Soil Factors in Three Populations of Endangered Golden Sedge (Carex lutea LeBlond)


John B. Taggart

Additional Authors:

Zachary T. Long


June 2012


Circumneutral, golden sedge, narrow endemic, pH, soil factors

ABSTRACT Three sites with populations of federally endangered golden sedge (Carex lutea LeBlond) were sampled to investigate whether circumneutral soil conditions were associated with a species distribution restricted to 208 km2 within two adjacent counties of the lower North Carolina Coastal Plain. Populations were selected to include different soil series found in a stateowned natural area. Observed golden sedge rhizome and root depths among three specimens, one per site, ranged from 6 to 8 cm below the soil surface, which suggested primarily topsoil influence. A total of 96 soil samples, 48 topsoil and 48 subsoil, were collected in transects and analyzed. Mean pH values within populations were very strongly (4.7) to moderately (5.7) acid for topsoils and moderately (5.8) to slightly (6.5) acid for subsoils. These values did not differ significantly inside versus immediately outside each population, but varied among topsoils and subsoils between populations. Other soil variables associated with marl and limestone parent material influence (i.e., cation exchange capacity, base saturation, calcium, and magnesium) did not exhibit any consistent trends either inside versus outside, or between populations. A prior study found a mean soil pH of 6.7 within golden sedge populations, but choices of sample sites and analysis techniques were questionable. Lack of soil specificity for this species encourages both searches for golden sedge populations outside the known range and restoration or enhancement of local populations.