Ecology and Physiology

Can delaying germination reduce barriers to successful emergence for early‐germinating, fall‐sown native bunchgrass seeds in cold deserts?

“…The number of plants established from fall seeding in a semiarid cold desert can be significantly depleted by mortality of germinated seeds throughout the winter, likely caused by a variety of barriers, such as pathogens and freezing‐related stressors (Crist & Friese 1993; Chambers & MacMahon 1994; Boyd & Lemos 2013; Gornish et al 2015; Matsumoto & Hsiang 2016; Roundy & Madsen 2016). We showed that a germination‐delaying seed coating treatment tested across six sites in each of 3 years reduced germination of one perennial bunchgrass prior to the onset of winter from an experiment‐wide average of 55% for untreated seeds to 12% for treated seeds.…”

“…Germination timing of native species used in restoration varies widely (Cline et al 2018). However, over‐winter mortality of germinated, fall‐sown seeds may be an important barrier to effective seeding efforts (James et al 2011; Larson et al 2015; Hardegree et al 2020) due to biotic forces such as pathogen activity (Crist & Friese 1993; Gornish et al 2015; Matsumoto & Hsiang 2016) or abiotic actions such as temperature‐related seedling damage (Boyd & Lemos 2013; Roundy & Madsen 2016). Germination and emergence timing and strategies are often adaptive in the species of this region (Meyer & Monsen 1992; Baughman et al 2019) and others (Volis et al 2004; Erickson 2015; Gremer et al 2016), though germination at unfavorable times is surely a frequent fate of seeds in restoration for several reasons.…”