting future C cycling. We used meta-analytical techniques to assess responses of two functionally different types of soil C; mineral associated organic C (MAOC) and particulate organic C (POC). This work is published in Science of the Total Environment.
Project partners: Dr. Francesca Cotrufo (CSU), Dr. Jocelyn Lavallee (CSU), & Dr. Catherine Stewart (USDA)
Nutrient fertilization and soil organic matter stoichiometry and stability
Increased nutrient availability with global change will modify future biogeochemistry. To better understand this variation, we investigated the responses of soil C and N coupling and stability in soil organic matter fractions to nutrient fertilization across a global set of grasslands, in collaboration with the Nutrient Network. This work is published in Biogeochemistry.
Project partners: Dr. Francesca Cotrufo (CSU), Kaydee Barker (CSU), Nutrient Network scientists
Biochar affects on seasonal nitrogen cycling in alfalfa
Biochar, a sustainable soil amendement that enhances carbon sequestration, is likely to affect other aspects of soil. We investigated whether biochar addition could affect seasonal dynamics of N cycling in an alfalfa field in semiarid Colorado. Surprisingly, we found minimal biochar effects, but strong seasonal dynamics in N cycling. This research suggests limited ability of co-benefits of biochar in this system. We published this work in Soil Systems in 2019.
Project Partners: Dr. Francesca Cotrufo, Dr. Steven Fonte, and Dr. Joseph von Fischer
Nitrogen fertilizer use and distribution as influenced by biochar
Biochar, a sustainable soil amendement that enhances carbon sequestration, is likely to affect other aspects of soil. We assessed whether biochar diffeerntly affected soil and fertilizer N in a greenhouse study. We find that biochar had a stronger influence on fertilizer N but fairly limited effects overall. Details of this work are avaiable here.
Project partners: Dr. Francesca Cotrufo and Dr. Steven Fonte
Undergraduate research projects
Methane emissions and isotopic composition over a thaw gradient in a subarctic peatland. Mentor: Dr. Ruth Varner, UNH
Characterizing ice nucleating particles at the Western US Coast. Mentor: Dr. Sonia Kreidenweis, CSU
Plant and soil biogeochemistry over a bedrock gradient. Mentor: Dr. Julie Bryce, UNH