Data from: Silver fir seed viability varies with age, fir-associated forest cover, and abiotic conditions of seed harvest stands across Austria

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 six 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. 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.