Authors

Kathryn Prive, The Understory Initiative
Holly Prendeville, USFS PNWRS
Matt Orr, Ron Reuter, OSU
Francis Kilkenny, USFS RMRS

Overview

This study measured the detailed phenologies of 27 bluebunch wheatgrass (Pseudoroegneria spicata) populations from six seed transfer zones (STZs) raised in a common garden to test whether existing STZs created using a combination of plant morphology and “first-day” phenological measurements adequately capture population-level variation in season-long, detailed phenologies. The number of individual plants within an STZ not producing harvestable seed during peak harvest levels indicated that 10–27% of individuals from a seed lot could be excluded from a single-pass harvest. The findings generally support current STZ delineations for P. spicata, but they also suggest sourcing from multiple populations and harvesting with multiple passes when resources permit.

Purpose

This study was designed to test whether existing STZs created using a combination of plant morphology and “first-day” phenological measurements adequately capture population-level variation in season-long, detailed phenologies.

Geography

27 populations from six STZs (3a, 4, 6a, 6b, 7a, and 7b) of bluebunch wheatgrass (Pseudoroegneria spicata) raised in a common garden (in Central Oregon, STZ 7b).

Results

Prive, K.; Orr, M.R.; Kilkenny, F.F.; Reuter, R.J.; Prendeville, H.R. 2021. Phenological variation in bluebunch wheatgrass (Pseudoroegneria spicata): Implications for seed sourcing, harvest, and restoration. Land. 10(10): 1064.