Great Plains Natural Science Society


The Prairie Naturalist

Date of this Version


Document Type



Proceedings of the 23rd North American Prairie Conference, August 2012, University of Manitoba in Winnipeg

The Prairie Naturalist 46: 21-28. August 2014


Published by the Great Plains Natural Science Society, 2014. Used by permission.


Variation in soil conditions and grass cover was assessed across a range of leafy spurge (Euphorbia esula L.) cover values on a sandy rangeland in Manitoba, Canada. Soil conditions varied by site but not in relation to cover of leafy spurge. We observed a significant negative relationship between total grass cover and increasing cover of leafy spurge. Only porcupine grass (Hesperostipa spartea [Trin.] Barkworth) had a negative relationship with leafy spurge, falling from high cover at low weed occurrence to only trace levels at the highest leafy spurge abundance. Neither prairie Junegrass (Koeleria macrantha [Ledeb.] Schult.), rough bentgrass (Agrostis scabra Willd.), nor Kentucky bluegrass (Poa pratensis L.) had any relationship to cover of leafy spurge. The negative correlation between porcupine grass and increasing leafy spurge cover is consistent with the interpretation that leafy spurge suppresses growth of this grass. Experimental manipulations are needed to identify causal relationships among these plants.