Lehmann lovegrass (Eragrostis lehmanniana) removal and black grama (Bouteloua eriopoda) restoration in the Chihuahuan desert

Abstract

Restoration of native grasses in the North America desert southwest has become a rangeland management priority, but restoration has been challenging for numerous reasons including persistent invasive grasses and water limitations. The invasive Lehmann lovegrass (Eragrostis lehmanniana) may interfere with restoration of the important native rangeland forage grass species, black grama (Bouteloua eriopoda). Superabsorbent polymers (SAP) absorb, retain, and slowly release large amounts of water with their cross-linked structure, and when used as soil amendments, they can increase plant available soil water. To determine if B. eriopoda cover could be increased through E. lehmanniana removal and subsequent restoration practices, we tested the effects of herbicidal E. lehmanniana removal, B. eriopoda seeding, and SAP soil amendment on B. eriopoda cover over 3 years at two sites in the northern Chihuahuan Desert, New Mexico. Neither SAP soil amendment nor seeding were effective. Bouteloua eriopoda cover change was positively correlated to E. lehmanniana cover reduction. Successful removal of E. lehmanniana and resulting changes in B. eriopoda cover differed by site and land use history. Overall, results indicate that despite challenges of restoration, herbicidal removal of a dominant invasive grass may lead to increases in desired native species.