0 - 1 1 Quality assessment of temperate zone deciduous 2 hardwood seedlings 3

10 Abstract. Research regarding seedling quality issues has been performed for decades and focused 11 primarily on conifer species, which comprise the greatest proportion of nursery production 12 worldwide. Demand for hardwood seedlings, particularly for conservation purposes, has increased 13 steadily in recent years, emphasizing the need for seedling quality assessment protocols specific to 14 these species. Important differences between conifer (gymnosperm) and hardwood (angiosperm) 15 species require the creation of seedling evaluative programs specific to each group. Variation in 16 phenology and ecological adaptability of hardwood species limits the validity of inferences made 17 between and within genera. Annual cycles of leaf emergence followed by abscission in temperate 18 hardwoods necessitate examination of seasonal variation in indicators of physiological condition 19 that do not require leaf tissue (e.g., mineral nutrition, electrolyte leakage). Also, it is crucial to 20 identify appropriate sampling periods and plant tissues for testing such that test results may be 21 accurately compared. Though certain parameters (e.g., morphological) may be readily used in both 22 conifer and hardwood seedling quality testing programs with little modification, additional 23 refinement is needed to improve predictive capacity for hardwoods across a variety of environ24 ments. We review the current state of knowledge regarding seedling quality testing of temperate 25 deciduous hardwood species, discuss limitations in incorporating traditional components of quality 26 testing programs, and set priorities for future study.