Offsite propagation for restoration projects benefits greatly from an understanding of seed germination requirements. Camassia is a North American forb, native to the Pacific Northwest and Eastern regions; it functions as a foundation species and a pollinator resource in grassland restoration. Previous studies indicate that cold stratification improves germination, but the germination requirements for Camassia are not well understood, and subspecies are rarely distinguished. We sought to understand the effects of taxon, habitat and cold treatment methods on seed germination. We also aimed to quantify difficult distinctions between closely associated taxa, and assess the viability of water as a potential mechanism for seed dispersal. We studied the germination rates of C. leichtlinii and C. quamash, including three subspecies and six populations from western Oregon and Washington, under both cold-moist and aerated water stratification.
Results/Conclusions
Preliminary results of model selection processes show that stratification treatment did not show significance after the effects of other variables were considered. This indicates that water stratification can be an effective pre-treatment, and that water dispersal of seeds is a potential mechanism for gene flow. Our data also implies that pre-planting germination is best predicted by subspecies while variation in cumulative germination is best explained by the combination of species and site. Among C. quamash subspecies, we observed similar germination curves, time to first sprouting and date of maximum germination. These factors may explain why different models are significant for different periods of our study. Overall a combination of taxa and habitat affected germination in Camassia. A possible explanation for observed variation between species may be regional adaptations within populations. Our results suggest it may be appropriate to consider taxa or source of Camassia for use in restoration.