Patch‐burn grazing management, vegetation heterogeneity, and avian responses in a semi‐arid grassland

摘要: Anthropogenic changes to disturbance regimes in grasslands, and associated homogenization of vegetation structure, have been implicated as factors contributing declines populations grassland birds North America. We examined the influence patch-burn grazing management, which employs spatiotemporal interactions between fire livestock guided by historical patterns, on structure bird abundance shortgrass steppe northeastern Colorado, USA. All study pastures were grazed cattle at moderate stocking rates from May October each year. In treatment, we burned 25% pasture autumn (Oct or Nov) year during 2007–2010; control not burned. Patch-burn management increased heterogeneity generating short (<4 cm), sparse recent burns. Although selectively burns, this did alter unburned portions patch-burned relative controls. Of 6 species examined, mountain plovers (Charadrius montanus) occurred exclusively whereas grasshopper sparrows (Ammodramus savannarum) for ≥3 years. Two (lark bunting [Calamospiza melanocorys] western meadowlark [Sturnella neglecta]) 2–3 times less abundant burns compared controls, densities horned larks (Eremophila alpestris) McCown's longspur (Rhynchophanes mccownii) unaffected burning. Lark bunting, meadowlark, sparrow varied substantially among years when they abundant, all 3 density across time-since-burning gradient. Consistent with pattern, reduced whole-pasture scale. found no evidence that patches within differed terms any species. was an effective strategy create breeding habitat plovers. However, our findings suggest steppe, additional strategies generate taller, more dense than occurs under need be considered combination sustain full suite native birds. Published 2015. This article is a U.S. Government work public domain