Software, mud, and everything in between
I’ve been working with Cullen this semester, and since Cullen works on pretty much everything in the lab, I’ve had the privilege of being exposed to many different lab activities. I’ve gotten to work with Dynacrush the soil grinder, help weigh and prepare soil samples for KCl extractions, and use SamplePoint software to look at land cover and plant species diversity in field sites on the Eastern Shore. SamplePoint is a manual image analysis program that is used to classify different land cover types on individual nadir images [1]. For each photo taken of the test plots, I classified one hundred different sample pixels as bare soil, plant litter, or one of about fifteen different plant species. SamplePoint then uses the manually-entered sample data to extrapolate the land cover classifications to the rest of the image. Quantifiable land cover data, such as the percent area of a plot that is covered by one specific plant species, can be a useful metric when assessing the impact of saltwater intrusion on plant species diversity.
One of the most rewarding experiences I’ve had so far in the lab has been the hands-on soil sampling work that we did over spring break at “soils camp.” We sampled several field sites that were experiencing saltwater intrusion, and it was fascinating to personally witness the visible signs of saltwater intrusion’s effects on these agricultural fields. There are generally very clear boundaries between the brackish water ditch inhabited by phragmites reeds, the adjacent area inhabited by low-lying salt-tolerant species such as salt marsh hay, the zone of generally bare soil, and then the transition into the agricultural field. By analyzing soil samples from these test sites, we can assess the impact that saltwater incursion has on nutrient release, carbon dynamics, nitrogen content, aggregate structure, and other soil properties [2] [3]. Soils camp was a wonderful way to spend time outdoors, get covered in mud, work together with inspiring and fun people from the lab, and understand where and how the Agroecology Lab obtains the soil samples that we process and analyze back in College Park.
References
Crawley, A. T. 2011. Using photo interpretation and publicly available software to assess revegetation ground cover on a shaded hillside. M.S. project report. Virginia Polytechnic Institute and State University, Blacksburg, VA. 11p.
Helton, A. M., Bernhardt, E. S., & Fedders, A. (2014). Biogeochemical regime shifts in coastal landscapes: The contrasting effects of saltwater incursion and agricultural pollution on greenhouse gas emissions from a freshwater wetland. Biogeochemistry, 120(1-3), 133-147. doi:10.1007/s10533-014-9986-x
Six, J., Bossuyt, H., Degryze, S., & Denef, K. (2004). A history of research on the link between (micro)aggregates, soil biota, and soil organic matter dynamics. Soil and Tillage Research, 79(1), 7-31. doi:10.1016/j.still.2004.03.008