Silver fir seed viability varies with age, fir‐associated forest cover and abiotic conditions of seed harvest stands across Austria

Abstract For silver fir ( Abies alba ), a species expected to play an important role in climate‐change adaptation of Central European forests, seed viability in Austria appears to be declining. Therefore, it is crucial to examine the constraints on seed viability and to identify ways to counteract the observed trend. In this study, we investigated factors associated with silver fir seed viability in seed stands and seed orchards in Austria. We hypothesized that seedling emergence is affected by endogenous (tree age, species abundance) and exogenous (climatic) conditions of seed stands, and that differences in emergence occur among seed production unit types, with higher success expected in seed orchards. We conducted a common garden experiment using seed lots from 63 seed stands and 6 seed orchards across Austria to investigate the likelihood of seedling emergence as a function of the proportion of silver fir‐associated forest cover in seed stands, tree age, climate parameters and seed weight. Our results show a positive relationship between seedling emergence and the proportion of silver fir‐associated forest cover, as well as between seedling emergence and the maximum age of the silver trees in stands. The effect of mean annual temperature on seedling emergence depended on annual precipitation levels: seeds from stands in warmer conditions had a higher probability of emergence, but only under sufficient precipitation. Synthesis and applications . As climate change, habitat loss and fragmentation intensify, seed‐sourcing strategies should explicitly incorporate ecological filters when selecting stands for seed harvest to safeguard seed viability and genetic diversity for nursery production. Seed stand management should be refocused on promoting structural conditions that enhance reproductive success, while seed orchards should continue to serve as essential sources of quality and genetically diverse reproductive material.