Soil

sampling locations

Students collected soil samples in 2013 from over 40 locations (pictured above) across the central portion of the YEW. They analyzed the samples for a range of substances and characteristics related to soil fertility, structure, and biogeochemistry, including phosphorus, magnesium, potassium, calcium, carbon, nitrogen, depth of litter layer, water holding capacity, and respiration rate. 

In 2014, students analyzed the samples for metals such as lead, mercury, and arsenic, because these heavy metals can be harmful to plants, animals, and people if found in high concentrations. At this site, they could come from leaking sewer lines, paint scrapings, atmospheric deposition, and the use of contaminated fill.  Most of the samples showed slightly elevated levels of heavy metals, as is common for urban soils. However, because soil in the YEW is used primarily for research, and there are minimal human-soil interactions, these high levels do not currently pose a significant health risk.

Soil Data Average Values

pH:
5.8
Water holding capacity (g of water/g per soil):
0.6
SIR(mg of C/g soil *hr):
2.5
Calcium (ppm):
1,755
Potassium (ppm):
137
Phosphorus (ppm):
8
Carbon (%):
4.7
Nitrogen (ppm):
0.3
Magnesium (ppm):
126
Lead (ppm) - Depth 1:
590
Lead (ppm) - Depth 2:
485
Mercury (ppm) - Depth 1:
802
Mercury (ppm) - Depth 2:
1,246

Reports

YEW Reports

Yale Swale Assessment

2014 YEW Assessment

Uma Bhandaram, David Jaeckel, and Catherine Kuhn

2014

Research conducted in 2013-­2014 focuses on site hydrology and instrumentation, soil testing, data management, avian habitat, and public outreach. This report provides both the methodology and results as well as recommendations for future research opportunities.

Yale Swale Assessment

2013 YEW Assessment

Ambika Khadka and Avishesh Neupane

2013

Following up on the recommendations of the 2012 report, important hydrological and soil parameters along with coarse woody debris were studied for baseline data collection.

Yale Swale Assessment

2012 YEW Assessment

Stephen Brooks and Ryan Sarsfield

2012

Report from fieldwork that took place during the summer of 2012 to characterize the site and provide baseline vegetation data in anticipation of future management and research. This report includes an assessment of all trees in the YEW over 4 inches at diameter at breast height (dbh).