Goldilocks forbs: Survival is highest outside—but not too far outside—of Wyoming big sagebrush canopies

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This study investigated survival of transplanted herbaceous seedlings at different distances from Wyoming big sagebrush canopies. We planted two native perennial forb species, Munro’s globemallow and common yarrow, and two native perennial grass species, bluebunch wheatgrass and bottlebrush squirreltail, at four distances from sagebrush canopies at six sites across the Intermountain West, repeated across 2 years. Under above-normal precipitation, proximity to sagebrush influenced first-year survival of the forb, but not grass, species. Globemallow and yarrow survival were highest mid-way between the canopy dripline and maximum interspace distance between neighboring sagebrush plants. Ground cover characteristics and globemallow survival covaried with respect to distance from shrub, suggesting ground cover characteristics as indicators of suitable planting microsites. Under drier conditions, survival of all species was low and unaffected by distance from canopies. Our results demonstrate the value of fine-tuning the canopy-interspace paradigm to more carefully consider how plant performance may differ across zones within the interspace region between plants, especially when the goal is to maximize plant establishment in nondrought years.