Differential seedling performance and environmental correlates in shrub canopy vs. interspace microsites

Shrubs in semi-arid ecosystems promote micro-environmental variation in a variety of soil properties and site characteristics. However, little is known regarding post-fire seedling performance and its association with environmental variation in former shrub canopy and interspace microsites. We compared post-fire seeding success and various soil properties important for seedling establishment between shrub canopy and interspace microsites in Wyoming big sagebrush (Artemisia tridentata) plant communities in southeast Oregon, U.S.A. We burned 5, 20 × 20 m sites and established paired canopy and interspace micro-transects seeded with bluebunch wheatgrass (Pseudoroegneria spicata, 193 seeds/m) or crested wheatgrass (Agropyron cristatum, 177 seeds/m). At one year post-fire, seedling density was 69% higher (p = 0.012) for crested wheatgrass (compared to bluebunch wheatgrass) and 75% higher (p = 0.019) for interspace microsites (compared to canopy). However, tiller and leaf area production were over twice as high (p